Thanks for the replies gentlemen. Sorry about the slow response, I forgot my password for a bit.

Good suggestion on the nut Martin; I'll check it out soon as I can get get it apart enough to get a clock on the ballscrew.

Getting very close to completion on my ORAC/Mach3 retrofit and am very pleased with how well the little fellow is working. Thank you Denford for designing such a nice machine! :D Question: I've been checking backlash and the Z-axis is very good...almost nil. The X-axis has about .003" though. Where ...

Yeah, I figured it was a wacky idea but with my meager electronics knowledge I figured I'd ask anyway.

My long-term plan is to upgrade to more powerful drivers & motors but for now I'll do the best I can with what I have. Thanks for your help!

Thanks for the speedy response! So it sounds like it wouldn't burn out instantly if the input voltage was increased. May be worth a 5 minute test just to see how it goes. It's being used in an ORAC retrofit using Mach3. It was a bare unit with only the lathe mechanicals and a stripped clean lower un...

The manual says 28VAC or 40VDC max but I'm wondering what the weak link is if the voltage input is 10% high. The transformer I bought to power it has 2 taps rated at 24 & 28VAC but actually measures 27.4 and 31.4VAC under load. I have the system working OK with the 27.4V tap connected but want to ge...

Great, thanks very much! That helps a lot. Looks like the conduit is one of those spiral plastic thingys with a plastic covering?

Man, I threw a similar one away a year or so ago...probably won't be able to find one now.

Hi all, I'm retrofitting an ORAC and would like to see a picture of, or get a description of how the original X-axis stepper motor wiring cable is routed and what type of protective sheathing it's in. Mine was completely gutted of all electronic gear (except for the cassette player) and I'm getting ...

Thanks angel, I looked again and didn't find a va rating anywhere but upon further review of one of the SmartStep/3 .pdf downloads available here in the forum, I found "18-28V AC, 3A input" so that's what I'll look for. I found a 115V/28V 3.67A open frame transformer on eBay for a good price. Do you...

Hello all, Can anyone give me the amperage rating for the power transformer on my 1996 Denford MicroMill? It's a USA spec model with a Smartstep/3 controller. Being USA spec, it has a 110v input and the board needs max 28v but I don't know what the amp rating is. I've looked over the schematic .pdf ...

Thank you very much; that gives me something to work with.

I'm doing a long run of parts with a 1996 MicroMill (converted to lathe use) which has a Smartstep/3 controller. Martin Ironmonger of Denford was kind enough to hook me up with a good used Smartstep for a fair price which will be kept as a spare until the project is completed in March. The original ...

Hi Martin, thanks for the reply.

Sure, I'd like to know what the price would be. Hopefully "old school" hardware is inexpensive.

That area on the base board around the stepper chips does get really hot and needs a good airflow. Yep, after running a couple of hours, I noticed they were running hotter than I liked so I added an additional small 12v computer fan that blows across the rectifier heatsink and onto the driver chips...

Surely someone has one of these lying around unloved, unused and looking for a home. It goes in a 1996 MicroMill and probably many other Denford machines. Mine died but I was able to resuscitate it by replacing the bridge rectifier. I'd love to get another one to have as a spare in case mine dies ag...

I thought I'd post the results of my struggles in case anyone has a similar issue. I got it fixed and working well by replacing the bad rectifier with an 8 amp part from Radio Shack...5 min from my house and $2.59 + tax! https://www.radioshack.com/product/index.jsp?productId=2062583 It was configure...

Hmm, I'll try some extra solder 1st. I was thinking that a big pair of Vise-Grips would crush the plastic case leaving the internals exposed so that they could be clipped out carefully leaving the wire pins exposed to be removed individually. Mind you, I've never actually done that before but it see...

Thanks! All three driver chips look good as new so I'm hoping they're OK. I'm having trouble getting all 4 pins hot at the same time to pull it out so I'll try test it in-situ so as to not destroy the board trying to get it out. 'Tis a moot point I reckon as I'm going to get a new one Monday & destr...

Can it be tested without removal? Could the ohmeter damage other components?

I tried to desolder & remove it but couldn't. I will have to crush it and remove the pins individually to replace it.

Hello all, my Micromill with Smartstep/3 control board died this morning in the middle of a big job; it blows the F1 on-board fuse repeatedly. I examined the board and it looks like the device pictured below, a KBU806 rectifier may be fried. The only spot on the board that looks like it's been hot i...

Thanks! I can breathe a bit easier now. I've seen many references on the web to a run of faulty caps in electronic equipment that cause premature failure. They showed pics of caps with their little tops all swollen up. They were mostly much smaller caps though. Have a great weekend gentlemen! Milton