Hi

I have some question about power supply for a plasma table i build. Let's start first with what i have to supply :

3 x Nema 34 465 oz-in (60v keling inc)
1 x Nema 23 270 oz-in (30v keling inc)
4 x Gecko 201 stepper driver
Breakout board
THC

Now if someone can point me a link or a ways to calculate, easily, the voltage that i requiere and the wattage i'll be very glad(like a tutorials). And if possible a place to buy electronics parts to build it.

Thanks a lot for your looking

Francis

Hi,

Thats an easy one. You are getting the stepper motors from Keling, just buy the power supply from them. They will sell you the correct size and voltage, and they are eager to help you in any way they can.

You can build one yourself, but for the novice cnc builder, i think your way ahead just buying one already made.

If you want to start waisting time, you can get a transformer from Antek, and all the rest of the stuff from Newark Electronics. Start by looking in Newarks web site, and a few hours later you will know what i mean. If you do figure everything out that you need, you may save 30%.

Another tip: check out Bob Campbells Break Out Board. (Campbells Design) I know you can buy others way cheaper, but there are some technical reasons i suggest Bobs board to novice cnc builders.

Good Luck

Hi Francis. welcome to the Zone!

Formula for optimum & maximum motor voltage = Square root of inductance in mH times 32.

Formula for combined stepper motor amperage = .67 times total amps.

Formula for Watts = Voltage x Amperes.

The 465s have inductance of 1.7 mH. They require a 42 Volt power supply for optimal operation. Three times 6A =18. 18 x .67= 12A required. A 36V, 12A PS would work fine.

The 270 has an inductance of 3.6 mH. It requires a 60 Volt PS for optimal operation. A 48V PS wouldn't be too bad, and would require 2.8 A.

You can't run all of these motors with just one power supply. A PS with enough voltage for the 270 would burn up the 465s. A PS with low enough voltage for the 465s will under-power the 270. Keling does not offer a 36V PS with enough amperage to run three 465s. You either need to alter the motor grouping, use multiple power supplies, or both.

The breakout board (Which one?) will require its own PS. (Probably 5V.)

Most of the Keling packages (As well as most of the other kit packages) usually under-power the motors with too-small power supplies.

CR.

Thanks a lot it clear things up a bit.

I think for the first one i will buy a PS or 2.

Now if you were to spend $39 and substitute THIS 282

http://kelinginc.net/KL23H276-30-8A.pdf

for the 270, then you could use 2 Keling 36V 8.8A KL-320-36 PSUs. $59 each. One PS would provide 8 A for two 465s while the other would provide for the other 465 and the 282.

CR.

Hi Francis. welcome to the Zone!

Formula for optimum & maximum motor voltage = Square root of inductance in mH times 32.

Formula for combined stepper motor amperage = .67 times total amps.


CR.

Hi CR,

I have a stepper motor from an old printer. It is an Epson EM-289 89300 6A. I measured the inductance of one coil and got 13.45mH. That works out with a power supply of 120V. Am I miscalculating this? Does the 6A stand for the optimum motor voltage. Also is there a way to work out the current needed?

Regards,
Ronan

If 465 oz in. is all you need on your MEMA 34s Why not use (4) NEMA 23 495 oz in motors. Although I didn't do the math to see what power supplies are avalible at Keling I imagine they will have something that will adequately power (4) matched motors. They may even have a supply avalible with a 5V. & 12V. tap built in to power other boards & ascessories.

All in all that may be the most economical & for sure less of a wiring nightmare.

Just tossing out an Idea.

Best approach is lots of research before spending any dollars.

I'd also have to look very hard at spending the extra bucks for the Gecko 203V drives. The 203V drives are protected from so many wiring goofs I personally think they are well worth the money.

I am not trying to promote one company's products over another here. I prefer to use www.candcnc.com for my BOB & other "Make The Wiring Simple" solutions. Take a look at their site & find product(s) called "Modular Quick Stepper Build". $155.00 the last time I checked. There are several components in that package that allow for a super simple stepper based machine build.