[BSims66173]

I have decided that I would like to try to build a cnc router. I know nothing about cnc other than I am amazed to watch these machines work. I have an uncle that owns a large CNC Machine shop with numerous machines and I love to sit and watch them work. I am mechanically skilled and am confident I can build the mechanical structure but when it comes to the electronics I am lost as a goose. I do know a little about electricity as I work at an electric generating plant but I just make it, and never learned how to work with it. I want to build something in the range of 48x36 and would like to be able to work with wood and soft metals. I haven't decided if I want a belt drive or direct drive yet and would like to know your thoughts on which would be best. Also, would this power supply work with these motors? Looking forward to this undertaking and I hope I can count on the experts here when I need help. This is a great board with a welath of knowledge and I enjoy reading and admiring everyones work.
Barry

http://www.candcnc.com/PSC-650.htm

http://www.homeshopcnc.com/page6.html

[Jason Marsha]

Welcome to the zone and your new obsession Barry. Getting the mechanics correct is key as the electronics are fairly standard especially if your purchase an assembled kit.

Jason

[ger21]

I haven't decided if I want a belt drive or direct drive yet and would like to know your thoughts on which would be best.

There is no simple answer to that question. I'd go with a proven design like the JGRO or Joes 2006, plans for both are available here on the site.

Also, everyone always wants to work with "soft" metals, but in reality, all metals are hard, and homebuilt wooden machines are not usually up to the task. It's usually possible if you take very light passes, but it's really not the right machine to work with metals on a regular basis.

[ger21]

Also, would this power supply work with these motors?
http://www.candcnc.com/PSC-650.htm

http://www.homeshopcnc.com/page6.html

There's a few different motors there, but generally no. You want to use between 10-20 times the motors rated voltage, and with those motors you'll want to use the parallel rated voltage. The drives you use also have a bearing on the power supply. Also, although that power supply shows the Gecko drives in the picture, they are NOT included with it.

[Coogrrr]

Thanks for the link to the steppers I love those prices per oz/in. as for plans I like the mechmate or solsylva.com plans for large tables and jgro for sub 36" builds.

I think you can find cheaper power supplies however.

just my .002" worth
Coog

[Coogrrr]

Power supplies

http://www.kelinginc.net/SwitchingPowerSupply.html

[BSims66173]

What size power supply do I need for the 600oz-in motor? They are 1.82v and 7 amp motors. Will the 36v 25 amp supply from camtronics be sufficient? If not does anyone have a suggestion on what size I would need? Coogrrr, I think I am going to follow your design somewhat but use direct drive screws. 1/2 inch 10 2 start acme screws with the dumpster nuts. I ordered the 20mm linear rails from VBX bearings. They arrived today. If I can decide on a power supply to order, I am planning to order all the electronics this week. Then I will just need the steel to make it out of. I will need to make some rail supports for the rails but that shouldn't be a problem. I have a bridgeport mill and a lathe for any machining that needs to be done. If I can successfully complete this project I hope to CNC the mill in the future and also the lathe.

[Coogrrr]

What size power supply do I need for the 600oz-in motor? They are 1.82v and 7 amp motors. Will the 36v 25 amp supply from camtronics be sufficient? If not does anyone have a suggestion on what size I would need? Coogrrr, I think I am going to follow your design somewhat but use direct drive screws. 1/2 inch 10 2 start acme screws with the dumpster nuts. I ordered the 20mm linear rails from VBX bearings. They arrived today. If I can decide on a power supply to order, I am planning to order all the electronics this week. Then I will just need the steel to make it out of. I will need to make some rail supports for the rails but that shouldn't be a problem. I have a bridgeport mill and a lathe for any machining that needs to be done. If I can successfully complete this project I hope to CNC the mill in the future and also the lathe.

well... At or past 36" i would watch out for the whipping effect of the lead screws Ger21 please advise here. Thats why I go to belts on my machine it is x60" x y40" and I didnt want and whipping. I do wonder if a nice straight acme would do 48" or more????

I can do much better at documenting how mine is built but I would tell you that the smartest way to go is to spend the dough and get the solsylva plans. Then build the belt (large) maching 4th in the book and modify for leadscrew design which shouldnt be hard at all. I would still say that unless you get something that can do more than 2000micro-steps then get some gets or belt drive the leadscrews so you can increase your micro-steps and torque also.

I think that 32v supply would do it as Ger21 says 10 - 20 times the voltage and that would be within that range. 10 = 18v to 20 = 36v. Try to buy a powesupply that has been tested with your drivers and has enough to work on your steppers. I like this link.
http://www.kelinginc.net/SwitchingPowerSupply.html

and I would suggest one KL-150-48 - $39.95 per stepper as they have what your looking for. Ger21???


I need to PM you BSims so I can ask about support rails....


Coog

[Coogrrr]

To a knew mistress in your life! Its great to have you on the zone and to see another fall into a great love of CNC!

Good luck on your build and let me know what info I can share all the way!

Coog

[BSims66173]

Thanks for the support and encouragement coogrr. I have so much to learn and I am looking forward to starting this build.
Barry

[BSims66173]

and I would suggest one KL-150-48 - $39.95 per stepper as they have what your looking for. Ger21???

Are you saying to use one of these per drive? I plan on going with the gecko 201 drives. These Power supplies say max current 3.2 amps and the motors are 7.0 amps per phase. See, I'm confused already.

[Coogrrr]

Yes I like one power supply per drive per stepper. redundancy is much better.

Ger could you please write a little chart for us?

Power supply
Drive
Stepper

equations?

I got all three parts of my setup from one place matched.

PS =
http://web5.automationdirect.com/adc...r/STP-PWR-3204

drive = http://web5.automationdirect.com/adc...r/STP-DRV-4035

stpper =
http://web5.automationdirect.com/adc.../STP-MTR-34066


And www.xylotex.com matches their power supply to their larger steppers also.

Coog

[ger21]

Read this for starters. http://www.geckodrive.com/photos/Step_motor_basics.pdf

[Coogrrr]

I read that document every word of it and I am a technical fella. I understood 80% and would have to read it 2 more times to conveye its information properly.

couple things I took from it was not more then 25x on power supply voltage and that the amperage should be at least 2/3 of the stepers need?

I may need to corect the amp side of this. I you select a stpper and or a driver we could get you the other 2 parts easily I think.


Coog

[ger21]

and that the amperage should be at least 2/3 of the stepers need?

Actually, it syas that the motor will always draw less than 2/3 of the motors rated current.

You usually want to use about 15-20 times the motors rated voltage, which is 1.8V x 20 = 36V. 2/3 of 7amps is 4.67amps, times 3 motors = amps. So you want something like a 36V 15amp supply. The KL-3815 looks like a good match for $129

[ger21]

Just reread some things.That was one power supply for all three 600 oz steppers. That's how most people do it.

[BSims66173]

Thanks guys, that really pointed me in the right direction. I will order the PS, drives and motors tomorrow. Next question is what about the +5v power for the geckos. Is there some way to get that out of the KL-3815 or just by a seperate 5v power supply? Hoping to get started once I figure all this PS BS(power supply Bull sh**) lol. Just kidding, I am having fun just reading all of this stuff and really love watching the videos of the machines everyone has made. I hope to be able to post pics and videos of my build once I get started. Again thanks coogrr and ger21. I hope I am not being to annoying as I will have more questions as time goes on.

Barry

[Coogrrr]

I think that at times I might be tho!!! That PS which will do all 3 drives with one shot is a good one. My preference is to go with one PS per that can drive 2 drives each this way if I loose one I have the ability to move that drive to one of the other 2 PS units and keep rolling while the replacement is enroute.

I know this costs more to do but its worth, and I hope no one ever finds out. I am a long time in the computer admin world and we do redundancy in everything we can as we know that right when you lease expect it is when electronics fail and your sitting there staring down a 20yr old Compaq lugable that still works!

I have one spare PS/Drive/Stepper setup and an exta belt for each size I use.

If you can spend the little extra cheese might I suggest this route or at least piece by piece get a spare set inline.

THANK YOU!!!! as always Ger you have been more a help for me than I have likely given credit for but now let it be known!

Just my .0002 worth
Coog

[ger21]

Talk to Gecko, but I think you need to get the 5V from the PC. There are a lot of posts on that subject here, and that's what I recall reading. Never used Geckos myself, so not sure. Thought I posted this yesterday, but it wasn't here when I just looked.

[BSims66173]

Just went ahead and ordered the Bob Campbell breakout board. I ordered the power supply, 4 motors and drives last night. What size acme would you recommend? I am looking at the 3/4 - 8 - 2 start acme screw. Will this work as a direct drive or should I use timing pulleys to gear it down some.