Will these steppers cause any problems

[Rift]

So a few weeks back I made a post about some Sherline mills. In short from what Iv read for what I want to do the Taig was a much better choice and it was cheaper too boot.

What I ended up buying for the steppers was these
http://www.automationdirect.com/adc/...STP-MTRH-23079

and the controllers are these

http://www.geckodrive.com/product.aspx?c=3&i=14460

Now I didn't do a whole heck of a lot of digging around here before I purchased these, but from what I gather bigger is definitely not always better.

I read one post (but don't have the link to it) that for this mill right around 166 -276oz torque is where you want to look for this machine. Did I make a mistake going with the 286oz ones? From what Iv read the drives I went with are definitely a bit overkill (the favorite for this seems to be the G540) but, I do have the option for future expandability, and what really enticed my decision is them being virtually burn proof, as someone new too this I have a feeling this will benefit me to some degree.

I'm still very new to this and have not yet had a chance to setup the mill . I'm trying to take this as slow as possible and learn as much as I can without making to many bad mistakes. So hopefully I didn't already make one with my stepper and driver purchase.

Thanks in advance for any help and advice.

[Jeff-Birt]

While I think what you bought will work, a G540 and some 166 oz-in, 2.8A motors will supply all the power your Taig will ever need.

[Rift]

Thanks for the reply! Any recommendations on a Power supply to power all this?

[themedulla]

If you have the budget I would go with a 70V power supply.

Also make sure you have a good ground in your outlet - otherwise you can run into a lot of troubles.

[Rift]

Is there a perticular brand you would recomend? So far I was just looking on Automationdirects website and came across this.

http://www.automationdirect.com/adc/...r/STP-PWR-7005

Now it is 70VAC but it doesn't look like it would providede enough amps to power all three steppers.

[awerby]

so I wonder if it would blow up Gecko stepper drives that want no more than 70 volts. While it's supposed to put out 70VDC at full load, that seems to creep up to 86.5VDC at no load, and it still puts out 79VDC at 1 amp. I'd like to get some more pep out of a system that's currently running at 50VDC, but I don't want to destroy anything either. <8 amps is probably enough for my steppers to share, but I wonder about this fluctuating voltage. If I put some kind of downstream voltage regulator on it, would that solve the problem?

Andrew Werby
www.computersculpture.com

[Rift]

I came across this website after reading some more stuff on here.

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

They have the KL- 7220 which is 72 VAC and 20amps. But again its unregulated =/

Would that work? Or should I really be looking towards a regulated PSU, possibly making one.

[Jeff-Birt]

Before you spend another $200 for an unregulated linear supply stop and take a look at what you could get out of selling the parts you have now and how far that would get you towards buying a G540, steppers and a power supply better suited towards your Taig mill. My guess is that even though you'll loose a bit selling what you have now you come out money ahead or at least even by starting over with parts that are better suited to the application.

[Rift]

I think that option is a bit extreme. While the motors are a bit more powerful then I might currently need, as are the drivers (which I have seen some people use on this machine before) I don't think it warrant's trying to sell everything and go another route. These parts can always be downgraded and used on future projects if the need arises. Besides that I like the safety features on the drivers. As a novice to cnc milling I have a feeling I will mess things up in the learning process.

Although price is not a concern for me, I would rather not loose out by trying to sell what I have now to go another route. I'm one step away, but its an important step. So if I can't find a prebuilt regulated PSU that will work for this then one will have to be made. But I'm not yet ready to just jump ship on what I have.

[ee_t]

Run two of these in series: KL-350-36 36V/9.7A $60

Outputs are adjustable by 10% if necessary.

[Jeff-Birt]

You CANNOT run a switch mode power supply (or most linear ones) in series or parallel UNLESS it is specicially desinged to do so. Trying it is a good way to let out the magic smoke.

[ee_t]

You CANNOT run a switch mode power supply (or most linear ones) in series or parallel UNLESS it is specifically designed to do so. Trying it is a good way to let out the magic smoke.

Sorry, yes, you should verify that the output of the supplies is isolated from chassis. Also that no voltage isolation specs are being exceeded.