OK start the ball rolling on a hardware store design CNC router.

Well, here we are in the hardware store design thread... Does that mean another black pipe design? Or is there a better option?

I'm not sure we want to go backwards to drawer slides...

And it'd be mighty difficult to do a conduit design like Ger21, cause we don't have a cnc machine to cut all the parts with.

Are we talking improved black pipe designs? Fixed gantry? Moving gantry?

Your thoughts...

Mike...

Hi Milke,
As a newbie with no machinist knowledge but plenty of electronics and lab experience, I've been forced to use the local hardware as a major source of raw material.

For me small means a small workpiece, so it makes sense to move the work not the spindle. I'm heading for a 2.5D axis setup with the z axis movement of the workpiece coming from a separately controlled arm. But I would put the z axis movement on the fixed gantry if I needed to use the spindle in 3D.

As the only source of steppers at the moment is old printers or ebay(limited funds) the timing belts will give me my transmission.
I do have a supply of old display framing - aluminium extrusion - so I plan to use 19mm chrome steel tube ( wardrobe fitting dept) epoxyed into the channel. This will be bolted down onto an offcut slab of formica clad 38mm kitchen worktop.
I'm using miniature bearing from the scrap box augmented from ebay, but would try skate bearing otherwise.
Any thoughts?

Drawslides work pretty good for the X and the Y. You can even you steel wire wrapped around a plastic wheels to move the gantry, like pulling a curtain.

Buying your hardware from ebay is definitely a good option.

As for using the components that you've gotten out of old printers, you'd have to include some photos and descriptions so that we could better understand what you have.

Mike...

Hi Milke,
I've been forced to use the local hardware as a major source of raw material.

As the only source of steppers at the moment is old printers or ebay(limited funds) the timing belts will give me my transmission.
Any thoughts?

I'm looking to build a machine using drawer runners. I've located a source with 450mm travel and minimal play in the bearings (heavy duty ball bearing runners).

I've got plenty of stepper motors now from 100oz in upwards and some toothed pulleys/timing belts.

Just need to build a workshop to house it all in before I can start building the machine.

hi
I am currently building a machine , mainly using MDF , but i guess the problem is some of the parts , like 20mm*20mm L section steel at 3mm thick that im using for the runners and supports and 20mm stainless steel bar for the bearing slides, are not available in most hardware shops , (but are available on the web ) and bearings are a problem also,

i thought about using unistrut , that is an excelant matirial for making the frame work , even if a tad expencive , but would require minimal machining
and m10 threaded bar for the lead screws

although i guess all the bits are not available from the big diy hardware stores here in the uk like B&Q and homebase ,but i have found that CEF(city electrical factors) in the uk (have shops in almost every major town) stock items like the treaded bar and unistrut and fittings

i designed my machine to use minimal machining as i only have access to a electric hand drill and the router that i am going to use as the cutting tool and hand tools like saw, file

sorry no pictures yet and its still a few months off compleation but looks like its going to be finished within the £400 budget i set for it and its got a workspace size of 900mm*500mm*100mm

i originally started with the same idea that i should be able to get all the parts from the local diy/hardware store but in the end found that way too restrictive on parts , threaded bar for example was not available , and local steel stock holders can supply steel some places will cut it to lenth also

i can only speak for what the uk hardware stores will stock , and not shure whats available in stores elsware things like good quality draw slides for example are not available

i need to solve a dfx export problem with my cad package (total cad ) to get the fonts right then i will post my design

Dave

My first machine used a combination of drawer slides for the X axis gantry and ball bearings and gas pipe for the Y axis table. I like the drawer slides and am in the process of modifying the table to use slides.

The combo I have worked out is one heavy duty full extent slide mounted 180 degress around and on top of another slide. This means that the table will always have support and the travel is obviously doubled. This will be interesting to test.

mikeschn,

Ger21's conduit design can be done without cnc If you have a good router and a laminate trimmer bit with a bearing. All you have to do is make a simple jig to hold the form that the bit follows & the work piece.

This reminds me of the Dave Gingery books. He talks at length about how some one had to build the first one. It's the old "which came first the chicken or the egg." In this case it is the egg because without the egg you can't make the chicken out of the hardware.:)

Also the draw guide system is not that bad. For a first time machine and a learning experience, I believe most beginners would be very pleased with the machine. I have read about many machines getting 1/32" accuracy from drawer guides. This is far more accurate than most cabinet shops could ever hope for.

I am a newbie my self and I do not have an unlimited budget to build with so I really hope that people will come to the cause with some new "cheap" ideas for the beginner.

Thanks so very much
Jimmy Southern

P.S. don't be afraid to throw out very crazy ideas, sometimes they work!! (group)

Having built a few machines now and used several different hardware store solutions for the slides, I would say that the number 1 consideration is rigidity.
This being said, the easiest way to make a rigid machine is to make a small machine. Drawer slides can work OK on a moving table if the travel is kept small enough. Drawer slides on the Z axis do not work well at all though, another solution is necessary there.
Also a moving table design with a fixed gantry will be far more rigid than a moving gantry design.
So, if I may suggest, lets work towards a small (8" X 12" travel??) fixed gantry moving table design.
Colin

Wow, I didn't realize there would be that much interest in a drawer glide cnc router.

Do we have 2 cad users here that would be interested in working on a drawer glide machine?

Mike...

mikeschn,

Ger21's conduit design can be done without cnc If you have a good router and a laminate trimmer bit with a bearing. All you have to do is make a simple jig to hold the form that the bit follows & the work piece.



Doesn't the laminate trimmer force you to cut the entire 3/4" thickness at one pass? Can you cut that much plywood or mdf at one pass?

Maybe we should look at a pattern bit.

Mike...

Doesn't the laminate trimmer force you to cut the entire 3/4" thickness at one pass? Can you cut that much plywood or mdf at one pass?

Maybe we should look at a pattern bit.

Mike...

He said router and flush trimming bit, he just was a little unclear. :)

A faster, easier way if you have a table saw and drill press:

Use a sliding cutoff sled with a stop to cut all your parts the same length.
Use a fence on the drill press with stops to make the cutouts for the pipes. Use a forstner bit.

For those of you in the UK who want decent quality drawer slides check out www.buller.ltd.uk - speak to Rafael - he's a really nice chap.

Go to Miscellaneous on the left hand side and Runners/Slides - you'll pick up a 500mm length runner for £3.84+vat per pair and up to 700mm for £7.98 a pair and they are pretty reasonable heavy duty bits of kit :)

Gerry,

Thanks for the correction on my post. I was in a bit of a hurry when I typed that.

If you are going to use the flush trim bit idea you will have to remove some of the waste material first and of course rough cut to length & width. But I would use one one master template for all of the pieces for each area to have consistency.
this willgreatly reduce the errors from operator input.

hope this helps
Jimmy Southern :)

I'd suggest you make it a rule that you keep the scope as the title "hardware store design". As example it is reasonable to expect you can buy gas pipe or drawer slides, mdf, drawier glides, rollers at a hardware store. I can't say I've seen IGUS or Thompson parts at one.

I agree with pminmo.....before we muddy up this site...perhaps we need separate threads...one for "hardware store design", 2nd for "gantry with rails"....you kinda have skill level categories....instead of requires 2hammers...we'll have have a machinist rating like "2 mills" with a 1 being the minimal amount of tools, 2 being need access to a mill, 3 being need access to mill & lathe....

...we'll have have a machinist rating like "2 mills" with a 1 being the minimal amount of tools, 2 being need access to a mill, 3 being need access to mill & lathe....

Most people will be more likely to have table saws (maybe) and drill presses. Very few will have mills or lathes, imo.

And there are a few different forums set up already. But yes, some ground rules need to be set up quickly.

I agree with pminmo.....before we muddy up this site...perhaps we need separate threads...one for "hardware store design", 2nd for "gantry with rails"....you kinda have skill level categories....instead of requires 2hammers...we'll have have a machinist rating like "2 mills" with a 1 being the minimal amount of tools, 2 being need access to a mill, 3 being need access to mill & lathe....

I agree with both of you. The hardware store design is exactly that, with all parts coming out of the hardware store. I went back and re-read the posts, and I can't see where the conversation was diverging, and maybe it didn't. But your point is well taken.

We also have threads for a cheapcnc design and a mid level design. That's where it starts getting less clear. For a mid level machine, do you assume access to a mill and a lathe? I like the mill code you started up there... I would suggest the ratings 0 mills, 1 mill or 2 mills.
0 mills is just basic tools, 1 mill is access to at least 1 mill, and 2 mills is access to a mill and a lathe.

With that in mind, the cheapcnc, the 80/20 and the hardware store designs can all be 0 mill designs. The midrange machine can be a 1 mill design, where a person is using his entry level mill to create the masterpiece he really wanted in the first place!

Mike..

Guys,
When you say hardware store supplies, does that mean exactly what it sounds like, or are bearings included? The reason I ask, the local Princess Auto store (think of it as a small town store that caters to farmers) carries almost everything a hardware store does, plus surplus parts and bearings and steel.
Using what they sell, I have built several different machines cheaply, using fairly basic hand tools plus a drill press.
Combine them with Home Depot, or your basic building supplier, and you have everything you need except software and the electronics.

HTH
Iain

Exactly... hardware store meaning your local home depot plus your local ace hardware, or equivalent. You gotta make an assumption that stores like these are more or less readily available in all countries, and the parts are reasonable priced, in various countries.

Of course there will be differences, and the builder will have to adapt... but hey, that's what makes building these fun!

Mike...

Where's all the CAD users? :confused:

Mike...

This is exactly what I am looking for. The machine I would want doesn't need to be super huge, infact 2' by 2' would be the biggest that I would need (and might even be too big). Most of what I would be CNCing would be anything up to 3/8" Balsa for wood and up or 1" in EPP foam. I would be ok even using a dremel as the cutting tool. You guys should setup a limit as well for travel/working/table size?

Mike,
Thanks, that clears it up for me then, as the only parts I can't get at Depot, Ace, or TruValue are the bearings. However, I can get the all thread, tubing, or aluminum angle at any of the above, and if you go to the housewares section you can also get those nice white nylon/polymer cutting boards that are great donors for slider pads. Line a piece of alu angle with it and use a piece for the rear and you have a decently simple, ridgid guiding way. Works a treat on the Z axis.
It's low profile too!
Or, using pipe or extruded tubing, and V groove pulleys you can make a decently cheap, simple and accurate moving table for larger size routers.

The possibilities are endless!!!

Iain

Hello Everyone,

I just have a few suggestions. Don't rule out the skate bearings. there are so many creative ideas available that use them. IMHO you will be severly tieing your hands if you do. Most people that visit the Zone use ebay regularly and even though I have heard some comments on the quality of most of the bearings on ebay they will still beat drawer guides hands down. For those that are in the hard to reach parts of the world I would still recommend the bearings. I have seen buy it now prices of $20.00 for 100 bearings. even if you were getting the drawer guides for dealer cost you would still have a horse race on the price issue, even with international shipping. Metric countries especially should love the skate bearings because they are an easy score for the bolts and hardware needed. We in the U.S. have to special order bolts to fit these bearings, or improvise.

What I would like to see is some "KISS method" designing. Keep the complicated rocket science ideas to your self. But also on the other end I don't want to see some 8th grade erector set science experiment.

Bottom line: we all should have a few simple tools in the inventory before we consider building a cnc machine, not to say we have to have them, but the guys who will be designing this will. We will have to expect a small investment in tools. Here are the tools I think are mandatory.
1. hand drill
2. circular (skill) saw
3. decent set of taps & dies
4. good scribe for marking hole locations
5. good square
6. at the very least a laminate router and a good assortment of bits
7. Assorted wrenches and hand tools

Here are the tools that I think are worth the investment. Notice I said "INVESTMENT", these tools will probably be passed down to your children. So get the best you can afford.

1. drill press. even if all you can afford is the ebay $20.00 special it will be far more accurate than you will ever be by hand!!!!! MUST HAVE!
2. table saw. not a must have but again far more accuracy!!!!
3. router table. If you can't afford the table saw then go with the router table at least. This is the least appreciated tool in the shop until you need it. Also contrary to popular opinion a router table will work with a good laminate router.

Don't expect to design something for the general newbies that we can build with a hand saw and a screwdriver, because you will alienate the general population of readers that would like to build a first time machine. I speak from experience because I am a newbie. I know it costs to learn anything that is worth while. Just keep the non hardware purchases cheap, available and easy to use.

Sorry for the rant :D I will now step quietly off my soap box and listen to the next speaker.
Thanks for all that you do for us newbies it is appreciated (group)

Jimmy Southern

KISS rules!!!!!! long live KISS! :-)

Jimmy,

I've build 2 small and very cheap machines using a combination of drawer slides and nylon guides.
The skate bearings are probably better, I have looked and thought about it but:
I do have the tools you mention (even some more) but don't see how I could build any of the axis using bearings and obtain the same precision.
Found several examples on the net but they all look too complex for me to build.
The drawer slides I use are Accuride one's recuperated from mini computersystems.
They are 35mm wide and ride very smooth, using 2 of these 20 cm apart gives an almost perfect axis and above all: it's dead easy to assemble.
Of course there are drawer slides of different quality.

BTW: I have a lot of bearings here, several sizes and still would like to give it a try, just don't know how to start.
Any pointers to something easy?

Luc.

My 2nd 2 cents :-). Drawer slides vary, what might be available one place may not be the next, and different manufacturers have different dimensions. And while rollerbearings may not be available at a hardware store, they are available retail, mail order and off the web, all around the globe. But they present a little more difficut problem of drilling well placed holes, or adding complexity with adjustments. I have been impressed by some designs here that use roller bearings and flat, angle or tubular stock. Attached is an example. While this machine is what I would consider out of scope for this thread, maybe the captive bearings and tube stock are not.

CADman here .. can do drawings ... please find attachments to see if you can open ...
dxf for older doods

Guys,
I too have read through the previous long attempt which just lost steam.
I am well into building a Jgro Machine so can't say how well I will be satisfied with the operation but the plans were great. I did use the former recommended list of tools without having seen the list at that time ( it didnt exist).
ie Drill Press
Table Saw
Router Table
& Hand Tools

I did not have access to any Machining capability but tried to accurately mark and use the first piece as a template using 1/16" drill to drill the first holes and using others to keep each piece aligned with the template as I drilled more. Center routed Dados were achieved routing from both sides. I mention all this to amplify that with patience and limited equipment it can be done.

Now on to the existind topic Everyone's comments even Jgro's seems to be that it is not stiff enough. All the engineering discussion concerning solid steel rods also points to the fact that these are only marginally better than Pipe of the same dimension.
Therefore a method is needed to stiffen them up.

Along comes Spalm's Design

http://www.cnczone.com/forums/showthread.php?t=12056

The Jgro plan could be easily modified in the torsion box aera with the linear bearings inside the gantry for the design. Or with Spalm's permission using his design and adapting it for the opensource requirements smaller or larger. Spalm's problems were as I understand bedding the rails (the solution seems to be fibreglass and cling wrap) and stiffening up the Gantry Sides. Either Stringers as he has done or what about double thickness Ply or MDF.

Please for the sake of the budding builders counting on the forum for the best posible solutions, which I know collectively we could achieve, don't have a particular axe to grind and let the discussion bog down and stall.

Those of us who have particularly set Ideas are the ones who least need the plans for the opensource machine as they could do their own on the fly.

Ok I'm off my soapbox now.

BTW although I'm a Nubie CNCer I am reasonably proficient in AutoCAD.

cheers

HI, I am glad that you guys are taking up this task to develop a good homebuilt cnc machine. I have been searching all over for a small cnc router that can cut wood and aluminum, and the cheapest I have found is made by Liberty cnc out of Tennessee, www.libertycnc.com. It sells for about $3500. I own a small part time business and I really could use a good machine. From talking to the guys at Liberty cnc, I learned that you need a slower speed to cut aluminum, grade 3003 or 5052. They sell a Trend brand router for such application, and it has 5 different rpm settings from 8000 to 23000. I do have a good tablesaw, drillpress. I don't know much about cnc, but if you can tell me what I need I can build it. I think this is definately a good thing that you all are doing here. Thanks for letting me give a small 1cent worth.

Gday all from Australia, I have not done anything yet with building a CNC machine, but
I'm looking into it for next year project.

I used to work for a company that ran a trumph cnc punch press. I programed, ran, repaired (mechanically) this machine.

I have found some supplyers of some interesting hard where and will be looking into for some of the parts needed for this prodject. http://www.tea.net.au/

Regards
Brett Fisher

Hi to any one that is out there my name is Dave I am English a cad draftsmen using acad. 14 and wood be happy to help with any drawing and design. I live in France and this will be my first CNC machine. I am looking at something more substantial than drawer runners and have found a supplier of engineering parts,hpceurope.com that are happy to supply small orders. the prices of the liner bearings are more expensive but the basic frame of your machine will be solid, there is also a dxf cad Libby of parts in 2D so you can just insert them in to your drawing

HI, I am glad that you guys are taking up this task to develop a good homebuilt cnc machine. I have been searching all over for a small cnc router that can cut wood and aluminum, and the cheapest I have found is made by Liberty cnc out of Tennessee, www.libertycnc.com. It sells for about $3500. I own a small part time business and I really could use a good machine. From talking to the guys at Liberty cnc, I learned that you need a slower speed to cut aluminum, grade 3003 or 5052. They sell a Trend brand router for such application, and it has 5 different rpm settings from 8000 to 23000. I do have a good tablesaw, drillpress. I don't know much about cnc, but if you can tell me what I need I can build it. I think this is definately a good thing that you all are doing here. Thanks for letting me give a small 1cent worth.

Hi chip sweeper
If you have a look on the net for porter-cable routers you will find a router that is built for DIY cnc the model no is 7518 it has a 3¼ peak hp motor and is 5 speed
www.porter-cable.com

It looks like we have 3 autocad users in this thread. Excellent. We'll be starting to draw soon!

In the meantime I am sensing that we have two different designs developing...

1) with drawer slides
2) with supported black pipe and skate bearings

The drawer slide design is definitely a smaller design, call it desktop if you will, and will probably have a machining area of 12" x 12" or thereabouts. It can probably be machined completely on a table saw, and assembled with some hand held tools.

The supported black pipe design is a little more complex, but should be a much more rigid machine, even more rigid than jrgo's design. It'll be similar to ger21's torsionbox design or spalm's second mdf machine. This design requires a bit more tools, table saw, drill press, router with pattern bit, etc...
The machining area is much larger on this machine, probably in the area of 24" x 36".

Is this the right direction for two hardware store designs? Your thoughts?

Mike...

The 24x36 does sounds quite a bit more appealing to me. Supported black pipe and skate bearing should be easy to come across here in Arizona.

I do have a nice band saw, drill press, and router. The only I do not have is any welding equipment if it is needed.

Hello Everyone,

I just wanted to put in my vote.

NO to the drawer guides
YES!!!! to the pipe & bearing machine

I do believe that jgro's machine is a very good start but I have seen modifications that would make it better. The 24"x36" cut area is a perfect size for a starter machine. You could use the hobby CNC kit for the electrics IMHO. This would keep the learning curve low, especially for the electronic illiterate, like me.

One idea I saw that would make this easier, is the eccentric bolt for the bearings. This particular design was very easy to produce, even for the novice. You simply take a bolt 3/8"-1/2", whatever size we determine will be most suitable, and offset drill and tap a hole for a 5/16 flat(flush) head stove bolt in the head of the large bolt. This should all be available at the hardware store. It is also very simple to understand. This would give a great deal of play to take up errors, and give alignment ability.

If any one has a link to the pics of the bolt idea please post the picture. I saw it somewhere in the forum but did not save the link.

With a good torsion box bed and gantry, full support for the pipe or rod, whatever we end up with, I believe this will be the next starter machine for the newbie just coming to the zone.

I am going to try to build whatever we come up with. I really appreciate what jgro designed but I believe we can make it better.

Watching & waiting on pins & needles
Jimmy Southern

I'm looking for a good way to secure the black pipe to the torsion box. We could JB Weld it... but then we can never take it apart. We could drill some holes in the black pipe, and use socket hd cap screws. Is this still in the realm of entry level hardware store machine?

Any better ideas for fastening the black pipe to the torsion box?

Mike...

Mike,

I like the capscrew idea but I would like to see a tee nut set in a pocket, or hole, like people have been doing on the jgro pipe supports. It would be easy to use a forstner bit to make the hole for the tee nut. You could even use a hole saw or spade bit, whatever you have. This would be much easier & stronger than tapping the MDF.

Everyone please jump in with any other Ideas,
Jimmy Southern

Don't you need some adjustability....some time back we came up with the idea of supporting the ends of the pipe with some adjustable bearing blocks.

You mean like this?

http://www.cnczone.com/forums/showthread.php?p=98533#post98533

Mike...

Viper,

If I am understanding you correctly, on the adjustability, I think if you use a master template to route all of the pieces then the only adjustment that should be necessary would be to the bearings on the gantry & the z carriage. Everything else should be very consistant. You may have to shim in a few areas but I don't think you would if you assembled the machine carefully, paying close attention to the alignment of the pieces and to the squareness of the parts.

If the design is well thought out it should go together almost like lego blocks. We should design this to have half lap joints in the torsion boxes so it goes together like a drawer divider. this will greatly eliminate the build errors.

Hope this sheds some light on the idea that I have
Jimmy Southern

May I suggest that if your going with black/gas pipe that you size it to commercially available cutoffs. Usually available in 1' increments. For a machine base, consider using 3 sheets of MDF glued/laminated, that will give you strength and weight for stability. Those that don't have a table saw will be pressed to do a good torsion box. The only thing you need there is a flat surface or jigged support.

what happened to the KISS principle .. and also First things First.. the simpler contains drawer slides, smaller, cheaper and less complex ..

it makes common damn sense to see how the simpler proof of concept can be completed before undertaking the whole gas pipe and roller blade bearing design..

start small and go forward.. remember, "He who is faithful in a little, can be faithful in alot."

Well actually, we are going to do both, the drawer slide and the black pipe designs. Both designs will be hardware store based, and also no mill required.

Here's what I am working on for the black pipe design. Each member of the torsion box will have an end like this, for adjustability over the entire length of the black pipe. Furthermore, if the holes are not perfectly centered, that's okay, you can center the pipe using the screws. The pipe is going to be 1 1/2" black pipe, currently 3.39 per foot, which has an od of 1.9". So you can drill a 2" hole, and have .10" to play with.

What do you think so far?

Hi, I am going to try and add a simple thought here, I think Jimmy is refering to a dado groove in the torsion box. Regarding the alignment of the pipe holes in the torsion box, once you measure, mark, and drill the first end piece accurately, you can lay it on top of the second piece and sqaure and clamp it. Then your first piece is a template for your second piece and should give you perfect matching holes.
As a possible substitute for the black pipe, has anyone looked at the ceiling fan drop rods that have a polished finish and are sized from 6" to 48"? If so, what did you think?
Thanks, woodworker21

Hello everyone,

Just need to clear up a few things. First I am greatfull to Mike for taking the lead on this. There has been some discussion on the drawer guide vs black pipe and I was glad to hear that we are going to design two different machines. Personally I have no use for the drawer guide machine, it is just too small, so my mind is centered on the larger machine. So don't take my lack of interest as oposition. I am just posting the ideas I have had or seen.

Now to the specific misunderstandings: The half lap joints are nothing more than half depth dados. Please look closely at ger21's new machine thread. This will clear up alot of questions about what we are talking about.

Now to the difficulty: I am just guessing here but I think there would most likely be no more than 5 pieces that would have to be precision cut and all of this can be cut with hand tools if very diligent. More tedious than difficult. Once these pieces are cut you simply use a pattern bit, or flush trim bit, to follow the master template. It seems more daunting than it is.

I would like to see the design team take this machine to the level of ger21's machine just use a little less material and make the plans include either scalable master patterns or very precise measurements. The only variables that should exist would be the thickness of the MDF, Ply or whatever the builder uses, and the available pipe sizes. this will greatly reduce the work that the builder has to do. This design is very scalable up or down and very rigid. Ger21 says in his post that he put his entire weight 220lbs (I think thats right, sorry ger if it isn't) and it only deflected 1/64". Jgros machine has nowhere near this strength. This is why I am pushing very hard for that direction. In my opinion ger and spalm are on the right track for the perfect "usable" machine.

I am very open minded if anyone has a better idea for this machine, but I have not seen anything that for the price gives the same quality.

I really hope that no one has been offended by my enthusiasm. I really do plan on building this machine so I would like to be the guine pig(not sure that is spelled right).

Thanks to Everyone!!!
Jimmy Southern

P.S. Keep the ideas coming (group)

i DID A little CAD of that nice Rib Mike --- please find attached and see if you
how it looks ...

Hi,

This end of the torsion box design may be unnecessarily complicated as Spalms design relies on the pipes being stationary, oK, (parallell and Level to the cutting surface} but so is the torsion box hopefully. All the adjustment is on the Bearings which in the case of the Gantry are moved in relation to the Gantry Legs (sides) the Torsion Box cut-outs must support the rail solidly to prevent the slight (but to some unacceptible) flex in the rails. These adjusters of course will do this but so will grouted ( for want of a better term ) with epoxy ends and the rails pulled into place. The end of the torsion box could be like shown with a screw pulling the rail into the opening.

However without a cantelivered end in the torsion box or leaving the bottom open it will be hard to adjust these bolts and reduce the cutting surface for a given size gantry. If the bolts are needed then it is possibly better to use countersunk screws from the outside. Must stay away from the bearing tracks though.

Spalm now believes he has cured the problem by pulling the rails together on the ends with allthread.

Hey guys,

I spent about a month trying to come up with an easy way to build these torsion boxes. The half lap dados are tempting, but just try to get them all in 3 dimension parallel (alignment) before the glue dries. I tried twice, and gave up. That is why is used the individual spreaders. Gerry’s boxes were a lot larger than mine and he used screws to hold them together. If you are trying to build thinner boxes, I found that the parts floated around a lot.

I used the base ply or MDF as the ‘base’. Double check this for square. If it was ¼ inch ply, I used double sticky tape to make it lay flat. Then I glued the first stretcher and checked for perpendicular while using my finger to make sure that it touched the 3 edges of the base. I then spread glue on the first set of spacers and squished them into place (placement is not important). I then spread glue on the second stretcher and squished it into place, again checking for perpendicular and using my finger to make sure that it touched the 2 edges of the base. Repeat this along the entire base. The last set of spacers never came out to the right length, so I custom cut them at this point to make sure that the last stretcher was just touching the far edges of the base. I then let this dry overnight before adding the second skin by applying glue and a weight to hold it in place until it dried.

I did not use a nail gun or other fasteners. Only glue holds the box together.

Just my $.02
Steve

The basic construction of a torsion box can be seen here...
http://www.diynet.com/diy/ww_materials_products/article/0,2049,DIY_14442_2278181,00.html

Chron,

Your cad drawing is a good start. The board is 3" x .75 thick. The upper and lower bolts need to be above and below the board.

I'll start modeling the torsion box this morning.

The other approach is to let the pipe lay on the bottom of the circular cutout, and just use the other two bolts to snug it up. The only reason you'd need the bottom bolt is if the cutouts are inaccurate.

When I built my sample rib, I found it very easy, because precision wasn't critical. And all 3 holes were very easy to drill and tap. Oh, and the drill and tap was available at the hardware store too, for $4.39. Throw it in your drill motor and away you go. I would harden the threads with some CA though.

Mike...

P.S. I threw a few lines on paper, to get a feel for where I am headed. The bolt size changed from #10-32 to 1/4"-20 (not changed on the drawing yet)!

Here's the lower torsion box and the skate bearings... I don't want to go any further until you guys tell me that's what you had in mind, and that we haven't created any weak links... :idea:

Mike...

P.S. Just added the centering bolts...

Mike, if you'd like, you can come by and take a look at mine.

Mike, if you'd like, you can come by and take a look at mine.

I'd like that! PM me your address and phone!

Thanks,

Mike...

spalm,

I was just reading your post and had a thought. If the pieces are cut like ger's, it should be a simple matter of putting together the outer shell of the box first. If this is square and true when the glue dries the rest should just follow it's lead. Also the assembly will only be as good as the master pattern. The more time spent making the masters perfect the easier the assembly will be. Just my opinion though.

Mike,

I did notice one thing I would change. On the bearing bolts I would go with a flush, or countersunk, headed bolt. This would give a bit more room for the supports to clear. It will also center the bearing on the bolt and take out any play in the bearing itself.

So far I like it!

Also did anyone find the eccentric bolt idea that I was looking for this might be handy for the cad guys if we can get them a picture.

See ya,
Jimmy Southern

About the best we could do is to go with a low profile socket head cap screw.

I'd like to see a picture of that eccentric bolt too!

Here's a major question for you guys...

do you want some kind of built in adjustment plate like spalm has, or do you want all your adjustment in the pipe adjustment blocks?

Mike...

I just dug out the pair of drawer slides I knew I'd scavenged some time back. Turns out that they are Accuride precision units rated 150 lbs the pair, with a retracted length of 28 inches. I'm going for a drawer slide design for my first machine.

One question for discussion. I am considering angling the mounts so that the slides are 30 degrees off vertical. This way I can assemble with preload without needing thousandths precision in construction. I'm also thinking that it will deal with sideloads better. Any comments?

Jimmy, I was just pointing out what I had learned. Note that Mike’s link on torsion boxes also uses individual spacers. Both ways work. Just watch out during assembly time. A couple of things that I was worrying about when building these were:

Most people at this level do not have a pneumatic nail gun. I do, but I was trying to build to their level of tools. I was using 1/2” MDF and screws at the cross joints did not work to well. Remember if you use Baltic birch ply, it is metric, so you may have to get metric router bits (or adjust cuts) for a good dado fit.

My most critical alignment was to make sure that the pipe seats were all in line and the box was square. This is a little different than normal box construction as the struts stick out.

Clamps just seemed to get in the way and can add twist to the box that you don’t realize until it’s dry.

I like where this is going,
Steve

My most critical alignment was to make sure that the pipe seats were all in line and the box was square. This is a little different than normal box construction as the struts stick out.



The top and bottom of my torsion box have a rabit along the edge with the tubes. The cross members are notched to allow the rabbit to fit in. By carefully adjusting the rabit, it can only go together perfectly straight. An alternative would be to cut a small slot in the cross members, and also in the top and bottom. Then use a spline during assembly to line everything up relative to the top and bottom skins. You could do this with a table saw or router table.

Gerry, my point exactly. All I wanted to point out is that these boxes are a little different than normal, and probably require some careful thought on how to assemble them.

Steve

Spalm, Ger,

You both have mentioned the technical aspects of the job, and I very much agree that this is not going to win the award for the easiest machine to build, but for the extra strength and rigidity I believe that most will agree when I say it will be worth it.

If we can put our heads together and be very thorough in the designing stage we will make a machine that will have the zone buzzing with new cncers(to coin a phrase).

My entire point for this discussion is: I have plenty of time to build the machine of my dreams, just no money. Also from what I have read and seen this machine can almost be scaled to a 4'x8' size without any loss of accuracy or strength. You can't say that about many other machines here. If we can pull this off it will be the best tutorial for the person who would like to build a solid machine for few bucks.

There are those who will say this is too difficult to build and you have to have a cabinet shop to build it, but I believe that what I have seen so far could be built with a jig saw, a router and simple hand tools. I have built much worse with alot less. In my opinion this machine will be technically easier to build than jgro's. It just looks more complicated.

Stay with it guys! We are on the right track!
Jimmy :cheers:

I just dug out the pair of drawer slides I knew I'd scavenged some time back. Turns out that they are Accuride precision units rated 150 lbs the pair, with a retracted length of 28 inches. I'm going for a drawer slide design for my first machine.

One question for discussion. I am considering angling the mounts so that the slides are 30 degrees off vertical. This way I can assemble with preload without needing thousandths precision in construction. I'm also thinking that it will deal with sideloads better. Any comments?

You won't have enough with just one pair...
If you build the system with moving X and fixed Y axis, then these are great for the X. (That's exactly what I did)

For the Y I used "the modified drawer slide" concept.
Below is a link to a picture of a test axis, it just gives an idea of how simple it can be.

http://users.skynet.be/sky50985/CNC/testaxis.jpg

The leadscrew is standard M10 threaded rod, the nut is home-made of nylon and the stepper directly coupled. On the opposite side of the stepper is a single bearing mounted on the frame and fixed with 2 nuts on the leadscrew.

I used a standard Accuride drawer slide and modified it, today I found these on the net:

http://www.cabinetparts.com/cgi-local/shop_2003.pl/page=acc_4113.html/SID=1124887696.24551

This is a US? based distributor but found several all over the globe, even in little Belgium here.
2 of these make a perfect Y axis.

I don't fully understand what you mean by 30 degrees off and what the advantages are. Think I have a bit of a clue, could you draw somehing up?

To obtain precise contruction, I did it as follows:
Screw one of the slides to the base plate, then mount the moving plate on the fixed slide and on the floating one, using slightly oversized holes then move the plate to one side and fix the screw on that side, the same for the other side.
The plate should now move freely over the entire lenght and all screws can be fitted.

Hope you understand what I mean, as said I'm from Belgium and English is only third language here.........(at least when I went to school a long time ago)

This is the best I can do on the eccentric bolt idea. This is also my first attachment. Hope it works.

Jimmy

Jimmy: "I believe that what I have seen so far could be built with a jig saw, a router and simple hand tools"

I agree. We should always keep the skill level of the target audience in mind, and at least offer them an option or a way to complete the job. I also do not think it will really be any harder to build than the other types.

Steve

Hi Lucas,

Could you, please, explain to me how did you modify the drawer slides? Eventually, send me an e-mail with the explanations. Also, please, post the link to sources of that "accuride" here in Europe. I am very interested in this solution.

Thank you for your help.

Zoltan

just looking at the tortion box design , kool

but i think this modification the the design of the rail supports may be a bit easier to make and uses 1 less bolt per support and may be a little easier to allign , but not too shure , what do you think

Dave

when thinking about building a machine i also thought about using a piece of angle iron rather than a tube or bar , i was not shure if this would be a good idea but theres a sketch of it attached ,

it would need a method to align it but the principle looks like less effort to make

Dave

when thinking about building a machine i also thought about using a piece of angle iron rather than a tube or bar , i was not shure if this would be a good idea but theres a sketch of it attached ,

it would need a method to align it but the principle looks like less effort to make

Dave

Square tubing might also be a alternative choice set into a V. The surface contact problem is then solved and one could drill a hole thru for a screw to help retain it.

Edit:
Then one could construct a jig to hold the router At a 45 deg. angle to mill the V in the torsion box once it is constructed. This would allow for a higher precicion placement of the V.

Square tubing might also be a alternative choice set into a V. The surface contact problem is then solved and one could drill a hole thru for a screw to help retain it.

Edit:
Then one could construct a jig to hold the router At a 45 deg. angle to mill the V in the torsion box once it is constructed. This would allow for a higher precicion placement of the V.


this would require a router and jig for it , thats why i thought of using angle section , if you did cut a v for it then you could use tube or bar that would provide a better running surface than flat angle iron or box , the problem is how to impliment alignment of it

it would be easier to align than multiple adjusments accros the lenth , maybe bolting the whole side piece using slotted holes may offer a way ,
if scaileing up the design is to be considered then having 1 suport every say 200mm is going to have a about 23 bolts to adjust on a 1m design
and a 3m design is going to have about 56 per side
thats got to be a pain and a long job to set up

i do think suport on the rails is a good idea , and the current design looks like it is going to be rigid and a capable machine , but tend to think that it could do with a easyer way to align it

hope im not stepping on anyones toes here

Dave

Hi Lucas,

Could you, please, explain to me how did you modify the drawer slides? Eventually, send me an e-mail with the explanations. Also, please, post the link to sources of that "accuride" here in Europe. I am very interested in this solution.

Thank you for your help.

Zoltan

Zoltan,

I found some distributors with google "accuride drawer slides", several in the UK and other countries but I didn't save them, I suggest you try Google.
Edit: look here: http://www.accuride-europe.com/locator2.asp?cat=ie&lan=english

For the modification:
I removed (sawed, drilled, grinded..) all stops and dismantled the rail completely, take care for the little balls, they roll very far and always somewhere where you just can't reach them anymore.

Cut 2 pieces of the outside part of the rail, let's say 25cm, this is the total lenght of the axis.
Then you need 2 pieces from the inner part for the mounting plate: 8cm in my case, file the sides where they contact the balls very nicely so that it can run smooth and doesn't strike the balls.
This results in a travel of 17 cm (25 - 8).
Now you need the ball holder section, this must be cut at 16.5 cm (17/2 + 8).
17 divided by 2 because it only travels at half the distance,speed of the inner part. This is badly explained, neither distance or speed is correct, can't find the correct term in English but i hope you understand.
Edit: distance is correct: if you slide the inner part by 10 cm then the ball holder only moves 5 cm.

Clean the whole thing up, reassemble, grease etc.

Result is a 25 cm slide with a 8 cm moving plate and always fully supported by the balls.
You can of course adapt these lenghts to suit your needs.

Remark: this works only for rails where the balls are kept in place when you remove the inner part, obviously. I have some smaller ones wich don't have this feature and thus these can't be used.

Remark 2: If you don't have some of these rails then you'd probably be better of by purchasing the ones I linked to before.

here is an image of a simple jig, It could be used to cut from both the top and bottom of the torsion box to center the V.

well a v shaped router bit should do the job without a jig

Dave,

You're not stepping on anyone's toes here... We're all friends here, right?

I looked at your dxf, and at first blush I liked it. But it would require some alignment stuff that you don't show on your sketch. At the very least, an angle above it all, to keep it from shifting down. Is there an overwhelming reason to develop this, rather than black pipe?

We are still considering all options... after all, that's what open source is... and the final plans could include an option to build with angle or square tube instead of black pipe... depends on what folks here what to see.

Right now I am working on the support of the roller bearings, and inboard adjustment on one side... it's not looking pretty... if anyone has any ideas, please bring them forward....

Mike...



hope im not stepping on anyones toes here

Dave

A router or a trimmer will be needed at the completion og the job as the cutting device, this shouldn't pose a problem if one is needed in construction buy it early.
Is a jig really needed most cheap sets of router bits come with a vee groving bit. I have one HSS about 1" wide. OK not the best quality but if the same method is used on all axis there are ony 6 groves.
Cheers

well a v shaped router bit should do the job without a jig

Of course my sketch is not to scale. Just think of how big a V-bit you would need for a 1.5 to 2 inch tube.

I don't think it needs to be burried in the side, just captured so wouldn't a 1" bit do.

Of course my sketch is not to scale. Just think of how bit a V-bit you would need for a 1.5 -2 inch diameter pipe.


true , i was thinking of 20mm (approx .75") bar ,
but if bigger is required you could do multiple cuts until its the size you need

re the angle iron method two grooves routed for the corners of the angle iron to drop into before bolting would stop any slip

think i found a way to do the alignment , just trying to come up with a sketch of it

will post it when done should be easy enough to make by the looks

true , i was thinking of 20mm (approx .75") bar ,
but if bigger is required you could do multiple cuts until its the size you need

re the angle iron method two grooves routed for the corners of the angle iron to drop into before bolting would stop any slip

think i found a way to do the alignment , just trying to come up with a sketch of it

will post it when done should be easy enough to make by the looks


I actually like that idea, Just route a couple grooves in the side of the torsion box to mount the angle, making the outside to outside a tight fit to the edges of the angle iron. defo a KISS idea.

I was also thinking of the achiestdragon’s angle iron rail on the way home. I like it. Just run two dados down the side of the torsion box for it to lie in. No adjustments needed as it will be a perfect match, and it is already straight. Main problem I saw was that achiestdragon’s drawing is missing the bolt that holds the aluminum angle in place. It seems like this bolt would bonk into the mounting screw(s) for the rail. Have to look at the clearances in cad. I guess the rail could just be attached at the two ends, or …

Steve

ok, sketch of angle method with adjustment , and also tube / bar method and v grove method with adjustment also

not shure if this is a bit over the top but should be strong enough

should be to drawn to scale for, 18mm mdf , maybe too big do not know

i used 4 mounting bolts each end , in light designs think 2 may be enough so aligning should be easy

i have not drawn the bearing holders just the runners

dave

added :-
should note the slotted holes on the end plates show vertical adjustment the end plates thay mount to should have horizontal slotted holes
doing it this way will allow for slight drilling errors also

I was also thinking of the achiestdragon’s angle iron rail on the way home. I like it. Just run two dados down the side of the torsion box for it to lie in. No adjustments needed as it will be a perfect match, and it is already straight. Main problem I saw was that achiestdragon’s drawing is missing the bolt that holds the aluminum angle in place. It seems like this bolt would bonk into the mounting screw(s) for the rail. Have to look at the clearances in cad. I guess the rail could just be attached at the two ends, or …

Steve

no it uses a bolt with a countersunk head ,and unless the rail is very small or the bolt too big it should clear easy

the problem is the bolt on the top of bearing support if the bolts there are too long they would dig in to the side of the MDF , but if the right size bolts are used or longer ones filed down there should not be a problem


dave

Okay, we need someone to look at the angle iron (instead of black pipe) in CAD... Any volunteers?


On an unrelated subject, here's the angle iron imbedded into the gantry for the roller bearings. How many degrees of freedom do we need to consider for alignment on this? We can embed it in the gantry, and hope it works. Or we can add horizontal adjustment. Or we can add horizontal and vertical adjustment. What do you prefer?

Mike...

You guys are making this way too complicated, imo. Routing 2 accurate dadoes down the edge of a box (which itself needs to be VERY accurate) is no picnic.

How much flex does gas pipe have? I read the other day (somewhere around here) that the stiffness of a tube increases by the cube of the diameter. So my 2" conduit is about ~8x stiffer than 1" gas pipe. I have a 5ft piece laying around and I can't feel any flex with a LOT of force on it. It measures 2.1" OD, so a 2-1/8" forstner bit should give a pretty nice fit. A simple drill press fence and stop should give near perfect results. As far as I can tell from my router (as yet unfinished :( ), no adjustment is needed. Provided the torsion box is dead flat.

Mike's going to stop by next week and have a look. Then he can see what I'm talking about.
Not a good picture, but here's a quick look for those who haven't seen it. Just the two endplates holding it in place. Nothing else needed.
http://www.cnczone.com/forums/attachment.php?attachmentid=5793

Okay, we need someone to look at the angle iron (instead of black pipe) in CAD... Any volunteers?


On an unrelated subject, here's the angle iron imbedded into the gantry for the roller bearings. How many degrees of freedom do we need to consider for alignment on this? We can embed it in the gantry, and hope it works. Or we can add horizontal adjustment. Or we can add horizontal and vertical adjustment. What do you prefer?

Mike...

I think that the same method could be used for the other half of guide way the in the torsion box. With a table saw a dado could be cut just like on the gantry. Or using a router with a fence it could also be cut. Make the Y axis alignment in the gantry where it attaches to the gantry uprights. The Xaxis only has to move in a straight line so parallel to the table top. use the table top as a Y axis parallel. Then the only adjustment needed is for squarness. of the yaxis.

I see how those bearings are riding the rail at a 45 deg. ... and they come close to the bolts securing the pipe. not the most desireable ?

what about the top and side support - where the bearing is on top of the pipe and the other thrust bearing is on the side - that way,you have one adjust bolt in the rib on the bottom and one on the side....

what are the pros and cons in that thought ?
( i havent built a torsion box , not even the bearing -angle iron assembly yet .. so ,,, not sure how it rides but the load would seem better supported (with more weight looad on one bearing) --- that criss cross design just seems to have an inherent .. i want to break away from the gantry feel to it ....

Just curious, Mike What did you create that .dxf with? AutoCAD 2002 wouldn't open it. 2006 did, though.

Just curious, Mike What did you create that .dxf with? AutoCAD 2002 wouldn't open it. 2006 did, though.

Gerry,

That .dxf file was created with turbocad 11.1. Of course, by now it's kinda obsolete, the design has progressed way beyond that today...

Once I get the design working on the adjustable skate bearing support I'll have some more dxf files... in the meantime I'll just throw up a .jpg every now and then.

I don't think we can assume that a rigid skate bearing support on both sides is the answer. One side, yes, but the other side needs some kind of adjustment. And if no one comes up with anything better, I'll just have to use what spalm has.

Spalm has a great design, there's no doubt, but can it be improved? That is the question...

How do we improve this? see attachment...

Mike...

Ye gads, that is the part of the design that I am least proud of. Seems so hokey. When I posted it in the linear bearing threads. not one response was logged. I think that is still a record.

That said, by golly, it does work. They can ride up and down on the edges of the pipe and obtain a true level. But maybe use sliding wedges or something more sturdy, at least a better carriage to slide in. Gerry seems to be able to pull his into level by tightening his threaded rod.

Steve

Too complicated routing two dados down the edge of box.

Gerry I love your work, but that was not quite fair. Lets see, seven perfectly placed half rounds per side, 4 perfectly placed end holes, 7x4x2 perfectly placed half lap dados screwed together, struts with bored out holes to reduce weight, and two carefully edge rabited skins that recess into the cross members.

Which sounds more intimidating to a newbie?

All kidding aside, after checking, the angle iron rail seems to negate the use of skate bearings. A much large O.D bearing would be needed. It also makes it hard to do a leveling adjustment.

Mike, IMHO, I think that the top and bottom of the half rounds are too thin. I do not believe that you really need the adjustment screws, and removal would allow you to increase the size of the skin over these for reinforcement.

(I’m in trouble now)
Steve

u guys ever read the book cnc shop bot .. ? in it the guy mountnts the long rails vertically without the complex rib and 3 bolt positioners.. see my sketch

those renderings are beautiful -- i'm not that good and fast with 3d as i am with 2d.

not everybody has a router, and of those that do, not everybody is very good with their router --- if getting those 2 slots into the strip for the groove of the angle is not too bad .. then i that almost seems like one of the hardest parts next to making the batter box .. i mean torsion box.. (sorry its late , im tired ) ...

ok .. of course you're not seeing the 3 or 4 or 5 bolts that support the rest of the length of pipe in the sketch.... ( .dxf )

Guys,
What about just supporting the bottom of the pipe with a step? I'm thinking something along the line of triangle stock, mounted to the side of the torsion box, but put in place after the pipes are levelled. The sloped side should give clearance for the bearings on a pipe measuring 1.5" dia.

It's simple, and if required, the pipe can be nested into it using an epoxy metal like JB Weld.
I've got the parts sitting on the bench, so I can check it out later today after getting some sleep.

HTH

Iain

What if were were to do something like this for the adjustment side?

The plate can float freely inbetween those two pieces of angle, and the adjustment can either be a shim (not shown), or 4 shim adjustment bolts (shown).

There is also the capability for up and down adjustment if needed. Just slot the holes in the angle.

Mike...

Gerry I love your work, but that was not quite fair. Lets see, seven perfectly placed half rounds per side, 4 perfectly placed end holes, 7x4x2 perfectly placed half lap dados screwed together, struts with bored out holes to reduce weight, and two carefully edge rabited skins that recess into the cross members.
Steve

:)

You don't need the half laps to make a good torsion box. And, as was mentioned earlier, you can use either a master template and flush trimming bit to get identical parts, or even a simple fence and stops on a drill press.

I've cut large pieces on edge on a table saw quite often. It's not that easy. You could do it with a handheld router, but like I said before, the box needs to be more accurate.

Mostly a matter of personal preference. I think it's easier my way. :)

[QUOTE=spalm]Ye gads, that is the part of the design that I am least proud of. Seems so hokey. When I posted it in the linear bearing threads. not one response was logged. I think that is still a record.

If it helps Splam, I used your idea on my jgro router. It made all the difference in the world.

Dave

Has anyone considered making the linear bearings out of MDF? Attached below are some CAD models of a LB idea that I came up with using MDF with eccentric bushings. I actually made a prototype using my table saw and drill press and it came out pretty good. The distance from the top surface to the rod was within .003/.004 from one side to the other. It was strong too. I put all 230 lbs of myself standing on one foot and it didn't break. I wish I would have taken some pictures of it before I tore it apart to try something else. Food for thought.

jgro

linear bearings and pipe suport

i sketched this now ok not the best method for mounting the liner bearings but very simple to make
mount the bearing bolts , fit nuts to cover the aria of the shaft that does not want to be bent , using a piece of tube over the nuts bend the bolt untill you get the right angle
also shown is a way to get a v slot without a router

not the best way for the bearing holder but with execption of the tube and nuts /bolts its all mdf

its got to be the silliest way of mounting the bearings anyway imho
worth a laugh

dave

Interesting...

If only you could put a hole in the top plate at 45* and thread in a stud. :confused:

Mike...

its got to be the silliest way of mounting the bearings anyway imho
worth a laugh

dave

Has anyone considered making the linear bearings out of MDF? Attached below are some CAD models of a LB idea that I came up with using MDF with eccentric bushings.jgro

This actually takes care of the split bearing problem on the cheapcnc design. Still need a good way to support the precision ground shaft!

Mike...

This actually takes care of the split bearing problem on the cheapcnc design. Still need a good way to support the precision ground shaft!


What I did on my second machine is attached below. I ran a piece of MDF along the whole length of the rod and held the rod to the MDF with some conduit clamps. I've been using it for about a year now with no problems. Think about it, when you use the square adjustment blocks, what is the first thing that you do when you want to start leveling/squaring thing up? You stick a couple of pieces of MDF that are the same thickness under the rods to hold them up at the same height. Why not leave them there as support?

jgro

I like it. You don't even have to make a v in your support...

Mike...

What I did on my second machine is attached below. I ran a piece of MDF along the whole length of the rod and held the rod to the MDF with some conduit clamps. I've been using it for about a year now with no problems. Think about it, when you use the square adjustment blocks, what is the first thing that you do when you want to start leveling/squaring thing up? You stick a couple of pieces of MDF that are the same thickness under the rods to hold them up at the same height. Why not leave them there as support?

jgro

Wow Everyone,

This is COOL! I have not seen this much brainstorming ever on the zone, at least since I have been here. I really like it.

Now I have read most of the posts but there still coming in faster than I can keep up and be able do my job. So if someone has already covered this then sorry for the repeat.

I really don't think the angle iron or aluminum is the way to go. There is just too much precision involved. I have a large table saw myself and I still would not count on the quality of the grooves for the angle. Also the angle offers almost no added support to the table. I do like the square tube idea this should be very available to most, not sure it will be at every hardware store. With that said I must agree with ger on the conduit idea being the better way to go.

Most of the posts that I have read are trying to make this easier by coming up with other solutions to the rod support. I have looked at mikes adjustment idea but this is unneccesary if all the pieces are cut from one template. any error in the master will be the same in all the pieces, thereby negating the error itself. Don't look at gers machine as a machine look at the structure, break it down into all the identical parts and you will find that there are only a few masters that will need to be made.

Now to the reason I like the square tube. Other than availability, there is only one thing keeping it out of the lead. This is having to cut a perfect 90 degree cut in the master template. If the angle is slightly off this will severly wear the bearings because they will be riding slightly on edge. Without some major planning and precision on the builders part this will be the weak link in the design. With a forstner bit the builder could get a very good fit for the conduit pipe with very little that could go wrong.

Just weighing the pros & cons of each idea. Hope no one took this the wrong way. Not trying to pee on your fire.

Keep up the good work! Looking good.
Jimmy

Most of the posts that I have read are trying to make this easier by coming up with other solutions to the rod support. I have looked at mikes adjustment idea but this is unneccesary if all the pieces are cut from one template. any error in the master will be the same in all the pieces, thereby negating the error itself.

True, but there is still no provision for adjustment in the system. To take out any slop you could JB Weld the pipe into the grooves. And this will probably be an option in the plans. But I am still looking at making the ribs a little taller to reinforce the weak looking area at the bottom of the 2" cutout. I'll have to see how long my tap is. I'm thinking about making it 3/4" instead of 1/2". If you need any more strength than that, you'll have to double the thickness of the ribs.

I'm not hearing any negative feedback on the adjuster plate concept, so I'll plan on that.

I guess it's time to move on to the gantry design. And thoughts or preferences?

Mike...

JGRO, thank you for your stuff. I don’t know whether to love you or hate you for starting me in this obsessive hobby. A couple of comments about the rail with the clamps. This would require a triple bearing truck as you have shown. Fair enough. Can you really reach around and adjust the inside eccentrics? Gerry has turned me into an anti-flex maniac and I see the possibility for a lot of side to side flex. It could be solved with screwing the rail to the support along its length, but how do you repeat this for the medium length axis that is up in the air?

Jimmy, I guess the angle or square channel concept is dead (?), because of mounting. But there are two other problems with it. You can not use the popular angle/skate bearing arraignment with two angles facing each other. They will rub on each other. A bearing with a larger O.D. will solve that, but… The other thing lost is the adjustment concept to obtain level just mentioned by Mike.

Maybe this has been finalized but just wanted to throw it out. Is 2 inch pipe a little large? Or is bigger better? I am sure it is stronger, but how much strength do we need? I used ½ inch which maybe too small, but it seemed strong enough. Gerry used 2 inch and had to drill holes in his torsion supports because he couldn’t lift it. Maybe meet half way, at least for a smaller 2x4 foot design?

Steve

Maybe this has been finalized but just wanted to throw it out. Is 2 inch pipe a little large? Or is bigger better? I am sure it is stronger, but how much strength do we need? I used ½ inch which maybe too small, but it seemed strong enough. Gerry used 2 inch and had to drill holes in his torsion supports because he couldn’t lift it. Maybe meet half way, at least for a smaller 2x4 foot design?
Steve

Hi Steve,

Nothing is finalized yet. I picked the 1 1/2" pipe (1.9" OD) because I have a machine with a solid 3/4" precision ground shaft, and it flexes like crazy. So of course, I am erring on the side of being too rigid.

Now if someone has a spreadsheet that would let me calculate the amount of deflection in any given size pipe, maybe we could downsize. Do we have any spreadsheet guru's here? ;)

Mike...

sorry for yet another pipe support design but .

i quite like this idea
it solves a lot of construction problems in that theres no high tolarance routing to do
as long as you got a nice straight edge on the MDF
also offers simple construction and should be easy to adjust the entire lenth of the bar with only 6 bolts for table alignment

should work with anysize bar with minor changes
think i may use this method myself

dave

Mike, Remember the torsion box is there to support the pipe. Not the other way around. :p

I agree, need to call in some big guns on the math of torsion box / pipe size. How may struts, width/thickness of struts, table size, etc. Complicated stuff but there are some people here at the Zone who know that stuff. Just got to bribe them.

(or we just wing it)
Steve

I am just posting what we have seen. Ger's is 2" so that is what I have been useing as the number. We may be able to get away with less but after comparing the price on the gas pipe vs conduit I believe the thin wall conduit taht ger used is a better bang for the buck. A tiny bit more expensive but very little. Also you have a very consistant finish on the conduit that the gas pipe can't match. Also the larger pipe make bearing clearance easier.

Also nothing is dead! I am just trying to weigh the pros & cons of each idea and share the results with everyone. These are just my views.

This machine can't be all things to all people, but I want to help design the best machine we can for the intermediate beginner. And when I say intermediate I mean someone who wants just a bit more than a small hobby machine. I personally want a machine that can do a days work if I need it but does not cost more than $500-$1000 complete. This should easily be achieved.

Please don't use the price numbers as a set in stone item. This is my budget. Lets continue on the path we have started and closely examine each item carefully. Don't pick it because it is the easiest, pick it because it is the best and easy!

I am enjoying this! Keep the good ideas coming!
Jimmy

Gerry used 2 inch and had to drill holes in his torsion supports because he couldn’t lift it.

Not so. My torsion box is 60" x 32", and it's only supported at the ends.It spans 60" with no sag. :) It was way overbuilt, so I tried to make it a little lighter so it's own weight wasn't working against it. It probably weighs around 40lbs, most of which is from the 1/2" mdf skins (which were the cheapest way to go, not what I really wanted to use).

The only hard part about lifting it is that it's a bit awkward due to the size. ;)

Sorry Gerry, didn’t mean to misstate you. Is the size of the 2" pipe in the “overbuilding” or would you go with it again? What about a 2'X4' size?

What size do people want?

Steve

ok

done a cross sectional view of the bed , think this should be easy to build and provide a ridgid structure ,, its using 20mm bar but i guess that 20mm electrical conduit should do the trick also
may be lighter than some other designs but i'm using 20mm steel angle at 3mm thick for bed supports could use mdf for these i supose

i set the width of the bed to 600mm as mdf from the local hardware store comes in in a 620mm *1200mm size could be scaled easy , may reqire more bracing not shure what do you think

Dave

Gerry,

I have got to ask you, since I brought up the price thing, I hate money it impairs creative thinking, but how much do you think you have invested. I know we are comparing apples to oranges because you went with the baltic goodies. I am trying to keep a bit of an idea of what this thing is going to take. Don't include the electronics, I'd rather not get that started yet.

One more thing I wanted to add is, we all have different areas of expertise. Mine is anylitical thinking. I love word problems, riddles and brain based engineering. :stickpoke I run a cad program in my head. I wish I was as good on autocad but I am not :frown: I tend to picture all of the problem areas instantly in my head. I also tend to be blunt, it's my nature. So don't get offended if I am quick to critique your design idea. I am very open minded so this does not mean your idea is shot down. We are a think tank at the moment, if you think your idea is the best, fix the problem and re-post it. I am loving the free minded feeling of the thread so far. If nothing else we will have a very good batch of ideas for the future builders visiting the zone.

Now last but not least, Mike I really do appreciate you leading the charge on this assault. You are doing a very good job.

I love this thread, thanks CNCAdmin
Jimmy

Dave,

Is there any way to put the bearings on the outside, so you don't loose so much table & cut area?

Jimmy

What size do people want?
Steve

Does this forum have poll capabilities? Maybe a quick poll to find out what size people are looking for. Paul?

Mike...

Now last but not least, Mike I really do appreciate you leading the charge on this assault. You are doing a very good job.
Jimmy

Thanks Jimmy,

It's fun... but there are not enough hours in a day to model up all the ideas that I am seeing here. And I do my fast modeling at work where I am familar with the CAD program, but I really don't have that much time at work. Here at home I am struggling to learn TurboCAD, so it's really slow going. But on the bright side, I can export parasolids and acis files, and jrgo knows how nice that is!

Ever hear the saying, "Teaching teaches the teacher"? Leading the charge, as you call it, does the same thing. I am learning lots! You guys are all wonderful, and chockfull of good ideas! Keep those ideas coming.

Thanks,

Mike...

Dave,

Is there any way to put the bearings on the outside, so you don't loose so much table & cut area?

Jimmy

i did think of doing that , in the end i decided to put them on the inside for a number of reasons

1 it offers better stabilaty , and the carage mounting reduces flex in the sides as there is no presure on the uprights
2 it makes the base lower profile
3 keeps the bearings away form the edge of the table and the tool side of the frame so less crap can get to them
4 it saves having to do routing for the bearing suport angle section
and
5 makes getting to the alignment bolts easier

shame that it makes it a bit wider than the other way around

dave

Is the size of the 2" pipe in the “overbuilding” or would you go with it again?

Steve


I'd use it again. One reason I used it is I have a vertical panel saw I made about 10 years ago using it and rollerblade bearings. The stuff is really stiff, and relatively cheap. Although it costs a lot more now then when I bought it. ~$25 for 10 ft.

Hi Steve,
Now if someone has a spreadsheet that would let me calculate the amount of deflection in any given size pipe, maybe we could downsize. Do we have any spreadsheet guru's here? ;)
Mike...

It's not great but heres a tarted up version of a spreasheet I did to do this a while back...

It's not great but heres a tarted up version of a spreasheet I did to do this a while back...

Very cool Andrew... I like it...

Thanks,

Mike...

Here's one that is not as complete as fyffe555, but I have schedule 40 (standard) pipe sizes filled in. If you want to compare the pipe to a solid bar, use the radius for the wall thickness.

Right on Weatherly...

Looks like .01 deflection before we add the supports... Kwel!

I think we'll use 1" pipe for the gantry. At 30" long that gives us .01 deflection again. We'll use the torsion box for the support, ok Steve?! :p

So far it looks like we have a working area of 36" x 22". Is this a good size for you guys? How about you Jimmy?

Mike...

Hey Guys,

Just got home ate a bite and read over the posts. Thanks for the spreadsheets those were handy. This thing is going to be strong. Don't want to get any hopes up but we may have an aluminum cutter here.

On another subject, This would not fall under the hardware catagory but if you have a steel supplier nearby you cansave some clams on the pipe by going with standard steel tubing. But we still can get the conduit at the hardware so we just have a place where the frugal shopper can save some cash.

Ger $2.50' is not that bad for a very good quality piece of kit (to quote the english among us). Never thought I would be bilingual. I now speak english and american HAHA :p I'm just having too much fun. :D

Holler at me
Jimmy

Railsupport is pretty nice .. u lay the mdf on the angle iron .. the mdf is precut so it is very square to make the holding fixture for the pipe.. then ther is only 1 push down screw from the hole in the rib .. it looks so nice on that 2d drawing , dragonchiester.

that would be cool to get a 3d rendering to bring it to life so we all 'could see the light' of it.

Just reiterating what Steve said. It doesn't matter what the deflection of the pipe is, because the plan is to make it supported, so you won't have ANY deflection.

Also, that Schedule 40 is a lot thicker than the conduit I'm using.

After looking at that speadsheet and seeing "simple mounted ends", here's anm idea that's going to go against everything we've been talking about. :)

If you want to build something easier, try this. Use 2" conduit. You'll possibly need a circle cutter for a drill press. Adjust it to cut a hole with a very snug fit on the conduit. Make a jig to pattern route the 2 holes for an end support plate. Once the first one is made, use it to make 3 more identical ones. Use 2 at each end, about 6" apart. This will greatly increase the stiffness of an already rigid tube. With about a 36-42" span, the deflection would probably not be noticeable with a 100lb load on 2 tubes. No support needed. I personally wouldn't use this, as my goal was zero deflection. But compared to the JGRO type designs, a big improvement. Just keep in mind that this takes up a pretty big footprint, which goes back to Mike's question - what size does everyone want?

Railsupport is pretty nice .. u lay the mdf on the angle iron .. the mdf is precut so it is very square to make the holding fixture for the pipe.. then ther is only 1 push down screw from the hole in the rib .. it looks so nice on that 2d drawing , dragonchiester.

that would be cool to get a 3d rendering to bring it to life so we all 'could see the light' of it.

i could do a 3d view , but takes me a long time to do them ,
and do not have the time at the moment , not tried 3d with my current cad program (totalcad)
im currently in the process of redrawing it adjusting the size so i the pieces can be cut from "standard ?" size sheets of mdf with minimal waste

seems that 1220mm by 607mm is a standard size ?? well B&Q seem to think so and sell it in that size ,need to check homebase see if there sheets are the same size also

what ever happened to 8'*4' ( 2353mm * 1176mm )

Dave

4x8 MDF is 49" x 97", or 1244mm x 2464mm. It looks like they're cutting it into quarters for you. :)

Everything is going metric....even the thickness is in metric....

. Just keep in mind that this takes up a pretty big footprint, which goes back to Mike's question - what size does everyone want?

Ah yes, the footprint... It's looking to be roughly 48"x30", to get a working area of 36"x22". Is this acceptable? Too big? What do you think?

or 1220x762 footprint and 914x558 working area, in mm!

Mike...

Mike,

Can we bump it up just a little to get a full 2'x3'. I am planning on rough carving signs with mine, so this will be a more convenient size for me.

Thanks
Jimmy

If the design uses supported guides, whether round or square tube, or even angle, It shouldn't be a problem to scale it up a little more.

Hey Guys,

The reason for the last post was foe the plans stage 24"x36" is a standard size in the sign industry so this would make it easier to get blanks if some one chose to do a sign for another person. I personally could probably build the machine from the discussion notes.

Are there any metric sign people here reading. If so what would be an equivelant metric standard size, so we don't run into problems with being 1 or 2 cm too small. I would hate for someone to have to scale up a perfectly good set of plans for a couple of inches.

Let us know
Jimmy

Sure it's easy enough to give you two more working inches...

You can either make the y beaing shuttle 2" smaller, from 8" to 6", or you could make the y pipe (gantry pipe) 2" longer.

I had hoped to keep the pipe an even length, in this case 5', cut in half! But since we still need a little extra length for the gantry wall and the adjustment blocks, we could just go right to 3' pipe, and keep whatever extra we gain on the y axis.

Mike...

If I had to cut material that was 24" x 36", I'd make sure I had 2" or more extra travel on all sides. You may have to get the tool to the outside of the part. And it's nice to be able to have the tool enter the work from outside as opposed to plunging down. This is important if using offsets (G41/G42) which need lead in moves.

Also, the farther apart your bearings are spread, the stiffer the machine becomes. I'd increase the pipe length as opposed to bringing the bearings closer together.

Mike,

I agree with you and Ger. Lets figur on 3' for the y pipes. I really would like to be able to do full 24"x36". Hope thats ok with every one. Let us know if it isn't.

Thanks again
Jimmy

I'm not sure 3' for the Y pipes will be enough to get you 24" of travel plus a little extra for good measure.

Consider that just mounting the pipes in your gantry sides you will lose 1.5", assuming that at a minimum your gantry is 3/4" thick on each side and the pipes don't protrude through.

Your 36" pipes have turned in to 34.5" pipes

Then, you take Ger's suggestion of having 2 inches on each side for working around the edges of you part and allowing for lead-ins and read-outs

Your 34.5" pipes are now 30.5" pipes

Add in some gaps of 1/4" on each end for safe limits and now you have 30" pipes

This leaves you with 4 inches of space for the width of your z-axis. Seems a little narrow to me considering the sturdy engineering you guys are putting into the rest of the machine.

A few more inches would make all the difference in the world.

This thing is getting wide quick... Lets work backwards...

Let's allow 1" around for working, so we are at 26" of pipe.

Then allow 8" for the bearing shuttle, so we are at 34" of pipe.

Allow a double wide gantry wall plus an adjusting block, that's 2 1/4" on each side or 4 1/2", so we are at 38 1/2" of pipe.

That's a big footprint to get 24" of quality machining in the y direction. Is this what you want to see on the plans?

Mike...

P.S. I don't own a bench that wide!

Mvaughn,

Yes I caught that after I posted and started thinking about it. I will have to depend on Mike or one of the other cad guys to figure the correct length of the pipes.

Ger,

Do you know what would be the least we could get by with on the lead in space. I don't want to go crazy on the floor space. I believe this will help the great gents in the cad dept. :)

Happy trails,
Jimmy

Howdy,

Mike I believe you and I will both have a bench that wide soon. If we use Ger's as a model even with 22" we will be almost 38" just figuring on scratch paper. I believe the achilles heal has been found. I think though most will live with the loss of shop space for the quality of the machine we are designing. I'm already clearing out a space for mine. HAHAHA

Any Solutions, I want my cake and a fork?
Jimmy

You can get by with just over the tool diameter, but programming will be more difficult because you have to be real careful where you drop that tool.

You also should have some extra room if you use limit switches. You don't want to be always working right next to limit switches.

When you start worrying about 4", what's the point. Just make it bigger. :) It was no longer a benchtop machine as soon as you passed 24".

BTW, mine has a Y travel of about 32". You "could" make this all useable, but I'll probably never cut within 2" of the edges. When all is said and done, it'll be about 44" wide, plus the stepper sticking out the side.

hmm if the design is going to be scaleable is the exact size important at this stage

ok so guess the same design could be converted to cope with metric or impeial sized materials ,

btw latest dimentions for the bed here get it to be 1136mm long 950mm wide for a 900*500mm cutting aria ( 44"L,37"W for 35"L 19"W cutting aria)

suppose it would be better to give the size in the following way
required cutting lenth + 236mm (10")
required cutting width + 450mm (18")

for the rail outside the bearing design

only reason im currently sticking to that is i have already have the rails cut
2*1100mm 2*700mm and 2*300mm ,

dave

ps , i should add that i do know that the actual cutting aria of my machine is going to be smaller than stated above ,
but untill built im not shure exactly how much ,looks like 56mm at the moment (2 bits of mdf )
but i only intend using it on 300*600mm matierial so it has not been my biggest concern anything above that is a bonus to me

I only had a few mintues today to play with the design... that rush job had to come first!

I quickly threw the gantry together, only to realize that it's a little tight inside that torsion box. I might have to open it up so we can get at that adjust screw in the center.

Do you have any thoughts on this? Oh, btw, the pipe is 39 3/4" long!

Mike...

While you always see everyone using 4 pipe adjustment blocks (1 @ each end of each pipe), you technically only need 1 to align the pipes parallel to each other. Fabrication skill may need to be higher, though.

Mike, for the torsion box to function properly, both skins need to be glued permanently. You can't have access to the inside. It's the skins that give it the strength, not so much the inside framework.

Mike, for the torsion box to function properly, both skins need to be glued permanently. You can't have access to the inside. It's the skins that give it the strength, not so much the inside framework.


Well that makes it hard to get the the adjustment bolt now doesn't it. :D

Personally, I think that it's way too complicated with all those adjustment bolts. Like others have said and Spalm proved (Ger used a CNC) it is possible to accurately cut the recesses in the torsion box so you don't need the adjusters.

While you always see everyone using 4 pipe adjustment blocks (1 @ each end of each pipe), you technically only need 1 to align the pipes parallel to each other. Fabrication skill may need to be higher, though.

well thought the use of 4 would allow the pipe to be adjusted at ether end

1 yes better if the drilling is out is off
and 2 so it may be aligned with the bed
if one end of each is fixed and the table not quite level then its going to be hard to correct and would be corrected by having them adjustable anyway

i would only say 1 per axis should be fixed to alow for correcting skew with the bed and so may as well make all 4 adjustable ,


currently working on the next axis , hmm y or z next , and if y then do i mount the rails side by side or above each other , z next could be an interesting thought ? driving it may be a problem

dave

Well that makes it hard to get the the adjustment bolt now doesn't it. :D

Personally, I think that it's way too complicated with all those adjustment bolts. Like others have said and Spalm proved (Ger used a CNC) it is possible to accurately cut the recesses in the torsion box so you don't need the adjusters.

That is why offered a jig and a V desgn, It can be machined with a router and a jig after assembly of the torsion box. then the use a square tubing would make perfect sense.

Well here goes guys, be prepared to read :D .

I will go ahead and write the portion of the assembly manual, that concerns the assembly of the gantry torsion box. Maybe this will explain why this is such an easy to build design even without the supports having adjustments.

Step 1. Cut master template for the gantry rail support found in figure blah blah. after satisfied with the fit to the rail itself, go to step two.

Step 2. Pre-cut x number of pieces for the rail supports. Cut them about 1/16-1/8"oversize.

Step 3. Drive two screws or nails, which ever is your peference, one at each end. These will asist in holding the pattern firmly in place and centered on the rail support blank.

Step 4. Using a router or quality laminate trimmer, with a pattern or flush trim bit, proceed to make all of the blanks perfectly match your master template.

Step 5. Following the information provided in the plan set. Cut the gantry sides. If accurate enough equipment is available, you can cut them seperately. If not use the same method outlined in steps 1-4. It is very important that all like pieces be Identical dimensions. Once all gantry side pieces are cut correctly go to step 6

Step 6. This is where it gets a bit tedious. Hang in there we will get through it. Stack the gantry side pieces exactly as they will be on the machine. Make absolutely sure that all pieces are aligned flush, square and true to each other. Clamp firmly together. Follow the plans directions for the exact location for the master template made in step 1. Once the position is found, carefully align the piece on the gantry side, then attach using the same method you used in making the rail supports. If you have followed the instructions carefully to this point the first major hurdle is past.

Step 7. Using the same forstner bit you used to make the master template for the rail support, in a drill press, put the bit against the template firmly and drill your hole. Be very careful not to let the bit wander. If you have been diligent in your measuring the pipes should be perfectly supported and absolutely parralel.

Step 8. This is where your measurments are used. Depending on how wide you have made the gantry, all that is left to do is to cut the filler pieces that fill in between the rail supports and attach the skins to the torsion box. A word of caution be sure the torsion frame is perfectly square and true before gluing and screwing it together.

I really hope this clears up the doubt in peoples minds about the ease with which precision parts can be mass produced. Worse case senario is you mess up a few pieces making the master templates but once it is perfect every one of those pieces will perfectly match the last one. I use this method alot in making custom fiberglass speaker enclosures. It makes a mess when cutting mdf this way. Your shop will look like a dust storm hit but it is relatively fast and the most precise way I know of making alot of the same part.

Let me know what you think,
Jimmy

Hey, just some random things.

Just stopped by Home Depot and got prices for pipe. This is not the biggest design cost at all, but I thought I’d document it anyway. Prices are 10 foot lengths. Size is inside diameter.

EMT
2” = $20
1½ “= $16.50
1 ¼”= $13.50
1” = $8.50

Black Gas Pipe
2” = $28
1 ½” = $22
1 ¼”= $18
1” = $13

It’s getting large! Let the design be adjustable in size. Maybe draw it smaller and then a builder can just add a documented offset in either or both axis to grow it. Identify these offsets in the drawings. Don’t scare away the newbie. (Just a thought)

The boxes need skins on both sides, and the pipes don’t need adjusters. If you really blow it and cut something too short, you can always add a shim. These should all be cut at one time with some kind of jig, so I promise they will all be the same. The bearing adjustment thingy will allow you to obtain level for X/Y and vertical for Y/Z.

I am still a believer that the box supports the pipe, and the pipe just lays in the trenches. It does not look like the box is attached to the gantry walls.

I am in enough trouble, so I will leave the double thickness gantry wall for another day.

Steve

Howdy again,

Are you tired of reading yet? :mad:

Just one thing that I wanted to say. We have tentativly decided on 2" conduit(this may change depending on the design work) and I am not sure if 2" is the precise the OD of the conduit so I thought I would make it a little easier to get the correct size hole for the templates. My local hardware stocks an adjustible circle cutter. It makes it easy to get a very precise hole any size inch or mm. If your local hardware does not carry them www.harborfreight.com or ebay do most of the time. I have seen them fo $6-20 depending on where and the size you order. You will wonder how you lived without it.

Live long and prosper,
Jimmy

thought the following would be suitable for what im trying to do

get wood cutting list
call at wood suppier ask for bits of MDF in the sizes needed

get bits home

cut them where needed ( non critical cuts required so 10deg of is only going to make it look rough)

drill out as marked ( 2 to 3mm with in the required positions anyway )

elongate any holes that don't quite match file or reammer normaly does the trick

screw together and assemble

the only real critical bit of drilling is making the bearing holders so far
and even those can be elongated a bit to get them right

sorry but even i would have difficulty doing the other design ,
and i will admit my wood work is bad
its the main reason i need a cnc :)



dave

Steve,

The more I think about it the more I agree on the size thing. This thing is becoming a MONSTER. Although that would be a good name for it "THE MONSTER ROUTER" (if we could only make it growl at you when you cut it on) sorry a bit of daydream typing there :o . But seriously lets back up and make the cutting area about the same size as the jgro machine. It should have a bit smaller foot print than the jgro since we are mounting the bearings to the outside. This also seems to be a popular size. Who knows if enough requests come in we may offer a larger plan beafing it up where needed.

May the swartz be with you,
Jimmy

Steve,

The more I think about it the more I agree on the size thing. This thing is becoming a MONSTER. Although that would be a good name for it "THE MONSTER ROUTER" (if we could only make it growl at you when you cut it on) sorry a bit of daydream typi