Chinese conversion

[byplane]

I have a old DoAll mill. It's a Bridgeport clone. So close that the that only the keys in the shafts and the bolts that hold it together are metric instead standard. I bought a CNC "kit" from Wantai Motor on ebay. The tech support is, well lacking at best. So I've come here begging for help. I am using Mach3 along with BobCad. But we're not there yet. Everything is mechanically correct (no binding or heavy loads). I can make things move but that's where it starts to go wrong. I have 1300 oz NEMA 34 motors on the X, Y and A. And a 350 oz NEMA 23 on the Z. The X and Y are direct on the end of the shaft. A is direct on the Shaft of a round table. Z is reduced about 2:1. through a chain system. Here's where I'm at. I've tried tuning the motors in Mach3 and at best I've got 70 rpm from the motor itself. I got a cheap laser tach from Harbor Freight. I have a 24vdc power supply to the drivers and a 5vdc to the breakout board. The 34 drivers are 24-80vdc the 23 is 24-50. Can I or should I get a bigger power supply? Will that speed things up. I'm not necessarily looking for speed, I just know that this isn't right. I should perform better than this.

[arizonavideo]

It would help if you posted a link but I think I found the seller and the kit.

I have that same driver sitting next to me but I have only done a little testing with it.

With high inductance steppers like the one's you have it is crazy to use a 24V supply. I have no idea why they would even offer a 24V power supply with those steppers.

I would get a 75V power supply fast. The drivers are good for 80V and the steppers would be good for 100V if you had it.

The steppers are 3A per phase but a 6A or 8A stepper would have been a better choise.

The simple way to look at it is to look at just the power.

Watts = Amps X voltage.

Your driver can give 80V at 8A so about 640 watts but you steppers are 3A so you will only get about 225 watts with a 75 volt supply or about 72 watts with a 24V supply.

My router table has more power than you system at 24V.

I would think you will triple your stepper speed.

[byplane]

Thanks. I had someone else give me similar advice. I'm bidding on a power supply now. I should have some results in a few days. I'll share my new found knowledge here for the benefit of anyone else trying to cut their teeth.

[elmerfud]

I cant believe you're driving a bridgeport with it, I bought this kit with an RF45 in mind.
Post a few pics please? The breakout board is a rip off from Keling, wires the same. The driver PDF is easy enough to find with google advanced search, let me know if you cant find it.

[byplane]

I found a 78 volt power supply on ebay. It made ALL the difference. I can run the X and Y up to about 35 ipm. Even that's a little more than the acme screws want. They chatter sometimes. So I slowed them all down to 20 to 25 ipm. Even that seems a tad fast sometimes. I tuned them though the wizard under settings. Just above the reset button. Auto tune, best thing since sliced bread. Now that Mach3 and the hardware are getting along. I ran the circle wizard and the pocket wizard in space (the knee way down ). All seems well at this point. I think I need a to do something different with the Z drive. Either a different ratio or a bigger stepper. I tried to bore a hole with the jog, maybe a bad idea I don't really know. I set Mach3 to jog by step and set the step to 0.001. You can't feel tool pressure from the jog button so I may have been crowding it too much, but I could here the stpper miss a step every now and then. I'll take some pics and post 'em for you guys. Any tips tricks or comments are more than welcome.

[byplane]

Here's a few quick and dirty. Sorry about the mess but I built it to use not to look at. The hand wheel is the original with a mod to the handle it self. Just push the button on the end and pull it out. I considered doing something similar for the Z but I'm shying away from that. I have a drill press. After I figured out Mach3 is geared for a touch screen I had to have one. Now let's get to the meat and potatoes and make something. I'm going to try a sproket. I use them on the hay elevators I build. Pretty low tech but vital nonetheless. I'll keep you posted.