Totally revised machine spec and can now attach pics so I've edited this original starting post... see big post later in this thread

Where's the pics??

Most people usually use the same motors and screw pitch on both X and Y axis. It's not a requirement, though, but if you're buying new, why are you choosing different components?

Were you planning on direct driving the rotary axis?

It sounds awesome, but I wouldn't want to have to write the check for the linear rails. Have you got prices for them yet? I'm curious as to what rails that long would cost new. I have seen them on ebay that long, but even there they were a couple of grand a pair. I picked up two 9.5 ft. THKsr15 rails and six trucks and a web belt and pulley system on ebay for three hundred, but the heavy rails are so much harder to find and so expensive.

Another thing you need to consider is the length of those ballscrews. If you try moving long screws fast they have a tendency to whip I understand. I dont know if yours are two long or not, but its something to check out. Its why people tend to go other routes, like rack&pinion or belt/pulley on machines with that much footprint. Ive seen ballscrews used, but they were very large and very expensive.

If you've got the budget it sounds great. What about the pic's you mention?

Gr21
----
I'm buying new components for the X+Y Ballscrews, All motors and controller but the Z Axis and the A Axis are pre-assembled items.. so I'm trying not to destroy them through inexperience.

A lot of these items are sourced from ebay and the like.. so you can't always pick and choose what you get. Hope this clarifies things.

I was planning on direct driving the rotary axis. If you check the pics of it you can see that it has a servo motor direct driving it at the moment. Is not that clear in the picture but it has a built in planetary gearbox. I hope to mount the pinion off the servo motor onto a stepper of similar characteristics and ...fingers crossed... it will perform just as it did in the first place. If worst comes to worst I will sort out an alternative means of driving it indirectly. As I said I'm still new to this game and learning all the time...

Halfnutz
--------

I've already bought the items on my list that do not have * next to them.. prices can vary a lot.

The Z Axis assembly in the pics cost me £ 153...
Rotary drive for the A Axis cost £ 17..
X and Y rails and guides ... paid about £ 270 to £290 for each complete set.

I priced up just the Hiwin guides new in the UK and for Guides without Rails it would have cost over £360.. and the 2500 mm rails would have cost at least the same as the guides and probably a lot more.

got to dig.. but it's worth it

again pics are here

http://www.cnczone.com/gallery/showgallery.php/ppuser/24752/cat/500

Thats great! Less than I would have thought, but not cheap. I have these 9.5 ft SR15 rails (about 2800 mm ?) that I got for a song, and I also have a pair of SR15's 6 ft long for the Y axis, but I dont know if they are heavy enough (I'm going to try them at some point anyway). They came off of a commercial vinyl cutting machine and include a really nice belt drive set up. I am also going to build a large format gantry with them someday, but I've got too many other projects going on at the moment, and I am not sure of where I want to put the thing yet. It will be welded square tubing and not easy to move once its built. My workshop is so packed....

Good luck, I'm anxious to see your progress as it develops, it looks like your off to a great start..

Halfnutz
--------

Appreciate your comments.. thanks.

So far have saved quite a bit of money on components. Thinking is that savings will offset the cost of some of the pricey parts that I want to buy new. Don't want to take a chance on used Ballscrews and Ballnuts etc.. but at the sizes I need they are quite expensive.

I meant to reply to your remarks about screw whipping earlier. This is a big concern with me and it's why I'm hovering around the Motor/Thread issue like a big nancy.. just don't want to get it wrong and bend something that costs a packet. Will most likely choose a motor/screw combination that leans towards under-driving rather than over-driving the X Axis. Not looking for many 100's of IPM out of this to start with and can always upgrade it at a later date. Accuracy and reliability are my main concerns. I plan to buy the biggest and best X Axis Ballscrew I can afford and treat it like a baby.. until I know what the limits are etc...

ger21....."Ah, the pitch for X and Y axis are the same.....5mm...."....aren't they.....Motors are basically the same aren't they....one is has a bit more torque....but if it has the same number of steps as the other.....it's basically the same....

I saw that the pitch was the same... was just curious as to why the different diameters, but I didn't realise they were from Ebay.

I don't know what travel rates you need, but you definately need to double check your calculations on the ball screws and steppers. Might be ok, but there is a reason most large machines use servos and rack or belt drive. If you plan to use this machine for a business, time(ie speed) is money.

Depending on what type of bearings you have on your ball screws, the maximum speed for your X axis without whipping will be somewhere between 1500 to 3000 mm/min.

The steppers might also have a speed problem. The torque curves in the Sanyo data sheets are with a 100v power supply, so with 65 volt max drives, your speed will be almost half of that in the curves. Even at 100v they might be too slow.


PS Whipping is not the only problem with long ballscrews. Longer and larger screws have more inertia, so acceleration and deceleration when changing direction are slower. You can download a free motor sizing calculator here. http://www.parkermotion.com/scripts/support_downloads.asp (look for sizing and selection tools)
This program lets you put in screw and machine characteristics including desired speed and acceleration, and outputs a graph of the torque curve required.

I don't know what travel rates you need,...... the maximum speed for your X axis .....will be somewhere between 1500 to 3000 mm/min.

The steppers might also have a speed problem. ......with 65 volt max drives, your speed will be almost half of that in the curves. Even at 100v they might be too slow.


jeffs555
--------

Thanks for your interest.

Regarding speed:

1.5 - 3.0 Metres per minute sounds relativly low speed for machine this size.. I hear what you are saying.. motors are under-driven at 65v also. I thought of both of these aspects which is reason for this post ... to check my thinking and conclusions.

I'm happy to under-drive to start with. Last thing I want to do is push the Ballscrews too far and encounter whipping and bending problems. Accuracy and reliability are my main watchwords at the moment.. saw a tagline/sig on the forum... can't remember who has it.. but says "1st get good.. then get fast !!". Sounds like good advice to me.

Will be business usage for this machine and time is money as you say. I'm a bit of a one-man-band operator and I will have finishing and assembly work to get on with while CNC cuts my work for the next job. If it only cuts and shapes as fast as I could by hand then it will improve my job turnaround times by 100%. I think it should go well beyond my hand-working speeds so will still be worth the investment.

Long-term I am thinking about upgrades to both Ballscrews and motor drive. but to my mind I need to test and prove the rigidity of my frame design in real work situation first. I've never built anything this big with 8020 type extrusion. No good to me if forces exerted make it sway and slop all over the place... so softly softly catchee monkey is my planned approach.

Thanks again for your input.. this is just what I need really.. before I buy items and commit myself to a dodgy plan. I do take all comments on board for serious consideration.... so please keep them coming :)

A 2HP router is on the low side for 3M/min feed speeds, if you're cutting 19mm panels in a single pass. I'd say use no less than a Porter Cable 7518. Tooling plays a big part in this as well. On our commercial machine, with chipbreaker spiral tooling I can cut 19mm plywood at 10M/min, but with insert tooling I slow down to 3-4M/min, or risk breaking the tool. This is with a 10HP spindle, btw.

You might also want to look at higher lead ballscrews, 10-20mm instead of the 5mm you mentioned. This will reduce whipping, and keep the motors spinning slower where they have more torque.

A 2HP router is on the low side for 3M/min feed....19mm..use no less than a Porter Cable 7518. Tooling plays a big part......

You might also want to look at higher lead....10 - 20 mm ..... This will reduce whipping, and keep the motors spinning slower where they have more torque.

ger21
------
Re: Spindle/tooling

Noted your remarks ...at this point in time I have no real reference or experience to make a decision without the kind of advice you offered. I appreciate the tooling issues so I'll definitely adjust plans with this in mind.

Re:Thread

Big thanks for sharing information above.. again this is exactly what I need... The cost increase for 10 mm or 20mm lead screws is within my budget and as you pointed out this would reduce motor speed and therby keep me in the higher torque ranges of the motors.

Also with under-driven motors this makes even more sense to me. I will get the most out of them with lead /thread as you suggest and this will also stand me in good stead for whipping avoidance.

Thanks for your sound advice :cheers:

This is a sort of off the point re: my build but it is connected to one of the best and cheapest finds I've made so far.

Remember the rotary drive I got for £17.00 ? Well you really need to see what some genius has acheved with a couple of them strapped together to create a spindle holder.. Phenomenal !

I've tried attaching images here but can't get it to work.. have disabled my firewall, let I.E have default security settings .. everything I can think of but still attach doesn't work. I'm going to post an image of the cutting head he's made in my gallery.. even if I have to lose a few pics to do it... believe me it's worth it.

The drives/tables are still available at the same price I paid. I can post the llink if you want.. also the link to the construction series photos of the 4th + 5th axis cutting head... I don't know what the policy here is on posting links to other forums.. where the photos are. He's also used steppers and servos to drive the head so it at least confirms that my own 4th Axis can be stepper driven with just a motor swap out.

here's the link to the first of the photo's in my gallery.

http://www.cnczone.com/gallery/showphoto.php/photo/2602/cat/500/ppuser/24752

You talking about this site? http://www.rainnea.com/cnc_5axis.htm

The tricky part is writing g-code to use it.

Well that's the handy part....

you will be aware of CNC_Toolkit plug in for 3dsmax or free G max version... this will generate G code for up to 6 axis motion.. and I think that's what he's using...

It's a bit beyond me at the moment tho.. I'll be happy enough to get my 3/4 axis machine built and working..

just thought inquiring minds would want to know..

Download GMAX while you still can, it may not be around long. http://www.turbosquid.com/gmax

Be sure to get the help files and tutorials, too. And register it here. http://www.turbosquid.com/Support/Index.cfm?stgSupportModule=SupportGmax&FuseAction=GmaxSupportHelp

ger21
-----

That is good advice alright but happily I'm a long-term 3DS and 3DS MAX user. I mechanical model with MAX 3.1. It's reliable and has a vast amount of stable shareware plugins..most of which should also work with GMax. Unlike the later versions 3.1 doesn't devour your system resources just to pretty up the GUI or incorporate features most people never use.

This machine build is aimed at bringing my 3D background (since 1989/90 3DS DOS version 1), my primary work-experience in woodwork/plastics fab and some other elements together into one cohesive and forward looking venture.

speaking of my build.. I just did some weight and pricing calculations on my frame... needs some serious design adjustments.. which I'm working on now... pics to follow shortly....

do you have the info of where to buy the rotary drives in north america? i just breezed over the post and was checking out the galleries, looks like a nice idea :)

check ebay

Well just a quick update on my progress...

last thing I posted was that I was revising machine design... was not happy with previous gantry and was sure I could improve the strength/ridgidity to weight ratio of the gantry.

I've attached a render of the latest revision... as attach seems to work now ..

in order to check slot alignment and connection methods on the 8020 I modelled the profiles I was using, detailing the external dimensions and slot locations on each of the 8020 extrusions. I've attached these files also in case they are of use.

Yohudi, I'd love the know where your getting those rotary axis's so cheap!


Thanks
Jerry

Latest Design revisions to my planned CNC machine.
==================================================
Have revised and refined the specification somewhat, so I've edited the starting post for this thread. I can now attach the images within this post so it should be a bit more coherent.

Review of my requirements:
==========================
Machine will sit on big bench/frame in my workshop. Usage will be entirely Woodcutting / carving from my CAD output. Once built will be used daily to speed up my work and avoid employing additional staff. I need the capability to make round parts ( i.e. bedposts) so will be 4 axis machine with removable rotary drive. A Axis adjustable for different stock lengths and/or multiple cuts across longer stock. A Axis will cope with up to 184 mm diameter stock across a total axis length of 1.45 metres. A-Axis Drive came complete with servo motor but will swap this out for suitable stepper. Working on the 4th axis design at the moment.. will post revisions when I've completed it to my satisfaction.

Current Progress
================
I'm still at parts aqquisition stage of this build. If anyone spots any glaring errors in design or components etc please feel free to say so, preferably before I've made purchase..... Specs and components are as below, most of the reference no's won't mean anything unless you know the supplier for these parts. I've used fairly accurate representation of 8020 profiling in my latest revisions so it should look pretty close to what I've rendered from CAD. I've increased the length of the gantry base from 300mm to 600mm so lost 300 mm in available cutting area... was a neccessary evil though for accuracy and rigidity.. now the gantry will be almost as long in the base as it is high.. this has to improve strength rigidity and ability to handle faster motion.

I've revised design re: ballscrew location, to reduce length but maintain travel and I'm checking on upgrading the Ballnuts and Ballscrews to between 30 - 40 mm. This is one of the reasons some of the related items are as yet undecided.

For the outlay I will be spending it's not worth "spoiling the ship for a ha'peth of tar" as the saying goes.. but depends on impact on costs a bit at this point. Would cost about £ 150.00 max to beef up the X and Y motors to 1500 oz/in but would definitely need serious nuts and threads to run this kind of power.. not sure framing could handle it either.. but I am investigating.

* = I haven't bought it yet.
? = waiting for measurements to enable selection.

Framing size and specs:
-----------------------
8020 Framing (UK equivalent) = 1.591 x 2.733 Metres *
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
Gantry Width and Height (overall) = 1.770 x 0.755 Metres
Cutting Area (W x H x D) = 1.454 x 1.841 x 0.184 Metres
XY cutting bed weight less MDF = 36.98872 kilos
Gantry weight = 39.78996 kilos
Z Axis weight(- slide and spindle) = 7.6 kilos

X Axis Items:
-------------
Ballnut = 1 x FSI 25-10T01 (Anti Backlash) *
Ballnut Mount = 1 ?
Ballscrew = 1 x D25 x P20 @ 2000 mm - Thread length 1800 mm
Ballscrew Bearings = 2 x ?
Ballscrew Bearing Mount = 2 x ?
Guide Rails = 2 x Hiwin LGR20H @ 2500 mm
Guides = 4 x Hiwin LGW20HCH (67 x 63 mm)
MDF Access Cover = 1591 x 608 x 25 mm
MDF SlotWall = 1591 x 2124 x 25 mm MDF
Stepper Motor = 1 x Sanyo Denki 103-H8223-6540 6 Amps 1118.64 oz/in *
Stepper Motor Coupling = 1 x SRJ40SRD01 (Elastic Coupling) *

Y Axis Items:
-------------
Ballnut = 1 x FSI 25-10T01 (Anti Backlash) *
Ballnut Mount = 1 ?
Ballscrew = 1 x D25 x P20 @ 1800 mm - Thread length 1760 mm
Ballscrew Bearings = 2 x ?
Ballscrew Bearing Mount = 2 x ?
Guide Rails = 2 x IKO LWH25 @ 1740 mm
Guides = 4 x IKO LWH25 (70 x 93 mm)
Stepper Motor = 1 x Sanyo Denki 103-H8222-6340 6 Amps-792.96 Oz/in *
Stepper Motor Coupling = 1 x SRJ40SRD01 (Elastic Coupling) *

Z Axis Items:
-------------
Aluminium BoxFrame = 1 @ 415 x 170 x 85 mm
Ballnut/screw = THK 10 x 3 X 400 mm Anti Backlash assembly
Guide Rails = 2 x THK-RSR 12 @ 400mm
Guides = 4 x THK-RSR12VM (28 x 30 mm)
Reduction Gearbox = 1:1.48 (62mm + 93mm Gears)
Stepper = 1 x Sanyo Denki 103-H8221-6241 - 6 Amps - 424.80 Oz/in *

A Axis Items:
-------------

130 mm Drive = Dual bearing - 25 RPM in = 4.5 RPM out @ 620:1 gear ratio
Primary torque: 33 in-lb - Secondary torque: 125 in-lb
Live Centre = ?
Stepper = 1 x Sanyo Denki 103-H8221-6241 - 6 Amps - 424.80 Oz/in *

Spindle
-------
Yet to be decided but minimum is UK equivalent of Porter Cable 7518 (as advised here)

Computer
--------
Already have a 4U Rackmount AMD Dual 1900+ MP system ready and waiting for CNC machine to be built. 2 G/Byte RAM, 400 G/Byte hard Drive, 128 M/Byte Graphics, 21 inch CRT monitor. Housed in a dedicated 10U enclosure. Running win2k sp4 or above I think. Permanently borrowed from my render-farm.

Other Items:
------------
Z Slide Plate 1 410 x 110 x 20 mm
Z Slide Strengthing Plate 2 300 x 100 x 25 - 30 mm
Dust Collection hookup 1 100 mm flexible hose 6 Metres (approx)
T-Slot Fixings ? Functional alternative to the purchased variety would be V useful.
25 mm 90% angle brackets ? Already have about 500 of these

General Info:
-------------
Motors and Controller will be brand new matched 4 axis micro-stepping package supplied with software and cabling etc. Optically decoupled, short-circuit safe, input voltage 32 - 65 V. Stated as being used in and capable of industrial applications. A pre-built industry tested deal seemed the best option for me. Having invested considerable funds to date don't want to blow it with homebrew controller.

I expect to earn the costs of this build back. In the long-term it should be the taxman who is buying my machine. Also this is the 1st of 2 builds. Hoping to use this and assess/prove it, then sell it on and finance the 6 axis machine I really want. Have lots of high definition sculpture and what have you just waiting for 6 axis machining.. but 4 will do for now.

Costings to Date:
=================
The big question at last... what's it going to cost ? I've been keeping a running total of actual costs to date as well as working through the budget projections for the missing items. This game is not cheap as someone else pointed out.. but it is considerably less expensive than buying a turnkey machine of this kind of spec.

My main reason for posting the costs to date and projected costs is quite simple. If you see an item I haven't yet purchased at an overly expensive cost then please point it out. Just like most people, I don't have money to burn. Bear in mind that shipping to the UK can be VERY expensive for heavy items

Unless otherwise stated costs include shipping and delivery, where possible I've indicated shipping costs in brackets:-

Framing costs (- fixings + delivery) = £ 693.78
X axis Guides and Rails (£ 40.00) = £ 315.72
X axis Ballnut/Screw (£ 23.50) = £ 185.81
Y axis Guides and Rails (£ 40.00) = £ 336.75
Y axis Ballnut/Screw (£ 23.50) = £ 160.06
Z axis box as pictured (£ 20.00) = £ 153.05
A Axis Rotary Drive (£ 17.00) = £ 37.72
Motors/Controller/Sware (-delivery) = £ 1,101.08
Computer + monitor reused = £ F.O.C
==================================================
Projected Costs to date: = £ 2,963.67
==================================================

Unknown Costs
=============
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
2 x Ballnut Mount
4 x Ballscrew Bearings
4 x Ballscrew Bearing Mount
1 x Live Centre for A Axis (ebay for this I think)
Z Slide Plate
Z Slide Strengthing Plates
Spindle and tooling
Dust Collection hookup
T-Slot Fixings
Misc Fastenings

I think once I factor in the as yet unknown costs my outlay will hit in the region of £ 4,000.00 UK pounds.. that's if I source everything else retail... not bad for an extra skilled worker who doesn't have all the human foibles..about 3 months wages... and a damn sight less than I could ever have bought this kind of configuration as a bespoke setup. It's ended up being a little larger and theredore a bit more costly than I anticipated but I think it will be worth it in the end... also I have a few irons in the fire to reduce costs.. will keep posting to let anyone interested know how it all pans out..

Don't touch that dial !!!!

U]First a bit of news:[/U]

I picked up a couple of 25mm Ballnuts and screws today.. They are decent size (1800 mm and 2000 mm) and at 20 mm pitch. Star/Bosch/Rexoroth units.

Will be able to test motion and motors with them. Even if X axis needs bigger screw for speed can at least get some building and testing done and sell on the items I may swap out at later date.... Have decided that if I tweak my design to suit these screw lengths I can still keep option open to add better/larger screw in future no problem. If I add in 1 item i've been saving I only need to do this one build as a 2 stage process. Get 3/4 axis up and running.. add my unique bolt on attachment style 5th and 6th at later date.

So I need to show the sexy item I was saving for my 2nd build. it's the entire basis for a bolt-on theme.. and i think it's the way to go.. I really do :)

I've listed the possibilities I'm thinking of below.. should say that my aspirations re: CNC are more carving, shaping and detailing than cutting. i.e. turn a plain object ito something unique, but with facility to repeat same thing many times. I do also want to cut and form larger panels into plain-stock for carving later. I see the addition/s below as being a detail cutter rather than anything else with the router also having a main or heavier duty cutting head.

Bolt on additional Axes..

I bought the device in the pic below in december last year on ebay for £20.00.. it's a pantagraph arm.. ex aircraft industry...holds a tool/spindle square for drilling or screwing. Has spring-loaded 2 - stage arm and adjusts for different tool weights...arms measure 300 mm and 533 mm giving horizontal ROM of 0 - 833 mm. Vertical ROM is 600 mm up/down from base bracket. I want to run this a few ways..

Application 1.
As separate 3 axis bolt on system:- anywhere on the XY frame or attached to moving gantry/ Z backbox. Sort of dual 3 axis if that make sense. If attached to gantry, cutters move in sync in X but independant in Y and Z. I envisage both cutters working on one large job in this configuration. like one 2 head machining centre.

Application 2.
As replacement for main Z axis attached above center of gantry and able to move over the span. Rotation / extension of the arm to replace normal Y axis movement, Y and Z would not need to run as rotation under the gantry and extend or retract of arm would position cutter anywhere main Y and Z could. This would be an extendable Z axis in practice I think.

Application 3.
As separate 3 axis bolt on system, anywhere on the XY frame. running entirely separate job. Can I split a single 6 axis control system in software like it's 2 separate 3 axis cutters ? Isn't this identical to a dual independant head machine with one head doing job #1 and 1 head doing job #2 ?

Application 4. As 2nd Z axis.. bolted on to slide of main Z axis duplicating the movement of the main Z axis locked at a fixed offset. i.e cut two of the same thing at the same time. Varying offset could enlarge or reduce at same time as cutting original etc.

Application 5.As entirely separate 3 axis bolt on above single axis rotary. but with the table static and the arm able to move 360 degrees around a post below the table..

Once having decided on a method of actuation (pneumatic/hydraulic/electric)for the arm I think all of the things listed above are just variations mounting 1 simple element and adjustments in control software. I really need opinions / experienced advice on this .... please feel free to sound off if it seems my thinking is adrift.

Spindle
-------
Yet to be decided but needs to be 10HP (as advised here)




I didn't say you needed a 10HP spindle. That would add about $5-8K US to the cost. :eek:

What I said was a Porter-Cable7518 minimum. I'd go that route to start, but allow room for upgrading. If you find that the 7518 isn't big enough, then upgrade to a Columbo or Perske type spindle, 3 to 5 HP would be plenty, but will cost about $3000 and up vs. $300 for the Porter Cable.

Can you even get a Porter Cable 7518 over there?

One more thing, you might want a bigger stepper on the Z-axis, especialy if you go for the bigger spindle.

I didn't say you needed a 10HP spindle......

What I said was a Porter-Cable7518 minimum. ........If you find that the 7518 isn't big enough, then upgrade .........

Sorry,

I obviously misunderstood and will amend main post accordingly.... thanks for the heads-up.

I think the saving I made on the ballnuts and screws would cover the costs for Porter-Cable7518 you mentioned..

the only info i've seen on that tho is from the USA.. and 110v ac is indicated as supply for the spindle. I'm looking for a similar power/quality unit in the UK capable of running on 220-240 volt AC supply.. will shout when I find something..

Finished up the design mods to match the actual sizes of the Ballscrews I'm going to try out... I've left scope for upgrade to heavier (and longer thread length) X Ballscrew at some point by just a swapout...

Also mods based on side mounted rails... looking to duplicate good results mentioned in cncfoams "quick build" thread....

side mounted rails reduced Gantry height and allowed shorter legs = better XY table ridgidity.. tweaks have generally reduced framing requirement and gantry weight a bit I think.. Gantry design should be more rigid also... will run some weight calculations when I get time.

next things I'm planning are mounts for Adjustable 4th rotary Axis below Main Z axis cutter. Once that's done I'll do the Attachable pantagraph in the various modes I mentioned.

If it looks anything like these latest renders in the end I'll be quite happy...the shadow above the XY bed represents actual cutting area on these screws.

I see you have a rectangle for your gantry, the sides being shorter, and the "legs" being the longer side.
THese will have a tendency to want to form a rhombus type shape, so the whole thing tilts to one side aibt depending on the load. With your machine, and the results you want (particularly speed of cutting), the loads are pretty decent. So I suggest you get a piece of sheet metal to support the back of the gantry

I see you have a rectangle for your gantry, the sides being shorter, and the "legs" being the longer side.

THese will have a tendency to want to form a rhombus type shape, ........ So I suggest you get a piece of sheet metal to support the back of the gantry

Hi there,

thanks for your interest and comment.

I see what you're saying and it would seem a bit weak. Looks like a piece of plate is required... what you can't see in that last render is the actual 8020 construction around the riser. I've put up a render where I hope the built in anti-flex mechanism is a bit more evident. fingers-crossed it should work out OK and if worst comes to worst I can always revert to plate as you say.

The gantry will be 1770 mm in width and 200 mm High. A full width plate would be 1610 mm x 200 mm. I was going to go with the plate till I ran some approx weight calculations on the whole gantry . I had to reduce the weight.. not add to it...

I thought I could maybe use multiple smaller plates spaced accross the gantry and how thick the plates should be... what was the lightest gauge I could get away with. Then I thought about why not 8020 itself as plates ? would probably be as strong and weigh less.

I came up with the structure shown.. a sort of bench-hook on it's side. I'm hoping this will do as well as pieces of plate would at a fraction of the weight and cost. It's really only the bracing marked A, B, and C that I'm hoping will be anti-flex enough to avoid using a plate. It will fasten as follows:-

"A" (4040 @ 200 mm) will have a top and bottom fixing to each span. 2 fixings to "B" and 3 fixings to "Main" at 90 degrees to the others.

"B" (4080 @ 160 mm) will fix to "Main" in 2 places, through the front in the other T slot. There will be 2 through fixings each from top and bottom spans and 2 x fixings through "C", from the side.

"C" (4080 @ 160 mm) will have 2 through fixings from "Main", from the rear into the side T-slot. There will be 2 through fixings each from top and bottom spans.

"D" is there to provide a bit of bracing for the +VE and -VE X-motion. I also thought if worst came to worst a similar piece of 4080 could be added between "D", "Main" and "A".

"C" could be altered if need be. The guide rail ends are far enough away from "C" to allow the bottom span to be shortened by 80 mm (40 mm each side). This allows "C" to be part of the front riser.. which is just about visible. I didn't do this initially because I wanted to get some bracing from the shorter front riser at 90 degrees to the bottom span, to help prevent twist.

I was also going to add 75 x 75 mm 90 degree bracketin corners formed between Front riser and Bottom span.

There is a similar fixing setup on the 3 x T-shaped bracing across the span, and naturally the same setup at the other side of the gantry. Before I order framing I'll do a scale mock up of the span/riser union in scrap timber to test the increase (if any) it can give in rigidity.

what do you think ? would appreciate any thoughts you or anyone else might have.

My advice is to gusset and bracket the hell out of the structure.
If weight is a concern, even a piece of sheet metal will do it. I went to hope depot, purchased a 36"x36" sheet of .020" thick sheet metal. Then I just cut it into thirds, and overlapped the pieces. THis is plenty, very light weight, and cheaper than 80-20 at 15 dollars.

The 80/20 is good stuff though still. I am using it for my router construction, for part of the base only though. The rest is all anodized plate

I see you are a fan of the plate then... I suppose I'm just concerned about working accurately with plate. I don't really have that kind of capability at this end.. .

I did initially look at a gantry entirely in plate.. but when I got the Z axis in my pics I knew it would have to be box-section of some sort. My Boxframe Z-Axis weighs over 16 pounds.. without the slide or spindle.. think I need blocks of metal rather than plate...

did consider I-beam also.. but again with me it's working it to shape accurately that's the prob...

Well, sheet metal would only be used to prevent this from parallelogramming.
I will try to text art this...

____
|___|

Above is what you want, this is your gantry

______
\_____\

Above is what you dont want, even sheet metal will prevent this.

I am pretty bad with sheet metal, but at .020" thick I could just use shears to cut it and it turned out fine.

Plate will do a lot more than you think. Doubling the height does a tremendous amount more for strength than doubling the width. I think it's either 6 or 9 times stronger to double the height

Where did you source that z-axis unit?

Where did you source that z-axis unit?

do ebay search for the phrase below..search "item description" or you won't find it.

"Unterteil aus plangefrästem Aluminiumblock 415 x 170 x 85 mm"

if nothing there then you'll have to search completed listings. I know he sold another one of these after mine. you have to read a little german as online translators can't handle listing like this properly. but pics say it all really...

big update coming re my own machine as soon as i get time but quick news for anyone interested is:

ballscrews/nuts arrived today.. bit of luck the X axis screw has a mighty flange on there.. I thought was same as Y axis but is bigger @ 75mm OD..

buying of extrusion and ballscrew bearings and mounts is imminent

picked up some 8020 connection elements also..

found guy in USA selling lots of 8020 2nd hand on ebay. ....search ebay for jandyshelz and you can bid or buy now.. he has plenty of the 8080 inside corner gussets complete with fixings with 8 gussets per lot.

I mentioned the 2nd user 8020 connection elements I got from this chaps ebay store.

to my knowledge he has the following items left:-

30 Joining Plates(5 hole)3030- 8020 T-Slot 80/20 (bid or BIN(4 for $22))
130 Inside Gus. 8 hole Corner Brackets (bid or BIN (8/ $35))
3 sets of 4 casters w adapter plates + hdware (bid or BIN ($99 set))

even at BIN these are good savings on normal prices especially in the USA
these are not listed on ebay yet.. but he will probably list them now as i've let him know the items I wanted from the list he sent me... if not message him and tell him how who sent you...

he also has plenty of 8020 profile but is probably only worth it for USA buyers..

Still on the go on this.... just in case anyone is wondering... have picked up 2 tidy mae hy200 4270 1402 Oz/in motors for X and Y axis....ex industry spares.... came with Flexi couplings as well...7 amp (4 phase /3.4 amp per phase/140v max rated) Paid £138 inc Shipping....

now just need to find high torque nema 23 motor for Z axis... gearbox is set up for size 23 motor.. and can't go above this size without losing ability to use gearbox... similar motor should also be ok for A axis rotary drive as have to stay within stated torque ranges.

currently researching self-assembly controller... not really looked closely prior to this as had ruled out "building" the controller. Having said that a quality controller seems to be available to anyone who can screw-terminal a few wires.. and I CAN do that just as well as anyone else.

Currently looking at a couple of options:-

PC - 2 - Route M2 breakout board
4 x Gecko 212
DC PSU

or alternatively

PMDX - 131 4 Axis breakout board
4 x Gecko 212
DC PSU

I like the PMDX - 131 for the fact that the geckos mount directly onto the PCB.. save about 50% of the wiring this way.. and hard to get it wrong... but don't think I can apply separate DC power to the geckos with this board.. there is a DC motor power input on the BOB.. and all the gecko connections are used mounting to the BOB.. this would mean that effectively it's combined control and power solution. And if I could separate the two it would be better for me

The PC - 2 - Route M2 breakout board IS a control only solution and requires independant PSU for the Geckos... this is useful for me in that 2 of my steppers will need above 48v DC to the drives and 2 nema 23's will probably to be happy to have 24v - 48v DC... Means I'm not paying for what I don't need in PSU capacity... Is also a modular approach and would allow better upgrade options if I change the setup.

There is only about $50 dollars difference between both setups... $ 1,153 for the PC - 2 - Route BOB setup and $1,203 for the PMDX - 131 with about $ 350 being allowed for the PSU in each instance. Costs would be + shipping...niether of these 2 budgets include additional costs for switches sockets and enclosures either.

The most cost effective pre-built solution that meets a similar spec to above is the PSU and controller packabe offered by locostcncretrofits.com... they would charge $1199 for the prebuilt controller and $329 for the PSU to match... $1528 + shipping.

Bearing in mind the good £ to $ exchange rate it might still be worth paying the extra $329 for the prebuilt and tested unit. It's from a single experienced manufacturer, which means at least some cover and support. And the upgrades to this controller are good to.. like the usb jog control addon.

will do a little more checking and then it's decision time....

425 oz-in stepper on eBay, one left right now: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7601982941&rd=1&sspagename=STRK%3AMEWN%3AIT&rd=1

I bought 3 from him, these are hefty motors.

425 oz-in stepper on eBay, one left right now:.......
I bought 3 from him, these are hefty motors.


Thanks for the heads up on that SuperNema23 motor. I checked the guy out and just so happened he had another 12.. so I bought two. Should be just the job..

Now I've sorted those out I can run serious calculations for PSU and Motor Drives requirement. Which in turn will allow me to finalise controller costs.
Will do a big update later in the week..

Just thought I'd post update re recent developments:

8020 Brackets:
==============
Bought a selection of 8020 brackets and gussets via Ebay. Pay through the nose for these parts in the UK ...they effectively double the price by just changing say $5.00 to £5.00. Including the shipping I still saved about 20% on UK price. Got the items detailed and pictured below:-

10 X Inside Gus. Corner Brackets (8 hole) (#4338)
8 X Inside Gus. Corner Brackets (4 hole) (#4336)
4 X Joining Plates (12 Hole) (#4328)
4 X Joining Plates(8 hole) (#4365)
4 X Joining Plates (5 hole)(#4351)
25 X Rt-Angle Brackets 1.5 x 1.5 (#4302)

Motors X+Y:
===========
Bought 2 MAE HY200-4270-0340-B Nema 42 Stepper motors, with couplers. Bipolar Parallel connected and driven with 75 volts at 4.8 Amps they will generate maximum torque of 1130 Oz/In. Couplers matched on both ballscrews too !!.. can't say fairer than that.

Motors Z+A:
===========
Size of other components dictated that these must both be Nema 23's.. best torque rated Nema 23 I'd seen was 270 to 280 Oz/in. Then followed up on tip from Enraged and picked up 2 of the Supernema 23 at 425 OZ/in.. Even this might be a bit lacking.. but is hobsons choice on motor size..no larger frame size will go anywhere near the gearbox on my Z Axis. Going to try this motor out before possibly stripping and rebuilding Z axis in some other form, but would rather not have to do this. Rotary drive motor access is restricted too. was originally a small servomotor on this.

Power Supplies:
===============
Bought a generic 80Volt 8 Amp Open frame PSU and a Mineaba 50Volt 9.9Amp PSU. Will go into reasoning behind this below.

Motor Power:
------------
Having located the Supernema23's I've been able to do the neccessary Drives/Power calculations. The MAE's max voltage according to calculations is 65v, datasheet shows example of 75 volt in pullout curves. However, according to calculations the Supernema23s could take as much as 100 volts, much too much for the MAE's. I think the voltage will most likely be limited to 80 volts anyway by availability of drives. Gecko's can live with 80v.. I've seen various other drives rated at 90 volts.. haven't come across anything that handles anywhere near 100 volts which is 25 x the nema 23 4v rating.

For a single PSU setup, 50 volts at 10 Amps would be a reasonable place to start. This should run all 4 motors at decent capability while avoiding over-current and over-voltage problems, especially in the Nema 42 motors. Should reduce the possibility of generating large voltages back through the drives due to gantry inertia. I'd also employ a voltage clamp across the power supply at a rating of about 52volts. The downside with this setup is that the Supernema23's are under-running by up to 50 volts. That's where the 80v 8 Amp PSU will come in.

Ultimately there will be 4 smaller motors. I'll get 2 more Supernema23's if they check out ok. To get the best options from all 6 motors needs 2 Power supplies. 4 Supernema 23's would prefer 80volts 8 Amps and perform much better on it. The MAE's would then use the 50v 9.9amp PSU. I could also try the MAE's at 75volts with this setup and 4 Nema 23's can run off the 50V 9 Amp PSU, although they would like more voltage. If the MAE's are that much better on 80v I'd just buy another of these generic PSU's or build one.. as I'll then have one I can duplicate.

Drives:
-------
I'd originally thought to use either Gecko 210 or 212 drives.. but I thought this through again.. Firstly I'd be paying for capacity in the drives that I just won't use. Not with these motors anyway. Peak current for any motor will never actually exceed 4 Amps. Based on 2/3rds peak current drive usage, 3.17 amps will be maximum on any motor. There is such a large disparity in requirement versus capacity that it would be foolish not to consider some alternatives. Secondly I have to consider support and or repairs on Gecko products. This is an ocean away for me.. there will always be a time and cost penalty for me on using any non-UK product.

I've found a 4.5amp, 90volt microstepping drive in the UK with 50000 microstep resolution and 4.2 Amp 50 Volt version from same people. If I factor this in I end up with a drastically reduced PSU controller drives cost and opportunity to build a 6 Axis controller from the outset.

Much less speculative is the option to build just the 4 Axis box for now. This is based on Using only the 50V 9Amp PSU to begin with. All 4 motors would need actually need 10 Amps. Bearing in mind on a 4 axis setup usually only 3 of the 4 axes are actually used at any one time this seems a good starting point. I would buy 2 drives at 90volts and 2 drives at 50 volts. The 90 Volt drives will be useful in 2 ways. Firstly they can be used to reduce the inertial voltage problem.. they can take a lot more voltage back than the 50volt drive. This problem is at it worst when PSU and drive voltage are on the limit of motor rating so a good bit of headroom will not hurt. Will also allow the MAE's to be tested at 75 Volts

At a future point it would be relatively inexpensive to add in 2 further axes (when I've built them) and then run the 2nd PSU fulltime. I can decide on the Motor/PSU options at the same time although the sensible option would be 50v to the MAE's and 80v to the Supernema23's. At this point It would be quite a reasonably matched setup.

4 Axis Controller with relay and spindle speed direction options will be as below:

PC-2-Route Mach2 BOB
2 x M845 4.5A 90V
2 x MSD542 4.2A 50V
1 x 50v 9 Amp PSU
Rack Enclosure
Sockets etc

At future point I add 80v 8 Amp PSU (already bought) 1 x CNC4PC BOB and two 90V motor drives to get the full 6 axis config.

Costings:
=========
The above activities have had positive impacts on my costings. In reworking them I've adjusted the presentation slightly so they are clearer.

Actual Costs to Date:
=====================
X axis Guides and Rail (£40.00) = £ 315.72
X axis Ballnut/Screw (£23.95) = £ 176.14
Y axis Guides and Rails (£40.00) = £ 336.75
Y axis Ballnut/Screw (£23.95) = £ 147.95
Z axis box as pictured (£20.00) = £ 153.05
A Axis Rotary Drive (£17.00) = £ 37.72
8020 Brackets (£64.00) = £ 176.98
X+Y Steppers + Couplers (£13.95) = £ 138.95
Z+A Steppers (+ Delivery) = £ 62.00
50v 9.9A PSU (£10.00) = £ 39.99
80v 8A PSU (£10.00) = £ 95.00
==================================================
Total to date: = £ 1680.25
==================================================

Projected:
==========
Computer + monitor reused = £ F.O.C
4 Axis Controller = £ 357.51
Software = £ 95.00
Framing costs = £ 544.99
X+Y Support Bearing = £ 468.04
Spindle = £ 300.00
===================================================
Total Projected Costs: = £ 1765.54
===================================================
===================================================
Actual + Projected = £ 3445.79
===================================================

2 Axis Upgrade (inc. motors + tables) = £ 285.00
===================================================

Unknown Costs
=============
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
2 x Ballnut Mount
1 x Live Centre for A Axis (ebay for this I think)
Z Slide Plate
Z Slide Strengthing Plates
Tooling
Dust Collection hookup
T-Slot Screws + Nuts
Misc Fastenings
cabling

Reading and mooching about for compatible components has continued to reduce overall budget....will continue with that..can still save some pennies I think....might also be sensible to just build the 6 Axis box from the outset.. save some on the Supernema23 postage costs to boot.... the delivery on the supernema23's will be only major increase to existing costings by maximum of about £100.

will keep updating... not far until actually start building something.. waiting the arrival of digital vernier before I order bearings..and will order framing after I know true distances for supports etc... making the space in the workshop now to start...

Gathering of components continues. Pics below and details below:-

Supernema23's:
==============
Increased my order on these from 2 of to 4 of. Seller says will only ship 3 or more internationally. I'm still awaiting shipping costs so have yet to actually secure these. Looking at alternatives as I'm getting a bad vibe in respect to laying my hands on them....

Controller decision time:
==========================
The 4 motor scenario above and also reduced cost overall have motivated me to build 6 axis capable controller from the get go. Have spent a lot of time reading published Info for CNC4PC, PC-2-Route and PMDX-131 BOB's. In the end I've decided to go with the CNC4PC units, explanation follows.

Once I'd moved away from Geckos as drives the PMDX-131 became dubious choice, main attraction was reduced wiring due to direct mounting of Geckos on the BOB. I never did like the motor power via the BOB. Had lots of other extras I would probably not make use of. I WILL want Spindle off/on and (eventually) dust extraction off/on via the controller but not much else. Maybe in the further distance a PWM speed control for a small detail spindle. Can't see I'll ever need anything more...

PC-2-Route was next choice, it also comes with lot of extras I will never use but does have capacity for safety charge pump, AC relays and PWM speed. Interfaces for 6 axis setup involving the PC-2-Route BOB would cost $211.00 (£121.26) including shipping. Thats the way I WAS going to go.

Then I thought OK.. but what if something breaks ?? In a 6 axis controller based on either of the 2 mentioned interfaces there is a Primary BOB which performs control on 4 Axes and a secondary BOB on another parallel port. The primary BOB could/would handle 4 Axes, Estop,limits, safety charge pump, relays and spindle speed.. and I'd always planned the secondary BOB to be a CNC4PC C1 optoisolated interface, as I would only need motion on these rotary axes. Any fault on the primary BOB and it's off to the USA with the BOB and everything dead in the water till such times as it gets back.

It occurred to me that at a push I could run XYZ off the CNC4PC BOB.. it would allow enough safe I/O for Step, Dir, Estop, and limits. In fact the main thing on the primary BOB missing on the secondary BOB was a Safety Charge Pump. That was the deciding factor really... I thought if that's all that was missing, was there a way to add that as a module to the seconday BOB.. and move it up to the primary. A potential $70.00 saving...

CNC4PC BOB is more modular and therefore more practical from my point of view. With functions being handled by separate modules it means faults are not such a big problem. The charge pump and AC relay modules are cheap enough to carry a spare. Repairs are simply a case of swapping relatively cheap modules. Interfaces for 6 Axis setup based on CNC4PC C1 BOB, excluding unwanted features come in at $ 169.92 (£90.31) including shipping. I've ordered the following, which should arrive in next 10 days or so

2 X CNC4PC C1 Optoisolated BOB
1 X Safety Charge Pump.
2 x AC relay

I've also picked up a suitable enclosure, a new 4U Rackmount RAID drive array case. 6 x motor drives and all PCB's will easily mount into bays directly behind the fans. Should adapt the existing hardware to this without problems. 50 volt and 80 Volt PSU should both fit in area normally occupied by 4 x redundant PSU. There are existing switches and LED in the case also which I intend to make use of and will add the rest, neatly. Will live happily with contolling PC in 10U enclosure I have. Matching Gas-lift keyboard/monitor support arm I already have will also be called into play at some point.

I was about to order the motor drives.. but the prob sorting shipping on supernema23's means I may have to use different motors.. so can't order drives until I get this sorted...will restrict choice of motors if worst comes to worst ..

EStop and Limit Switches:
=========================
Have been shopping for these also. Machine overall L x W will be 2.5 metres by 1.9 metres. I think this requires a minimum of 1 x EStop button at each corner of the machine and 2 x EStop buttons on the gantry, 1 on each side. Managed to do a deal on 6 Telemecanique EStop Switch units so they are on the way.

Limit switches are already here. I bought 4 x Telemecanique Plunge roller Limit Switches and 6 SPDT mini roller lever switches. Not all the axes will run limits in the end but got enough for them all anyway. X and Y will use large Telemecanique units. Z already came with SDPT roller limits in place and all the other Axes will use SPDT mini switches.

Framing:
========
Developments with this. Approached a neighbour who does a lot of welding and metalwork. Initially just picking his brain re: difference in cost of making my frame involving steel, before I ordered 8020. Anyway we got to talking. I'm now definitely planning a steel sub-frame for my machine. My neighbour has some strength-rated steel materials he says should be ideal. If this works out it will slash the required 8020 costs by about 50% and Mr Neighbour and I will strike a suitable deal for the steel. Will post pics of materials and final steel/8020 hybrid design when I've decided if the proposed steel sections are suitable.. will be about Tuesday next week before I see them.

Bearings:
=========
Digital measuring tools arrived this week so have accurately measured up both X and Y ballscrews for bearings. Will be the biggest single expenditure now that framing costs should be reduced. Checking suppliers and stock availability.

Speculative cheapo buy:
=======================
Picked up a couple of Electo-Pnuematic actuators to (hopefully) use on the Pantagraph arm at some point. Don't know anything about them at all but were so cheap it won't matter. I'll use them for something..at some point. Photo shows round steel label with "RGN" or "KGN" in blue capitals.

That's about it for now... have posted costing adjustments below.. I'm just about at the point where the remaining missing items will all be brand new retail purchases so costs at this point are pretty firm. When looking at costs bear in mind that machine spec has changed a lot. Now includes electronics, power and motors for 6 Axes not 4 as originally intended. Would only need 2 Drives and mechanical elements to be fully functional 6 axis with CUT area of 1.7m x 1.5m x 200 mm. CUT area can be increased to 1.9m x 1.5m x 300mm in future by X Ballscrew or (more likely) Rack and pinion upgrade and adjustment to Z Slide mounting.

Soon as I sort out what's going on with the Supernema23's I'll complete final purchasing.. Will start building controller when PCB's arrive in 10 Days. Will have resolved all motor issues by then....

Costings (Revised 9th April 2006):
==================================

Actual Costs to Date:
=====================
X axis Guides and Rails (£40.00) = £ 315.72
X axis Ballnut/Screw (£23.95) = £ 176.14
Y axis Guides and Rails (£40.00) = £ 336.75
Y axis Ballnut/Screw (£23.95) = £ 147.95
Z axis box as pictured (£20.00) = £ 153.05
A Axis Rotary Drive (£17.00) = £ 37.72
8020 Brackets (£64.00) = £ 176.98
X+Y Steppers + Couplers (£13.95) = £ 138.95
2 X 50v 9.9A PSU (£20.00) = £ 78.98
80v 8A PSU (£10.00) = £ 95.00
6 Axis BOB,SCHP,relay (£ 7.00) = £ 90.31
4U RAID 19"Rack Case (£10.00) = £ 56.56
6 x EStop Unit (£ 4.00) = £ 40.00
4 x Limit Switch (£ 5.80) = £ 25.80
6 x Limit Switch (mini) (£ 1.00) = £ 6.00
==================================================
Total to date: = £ 1877.92
==================================================

Projected:
==========
Computer + monitor reused = £ F.O.C
Z+A+B+C Steppers (+ Delivery) = £ 124.00
2 x M845 4.5A 90V drive = £ 120.00
2 x MSD542 4.2A 50V drive = £ 100.00
Software - Mach2/3 = £ 91.52
8020 Framing costs = £ 259.75
Steel Sub frame (estimated) = £ 150.00
X+Y Support Bearing = £ 468.04
3.25HP Spindle = £ 170.00
===================================================
Total Projected Costs: = £ 1483.31
===================================================
===================================================
Actual + Projected = £ 3320.23
===================================================

add when B + C axis mechanicals completed
==========================================
2 x M845 4.5A 90V drive = £ 127.50

Unknown Costs
=============
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
2 x Ballnut Mount
1 x Live Centre for A Axis (ebay for this I think)
Z Slide Plate
Z Slide Strengthing Plates
Tooling
Dust Collection hookup (hose + clips)
T-Slot Screws + Nuts
Misc Fastenings
cabling
Sockets

Electro Pneumatic parts arrived today.. bit of luck they are exactly what I thought they were.. pneumatically activated Rams... Made by RGS Electro Pneumatics Ltd in Accrington UK. They are still in business which is another bit of luck.

The Rams have threads for attaching solenoid activated valves at each end of the cylinders. I need to get my head around a bit of Pneumatics control and at some point these should be operational again. Tried them for size against the Pantagraph arm and good luck again.. looks like they will have just enough throw to fully extend both sections of the arm...

While looking for data on the Pneumatic stuff I located the original Datasheet for the MAE HY 200 4270 340A8 motors. The datasheet I got with the motors is for the current version of this motor (MAE Y 20 4270 0340). The original datasheet has an important note re: holding torque which is missing on the specs sent with the motors. Basically the Original sheet notes that the stated values are with 2 PHASES ON.

The MAE can be configured about seven different ways. Configured as Bipolar Parallel with 2 Phases ON means that the MAE motors will need twice as much power. Two active phases per motor will need 4 x 4.7 amps Peak available per step.. or in other words a 50volt 9.9Amp PSU EACH. The guy I got the 50volt PSU from has plenty more.. so I was able to order another identical minebea PSU for the same cost as the last one £39.99. I've adjusted last lot of costings to include this addition.

this is interesting. please keep posting!

Latest Update:

Gathering of components continues. Pics below and details below:-

Supernema23's: The Saga continues....
=====================================
Well, STILL no news on these. Have contacted seller today by email to determine what on earth is going on. I used BUY it NOW to secure at least 2 of these motors 17 days ago. The listing said there were 12 available.

The Ebay listing asked overseas buyers to contact seller re: postage. That's exactly what I did on 30/03/2006. Reply stated seller would have to weigh the motors then get back to me. When I'd heard nothing by 3rd or 4th of April I mailed again.. seller THEN said that he would only ship 3 or more over seas. I increased my order to 4 motors. Seller replied saying he would be in touch re: shipping. I'm still waiting.

Definately feels like I'm getting the runaround of this chap.. and I'm not happy about it. Will definitely raise it with Ebay if he backs out of deal. I despise timewasters like this to the nth degree as there's no need for it. Think if he wanted to ship them then they would be with me by now.

Have been in touch with alternative supplier who is waiting same motors to clear customs in US. Hopefully will get better service from him. If worst comes to worst will have to design a way around the Nema 23 limitation. Might even save some money if I do this....

Electronics:
============
Getting the rest of the bits and pieces together for the controller. Hoping to start building the main elements PSU's, BOB's Relays etc as soon as the PCB's arrive from the USA. Should be by the end of the week. Items I've picked up are as below.

1 x Low Voltage PSU:- 40 Watts Dual Output +5/+12VDC
1 x Telemecanique E Stop Unit - Key Release
5 x Panel mount Fuse Holders
5 x illuminated Switches
50 x Pcb pillars:- 12.7mm nylon standoffs
100 x Asstd 6.3mm Spade terminals (red/blue/yellow)


Low volts PSU is to give BOB's, Charge Pump and relays an isolated supply on the controller side. BOB's use USB link from the PC to power the PC Side of the board. I'll use 2 x mini jack socket to link that to the BOB's, just to keep things neat. Going to have a Switch and Fuse dedicated to each PSU to reduce the current load on power up. Added a keylock Estop switch to use mainly as a lockout when I'm not around and to guard against human stupidity when cleaning and setting up the machine.

Can't decide on plugs and sockets for the motors at the moment. Hard to find 4 core shielded cable at the right gauge without buying a lot more than I actually need. Will need about 30 metres maximum.. so don't fancy buying 100 or even 50 metre roll, this stuff is expensive. Without knowing the cable OD I can't really buy plugs or sockets yet.

I plan on using 4 pin screw on plugs and sockets, like they use in CB and HAM radio as mic connectors. My dad has been into HAM radio since the late 50's (G3NTY is his callsign btw). He reckons they should be good to handle the current/voltage. Have seen others using metal 5 pin DIN audio connectors for motor power but I want something that locks into or onto the socket. I reckon if DIN plugs can handle it the HAM radio plugs should be OK. They have good insulation between each individual pin although they are slightly smaller than DIN audio plugs/sockets. Have also considered 4 pin XLR sockets, which to be honest I would prefer, you know where you are with XLR's. Any input on this would be appreciated.

Another development with the controller relates to power calculations. As mentioned in previous post if I want to run the MAE motors at max power then I have to run 4 phase motors in 2 phase Bipolar parallel configuration. This means that for each step of the motor there will be 2 phases active, not 1 as I'd previously thought. Each phase will draw 2/3rds of 4.76 Amps or 3.17Amps at peak so this means the drives for the MAE's will have to be 7 Amp drives. Have revised costings to reflect this.

Machine Speed:
==============
I'll be using Mach2/3 on a dual 1.9 Ghz machine. It should easily run at an engine frequency of 45,000 Hz if need be but I think even at 35,000 Hz I'd have oodles of headroom. Working through the setup calculations for Mach 2/3 has produced some interesting results for the ballscrews I bought. Calculation info is below.

X axis:
-------
The X axis ballscrew/nut were sold to me as 20mm pitch. In fact this is not the case. The screw is a 2 start screw with an effective pitch of 25mm and will be a direct coupling to the motor. The drives I'm planning on using can use up to 256x microstepping in increments of 2,4,8,16,32,64,128,256. Based on this at 8 x micro stepping I'll get a cut resolution of 1.5/100 mm (25mm/1600 = 0.015625mm). 500rpm from the motor would give a maximum feedrate of 12.5 metres per min or 492 IPM ! A full traverse of the X axis in about 8 seconds. I could gain resolution if need be by using 16x microstepping. This wouldn't affect the feedrate either as would still only require 26,666.66(recurring) pulses per sec from Mach2. I hardly think I'll need this resolution for wood though.

Screw Revs per unit = 1 / 25mm = 0.04
Motor Revs Per unit = 0.04
8 x Microstepping = 1600 steps per rev
Mach2 Step per unit = 1600 x 0.04 = 64
Mach2 Pulse per sec = (500 x 200 x 8)/60 = 13,333.33...recurring

Y Axis:
-------
The Y Axis ballscrew/nut is also different from description. It's 10mm pitch not 20mm. Resolution at 8x microstepping would be 10mm/1600 = 0.00625mm. Feedrate at 500 rpm would be 5 metres per minute Or a traverse of the 1.5 metre Y axis cut in about 18 seconds.

Screw Revs per unit = 1 / 10mm = 0.1
Motor Revs Per unit = 0.1
8 x Microstepping = 1600 steps per rev
Mach2 Step per unit = 1600 x 0.1 = 160
Mach2 Pulse per sec = (500 x 200 x 8)/60 = 13,333.33...recurring

I was going to flip the stepper on the Y axis through 180 degrees. This was primarily to avoid having a 7 kilo motor hanging off one side of the gantry. I'm thinking of applying gearing in this process to more closely match the feedrate to the X axis.

I found a local supplier of Martin pulleys and Fenner timing belt. They were a bit pricey though. It's the old $ value = £ value foolishness again. I bought 2 x Martin 26L100 (3/8 pitch 1" belt) pulleys in the USA which cost less inc shipping than I could buy them for locally. I'll source the correct size belt locally and obtain a pulley to allow 1:2 gearing of the Y axis (1 turn of the
motor = 2 turns of the screw) at the same time. This will at least allow me to try to get a faster feedrate on the Y axis so it more closely matches the X axis. It wouldn't need any more steps to acheive this.. but I would run 16x stepping to keep resolution as this would be halved by the gearing if left at 8x. Again it would require no more than 26,666.66(recurring) pulse per second from Mach2. I also bought some shaft collars to ensure the pulleys remain in place. They are secured by setscrews but I'll be happier if they have something to butt up against.

z Axis:
-------
Z axis thread pitch is 3mm. That's what came with the unit.. at 2x stepping this gives a resoultion of 0.0075mm. Feedrate is a lousy 1.5 metres per minute.. but as the Z Axis is only going to travel 200 - 300 mm this would give a full traverse time of 8 to 12 seconds.

Screw Revs per unit = 1 / 3mm = 0.33333333333333333333333333333333
Motor Revs Per unit = 0.33333333333333333333333333333333
2 x Microstepping = 400 steps per rev
Mach2 Step per unit = 400 x 0.33333333333333333333333333333333 = 133.33333333333333333333333333333
Mach2 Pulse per sec = (500 x 200 x 2)/60 = 3333.3333333333333333333333333333...recurring

A Axis:
-------
Haven't performed calculations on this yet as I will have to strip the rotary drive and do some tooth counting to work out gear ratios first.

Spindle.
========
Bought a used but good condition Makita 3612BR to try out as the spindle. It's 3 1/4 HP, with electronic brake but WITHOUT constant speed control. I've read that a few people have had probs with the 3612C and 3612CX which do use constant speed control.

If the 3612BR doesn't cut it as spindle (no pun intended btw) then it hasn't cost me the earth and will replace it, although I don't really know what with at this point ;) It comes with Makita router table which I can always make use of in my workshop or sell it on if I don'tuse it that much.

Just as a matter of interest you can actually find a 3HP + router in the UK for about £69.00 by RYOBI. Can't see it matching Bosch, DeWalt or Makita though as they all cost over 3 to 4 times as much retail so Ryobi have to be cutting corners somewhere (again no pun intended).

Framing:
========
Another let down I'm sorry to report. Mr Neighbour who was so up for constructing a steel subframe for my machine has been nowhere to be seen for the last 10 -14 days. He is at home but is making himself a bit scarce. I've got to the point where I'm thinking of just building the whole thing in 8020. Will add about 10% to my overall projected costs. I've more than saved that amount on other items so I'm just going to have to bite the bullet and get my hand in my pocket I suppose.

My preference is to use all 8020 really. Will be a better job and will remain adjustable to the end. I'm going to give it till the end of the week, at which point it will be almost 3 weeks since he and I last discussed his involvement. If he hasn't bucked his ideas up by then I'll just get on with it.

Well that's about it for this week. Have been a few +ve developments and a couple of -ve turns but never fear this build is ON and that's all there is to it. So come hell or highwater it's all the same to me. Nil desperandum carborundem illegitimi, thats my motto (Don't let the *arstads grind you down). ;)

L8r

Revised Costings:
=================

Actual Costs to Date:
=====================
X axis Guides and Rails (£ 40.00) = £ 315.72
X axis Ballnut/Screw (£ 23.95) = £ 176.14
Y axis Guides and Rails (£ 40.00) = £ 336.75
Y axis Ballnut/Screw (£ 23.95) = £ 147.95
Z axis box as pictured (£ 20.00) = £ 153.05
A Axis Rotary Drive (£ 17.00) = £ 37.72
8020 Brackets (£ 64.00) = £ 176.98
X+Y Steppers + Couplers (£ 13.95) = £ 138.95
2 x 50v 9.9A PSU (£ 20.00) = £ 78.98
80v 8A PSU (£ 10.00) = £ 95.00
6 Axis BOB,SCHP,relay (£ 7.00) = £ 90.31
4U RAID 19"Rack Case (£ 10.00) = £ 56.56
7 x EStop Unit (£ 8.00) = £ 52.76
4 x Limit Switch (£ 5.80) = £ 25.80
6 x Limit Switch (mini) (£ 1.00) = £ 6.00
Electronics components (£ 7.80) = £ 23.87
3612BR and Table (£ 20.00) = £ 152.00
Pulleys and Collars (£ 20.56) = £ 36.99
====================================================
Total to date: (£ 353.01) = £ 2028.81
====================================================

Projected:
==========
Computer + monitor reused = £ F.O.C
Z+A+B+C Steppers (+ Delivery) = £ 124.00
2 x MSD980 7A 90V drive = £ 170.00
2 x M845 4.5A 90V drive = £ 120.00
Software - Mach2/3 = £ 91.52
8020 Framing costs = £ 583.74
X+Y Support Bearing = £ 468.04
====================================================
Total Projected Costs: = £ 1557.30
====================================================
====================================================
Actual + Projected = £ 3586.11
====================================================

add when B + C axis mechanicals completed
==========================================
2 x M845 4.5A 90V drive = £ 127.50

Unknown Costs
=============
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
2 x Ballnut Mount
1 x Live Centre for A Axis (ebay for this I think)
Z Slide Plate
Z Slide Strengthing Plates
Tooling
Dust Collection hookup (hose + clips)
T-Slot Screws + Nuts
Misc Fastenings
cabling
Sockets

Latest Update:

Supernema23's: The Saga continues....
=====================================


The supernema prob looks like it's resolved. Got email from the seller this morning with postage info... asked him to invoice me which he has done, and I've sent the funds by return. Costs with SuperNema23's and postage factored in are below.

Revised 17/04/2006
=================
Actual Costs to Date:
=====================
X axis Guides and Rails (£ 40.00) = £ 315.72
X axis Ballnut/Screw (£ 23.95) = £ 176.14
Y axis Guides and Rails (£ 40.00) = £ 336.75
Y axis Ballnut/Screw (£ 23.95) = £ 147.95
Z axis box as pictured (£ 20.00) = £ 153.05
A Axis Rotary Drive (£ 17.00) = £ 37.72
8020 Brackets (£ 64.00) = £ 176.98
X+Y Steppers + Couplers (£ 13.95) = £ 138.95
2 x 50v 9.9A PSU (£ 20.00) = £ 78.98
80v 8A PSU (£ 10.00) = £ 95.00
6 Axis BOB,SCHP,relay (£ 7.00) = £ 90.31
4U RAID 19"Rack Case (£ 10.00) = £ 56.56
7 x EStop Unit (£ 8.00) = £ 52.76
4 x Limit Switch (£ 5.80) = £ 25.80
6 x Limit Switch (mini) (£ 1.00) = £ 6.00
Electronics components (£ 7.80) = £ 23.87
3612BR and Table (£ 20.00) = £ 152.00
Pulleys and Collars (£ 20.56) = £ 36.99
Z+A+B+C Steppers (£ 42.63) = £ 165.40
====================================================
Total to date: (£ 395.64) = £ 2194.21
====================================================

Projected:
==========
Computer + monitor reused = £ F.O.C
2 x MSD980 7A 90V drive = £ 170.00
2 x M845 4.5A 90V drive = £ 120.00
Software - Mach2/3 = £ 91.52
8020 Framing costs = £ 583.74
X+Y Support Bearing = £ 468.04
====================================================
Total Projected Costs: = £ 1433.30
====================================================
====================================================
Actual + Projected = £ 3627.51
====================================================

add when B + C axis mechanicals completed
==========================================
2 x M845 4.5A 90V drive = £ 127.50

Unknown Costs
=============
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
2 x Ballnut Mount
1 x Live Centre for A Axis (ebay for this I think)
Z Slide Plate
Z Slide Strengthing Plates
Tooling
Dust Collection hookup (hose + clips)
T-Slot Screws + Nuts
Misc Fastenings
cabling
Sockets

Once the motors arrive I'll buy the Framing, Drives and bearings...and in the meantime I'll be tracking down the other sundry items... watch this space.

Latest Update:

Gathering of components is reaching conclusion, I've been busy. Mostly just a few pieces of Aluminium plate to sort now. Pics and details below:-

Framing Deveopments:
====================
Completed redesign of framing, trashed the steel subframe idea. No further contact with Mr Neighbour about this since last update. Obviously he's not as keen as he appeared. Sounded attractive from the cost point of view but wanted to see what the materials were before deciding. Can't hang around forever waiting to see what's what, so decision had to be made. Decision is go with 8020 and take the pain in the pocket. Having invested the level of funds I have so far I can't balk at the cost of the framing.

I've lengthened legs and will be well braced and gusseted at every joint, before anyone starts telling me that the bottom of the gantry needs some bracing i'll point out that I haven't bothered putting them in the model but there will be braces and gussets. Had the good fortune to stumble on a mega-bargain in relation to some brackets whilst keeping an eye out for T-Bolts and Nuts. The cost of T-Nuts/T-Bolts is phenomenal in the UK. Around £10.00 for 4 standard nuts and bolts. Was lucky enough to spot and win quite a few on Ebay. Came with some feet, endcaps, 50 angle brackets. The brackets were the main item for sale and there were so many T-Nuts and bolts they didn't bother to count them, a lot of the brackets new and un-opened. Have a look at the pic below.. see how many nuts and bolts you think there are. I haven't bothered to count them myself to be honest, I'm definitely going to have a LOT left over.

I'll sell most of the spare items on after I've finished building. I don't really need the brackets as I've got spares already. I've saved a a lot of money on the Nuts and bolts tho.. and I will use the feet. Selling on unused brackets Will make a decent amount back towards extra 8020 costs, Each bracket costs £ 4.17 +VAT from KJN in the UK. Will also be able to pick the best means to lock the machine rigid.

I've included 8020 costings to give an idea of current costs in the UK the column marked Kg is weight in kilos. One more thing.. the chap supplying the 8020 in the UK is a "Zone" member, Kevin Marchant, his firm is called MarchantDice and they trade on Ebay in the UK as well as at their own website. He's also supplying the ballscrew support bearings mentioned later.

8020 requirement: Kg
=======================================

2 X 8080 @ 2500 mm = £ 174.60 24.700
2 x 8080 @ 1980 mm = £ 138.28 19.560
1 x 4080 @ 1823 mm = £ 33.71 4.780
2 X 4080 @ 1484 mm = £ 54.87 7.777
4 x 4080 @ 719 mm = £ 53.18 7.530
4 x 4080 @ 620 mm = £ 45.86 6.497
5 x 4041 @ 1484 mm = £ 67.01 10.388
2 x 4041 @ 1800 mm = £ 32.51 5.040
2 x 4041 @ 286 mm = £ 5.17 0.800
8 x 8080 Endcaps = £ 10.00 0.000

23 Cuts @ £ 0.80 = £ 18.40 0.000
---------------------------------------
= £ 634.31
VAT @ 17.5% = £ 111.01
Delivery = £ 101.55
---------------------------------------
TOTAL Framing Costs = £ 846.67

Electronics:
============
BOB's and other PCB have finally arrived, yesterday would you believe. Had been impounded by UK customs until I paid import duty. Unfortunately they neglected to let ME know about this. First I heard was a letter from the post office saying that there was a parcel they could not deliver. Anyway I chased it up and secured them safe and sound. Duty was £ 12.00. First time I've ever had anything pulled for duty payment so I can't complain really. Was picked up because seller had marked parcel as "commercial samples". I've advised him NOT to do this when sending to the UK. Customs see the word "commercial" and can't wait to get their hand in your pocket.

While waiting for the PCB's to arrive I've been gathering the items below for electronics side of the build.

PCB PROTO-TYPING MTG KIT
2 x Omron G7J-3A1B-B Relay
Push button Fuse
Momentary Switch
STUTTGART 115CY Olflex Classic 115CY cable (23M of 5 core, 10M of 4 Core)
3 x 3Metre Cable wrap
10 x NC515 4 pin plugs and sockets (Screw on locking type plugs)
Step Drill 4 - 22mm

PCB mounting kit to allow for all eventualities when comes to fitting everything into the case. With this and the standoffs I bought earlier I should have no problems siting and mounting anything. Relays are to allow Estop to kill power to everything, a REAL Estop as opposed to a software based stop. Might be other people using the machine at times, MUST be SAFE or could be seriously costly in event of injury etc. Momentary switch will be used in this also.

Will use one Omron relay a la "Madvac". Bought 2nd as cost no more to post and got them cheap. If you've seen "Madvac's" machine then my controller will be similar, from the Estop point of view. I've also tried to cover for the eventuality that the smaller stand alone relays from CNC4PC might not be able to take the current required by the spindle and dust extractor when they both power up. Resetable fuse, plugs, sockets and cable wrap all self-explanatory. Step drill to make holes of correct size, as I didn't have one. Don't do much sheet metal work. The Olflex cable is just the job, made for CNC, rated at 400v and flexible use between -3 and 50 degrees Centigrade.

Supernema 23's
==============
These have arrived safe and sound and without additional taxation, it's all down to what's on the label.

I've also discovered that this motor is available WITHIN the UK but as an 8 wire 4 phase unipolar variant. Sold by the firm who I bought my drives from. You'd never know it unless you speak to their tech dept. I had to discuss Supernema23's with them when ordering the drives. I was told they have the same motor but they only advertise it's at the 4 phase unipolar rating at the moment. The tech guy said that bipolar parallel connection will yeild 3Nm (424 Oz/in) which makes sense as you get about 1.4 x the output in this config.

They don't sell it on it's own tho.... At the moment it's bundled with a 32v 2.5 amp drive for £65.00. They are phasing out the 32v drive. This is why they are only offering the motor at it's uniploar rating of 2.4 Nm. To run the motor Bipolar you need a higher power drive as it requires 2x the power. Same as the MAE's, 2 active phases per step, which is where extra torque comes from.

They wouldn't get rid of the 32v drives if they let on that the motor will deliver a higher torque in bipolar config, so they keep it quiet. The tricks some companies pull you wouldn't believe... Bringing the bare motor in from the USA still cost much less even with the postage costs.. and the USA version is internally bipolar wired and breaks out to just 4 wires, a lot simpler to use.

Motor Drives:
=============
Bought 4 motor drives to begin with. 2 x 90v 7 amp drives for the MAE's and 2 X 80v 4.5 amp drives for the Supernema23's. Both drive types are optoisolated, overvoltage and overcurrent protected. They both resolve to 51000 steps per rev (256x microstepping) if need be and all current and voltage settings are via dip switches.. no resistors to add etc. Any probs and my solution is a phone call away within the UK. Will report how they drive in due course.

Gearboxes:
==========
Mentioned last update that was going to have to gear up the Y axis to match feedrate with X axis, pulleys have arrived for this now. Saw the gearbox below. Was in a listing on Ebay but the seller closed the listing. I messaged him to find out why, Ebay note said error in the listing . It turned out he had another gearbox and an adaptor to be used on Z axis. He was planning on relisting them all as a single lot. I asked what kind of money he would want for them as a job lot and the rest is history as they say. Will need adaptation to suit MAE Motor and ballscrew (is setup for Nema34 frame motor) but will be a good starting point.

I'm considering changing the Y axis motor to suit the gearbox. The unused MAE could remain as a spare. I got the MAE motors at below 1/2 price anyway. One problem with using the MAE motor on the gantry is that they are HEAVY (16lbs). Might cause a lot of unecessary problems adding so much weight to one side of the gantry. Will see what the situation is when the gearbox arrives and decide then.

Someone mentioned earlier in the thread that, in view of the planned spindle weight, a 424 Oz/in motor might not be able to cope. I agree entirely. Unfortunately Existing Z Axis Gearbox will ONLY take Nema23 frame motor. So 2nd gearbox and Z axis adaptor will give me some cover just in case. Again anything I don't use I'll sell on. Got both gearboxes and Z Axis adaptor for much less than 1/2 the cost of single new gearbox of this type.

Bearings:
=========
Bought in the bearings for less than I anticipated/priced. They are class 5 bearings, zero play. BK 17 for the fixed sides and BF 17 for the supported side. If you check Rino or Ondrive in the UK the current price per unit is a minimum £ 100.85 for the BK's and £ 32.32 for the BF's + 17.5% VAT. I got the BK's for £74.60 and the BF's for £ 28.68 +17.5% VAT. Got them from the same zone member who supplied the 8020.

Energy Chain:
=============
Waiting for 2 x 1.85 Metre IGUS Echains to arrive from Singapore of all places. Guy is sending them F.O.C. for me to checkout and then I pay when they arrive. Was another Ebay find. Probs with his paypal account and fact I wouldn't agree to pay off Ebay means he'll send first and trust me to pay when he'd sorted things out with Paypal. Seemed genuine enough and will soon see if/when Echain arrives in about 10 days...

Spindle:
========
Bought 2nd hand Makita 3612BR to try as a spindle as previously mentioned, has now arrived. 3.25 HP and in good condition. Decent amount left on the brushes and runs nice and smooth with no chatter. As I'm only trying it out for suitability I didn't want to lay out a lot of cash for a brand new one. For what they are they are expensive.

Came with Makita table and about 35 freebie router bits. Tried it in the table and cuts like a new one. I don't need the table, it's the sort of thing a contractor would use on site, robust but a bit basic in terms of facilities. I have a better table already, might not say Makita on mine but will do stuff the Makita table won't. Will clean the table up (it's a bit used looking but no scratches or damage) and move it on. Again should contribute something back towards overall costs.

Tub Vacuum/dust extractor:
==========================
Bought a brand new 1200w tub type vacuum cleaner to use as a dedicated dust extractor. 12 months warranty and seller lives an hours drive away. Got this because my main dust extractor is a BVC industrial job. It runs off a small 3 phase motor via a soft-starter and a safety switch.

There's no way I could switch this on an off with a relay without making it fully dedicated to the machine, and breaking into the soft-starter swich etc. Obviously I don't want to do that, I wouldn't have dust extraction on the rest of my shop equipment if I did. Got the tub vac nice and cheap, even If I kill it in 12 months it will have paid it's way many times over.

Buy or build ?
==============
I saw a 2nd hand 3 axis machine for sale in the UK this week. Slightly larger cut area on it than mine will have but not by much. Mostly steel construction with some 8020 used to mount rails etc. Plywood used to brace the gantry by the look of it !! Build based on plans from the US.

Came without spindle or dust extraction but with PC and software. The asking price was £ 3,525 plus cost of delivery. Looks like it's been used in commercial environment for a while, so who knows what the Ballscrews, bearings,guides etc are like. Only real saving would be build-time and would still have to add motor, drive and mechanicals for a 4th axis. Think in the long term would have worked out MORE expensive than building myself. As a matter of interest there were no offers on this. Link to the ended listing is below if anyone's interested. Dude's phone # is listed so might even still be up for grabs. I've upped pic of it as well.

http://cgi.ebay.co.uk/CNC-WOODWORKING-ROUTER-TABLE-PC-SOFTWARE_W0QQitemZ7611404621QQcategoryZ20781QQrdZ1QQcmdZViewItem

Starting to build:
==================
Next update will be when I've started building the controller, sometime next week once step drill gets here. May 12th is the earliest the 8020 and bearings will arrive so can't start mechanicals until then. Still have to pick up some Aluminium plate which I'll get out of the way in the meantime. Can't wait to get this show on the road.

Revised Costings:
=================
I've updated the costings to reflect the latest round of purchasing. Adding the legs, gearboxes, T-nuts and brackets has bumped up the cost a bit. Can't complain tho.. once I've completed the build can sell on all the spares and extras which will offset the increase. Will drop costs back to less then 4K. If I have enough leftover and my own build goes well then I might even knock up a small machine and sell it on that way. Maximise my return.

Have tried to cover all eventualities in my purchasing which has added about 10% to 15% but I don't want build to be stalled because I'm waiting for something I didn't think about to arrive. Once I start I want a clear run to completion. Also if all goes well, I'm hoping to turn the extra costs into about a 25% reduction if I sell on the extras in the form of a complete machine. One thing that did get my attention is the accumulated delivery costs of £ 600. Post office and couriers certainly do well out of everyone.

Actual Costs to Date:
=====================
X axis Guides and Rails (£ 40.00) = £ 315.72
X axis Ballnut/Screw (£ 23.95) = £ 176.14
Y axis Guides and Rails (£ 40.00) = £ 336.75
Y axis Ballnut/Screw (£ 23.95) = £ 147.95
Z axis box as pictured (£ 20.00) = £ 153.05
A Axis Rotary Drive (£ 17.00) = £ 37.72
8020 Brackets (£ 64.00) = £ 176.98
X+Y Steppers + Couplers (£ 13.95) = £ 138.95
2 x 50v 9.9A PSU (£ 20.00) = £ 78.98
80v 8A PSU (£ 10.00) = £ 95.00
6 Axis BOB,SCHP,relay (£ 7.00) = £ 90.31
4U RAID 19"Rack Case (£ 10.00) = £ 56.56
7 x EStop Unit (£ 8.00) = £ 52.76
4 x Limit Switch (£ 5.80) = £ 25.80
6 x Limit Switch (mini) (£ 1.00) = £ 6.00
Electronics components (£ 14.80) = £ 37.87
10 x NC515 plug/sockets (£ 2.00) = £ 26.90
3612BR and Table (£ 20.00) = £ 152.00
Pulleys and Collars (£ 20.56) = £ 36.99
Gearboxes + Adaptor (£ 23.95) = £ 135.00
STUTTGART 115CY Cable (£ 6.50) = £ 16.50
T-Slot Screws + Nuts (£ 17.25) = £ 62.09
9 Metres Cable wrap (£ 3.49) = £ 12.46
Z+A+B+C Steppers (£ 42.63) = £ 165.40
2 x M845 4.5A 90V (£ 7.50) = £ 127.50
2 x MSD980 7.0A 90V (F. O .C ) = £ 171.20
8020 Framing costs (£ 101.00) = £ 846.67
X+Y Class 5 Bearing (F. O. C.) = £ 317.07
Dust extraction (F. O. C.) = £ 22.00
Computer + monitor = £ F.O.C
Heat Shrink tubing = £ F.O.C
====================================================
Total to date: (£ 588.46) = £ 4096.31
====================================================

Projected
=========

Software - Mach2/3 = £ 91.52
M5,M6,M7,M8 Allen bolts, washers = £ 40.00
3.7 Metres IGUS Echain (£ 24.13) = £ 77.99
====================================================
Actual + Projected = £ 4305.61
====================================================

add when B + C axis mechanicals completed
==========================================
2 x M845 4.5A 90V drive = £ 127.50

Unknown Costs
=============
Clamping Area (T Slot- 20mm MDF) = 1.591 x 2.124 Metres *
Access / Maintainance Cover (20mm MDF) = 1.591 x 0.608 Metres *
2 x Ballnut Mount
1 x Live Centre for A Axis
Z Slide Plate
Z Slide Strengthing Plates

Final Update re: aqquisition Phase.
===================================

Now have most of awaited components here and ready to go. Last thing to arrive was the gearboxes and I've put details regarding them below with some better pics. Have started building controller but not going into that here. Will be posting about that in separate build log. Keep the trials and tribulations of finding parts out of the actual build.

Gearboxes:
==========
These have obviously arrived. Gearboxes are complete and fully functional. Even came with matching bearing support blocks. One gearbox is ideal for my Y axis and can even cannibalise parts of the larger Z axis adaptor to gain an increase in Y axis screw rotation until I can order the correct pulley/s for the 1:2 ratio I need. I will definitely be changing the motor used on Y Axis to suit this gearbox. It would cost a lot more than motor cost to have adaptations made to suit nema 42 motor and would be nothing like as good a job as using correct motor with gearbox just as it is.

Also from the photos you can see I've been playing with the idea of using the largest gearbox housing to mount my rotary axis. If possible I'd mount it in the centre of the large side of the housing. Should be able to use the existing holes to mount the body of the rotary drive. Would need to drill some holes to mount motor and allow shaft to reach pinion. Direct drive would give 6:1 ratio (Pinion = 20 teeth, Circular rack = 120 teeth). Will do some testing during build to see if this is enough. Worst comes to worst I could use the gearbox to drive the pinion. Pulleys that came with gearbox are 4:1 ratio. (20 teeth on motor - 80 teeth on output). This would mean mounting the rotary drive in postion I've mocked it up in, so that pinion could be driven from centre of large gear pulley. This might be a bit too high in relation to Z Axis in practice.

Just in case anyone is wondering, the label on the Z Axis gear box is a warning relating to a glass linear scale that must have been used as an encoder with this in the past. I'm fairly sure the gearboxes were originally from a servo motor actuated machine.

Bearings and Framing:
=====================
Stock issues mean this delivery has been delayed. The 8080 framing that makes up main siderails and spans on my frame is out of stock at my supplier. Last I heard was on 12th of May 2006. Provider mailed to say had located alternative source in France if profile spec was acceptable to me. Stated if so, full delivery of my order should then take place in 7 to 10 days. Fingers crossed for 22nd May 2006. If I were to wait for normal stock replenishment at supplier would be past 9th of June 2006 before delivery of full order.

I should point out this is partly my own fault. The profile I've ordered is obviously not the run of the mill 8080 that is readily available in the UK. I found supplier of a heavier version of this extrusion when I was 1st planning and designing the machine. As the machine is above avaerage size I decided to go with the heavier profile for better rigidity and support. Full gantry weight will be approaching 90 kilos (approx). This won't bother the guides and rails as they are rated for super heavy load but the extrusion needs to be up to the job.

Energy Chain:
=============
Well what can I say.. these don't seem like they are coming at this point. Were supposed to be on the way from Singapore on Monday 22nd of April to arrive within 14 days. COD was the deal agreed in the end. Paypal would not complete transaction due to sellers account probs and I wouldn't pay off ebay. Seller had multiple harsh feedback from EU buyers proclaiming fraud.. taking payment, no goods sent etc. Just couldn't take the chance and told them so, which is when they suggested the COD deal.

Is very slight possibility they might still turn up. Thinking of the situation that developed with the BOB's from the USA. UK customs held them and I didn't find out about it for ages. Anything from outside EU could fall subject to this. However I have chased the seller re: whereabouts of goods, did they send etc. To date I've had no response. Last mail I sent said if I didn't get response in 48 hours then I'd be looking to buy elsewhere and abandoning purchase. I think I'll end up sourcing these elswhere. It's a pain really as the items and the price were hard to beat. I'll have to pay considerably more for these within the EU.

What's next ?
=============
That's Pretty much it for purchasing news and info, all future posts will be in the build log I'm starting.

I've been doing some checking and revision of costs. I'd made a mistake in the addition of Total spent to date. This is actually £ 4018.32 not £ 4096.31 as I'd previously stated. A full components list with costings is below in PDF format. Keeps the doc layout better so is easier to follow the figures. I'll put a link to the build log as a final entry here when it's created.

Thanks to anyone who took the time trouble and interest to offer tips and advice during buying and planning. I do appreciate the input, although these days it's gone a bit scarce... see anyone interested in the build log.

http://www.cnczone.com/forums/showthread.php?t=20656

Yohudi, looks like your really making progress, It's amazing how the costs can add up.

Question for you, In your estimation, how robust are those rotary heads? I'd like to mount a spindle to them [ make a 5 axis head] and then do some foam/wood cutting. Do you think they would stand up to a couple hundred pounds of cutting force [if properly mounted]? I don't know at this point exactly how much force I'll be putting out to cut foam or wood, but my machine should be able to deliver about 800lb's force max.. not that it should need this much but...

Curious..
Jerry

how robust are those rotary heads? I'd like to mount a spindle to them [ make a 5 axis head] and then do some foam/wood cutting. Do you think they would stand up to a couple hundred pounds of cutting force [if properly mounted]? .....

Curious..
Jerry


Hi jerry, thanks for the encouragement.. as you say the costs can creep up.. but still a lot less costly than buying something similar new.... and there is a bit of slack in my purchasing. When the build is over I'll recoup a reasonable sum of money on the surplus which will ease the strain a bit.... got nice surprise today though.

Mentioned that the 8020 profile had been delayed... well it's arrived... today.. totally unexpected.. Kevin at Marchant Dice Ltd has really gone out of his way to help me avoid delay. Was not his fault his normal supplier was out of my particular flavour of 8080 profile until June so in the last week or so he's found an alternative supplier, got the spec to me for approval, then arranged purchase, cutting and delivery.... can't say fairer than that. I'd thouroughly reccomend MDL to anyone looking for new CNC components in UK.

re: the rotary heads... It's hard to say how much cutting force they will handle without me having cut with them.. they seem very robust and the dual bearings are hefty units. Best thing to do I think is point you in the direction of rainnea (rab) at CNCtoolkit forum. It's a yahoo group so you'll have to be yahoo member or join to get full access.

The point of this is that it was rainnea who came up with the head design using the globe rotary tables. There is a vast amount of discussion and info about this head on the group and it's rainnea's group so if you post any question there re his 2 axis head set up he'll answer it direct. Think that should sort you out...

If you want to see the kind of work he's using it for go to

http://www.rainnea.com
and
http://www.rainnea.com/cnc.htm

He makes celtic art items in a wide variety of materials, knife handles and the like. There's loads of info about both the head and the gmax or 3dsmax plugin he uses to generate code for 5 axis work... hope this helps you out...

Just a quickie while I'm here.

Goods news re: required Echain. Have 6 metres on the way from Germany at cost of 114.50 Euros.. about £80.00... Gave up on Singapore seller after a month of waiting.. did me a favour as new chain cost less per metre from German supplier..

don't forget check build log for updates..

oh and one more thing... before I get any more PM re rotary drives.. the off ebay link I had is not active anymore... I wonder why????

ebay is the only place you will find these now... current BIN on them is $49.95.. when they are available... talk at other forum is that the supply of them is over.... ebay search that will find them is "cnc rotary table +(globe,5 inch,vertracer)"

Echain arrived no probs from European supplier.. he has more if anyone needs any.. cost me £31.25 + postage for each 3.1 metre length..

dimensions are 3100 x 50 x 54 mm minimum bending radius 200mm...

Well Hello there!!! :cool:

Yep it's been a while since I posted anything.. but have been mooching around for someone in my locale to make some mechanical parts before I start work on the machine frame.

My controller build has gone reasonably well. I thought I had a wiring problem but this has turned out to be a faulty terminal connector on one of the drives. Anyone interested can check the full story at my build log..

The story HERE is obtaining the missing mechanicals to unite all of the purchased components into a working machine. Is no point starting any of the mechanical build until I've sorted this out. Decided that any attempt to make them myself was fraught with the opportunity for error. This would effectively be a complete waste of time.. i might as well have opted for MDF and all thread if I wanted to go this route.

I wanted to source the machining locally, so that if need be I can provide the guy doing the work access to the actual parts. For the purposes of pricing I had to design all the components I require accurately, as opposed to blocking them out. Some JPGS of the required components are below in case anyone is interested.

I'm not sure about the cost yet... some of these are large pieces of stock so I'm not expecting it to be a cheap job... the guy I think will be making the parts has been back in touch suggesting some ways I can save some money substituting steel for some non-critical pieces.. aluminium is VERY expensive in the UK.. why is anybody's guess as no one can give a good reason.. they just smile and take your money.... I should have a price for the job and details of his suggestions by friday of this week....

I did go shopping for Aluminium stock among the guys putting it about on ebay.. a right waste of time.... they will all happily sell you something they might have lying about.... but providing sized stock for machining... forget it... I had one guy express interest but I had to chase him to get any response at all. After I sent him sizes for pricing I never heard from him again...

Anyway that, checking the controller and setting up my sexy 10U rack is pretty much what I've been up to.. will post the machining costs when I get 5 mins... Pics of the controller and rack setup should be up by the weekend... busy, busy. busy at the moment.. and I've been coerced into building some new accomodation for the better-half's equine interests....

oh also.. again for those peeps who messaged me about off ebay site for those rotary drives.. well the link is active again.. There are some available at $49 BIN on ebay.. some others in auctions also.. starting bid usually $36.... price at the link i've got... $36 and it's yours....

I know I said i didn't think the stock and machining for these bits would be cheap but got quote today...

Supply of materials and machining to spec £1100.... yes you read it right....
doing some checking elsewhere but don't think will get it for much less... labour costs come in at £25.00 per hour.. and stock will all be certified etc.. I should be giving the go ahead for the guy to make the parts next week.

will bring my overall build costs up to the £5400 mark BUT... I've recently seen a brand new machine of very similar spec to mine advertised in the UK... that cost £17,900 plus VAT and Delivery of about £400 a total cost of £21,482.50.

Now you know why I'm building rather than buying mine.... for about a quarter of the cost I should get almost the same capability....

wow.

while im not sure about the cost/performance ratio, impressive lot of parts and nice drawings. i keep seeing yout posts and thinking 'oh, thats a nice bit...'

carry on.

vacpress..

thanks for the kind words... have been lucky a few times with bits etc..

assessing those gearboxes I fell on at the moment... I reckon as opposed to using 1 on the Y axis 2 of the units might make a robust and compact 2 axis head, suitable for attachment direct to my Z slide component...

I'm meeting up with the machinist I found tomorrow... taking the Z axis box with me.. is critical to 2 of the parts I want made.. the Y axis cradle assembly and the Z slide assembly... he can check my specs and measurements for himself.. think it always helps to let someone see the job... if it goes well and I give him the OK he says I should be looking at completed parts in my hands in a week to ten days..... and a hefty dent in my pocket to boot :)

and here are the parts......

This is one mother of a machine you are building. BTW i am not a million miles away. Other side of Welsh border, Abermule. Keep up the good work.

Very nice work Yohudi, should turn out to be an awesome machine. I am entirely with you as far as building a great machine from the start. If you do your homework here first theres no point in building anything but. The cost difference is a small issue when considering the amount of work involved in building one of these. Keep up the great job!

and the cost will really not be an issue when you have to redo, and or mess something up and have to replace it, do it right the first time....

Just been reading back over this.. and noticed that there's no link to my build log here.. so I've pasted it below.

http://www.cnczone.com/forums/showthread.php?t=20656

Just trawling the forums for interest of any sort in CNC_Toolkit. And found mention of it in my own thread ;)

Part 1 and 2 of a brand new detailed user guide for CNC_Toolkit are out TODAY.. available as a free download from the yahoo group in my sig.. I made the guide..

Rab Gordon, the creator of CNC_Toolkit has contributed suggestions and has approved the distribution. Part 3 covering the deployment and use of multi-axis rotary configurations is currently being developed and tested...

If you have any interest in CNC_Toolkit then it's worth a read, feel free to pick up copy...

ttfn

Danny (aka Yohudi)

Hi Danny,
Wondering how is everything running ?
I’m hopping to ask you a few questions but first I’m verifying if your still on this thread !
Also interested in to how are you motors gearbox and your controller. Any changes / upgrades from original in 2006 ?
Later, Robert :wave:<O:p</O:p

Hi there Robert..

Thanks for your interest..

Happy to say my machine is still running fine and no sign of any problems to date with anything... I added a 4th axis towards tail end of last year.. using a prototype drive from Colin Doughty at http://www.doughtydrive.com/

Colin very generously sponsored my recent tutorials for CNC_Toolkit and my new CNC related website at http://cnc4free.org I can honestly say that his rotary drive units are truly something to see.. he has links to video of them running at his site....

I'm planning to up some photos of the upgrades to my machine when I get a minute.. Will be using the prototype rotary in the third part of my guide for CNC_Toolkit as a 4th and 5th axis...

Time is tight as they say.. and don't get as much opportunity to update the build log.. will try and up some pics of the 4th in the next few days as it was a relatively easy mod.. and is pretty cool if I do say so myself.. helped in no small way by the spot on design of the rotary prototype...

once again thanks for your interest...

TTFN

Danny

To anyone watching really...

got 5 mins to pull some pics from the camera I took just before and while adding the 4th axis...

00ModelCut.jpg and 000Modelcut.jpg

Took these on finish cut of my Dragskull model.. made using methods in my bitmap to models tutorial

01Stripped.jpg

Table on machine after I removed old sacrificial strips to mount profile for A axis

02MountA1.jpg

Colin Doughty's prototype rotary axis mounted as an A Axis... Square should give idea of dimensions etc

03MountA2.jpg

4-Jaw Chuck mounted onto the rotary

04MountA3.jpg

The view down the table from the drive end

05MountA4

Completed Table setup.. Added heavier ribs as will now be used for fastening rather than just spacing off the table

06MountA5.jpg

View of the completed job from the tailstock end

will add more pics once I get time to sort them out

ttfn

Danny

Colin very generously sponsored my recent tutorials for CNC_Toolkit and my new CNC related website at http://cnc4free.org I can honestly say that his rotary drive units are truly something to see.. he has links to video of them running at his site....

Great web site Danny. One thing I enjoy about this forumn is that I learn something new everyday... and your site will keep me busy for a month or so with all the new applications.

Great web site Danny. One thing I enjoy about this forumn is that I learn something new everyday... and your site will keep me busy for a month or so with all the new applications.

Hi there.

Thanks so much for the positive remarks.. I try to make the site different to the other CNC related stuff I've seen and provide useful links to stuff we can all use.

When people actually find it useful it's a big encouragement..

thanks again

ttfn

Danny (aka Yohudi)

When people actually find it useful it's a big encouragement..

Another guy saying THANKS for your time to share your info, findings and links.<O:p</O:p
Thanks a mil.
Robert :)<O:p</O:p

Another guy saying THANKS for your time to share your info, findings and links.<O:p</O:p
Thanks a mil.
Robert :)<O:p</O:p


Hi there Robert,

thanks for the THANKS.. glad you like the site and hope you find it of some use..

ttfn

Danny