Power Supply

[KrashKing405]

I'm planning on using a few compuer PSUs connected together for my power. My steppers are 24V, would this work? Any suggestions on dirt cheap [read almost free] power supplies?

[NC Cams]

1. Go here:

http://www.cnczone.com/forums/showth...015#post142015

http://forums.bit-tech.net/showthread.php?t=108208

2. Follow the instructions

3. Don't get creative.

4. Safest method is to use MATCHED units (make, model, size).

[ger21]

Your going to need different steppers, rated 6V or less, preferably 2-3V. 24V steppers will spin very slowly.

[KrashKing405]

Originally Posted by ger21 Your going to need different steppers, rated 6V or less, preferably 2-3V. 24V steppers will spin very slowly.

Why, with a couple PSUs connected I can get 36V or more.

[ger21]

You'd probably need over 100V to get any kind of performance at all. Ideally you want to use 10-20x the steppers rated voltage.

Try them and see how it works.

[KrashKing405]

What kind of power supply do you recomend? I'm running on a shoe string budget here, figure my controller is going to cost me ~$30 to build, a sheet of 3/4 MDF is ~$20, and leadscrews at ~$10. That will leave me with ~ $10 left. My entire budget is from selling a calculator on Ebay. I am searching for some of my spare stuff around the house to ebay, have a small pile started already.

[NC Cams]

For a PS that will operate at 100vdc, you're pretty much relegated to a linear with an output somewheres in the vicinity of 70vac.

Then again, with a $10 budget and 'almost free' computer p/s's available, all you'd have to do is score 8 matched @ 12 volts each should be close enough - don't forget to get a free terminal strip or two to plug them into....

IF you do go the linear route, the following links (adjusted as needed for voltage and current of course) should handle the design aspect of the project:

Linear P/S design/construction
http://www.campbelldesigns.com/files...ply-part-1.pdf

Servo amp P/S design
http://www.elecdesign.com/Articles/A...7635/7635.html

Servo motor, servo amp & powersupply sizing for CNC
http://www.rutex.com/pdf/Mystique2.pdf

As far as sourcing goes, start looking for/through surplus houses or machine salvage places or motor/transformer service shops. Old transformers from machines can be a life saver for a low budget operation but even so, a $10 budget will be excruciatingly TIGHT.

BTW, Rutex has servo drives that will go 200v which should easily cover a 100 volt system. I would NOT use a drive rated at 80 or 90 volts to drive 100.

[ger21]

Will the $30 controller your building handle 100V? You really should try to find some different motors.

[2muchstuff]

Try some of the bigger copy machine sellers. They usually take the old machines back with them and trash them. It is a good source of free parts.

[KrashKing405]

Originally Posted by ger21 Will the $30 controller your building handle 100V? You really should try to find some different motors.

Got some cheap? I'm suprised these are rated at 24V, they came out of printers that had nothing over 12V in them. Although I do still have the PSUs out of the printers. Also possible is that I don't know how to read the data sheets on these, anyone willing to confirm for me? Here they are: http://www.eminebea.com/content/html...f/pm35s048.pdf 2 of these http://www.eminebea.com/content/html...f/pm55l048.pdf 2 of these [planned X and Y -axis] and http://www.mitsumi.co.jp/Catalog/com.../4/text01e.pdf 1 of these.

[KrashKing405]

Forgot to mention, the controller I'm planning on using is Phils [Pminmo] 3axis Self Contained board . It says it can handle motors up to 30V, so if I'm reading it correctly, it can handle it. If I'm wrong, someone correct me, and point me to a better controller.