Here are the specs that I'm trying to get.

36"x24" table
5" Z travel
214 ounce steppers
Xylotex Stepper Board
Thomson linear round shaft for all the axis
10mm ballscrews for the X and Y
1.75hp Porter Cable Router
All machined aluminum frame

Here are some pictures of it in Cad.

The big problem that I forsee is shaft deflection. For the longest time I've been trying to figure out what diameter rod to use. Right now I've got it setup with a 1.5 on the X and a 1 on the Y. My gauntry will weigh roughly 60 pounds and will ride on single bearing Thomson pillow blocks.

Right now I'm fairly sure I can get it done for $1100. If you would like to see the price list I can type it up for you.

Ballscrew for X and Y (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2596337531&category=55826)

And now, let the critiques begin!

Another Picture.

Ew, I hate criticising, so lets assume your model is un-finnished, ok?! I think you realy need to double up on the linear bearings, four per axis would be a lot more stable, and the increased width of the frame, both in x and y, would help your deflection problem. A cross piece between those gantry sides would also help stiffen it up nicely. Go and dig out Jeffs (HomeCNC) router thread, and take a look at his structure. If you're going to buy ballscrews, it's worth having a decent frame to mount them on, or you will not gain anything over using all-thread.
Sorry!:D

I thought about dual pillow blocks per side but the problem is travel room. I would need to add a good 10 inches to the X so I could retain my cutting area. This would mean more shaft delfection? Maybe I'm alittle obessesed with it, but it would be better to get everything right before I buy big items such as linear shafts.

I asked the guys about shaft thickness a few months back in this thread (http://www.cnczone.com/showthread.php?s=&threadid=1305). There is a link in there to a website which has a deflection calculator which may prove useful.

Why not use supported linear shafts? No deflction with that. The extra cost could be reduced by using smaller shaft.

That's a great 3-D model Cold Fusion. Kong is correct about doubling up on the bearings. Round-shaft type linear bearings usually have some compliance to make up for less than perfect mounting. That's good under the right circumstances, but makes them nearly useless in your application. Even THK type bearings aren't great for this setup unless they are the extra-long type. Shaft deflection will be insignificant without a rigid linear bearing setup. You'll probably need longer axes to get the travel, no matter how much it hurts...

Cold Fusion, is you don't have the rails yet, don't discount using THK types rails and ways.

Especially if deflection is a concern, THK rails solve this problem.

Also, you don't need a very big rail, a 1/2" THK is stronger than a 1-1/2" round rail. (For load ratings)

That will keep your costs down. I've seen these on Ebay fairly regularly.

I also agree with the 4 bearing concept as being almost mandatory. Especially on a machine as big as yours. Check the Thomson website for shaft deflection. It's a different calculation for a two bearing load versus a one bearing load.

Good luck.

THK rails are alittle pricey for me. All together my X and Y will end up costing $200-$250. I don't think I could even get a pair of 36 inch thk's for that much.

1

2

1.25 shaft, dual pillow blocks, extrusion down the X for bracing.

Hey, i am building the same route(in aluminum).

i'm use 4"x24x1/2 for base
17x4-1/2x3/4 for 2 sides
bearings link (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=25284&item=2583051303)
acme leadscrew, oil harden rod from enco

planning to spend less than $800

i'll try to post some picture when i get all parts togather

good lurk on your machine

i also though about using thk linear slide, but they cost little bit too much for me. any cheap thk around?

Cold,

Better. But you still have a bullet to bite...

Need to add at least ONE more linear bearing to the y. I'd put it on the bottom shaft(nearest the cutter) to decrease deflection.

Raise the black frame supports ands they will add support for your table.

Definitely need a cross brace between the gantry uprights...

Hope this helps,

Ballendo

P.S. I think you may later "wish" your steppers were larger. 3210 will work, but is a bit on the small side if you're planning for any kind of fast traverse speed.


Originally posted by Cold Fusion
1.25 shaft, dual pillow blocks, extrusion down the X for bracing.

As far as the steppers: I would only be cutting up to 3/8 Lexan or 1/2 wood. Any metals can be done with a friend's cnc router.

Hey Cold fusion,

Now thats a familiar setup! ;) Great work on the CAD drawings. Think your gantry will probably come out lighter than 60lbs. I have -lots- of steel where alu could be used, for instance in the bearing blocks and Z-assembly, and that gives around 60lbs.

About the double bearings: What accuracy are you aiming at? Mine has double bearings in a single block, 16cm (6.25") wide, giving up to 0.5mm (0.02") gantry skewing in both directions when pushed fairly hard. If thats too much for you and you're not willing to give up travel think about dual leadscrews?

Good luck,

John

Cold, another thought. You probably don't need as large a stepper motor on the Z axis. I would think that 100 oz-in would be fine.

This might allow you to offset some costs for the additional linear bearings.
T

Ok, things just swung 180 degrees. I am now the proud owner of 4 30 inch Thk rails. Here is the auction I won. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3802598158&category=42899

Congratulations.
That settles a lot of questions.
Now for the best way to utilize them.
Hager

Hager..."Now for the best way to utilize them"

how about on a CNC machine? HAHAHAHAHAHAHA (sorry, couldn't resist!)

if you moved the bearing blocks to the outside of the frame you might be able to get some more workable table movement

"Now for the best way to utilize them"
The tips have started to come in. These bearings are small and strong, and require different mounts and save a lot of space over the "rail bearings"
Good luck, now let's see some new drawings.
Hager

Here are pics of the latest cad. The red and grey square stock is 1.75 inch aluminum (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3801479235&category=45024) , the green sides are .5 inch, and the red end plates are .375 inch. The pockets in the gauntry are for extrusion, which has not been added yet. Tomorrow I'll get the ball screws in along with the cross gauntry brace.

Pic

Cold Fusion

I have a trivial question which is what software drew your pictures. I use autocad which is really great but it doesnt take 3d objects and handle the coloring an shading that is evident in your pictures.

please advise,

Owen

I have friends do it in Solidworks. Here is a picture of the latest design.

2

3

from the latest nice picture I could see that you have extra room on your y axis, you could use that to spread the z axis apart to better stabilize the router. IMO.

what are the white pieces at the bottom of the gantry? Why do you want to put them there? Oh...GANTRY, not "Gauntry". I think it is coming along really well. Nice job. Can't wait to actually see a few build photos.

Nice job Cold Fusion,
What is the cost estimate for a DIY CNC router minus the controller and misc. electronics?

Update:

Thk Rails will be here tomorrow. I bought a nice stepper setup yesterday and it will be here in a week. Part of the aluminum frame (1.75 aluminum square) will be here in two weeks. The extrusion will be here in a week.

Total price for everything=$1200

214 ounce steppers
7 amp stepper drives
24v 12amp power supply
3mm lead ballscrews
20mm Thk rails
All aluminum frame
1.75hp Porter Cable Router
30x30x5 total size

Shoudl be a pretty sweet setup once it's running. I'm hoping it will handle 1/4 aluminum plate. 1/4 Lexan will be a breeze. Any advice on feeds for both those materials?


http://home.att.net/~fair451/ebay2/centent3drives.jpg
http://home.att.net/~fair451/ebay/thksr20w_3at.jpg
http://i5.ebayimg.com/03/i/01/64/52/d0_1_b.JPG
http://www.anodizing101.com/images/8020_3.jpg http://contractorsupply.biz/graphics/porter/690LR_72dpi.gif
http://cnconabudget.com/slideback.JPG

Looking good their Coldfusion. Can't wait to see progress once the rails make it.
Where did you find the ballscrews?

http://cgi2.ebay.com/aw-cgi/eBayISAPI.dll?ViewFeedback&userid=lagolas&item=3801272683&frompage=284&de=off&fromasq=1

Contact that guy. He has 50 sets of ballscrews for sale. He will also cut and turn them down.

Updates Cad pictures. I may be making a different style Z axis becuase this one is too thick.

http://www.coldfusionracing.com/images/Andrew/router2.jpg

Thanks for the link Cold.

This is really coming on ColdFusion, some nice pieces you have bought too! One thing I would recommend though, is to add another brace between your gantry sides - perhaps a couple lengths of 1/2" ali. If you take some heavy cuts, you will be suprised how much the gantry flexes. I know mine does. Just an opinion though:D
Hmmm, ofcourse, if you are using that solid bar, it may be alright?!

I do plan to add atleast two pieces of .785 extrusion between the gantry sides. I may add more aluminum square if the budget permits. Yes, the green squares between the gantry are solid, not extrusion.

I just got my THK rails.

WOW

The quality is just amazing and the motion is silky smooth. With all the parts coming in, I'm getting really excited all over again:)

About the gantry flex. I have all the beams running across it set in .1 deep pockets. This helps flex and increases rigidity.

Suggestion: tie the upper and lower gantry beams together to help prevent twisting between the two beams.

Nice lookin parts. Yeh, THK is nice stuff.

Update. I have a 1x3.5 inch piece of aluminum going under the router table acting as a connecting beam for the ballscrew mount. Should stiffen things up alot.

http://www.coldfusionracing.com/images/Andrew/router2.gif

just a suggestion, you'll need to reinforce that top surface. it will sag in the center. what about putting the bottom gantry crosspiece underneath the x rails. prop each corner of the base with some feet or standoffs. the top surface could then be bolted directly to the solid bars. maybe add one more support off center for top.

look forward to seeing your future progress.

Good idea, I'll work on it.

The Z axis is givng me problems though. I want to do THK, but am having problems with room on the mounting plate.

There are some problems with putting the beam under the rails. What about using a roller system on the beam under the table? It would move with the tower and if setup right, could eliminate any table top deflection. Did I mention the table top will be at least .250 aluminum?

1/4" ali will still flex. I added some ali angle bars under my table top to help control the flex. Seems ok so far, and they just clear the leadscrew/nut assembly.
http://www.btinternet.com/~jasonrsmith/uber_router/Supports1.jpg

What in particuar are you having problems with on the z axis? Sorry, I don't quite understand!:(

The Z axis still needs work.

http://coldfusionracing.com/CNC/router.jpg

Go take a look at Balsamans z-axis, he got it sussed! The use of an ali plate on the slides will leave just enough room for your leadscrew. Hope this helps!

Update. I got off the phone with a friend from a cnc shop. The Z axis will be using 7 inch long Sr20 THK rails. I'm going to have him machine the ballnut mount, both z axis plates, and the motor mount. I also have the chance to pick up a pair of 8mm SKF ballscews for my Y and Z axis for a great price. There are two things I'm concerned about though. Shaft whip on an 8mm screw over 29" could be a problem. Also, they are single nuts. Is this going to be a big problem concerning accuracy? I really want the machine to run soon, but then again, I want it to be as nice as possible the first time around. I am also considering buying 5/8 thomson ballscrew and preloading my own nuts. Please help!

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2

Muahaha, I finally got a Z axis. It's a little too long now, but I'll be modding it to fit. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3804634376&category=42899

Man "Cold Fusion" you really scored a fantastic deal on that Z-Axis setup. You don't see sweet deals like that come up often. Nice job. :)

Seems like there are always Parker slides on ebay, but they normally go for around $150. I know that steveald uses one for his 2x2 and his 4x8.

Question for the experts. Do I really need precision ground ballscrews? I already have one rolled single nut skf and was planning to get the matching one for the Y, but it bugs me that there is something better available;) Do you think its really worth it? I was hoping to get tolerences in the range of .005 with whatever kind of screws I use.

Cold, since your THK's are SR20's, you may want to place your X rails so that the trucks are horizontal, rather than perpendicular to the ground. SR's have better load capability horizontally. If they were HSR or SHS (4-way load) then they'll do fine loaded in any direction.

OTOH they are so strong it probably wouldn't matter one way or the other. Looks nice!

Fedex just drove up. It was like Christmas again:) Centent cn0143 Microstep drivers, Powermaxx 2 hybrid 190oz steppers, 24v 12 amp power supply, and a 5v power supply for my drivers. I bought this whole package from fair451 on ebay, who also sold me my THK rails. I highly suggest him for any cnc parts you might need. I just missed an awesome ground ballscrew from him:mad: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3806098044&category=25290

I'll spend today figuring out how to wire everything.

Next parts will be the 1.75 inch aluminum squares that most of the frame is made of.

The Parker Z axis should be here in a week. Since it's 12 inches too long I will take it all apart and cut the ballscrew and linear rails down.

http://www.coldfusionracing.com/CNC/driver.jpg
http://www.coldfusionracing.com/CNC/motor.jpg
http://www.coldfusionracing.com/CNC/motor3.jpg
http://www.coldfusionracing.com/CNC/power.jpg
http://www.coldfusionracing.com/CNC/package.jpg


And did I mention I'm pretty serious about this project:D

For best performance, wire the motors bipolar parallel and set the current @ 6.5a. See page 49 of the data sheet here:
http://www.xylotex.com/PacSciDS.pdf

Did you know Mariss of Geckodrive designed those drives?

Eric

Yeah, I posted a topic on them and he replied saying that very thing.

Originally posted by ger21
For best performance, wire the motors bipolar parallel and set the current @ 6.5a. See page 49 of the data sheet here:
http://www.xylotex.com/PacSciDS.pdf

What is the relation between driving unipolar@4.6A and bipolar@6.5A? Cannot figure it, and I got a bunch of 1.3V/3.9A unipolar steppers and want to know how to size the bipolar driver I'm building for them..

I mean, I understand how to do the physical wiring, what I do not know is how do you derive the 6.5A

If R=2V71/4A6=0.589, then wiring // implies R'~0.6/2=0.3, so the current will be I'~2.71/0.3=9.1A

Where gone the amperes between 9.1A and 6.5A ;)? If is related to the centent or something similar excuse me, I've not revised that.

Thanks in advance

Fer

The voltage, resistance and current all change when you change the wiring type. I'm no electronics guy, but If I recall from a chart I saw somewhere. Read the page I posted the link for. It lists the specs for the motors you have.
If I recall correctly, an 8 wire motor from unipolar to bipolar the current changes by a factor of 1.4, and voltage drops by a factor of 0.7. I'm not 100% sure, but that seems like what I remember seeing somewhere.

Ok, its only I always am happier when I understand the maths behind. By the way my motors are surplus 6 wire so maybe that V and A relations are not applicable. Thanks anyway.

Fer

I need help with the terminal connections. Everything is done except for the 5v line to power the driver. I have a 5v power supply, but how do I connect it? Keep in mind everything is the same as a gecko.

YESSSSSSSSSSSSSSSSSSSSS:D :D :D

Can you tell that I'm excited? I just ran my steppers for the first time. Everything ran very smooth and quiet thanks to the built in microstepping. After 3 hours reading the Centent manual, Gecko manual, and powermaxx manual, I finally figured out where everything went. It was only the X axis this time, but soon I will have all 3 going. Mach2 was the choice for this test because I plan to buy it and need to become familar with the setup. After spending a good hour with all the wires I decided a breakout board is going to be bought! Probably the Axxus one I hear so much about.

Great to hear! Looks like a real nice setup. Never seen that brand of drive, I take it they are like/better then Geckos? Keep up the posts, really enjoy following along.
Bill

They are the exact same as geckos minus a couple things. I think geckos have ajustable microstepping where these are fixed. These also can handle 14 amps per phase!

I have some similar Pac Sci motors, just haven't convinced myself to shell out the bucks for Geckos, YET. I can run the motors with the 3A boards I have but I would really like to see these motors sing.
I'll keep an eye open for the Content drives. It's hard finding a drive for these low inductance motors, Geckos seem like the only choice. Oh Well, half the fun of building a machine is scrounging for the parts!
Great to see your progress,
Bill

Now that I'm awake I have the forthouht to setup the proper units and such in Mach2:P Question though, are the stepper motors suppossed to run a little bit choppy at low speeds?

The Z axis is here. All 20 inches of it:eek: Yeah, a little bit bigger then I thought. This thing is built like a tank though. The entire black frame is is milled aluminum. Supported thomson rails, ballscrew with double preloaded nut, 4 open pillow blocks, and great looking ballscrew bearing ends. And what did this cost? $65 shipped!


http://www.coldfusionracing.com/CNC/z1.jpg
http://www.coldfusionracing.com/CNC/z2.jpg
I hope I don't need those;)
http://www.coldfusionracing.com/CNC/z3.jpg
Double Preload Nut
http://www.coldfusionracing.com/CNC/z4.jpg
http://www.coldfusionracing.com/CNC/z5.jpg
.997inches for 5 ridges. This is the same on all places of the ballscrew. I guess it's a .2 pitch.
http://www.coldfusionracing.com/CNC/z6.jpg
Riiiiiiiiiiiight
http://www.coldfusionracing.com/CNC/z7.jpg

Just hooked a stepper to it. I'm getting .001 of an inch. Not too bad, considering I'm standing on the carrige and the motor coupling is not even built.

Congratulations! Seems like a real find! I guess just the screw and nut cost 10x what you paid for the whole thing :D

Arvid

... considering I'm standing on the carriage ...
Coldfusion Numerically Controlled

LOL

I have a problem with my steppers though. They only turn in one direction. I've tried running g codes, jogging, different programs, but nothing fixes it. I've also tried switching the output pins around, but to no avail. I'm runnning Centent drivers, which are the same as Geckos.

Here is an updated picture. The Z axis is the correct length but has no features yet.


Solidworks makes it look alot talled then it really is. The total gantry height is only 19 inches. The total length of the X is 31.

http://www.coldfusionracing.com/CNC/router.jpg

I got the 1.75 aluminum square today. It took about 2 hours to measure all the hole positions, but atleast I got them to .002. So far I've drilled 13 holes, with 39 to go.



http://www.coldfusionracing.com/CNC/cut1.jpg
http://www.coldfusionracing.com/CNC/assembly.jpg

Cold fusion..

I had the same problem once with my machine (steppers only spinning one way) I think I had my Step / directions pins swapped, although it sounds like you already tried this? ummm...the wiring of the coils may do this as well...I may have the answer inmmy notes..I had so many problems builing my machine they sort of merge together :)

I have pic of my first machine here http://members.cox.net/walachcnc[/URL]

I am building a new machine, pic should be up soon.

Anyone have much luck making their own linear bearings? I have been working on my opwn home brew with Delrin. Work fairly well for the price.

Your probably right about the coils. That was the one thing I wasn't 100% sure about.

Ok. All the hole drilling and tapping are done. The THK rails are bolted down. The new Kuroda precision ground ballscrew is delayed one week.

It's funny how the mind works. I swore to myself that the design was final, but after seeing it all in real life, I am changing it. The gantry will be receiving some major support. Instead of 1/2" plate, think 3". My design is going to be similar to CAD CUT. The router will actually be below the lowest point of the router frame. This allows me to use the ultra long Z axis I bought, but still have everything close together and maintain ridigity.

Here are some pictures of the parts I have done so far.

2

3

4

And finally, my new toy.

3ghz P4
512 Ram
30gb
15" SXGA
64mb Video card
Super G wireless

I just received my Kuroda Ball Screw. It's HUGE. Just the ball nut is as big as my fist. I hope my steppers can turn this beast. It has a 25mm pitch, which I plan to gear down 1:4.

I think I'll mount in on the inside on the THK supporting beam on the right side. The nut will be mounted to the underside of the gantry.

I'll have pictures soon.

The controller cabinet is almost done. It's 5 feet tall with the computer on the bottom, all my cnc equipment in the middle, and my monitor on top. What is great about the box I picked up is the front hinged door is made of glass so I can see Mach2 but the sawdust doesn't get to it.

Pictures coming soon if I can find that dang camera cable.

WOW Cold,

thats uncannily like what i have planned. i have 2 32" NSK linear slides, and 1 36" doublewide slide.. with 2 blocks each..

what are the rest of the components you have planned? i have a 1.75hp porter-cable to put in it, just gotta figure out steppers or servos. and mainly, if cliftons can work for this, with propper reduction..

what're your plans?

oh. after looking, i see i am wrong. your design is far different than mine. i thought what you had going looked like budcans machine, but now isee its just parts.


still interested..

I've got a 1.75 HP Porter cable going in. I just bought some 680oz Camtronics steppers for my X and Y.

Update:

I've bought all my GT2 5mm pulleys and belts for the X and Y. My ratio is roughly 1:1.5

The whole frame is out of the house and into the garage. I found the perfect enclosure system while I was working out there. After some modding I have a perfectly solid 48x48x30 box (without the sides which I haven't bought yet).

The aluminum legs were also bought today. That should be the last aluminum bought for this (unless something changes).

Kong has been so kind as to offer his machining services for my router mount and ballscrew bearing holder. I truly appreciate that generous offer and the patience he has had with me while we got the design done. Kong Da Man :D

Once I get some 1/2-13 screws in I will be able to bolt the whole gantry together in one piece.

I need to buy some 1.5 inch aluminum standoffs for my z axis motor mount. Probably hit Mcmaster for those.

I'm still debating on what kind of coupling to use on the Z axis motor. Both shafts are .250

The Y axis ball screw is still being searched for on ebay. I really wanted at least a C5 class one as that is what my other one is.


And lastly, I would like to thank everyone for their support and advice. Being only 14 years old is a slight handicap, but with help I can keep up with all of you old guys;)

Looks like it is really starting to come together Cold Fusion. Looks good.


I just finished some of the major machining on my machine's Y & Z axises this week and got a chance to do a trial assembly on them yesterday. I have a few holes (60 of them) on the THK rails I'm using that will need to be opened up abit next week but that's only because I am using 6-32 screws to mount rails that were drilled for M3's which didn't allow me any room for adjustment of rail alignment but this is only a minor problem but easily fixed.
Now if I could only get the feeling back in my hand from tapping those 60, 6-32 rail mounting holes. LOL ;)

Here is a photo of what it looks like so far.

Yeah, tapping those long rails can be a Pita. I had 13x4 plus 30 misc holes.

Your machine looks good. What size rail is that?

Originally posted by Cold Fusion
Yeah, tapping those long rails can be a Pita. I had 13x4 plus 30 misc holes.

Your machine looks good. What size rail is that?

Damn good arguement for a tapping head :)!

Tapping head=$$$

If I can get the same results through hours of manual labor and save some money, I'll do it;)

LOL CF I guess it all comes down to what your time is worth to you :)!

In an ideal world someone would buy a head to build their machine then sell it to the next guy and so on down the track.

(In one of the things I make I have to tap 2.5x.45 mm holes and hate doing them by hand, can't use the tapping head as it breaks the taps so I remove the belt from a small bench drill unhook the return spring and use a pneumatic right angle air drill to drive the spindle with a rubber cone in the chuck. This allows some slip and stops breaking the tap)

I tried tapping under power but it always broke the tap. I'm tapping 10-24 to the depth of an inch. I've found that spiral taps works best because they actually take metal out instead of displacing it.

The Y rails are 12mm and the Z ones are 15mm. I am abit concerned whether or not the 12mm rail carriages will be able to stand-up to the weight of the complete Z axis when the router is installed. Will be ok for awhile but I am going to continue to watch ebay for another set of 15mm rails & carriages just in case.
I have 3/4" Thomson rails for the X axis so weight will not be a problem for them.


I also powered up my controller (Xylotex) today for the first time with some steppers
and all worked out fine. Now that the electronics are almost complete I can dedicate more time to machining the rest of the mechanics.

Carl

I always use spiral point taps since they push the waste material forward out of the hole. This of course creates a problem for blind (non-thru) holes where the cuttings get pushed to the bottom of the hole, so you need to either drill a deeper hole to allow the cuttings to collect or make sure to remove cuttings every couple of turns.

Score!

My waiting has been rewarded. I just bought a C3 preloaded ground NSK ballscrew for $50. The motor power cables came in today and look very nice (18x4 shielded). Kong is almost done with my Router mounts and ballscrew blocks. The 1.75 inch supporting blocks needed to raise the whole frame above the ground level should be here soon.

The Z axis is still awaiting it's bearing blocks due to my laziness and lack of bolts (need to make another order at McMaster).

Coldfusion,

How are you so lucky on these finds???? Your Z-axis purchase was a real steal. BTW, it looks way too large for your router, I'll be happy to take if off your hands!!! Keep up the good work and thanks for the stepping motors too.

--Colin--

Ebay. Find something you want and stake out the market for a few weeks. Most of the good deals are from salvage people. They find the item, it looks nice, and they put it up without knowing anything else. Model numbers help, but you can normally find out if a ballscrew is nice by looking at it. Is it ground, what kind of preload does it have, single or doubt nut, ect. Here are a couple nice ones on ebay now.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=55826&item=3817191565&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12577&item=3817614987&rd=1 (This is a SUPER nice one)
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=25290&item=3817687583&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=11805&item=3817296285&rd=1

Here is the one I got. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26261&item=3816863071&rd=1

Hahaha. No way am I releasing my Z. I know it's a bit long but I've worked around that. I suggest looking out for items with these keywords. Parker Slide, Cnc slide, linear slide, and parker daedal.

I've been out in the shop for a couple hours drilling all the 1/2-13 holes for my gantry. It's WAY to hot and humid out there:(

Colin, if you want, I can talk to you on the phone about all the rest of my ebay secrets:p

CF: Looking forward to more pics of your machine !

And I am looking fowards to posting them once I find that stupid camera cable!

By the way IJ, I love your machine. Oh the things I could do with a mill. Having only a drill press and other tools tends to make everything harder.

CF: Thanks I'm lucky to have my second Mill with the DRO to make parts for the CNC one :)!

I hope to run it for the first time this weekend and will post some more pics at the end of work today.

(Find the cable......find the cable...... ;) )(I browse the forums each morning before I start work and enjoy checking peoples progress... 7:30 am here as I post this)

Today I made a run to Home Depot and picked up some 1/2 13 screws so I could bolt my gantry together. It's so amazingly solid.

Also got my 680oz steppers today. The Y axis mounting will be easy, but not the X. The bolt pattern is 3.4 inches wide and I'm using 1.75 inch aluminum on the X beams...

If I get some time I'll go to Best Buy and get a card reader. Stupid cable hasn't shown itself yet.

THK rails and blocks are a PAIN to get straight. After a couple hours I finally did get everything smooth though.

The bad news is UPS won't bring my ball screw until the 4th. Until then, I'm out of things to do.

Finally found that cable! Here are some pics of the progress.

2

Here is the whole photo gallery. www.coldfusionracing.com/CNC/index.html

CF: Thanks for that :)!

Bummer on the BallScrew though.....

Very nice CF. Looks like it is going to be a good size machine.

I have a question for you about those 3 Pacsci steppers you have. What is the holding torque on them and seeing how they are 4.6A Unipolar do you think those type would be ok for me to run on a Xylotex drivers in Bipolar Series? If I am not mistaken 4.6A Uni would work out to around 2.3A hooked up in Bipolar series?
I am still trying to find the right motors for my system but I want to get ones with as much torque as I can but still have good speed.

The PacSci motors rated 4.6a unipolar would be 3.3a bipolar series.

I've got some 252oz PacSci motors rated at 2.3a bipolar series. The number is M22NxxB-something. There is also a P22NxxB, with about 214 oz-in I believe. The B in the number specifies the current. Cold fusions are A, which are higher current motors.

The torque is 196oz.

Ooops.. Thanks for the correction "ger21".

Something in the 180oz to +200oz range is what I am hoping to get.

Thanks :D

Wow. It's been a long day. I finally stopped putting it off and installed the Z axis. To my great joy everything rides perfectly smooth without the slightest ajustment on the Y and Z.

I think the quality of my work is improving. The X need a good amount of ajustment before it ran smooth (it still could be better).


Can we say rigid? I think we can:D No noticible deflection when I put about 80 pounds of linear force against the stopped gantry.



http://www.coldfusionracing.com/CNC/tn_DSCF2539.jpg (http://www.coldfusionracing.com/CNC/DSCF2539.JPG)

http://www.coldfusionracing.com/CNC/tn_DSCF2540.jpg (http://www.coldfusionracing.com/CNC/DSCF2540.JPG)

http://www.coldfusionracing.com/CNC/tn_DSCF2541.jpg (http://www.coldfusionracing.com/CNC/DSCF2541.JPG)

http://www.coldfusionracing.com/CNC/tn_DSCF2544.jpg (http://www.coldfusionracing.com/CNC/DSCF2544.JPG)

Hey C.F.!!! Is that all solid blocks of aluminum you are using? Man that machine is going to be solid if it is.

Carl :cool:

Yup. 1.75 inch aluminum for the X and Y THK rails, 3x3.5x6 for the gantry supports, 3x3.5x4.5 for the upper Z support, and I have some 1.5 square coming in for further gantry bracing.


I also have a 1 inch thick 4x20 aluminum plate coming in that will go accross the bottom on the gantry. This will tie the 2 sets of THK blocks together better and ensure that I have NO skew.

How is the pricing for aluminum in the US?

I just picked up some more aluminum plate from the supplier today for my gantry uprights and for the bottom plate that ties the gantry uprights together and also provides a place for my X-axis bearings to mount to. The 3 pieces cost me $190.00 CND which includes the cut charge.

Two pieces of 1/2" x 24" x 8-7/8" and
One piece of 5/8" x 32 x 8-7/8".


Well no one said this hobby was cheap. LOL

The aluminum square is fairly cheap. I got four 1.75 30 inch long pieces for $80 USD shipped. It's much stronger then extrusion and alot easier to work with because you can drill holes anywhere on the face.

I got a really good deal on the big plate. $12 plus shipping.

Your prices sound good. I've made the mistake of not paying extra for the cuts and spent many hours regretting it.

Yes having it cut near to size is a big help and worth the extra cost when it comes to large pieces.
I had the pieces cut abit larger all around to give me some material to mill off so I can get them all to the exact sizes I need.

That is one beefy machine you are making! I was wondering, how thick material will you be able to fit under the gantry? will the x-axis linear rails be placed on top of tall square stock?

Pat

The X rails are bolted on top of the 1.75 aluminum square. I have already bought some big aluminum legs to raise the whole table off the ground. My under the bridge clearence will be about 5.5 inches.

Kong just shipped out my parts. It will be about a week before I get them:( Once I receive them I should be able to get the X and Z under power. **Cold Fusion is tempted to start cutting with a manual Y**

Originally posted by Cold Fusion
The aluminum square is fairly cheap. I got four 1.75 30 inch long pieces for $80 USD shipped. It's much stronger then extrusion and alot easier to work with because you can drill holes anywhere on the face.

I got a really good deal on the big plate. $12 plus shipping.

Your prices sound good. I've made the mistake of not paying extra for the cuts and spent many hours regretting it.

What supplier did you use, mind sharing?

Thx
Cliff

http://cgi6.ebay.com/ws/eBayISAPI.dll?ViewSellersOtherItems&userid=metalconnections&completed=0&sort=3&since=-1

Thanks. Did you find the pieces in an auction or contact them and tell them what you want. I've got 47" rails so...

Cliff

I bought it from an auction. Here is the person I use for custom sizes. http://cgi2.ebay.com/aw-cgi/eBayISAPI.dll?ViewFeedback&userid=coram96&ssPageName=STRK:MEWN:SID

Finally got my ball screw. It's extremely nice. A C5Z with NO axial play. The only problem is how to mount it. I've got something in mind but it will take some time to get in all the parts.

Update. The Y axis ball screw is now mounted to the Z axis slide. I've drilled and tapped all my aluminum legs.

I might have found a suitable base for it. A friend of mine has a 3'x4' slab of granite that is 2 inches thick. If I can get it over here and mill down the surface, I should have a pretty solid mounting base.

Did you fix the problem with your motors not reversing?

Not yet. I'm mostly working on the mechanical side of things now.

Router Mount from Kong. Sorry for the quality but the weather is just terrible and the garage doesn't have proper studio lighting ;)

Bearing mount and ball screw mount, also from Kong.

And finally, the Y axis ballscrew.

Well done CF :)!
What pitch is your BS?

8mm on the Y and 20 on the X. I've ordered some pulleys to even out the gap so it should preform well. Most of power from my 700oz steppers won't even be used because I cut plastics and light wood.

CF: I thought some software had problems cutting circles if you had different pitches on X and Y? (Not sure if this is an issue or not but seem to remember reading it somewhere)

:eek:

I never heard of such problems.

CF: I can't remember where I read it and am still trying to find it!

I'm sure if it's an issue one of the resident Guru's will jump in and let us know. (sorry for any alarm if I'm wrong)

CF: Found it and maybe it's only a DeskCNC thing >>

Pitch Thread (http://www.cnczone.com/forums/showthread.php?s=&threadid=3747&highlight=x+and+y+different+pitch)
Post #7 onwards.

Thanks IJ!

After chewing through the info it looks like it won't be a problem. I'll be using Mach 2, which I'm sure works with elliptical interpolation. The only limiting factor is the cpu speed, but who needs to cut a circle at 250ipm?

LOL CF that's the problem with reading ALL of the posts on the Zone sometimes a certain thing sticks in my head and at first look it appears to be a problem!

I just didn't want to see you have an issue in the mechanical design stage due to the circle interpolation thing!(non issue as it turns out anyway)

Update. I had a gentleman on the boards machine a motor mount for me as well as a thrust bearing assembly. All I need now are about 20 misc bolts, 1 timing belt, and a 20x42 bearing.

The granite base turned out to be in use so I couldn't take it. Eventually I'll get one off ebay.

My work pales in comparison to IJ, but then again, I don't have an existing mill to do stuff on (Just read IJ's thread again). I hope to have the router running in a week when the Porter cable router arrives as well as my last shipment of hardware and belts. Hopefully I can have the machine then build itself, so to speak. Little things like machined ball bearing mounts that I can't do without some sort of machine will be cake once it works.

I talked to Michael (who sold me the drivers) today. He is positive we can get this lack of reversal fixed.

Today I got the X ballscrew (Kuroda 20mm) mounted as well as one side tower bored for the Y ballscrew (took a loooong time with my 1/3hp drill press). Needless to say, I don't look foward to doing the other side. As soon as both towers are done I'll be able to make the final mounts for the Y ballscrew and bolt it down. All that will remain after that will be the Z motor coupling, Y motor mount, and X timing belt.

Closer, ever closer.

Well done CF:!

I've said it before and will say it again here I admire you guys that scratch build a machine with minimal tools/equipment.

The amount of obstacles you face in each phase must be staggering (I know I decided to go for the knee drive as it would save me a week or so of work but in the end had to go to a quill drive).

Can't wait for more pics and the first time your machine moves under it's own power!! (A HUGE BUZZ for me).

The Zone has been a great help in my project just in seeing what the guys here have achieved is an inspiration.

One thing that helps is to have room for ajustment on EVERYTHING. My Z has already moved under power with me standing on it:) The X just needs a belt from Sterling (ordered the wrong size last week).

Originally posted by Cold Fusion
My Z has already moved under power with my standing on it:)

LMAO Now this is something you have to post a vid of :)!

I'll try to dig up the video. It's somewhere in the depths of my hard drive.

www.coldfusionracing.com/CNC/slide.AVI

I still can't find the video with me standing on it. Don't worry though, I'll take a new one as soon as I get that helical coupling in.

Thanks CF :) (still wanna see the standing on it one)

I'll borrow my Sisters cam corder and post some footage once I start cutting parts on mine!

That would be great. None of the videos I've seen show the guts of the machines (belts, gears, ect) so please try to get some shots of those pieces.

Will do!

One of the first parts I'll make is a belt cover for the Z so I'll get some vid of it bare.

Finally the Y axis is complete! Rock solid and NO backlash.

That is great news. Got any photos? :D

I will in the morning.

Wow, that was a long work day. All the mechanical parts to the router are done!:banana: :banana: :banana:


Now I just need to put the belts on (not here yet), tighten up the screws, and get that computer working.


Go here for the full pictures.Gallery (http://www.coldfusionracing.com/CNC/index.html)

Looking good CF. I do have one question for you. In photo "DSCF2753" it shows you using threaded rod to mount your Z-axis motor. Is this the final mounting method or are you planning to make some sturdier stand-offs to prevent any twisting when the motor first starts up at higher speeds?

Carl

This was just to mock something up. I'll be buying 1/2 inch aluminum standoffs and milling a motor mount soon.

The last picture is bad. The full size one, that is. It won't load.

Thanks for letting me know. The FTP server was going crazy last night and not uploading everything smoothly. It should be fixed now.

CF: Lookin good :D!

How much longer do you think you have left on it?

One more week if nothing goes wrong.

Originally posted by Cold Fusion
One more week if nothing goes wrong.

LMAO !! :D Now that has to be the BEST answer you could give when it comes to building these things! <golf clap> (one step forward two steps back most of the time)

Yup! Here is an example.

My control computer hard drive crashed so I have to re-install windows. All of working computers are Windows XP. The copy of windows for the control machine is 2000 pro. Windows will not let me install pro to the other machine while slaved up to my working desktop because it's an older version. Dang you Microsoft! I'll either have to trick it in Dos or go to a friends who has Win 98.

Did I mention how much fun I'm having in Onecnc? Three magic words, "Automatic Drilling Cycles".

quote:
--------------------------------------------------------------------------------
Originally posted by Cold Fusion
One more week if nothing goes wrong.

From my experience, you had better plan on a month or two then.
You are doing a great job, keep it up.

Trent

I got the MDF base cut to size today and bolted to the frame. The mechanical overtravel blocks were also installed at the ends of the X axis (the Y is limited by the X beams).

Of course something had to go wrong. Somewhere along the line I must have missed about 20mm for my belts. So now I have 3 GT5 belts which are useless. Hopefully I can get SDP-SI to exchange them quickly. The good news is I finally got my helical coupler in and the Z motor is mounted.

The new belts are on their way! Also ordered was a ton of misc. screws needed to complete the job.

I'm about to win a 30x5x1.5 piece of aluminum on ebay(40lbs). This will be drilled by the cnc router for a MUCH more sturdy gantry bridge. Right now the design has one beam going all the way across with two half beams on the second row of thk blocks. This works ok and was really the only way to do it because I lacked the precise drilling abilities.

Tooling is already being bought so I can get this baby cutting asap. I'm going to try a wide range of 1/4 end mills and let everyone know how their preform.

You might want to look at http://www.onsrud.com .They make a large variety of router bits for cutting aluminum and many other materials. You're using a Porter Cable router, right? You may get better performance with these bits, as they are designed to work in routers, as opposed to most end mills which are designed for slower rpm's typically found with milling machines. But they probably cost a bit more, though. Just giving you some more options.

Just bought a 690VS Porter cable router, end mills, and a custom 1/8 collet from Jeff. Hopefully I can be cutting in a week so I can repay a favor to my friends over at Onecnc.

Cold, what are you doing for coolant with those 1/8" bits? Even if you use a single flute cutter, they may still clog-up.:(

The 1/8 ones are almost always going to be used in a drilling cycle or a .01 cleanup pass. Right now I have not got a coolant system setup but I did want to buy an microdrop system down the road.

GRRRRRRRRR:mad: :mad:

Why are things so hard? The dang motors hate me! I can them to reverse but then it's really choppy. I can get them to run smooth but then they don't reverse. On top of this I exploded some capacitors.

Any help?

CF I have not read all this thread so I have no idea what kind of setup you are using...other than Mach2, which in my humble opinion is the best for the money.:D What kind of drives are you using. I have Gecko 201's and had the exploding capacitor episode myself. I can help you if you are using the 201's so let me know. I am not sure what your problem is with motor either so hit on that while you are at it. If you prefer to pm I'll probably be able to get back quicker. I don't have long on here tonight and and there are a ton of posts to catch up on and this is just one of 5 forums!:D

Mike

I'm using Centent drivers which have the exact same layout and specs as a Gecko 201 (they are not the pirated ones but an older model gecko). I would be grateful for any advice you have time to give me. This problem really has been driving me crazy:(

Cold, I am in the process of trying to come up with a design for my cnc router. 1. do you like screw drive or rack diven axis?

Since I've never had a rack and pinion driven machine I can't comment about that. The ballscrews I have are great! The smoothness and precision are wonderful and they are easy to mount. I would suggest going with ballscrews unless it's a realllllly long machine.

I have a cnc plasma that uses rack it is a 4x8 it work good but iam not sure of the precision i will guess it is with 3/32 which for my purposes it is close enough. bu ti think for a router it need to be much tighter. i a m planning on building a 4x4 or 4x8 router. what would you recomend as far as thread and size of ball screw?

Rolled ballscrews have a lead error of about .003 per foot. Watch ebay under the keywords ballscrew, ball screw, and lead screw. 5tpi is a good starting point.

I am considering running each side with a seperate motor but I am not sure how to hook them to the driver. i assume they both wire together but I not sure.

Mach2 has a slave motor feature built into it for this purpose.

Update on my driver problem.

I think I know what's causing the problem. The voltmeter is reading 4 volts on a CW motion and 6 volts on a CCW motion. This reading was taken from the 1 ground pin to the direction pin on the driver. I know for a fact that the signals coming out of the computer are 0 and 5 volts. Now how in the world do I fix this?

Can anyone help? This is the only thing holding me back from cutting.

What voltage do you read between the 5 volt input and ground? You should not be reading 6 volts on either the step or direction pins. What type of power supply do you have for the 5 volts?

I read almost exactly 5v between those two. Should I try using the PP 5v line instead of my external one?

I just downloaded and looked at the manual for your drives. How do you have the 5 volt supply connected, and how do you have the PP connected? The inputs to your drives are opto coupled, and the 5 volt input is only for the optoisolators. Evidently, the other electronics in the drives are powered off the motor voltage. Because of this, there should be no connection between the PP connections or the 5 volts supply and the pin1 ground on the drives, and any readings between pin1 and the step/direction inputs don't mean much. The - side of your 5volt supply should connect only to the ground on the PP, and this ground should not be connected to the Pin1 ground. There is no 5 volt pin on a standard PP.

1. Ground wiring is important, easy and safest is to use the gnd lug on your motor power supply as the 0 volt reference. Each device ground gets it's own wire from there. i.e. computer, three driver boards = 4 wires at the terminal.
2. Make all your voltage measurements from that common point (0 volt reference).
3. If you have a seperate 5v power supply it's ground should also wire to the 0 volt reference. i.e. 5th wire.

See attached

Phil

p.s. pardon my poor artwork

The big question is where are you deriving your 5V to power your drivers?

Thanks for the visual pminmo. I'll go out and try it in a few minutes then report back.

CF,
I'll check back in in the morning, it's been a long day. Also is your spindle motor controlled via the PC? There is another potential gotcha.

Phil

No, the spindle in on a dedicated power line that is seperate from my cnc line.

Though I am just getting into CNC, I am an Electrical Engineer, and I have to disagree with pminmo. There should be no connection between any of the PP pins and the pin1 motor supply ground on the drives. The 5 volt supply should be separate from the motor supply(you could get this 5 volts off the keyboard connector on your PC). You should connect the ground from the 5volt supply to pin25(actually pins 18-25) on the PP. Pin25 on the PP should not connect anywhere on the drives. You then connect the positive from the 5volt supply to pin 10 on your drives, and the signal pins from the PP to pins 8 and 9 on your drives.

jeffs55,
Good catch, I forgot it was opto isolated. I'm an EE too, but it was late last night. No excuse, but I was trying to get on a level playing field, was just to fast to tired.

Phil

diagram corrected

YEAHHHHHHH:banana: :banana: :banana: :banana:

I hooked up the 5v ground to pin 25 and it worked right off the bat! Now my motor is running smooth rapids of 500ipm and the force at 50 is amazing. Thank you all so much for helping me! I knew it was some simple thing I was overlooking.

CF:<golf clap> good news :)!
Ya gotta love the Zone for this, don't know something?? wait 5 minutes and someone will come along that does!!

I don't know what I would do without this place.

If only my X axis belt would hurry up and get over here! UPS will bring it on Monday but I'll be out of town until Tuesday night.

Great to hear.

Phil

I knew that this was all too good to be true. All of my electronics are officially against me. After extensive testing I have this problem. The direction output does not work on any pin except 1 on my parallel port. Same result on two computers as well. I'm about smash it all with a hammer if it doesn't work soon:(

:( bugger.....

Yeah, the X is great but the Y and Z have my orignal problem. I'll draw up a diagram in a few so that maybe someone can help me fix this problem.


**Cold Fusion goes to smash something with a golf club**

Originally posted by Cold Fusion
Yeah, the X is great but the Y and Z have my orignal problem. I'll draw up a diagram in a few so that maybe someone can help me fix this problem.


**Cold Fusion goes to smash something with a golf club**

LMAO is a CNC machine a par 3 or a par 4 ??

I live on hole #1 of a golf course so hitting the Centent would be a par 3.

CF: "Caddy hand me my #9 Sledge"

WHACK CRUNCH ZAP ;)

Yeah, it's funny for you because your electronics didn't do this :( Right now my router isn't here so it's not like I could be cutting anyway.

I had a few electronic bugs CF (I know how it feels when it won't cooperate trust me I reached for the sledge a few times) ... just trying to lighten the moment a little :(

You'll get it sorted and then be able to look back and laugh!

Here is the way it's setup right now. I left out the motor leads for the sake of space.

http://www.coldfusionracing.com/CNC/AHHH.gif

It has been proven a hundred times over the drivers are not at fault. Somewhere in my software something needs to be changed,

If the drivers are opto isolated that is correct. Are you sure your software is correct?

Phil

Yup, Centents are opto isolated. I've tried both Mach1 and Mach2 but to no avail. Maybe I should re install?

Are there any particular setting on the parrallel port that need to be changed?

A way to troubleshoot. Pull the wires at the computer for Step and Direction for an axis your having trouble with. with the direction line disconnected your should be able to touch and remove the step line to the 5vps gnd and get it to step in one direction. You may get multiple steps each time you make and break the wire connection but that is ok. You should be able to then hookup the direction wire to that 5vps gnd and repeat the previous (make and break the step line to ps gnd) and it should step the other way.

Phil

But wouldn't that just be testing the driver? I know they work. If I hook any one of my three drivers direction lines to pin 1 they work fine.

yep, did you configure the machx parallel port output?

Of course.

what happens if you swap software setup? i.e. the working port x define to machx as y and y define as x.

Basically whatever driver has their direction wire coming out of pin 1 works and the others don't.

try swaping pin 1 and associated direction line with another axis. i.e. if x is pin 1 and 2, and y is 3 and 4, at the computer connector remove and what was in 1 put in 3 and what was in 3 put in 1.

Is there a manual for your drivers? One of the things that is marginal is that most optoisolators require the driving source (parallel port if there is no breakout board) to sink 16ma of current. Some pc's are spected at 14ma and wouldn't be able to reliably work.

CF I apologize for not being here but I have been ill (not like a hornet either:D ).

After reading all the posts here, yes I went back and read them all, I am going to make you two suggestions.

#1 Contact Art at Mach2
#2 Contact Bob Campbell and get you a breakout board. The board Bob sells is designed specifically for the Mach2 and it is well worth the extra money.

If you have a friend who has a o-scope you can also check your pin signals much better that way.

Mike

Hello Turmite,

I'm going to be gone until Wednesday but I'll try to fire and email Art's way before I leave.

How much is that breakout board?

No. I have the most electrical gear of anyone I know but no O scope.

IJ, ygm.

CF where are you located?

Right outside Houston Texas.

St. Louis here, to far.

CF the price of the board is $130 and the url is:
http://www.campbelldesigns.com

I woud talk with Art first before purchasing the board. I will make this prediction: Something ain't right:D ! Sorry I just could not resist. I went through much of the same frustrations but mine was more of a time pressure thing since I try to make my living with my machine and it had been down several months. Needless to say I was desperate to get it going. I will tell you to step back, re-read everything again, check and the re-check all your connections. I had one wire that was not getting a good connection and caused me much grief till I found it.

Mike

Cold, i think pin 1 on a par port is an input, not an output. According to your diagram, you have it as an output. This could be the problem. I have a geckodrive wiring diagram here in front of me, but I have no ideas where I got it, so if you want i can email it to you. It should be a good match to your current drivers.

edit - it's on it's way to you anyways, since it is a small file.

Kong pin 1 is an output from the pc it was the strobe line for the printer.

CF, it just dawned on me today. Pin 1 is at a different port address than 2 thru 9. Look at your setup file again.

Phil

I am lost already, but I found the Gecko wiring guide on the net, which (if I read it right) has pin 1 as input, although it is unused. I am not arguing, like I said I no nothing about electronics, just trying some ideas:D
http://www.timgoldstein.com/cnc/GeckoG320Wiring.pdf

Looks like were both correct. Looks like the original IBM PC pin 1 was only out. Later implementations made that output usable as an input. I don't know how MachX uses it.
Here is a some webpages on the pport pinout: ftp://ftp.armory.com/pub/user/rstevew/LPT/lptskmtc.asc
http://www.repairfaq.org/filipg/LINK/PORTS/F_PARALLEL11.html#PARALLEL_006
http://www.doc.ic.ac.uk/~ih/doc/par/
http://www.beyondlogic.org/spp/parallel.htm

Good news! I made my first manual cuts today. 10k rpms, 1/8 deep pass, 2 flute carbide. The gantry wasn't even tightened down but it still cut with NO vibration. The bottom of the cut was like a mirror. Cutting force was slim to nothing, a slight hand pressure on the 30t pulley wheel.

Now that I know the machine will cut anything I throw at it the electronics need to be fixed for good.

SO what was the fix???

It's not fixed yet. Note that I said MANUAL cuts. Still fun though!

CF did you see my note on the fact that pin 1 is a different port address than 2 - 9?

Sure did. I'll get everything hooked back up tomorrow and it see if it works with the new changes.

Found the problem! The direction voltage coming out of any of the pins except #1 measures 3.5 volts (Step is a solid 5v). Would getting a new parallel port card solve this?

Eek, I had the same problem, and ended up with a new PC! Hopefully a new parallel port card would do it though!

Same exact problem?

I only payed $50 for this computer and moniter so it's not a big deal. The thing that is driving me crazy is the thought that it COULD be working now.

I am able to cut with one CNC axis at a time right now. The sight of those aluminum chips flying keeps me motivated.

Yep, same problem with the 3.5v port. I had my motors wired up like in the PDF I sent you (pins 2-7) and the motors would only jog in one direction. i had a spare pc (or motherboard, I don't recall) which fixed it. My fingers are crossed for you buddy!

I'll go to Office Depot and buy a new card ASAP. If this doesn't work I'll bum an old computer from a friend.

It's encouraging that you had the same problem. I thought that maybe I was the only one that was being tormented with it.

Building a Cnc Router
many persons talk about cnc router
what about softwares to control this router
iam a beginner and i need to learn the basics of cnc
like converting dxf file to g-code & interpreting g-code to signals(steps&diraction) via parallel port ...

:banana:

Today was a good day! I finally said screw it and switched my office computer (2.2ghz, 256ddr, XP) with the cnc computer. I plugged everything in and all the axis worked on the VERY FIRST run.

After I clean up the shop the first part will be made. Since I only have a 1/4 bit to work with (Jeff's 1/8 collet is in the mail) the part will probably be an updated bearing mount in aluminum. And yes, there will be a video.


The moral of the story, never EVER think that your computer motherboard is not at fault.

CF: Great news :)!

Told ya one day it would all just fall into place !!

Just made the first cut! 40ipm in MDF. Came out perfect except that the wood shifted in mid cut (need a clamp system). I hope to drill out that tonight and start in on my aluminum cutting tomorrow.

IJ, it really did. That new computer solved everything and all that was left was to swap a few pins on the Z axis and tighten up the machine.

Way to go! I plan on building a plasma table and retro a mill once I get my shed done, and paid for.

Ooops! First day of cutting and a first broken end mill. 1/8 deep pass at 30 ipm. It's not the speed that broke it but the way it entered the cut. I was taking 50% stepover passes and this was the first on the edge of the stock. The flute grabbed the aluminum too deeply (high helix flute) and the 1 3/4 HP did the rest. I actually got it on video because I knew that someone might go wrong and the people at CNCzone would enjoy laughing at it.

http://www.coldfusionracing.com/CNC/broken.AVI

Otherwise the machine is cutting great! I think that it has more rigidity then my cutting bits can surpass. The accuracy is pretty good too although I havn't tested it on an actual cut. The axis will jog to within .001 according to my calipers.

All is well I hope, you didn't get the cutter in the face did you?

CF: I broke one the other day on a roughing pass when the coolant pipe was feeding off the side of the work!

Uncoated cutter no coolant + fast feed = buildup on cutter and missing flute!

LOL just watched the vid bet that scared ya !! (advantage of the Mill slow spindle speeds!)

looking at the vid it seems the cutter may have loaded up, the steppers missed a step or 2 and whamo

What is a good resonable goal for backlash on a homemade CNC router?I am building a small cnc router.I will be using it to ball mill text into aluminum valve covers and some engraving work.
Thank you for any help.

The video makes it look worse then it is. I had the camera zommed in when it broke and the noise about gave me a heart attack.

Yeah, the high rpms make me nervous. I have yet to crank up the router past 10k with a bit in. The nice thing is the noise level at the low speeds is low enough so that you can talk to someone with it cutting.

I used the manual jog control to move the axis and it had a jerky movement to it. That probably had something to do with it.

Jim, I think that a backlash of .005 would be acceptable for your work.

CF That was a great recovery with the camera!:) I have heard the bang and if I had been filming at the time all you would have seen would have been a blur of the shop then snow.:eek:


Thanks for the video

Hey Mark, I see that you're in League City. We are located in Missouri City if you ever want to come by and see my machine break bits in person.

As of now the machine is halfway done with a Z axis motor mount. The part is 1/2 inch thick and being machined from 1" 6061 stock (all I had). I had Onecnc do 5 pocket passes at .1" and then it will cut the mounting holes and profile. So far the surface finish is nice but the edges are slightly rough and look like they need a finishing pass (which I did not program in:().

CF: I'd love to come and have a look in person but it's a bit of a commute from here ;)!

Keep up the good work though and always remember "safety"!

I've been having a few problems with safety on this part. I paused the program and when I resumed it the Z axis wanted to dive into the part with a .2 inch pass instead of a .1 inch. This would have broken my bit had I not hit the E stop. Of course when I hit the E stop on both my hardware and Mach2 it messed up my program run. Now I'm having a heck of a time getting it to work on that 3rd pass. Maybe I should dry run with a pencil before starting again with the router?

In the near future I will have bullet proof Lexan panels installed around the machine to keep those broken bits out of me and to keep the chips in a reasonable area. It's hard to believe how much chips can actually come out of just a few passes. Pretty soon my shop will be a foot deep with them :P

Maybe try an "Air Pass" first until you're confident with the machine?

Swarf is a problem the pic is after a days machining on my Manual Mill and the CNC produces it much quicker! (The high tide mark is about level with the X Handle)

I fill a 44 in a few weeks of work and have considered adding lexan guards to contain it and the coolant (just using an aluminium one to keep from drowning at present).

http://members.optushome.com.au/cougarmod/run406t.jpg (http://members.optushome.com.au/cougarmod/run406.jpg)

CF, Thanks for posting the link to the AVI file with your machine actually cutting.

In production, you aren't considered a real CNC operator until you crash the machine at least once, so you have a ways to go.

I have some unsolicited advice for you.

Each stage of build requires a unique skill set; design, procurement, mechanical, electrical, build, etc. You have already learned quite a bit about all of these.

Now you have a learning curve in actually getting the machine to work.

It cannot be overstated that you must take each area in steps. Its always the things that you didn't anticipate that will bite you.

You have to learn CAD, then CAM, then the machine controller, then how the CNC operates, how to clamp the parts, and then how to cut each material.

It looks like from the picture, that you are doing well in all of these. I would suggest that you take the air cycle advice to get a good handle on what the CNC will do with respect to your programs. If the machine is doing anything unanticipated, take a step back and figure out why. You can then build on this knowledge.

You should stick with MDF until you get the bugs worked out of your individual programming needs. Take good notes and write down all of the cutting conditions. Then move on to Lexan. It will take quite a different set of cutting conditions. Then maybe your carbon fiber, I would try aluminum last. It has unique problems (coolant)and may require your best skills.

You are doing a great job and should be very happy so far.

One more thing, in the movie I noticed that your router motor is mounted too high up on the Z axis. If you cut much deeper than you are in the movie the Z axis will hit your parts. Or if you use a shorter router bit, you might have problems.

I suppose if you are only cutting 1/4" lexan, then you'll be OK. I like to mount my router so the bottom of the collet a few inchs below the lowest part of the Z axis. That way I know I don't have to worry much about it.
Trent

Glad to see you got it going. Those electrical problems can be a nightmare.

Have any pics of the machine lately? (I could not play your .avi file)

CF

what kind of bit did you have in the machine when it broke?

High helix 2 flute 1/4 carbide end mill. The Z axis was fixed long ago. I've made a good amount of runs in MDF but am out of Lexan right now. I have crashed a couple runs so far but nothing was broken. These were in a fairly deep aluminum cut. The limit of my machine (or maybe my bits?) seems to be about .8 inches deep in a single cut profile in 6061 aluminum. Maybe later on today I'll get some pictures of it.

It this forum hosed or is it just me and my system. This is the only new message that I find.

Garry

Cold, are you talking about a 1/4" EM in a slotting type cut at .800 DOC? Or just a light cleanup pass around the edges? Generally about one diameter deep is all you can safely run in a slotting cut per pass, unless there's lots of well aimed coolant to keep the chips blasted out.

Depending on what edge finish you require on the aluminum wouldn't a solid carbide roughing mill be more suited for cutting aluminum with these machines? I am just curious since they really do allow for a deeper cut and a high feed rate not to mention the chips are much smaller. Anyone tried roughing mills on their system yet?

Carl


Oh I almost forgot to ask.

Cold Fusion what are you using as a speed control for reducing the routers rpm?
I need to get one myself and just wondering what you used. :)

This was a series of .08 inch deep passes.

Maybe so but I've never tried it. The Porter Cable router I'm using has a built in electronic speed control system that ranges from 10k to 27k.

Here are some pictures I took yesterday. For some reason the surface finish looks terrible but it turned out great :rolleyes:

Try a spray of CRC or some light lubricant while it's cutting CF, Just looks like a bit of adhesion/buildup is all!

Now I remember what happened! The first picture was without an type of lube and with a high chip load. I got smart on the second one and backed it down and gave it a shot of wd40.

On the first picture you can actually count the chips being flung out of the bit. Amazing!

This is half the battle CF learning a new machine always takes time :).
Buscht's post is chock full of good info!
(I've managed a few crashes so guess I'm now a real CNC operator ;) )

does anyone know if these formulas and table are any good?

http://www.endmill.com/pages/training/spdfeed.htm

What a Great Find! There's a goldmine of info there - sure hope its good speed/feed data! Thanks Dan. Cheers - Jim

Finished a real part today! It's an upper swing arm for my rc truck project. Tolerence is good at about .005.

It seems like my carbide end mills have gone through one crash too many though. I'll have to order some more if I want to keep making chips.

CF: Great stuff :D!!

I'm sitting here eating lunch while the CNC happily cuts a run of parts !!

Isn't the first "real part" a buzz??

Yeah, feels good to finally have the machine start paying for itself.

Since I have about 20 different cycles of parts to run that's alot of nervous watching and waiting. Those first runs never go right, even if I do a air run.

The next parts will be the more complicated lower swing arms. I would cut them now but the neighnors need some sleep, unlike me.

While machining the lower arms the electrical transformer for the neighborhood got struck by lighting. Of course I lost power to everything in the middle of the cycle. Oh well, more paperweights.

I finally did get a good cycle done with no freak accidents. Here are the results.

http://www.coldfusionracing.com/Truggy/4th.jpg

CF: Brilliant !! <golf clap>

Funny last night must have been the night for power failures!
We had one here that took out the grid right next to mine! (I was in the middle of a run of small parts and saw the lights all go out)

Have you thought about getting a radiused cutter and taking a finishing cut around the out line of your arms?

I've considered it. This part is for the prototype truck though so looks are not too important. Maybe a 45 degree .1" chamfer would work on the production arms?

Going out to machine some bearing mounts now. Be done in an hour.

I was thinking just a plain 2mm radius on all of the edges to give them a "finished" look :) 45 degree chamfers still look a bit "Proto".
<edit> Either that or use a small ball end mill to turn your arms into H beams!

I'm inside for most of today so I'll keep an eye on your progress!
Keep the pics coming.

I could use a 1/4 ball mill and skim the edges at .01.

The chamfer look is used on many big name arms and looks great. I'll pull up a sample in just a minute.

CF,
What settings have you found work best for you so far when cutting the aluminum? (ie. spindle speed and i.p.m. travel)

Carl

Right now I'm cutting with a 1/4 inch 2 flt carbide at 8 ipm with a 10k-14k spindle speed.

Cold Fusion
Are you happy with the steppers and drivers that you
purchased for this project?
speed?torque?ect?

Very happy. I've never had a missed step or had a driver glitch in all the cycles I've done. The torque is amazing, even with my high lead screws. It can rapid at 400ipm and cut at whatever speeds I need it to.

Now I just feel stupid. While machining some parts yesterday I noticed that the X axis seems to have a good amount of backlash. I thought this was coming from the timing belt that wasn't tightened all the way. It turns out that my ball screw mount wasn't tightened all the way!

Since the garage is being buried in chips I've been trying to come up with a way to reduce or eliminate the mess. It's come down to two ideas. Enclose the whole machine and put a front window of Plexiglass or use a vacuum system at the nozzle. Obviously the latter is the easy way to go but the enclosure would increase safety.

Yep the enclosure would keep the flying tools at bay :)

Exactly what I was thinking. It could also allow me to use a flood coolant system. Right now I'm manually applying it. This works ok for single parts but when I need to do a whole sheet it will become quite laborious.

You could still use a wet\dry shop vac to collect the chips, just make sure to get one with a drain in the bottom to reclaim the coolant. You could get fancy and put a tray in the vac can and mount a small xfer pump in the bottom to return the coolant to the main tank! Sounds so easy...

Interesting idea. I already have the shop vac and there are plenty of flood coolant systems on ebay for cheap. Like you said, it sounds so easy it just might work.

Make sure the pump is self priming, and you put a check valve in the system---> remember it is a vacuum and you won't want to be sucking air thru the pump for no good reason, and you would waste suck power without it.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=11805&item=3829876443&rd=1&ssPageName=WDVW

Something like that should work good.

I don't think a 2 gallon tank is big enough. You would empty it in seconds, and I doubt that the coolant would recycle back into the tank quick enough for a table as big as your's. For the vac reclaim pump I would be tempted to find a small centrifugal pump and a pneumatic drill, mounted in the vac can. You could probably find both at Wal Mart. Since the recovery of the coolant would only once happen in a while you wouldn't need to worry about a large air compressor. I also prefer to use air motors in a wet electrically conductive environment.

Concerning the vac reclaim. I think a small, yet high flow fountain pump would be the ideal thing. They are designed to be submerged and work for long periods of time.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=46312&item=4315719076&rd=1

Yep that looks like the ticket, as long as the plastic won't "melt" from the coolant. Those pumps should also be able to handle a fair bit of trash (small chips).

To reduce flow from the ebay kit I guess I could use a smaller output nozzle. 15gpm is WAY too much. I'm aiming for about 4gpm with enough pressure to knock out the chips from those deeper passes.