[mrcodewiz]

I originally installed Keling's 425oz kit with 24V power supply on my converted X2. It has always been OK but I could never get much speed on the the Z due to the weight of the head. I have to run it pretty slow with a pretty slow ramp up in acceleration or I start missing steps. If I forget to oil the ways once in a while, it is quick to start binding too. Would converting to a 36V power supply give me noticeably more grunt?

[ellik]

Are you using a ACME or Ball screw on your Z axis and what speeds are you getting? I have a Hobby CNC controler and a 305oz stepper on the Z and a 36V power supply. With a 10tpi ACME screw I got 45ipm, at 1/2 step with a gas strut to counter balance the weight of the head. After upgrading to a ballscrew I got 150ipm with the same stepper without any need for a gas strut.

Its all relative.

[mrcodewiz]

I am using ball screws. I initially had a gas strut conversion on it but I removed it when I did the conversion because I used the same mounting locating for the ball screw. Maybe I will try adding it back on somehow.

[mrcodewiz]

Oh, and I max out at about 20 ipm

[multiplex]

what stepper drive are you using?

I previously had the 425's, on 24v with the small keling drives. It made a dramatic difference stepping up to 38volts. That maxed out the driver voltage, but those motors still need more. They are rated at 86volts.

instead of reinvesting in a power supply, and new drives - i opted to switch to servos

[ellik]

20 ipm is really slow. Are you sure the gibs arent to tight? I initially had a 24v supply and did notice improvements by going up to 36 volts. What settings are you using on you stepper driver, steps, amps etc.?

[mrcodewiz]

I will have to look at what setup i landed on later tonight. The gibs are tight but if I loosen them up much more, its too sloppy. Maybe I need to lab the gib again.

[mrcodewiz]

Well, I opened my controller box to see what I had the drivers set at but now I am scratching my head. I am using the keling 4030 drivers and the dip switch settings are as follows:

X:10101100
Y:10101100
Z:10101101

That would lead me to believe I set them up for 1/4 steps at 2.7 amps since the keling documentation shows those settings for dip switches 1,2,3 (for steps) and 5,6,7 (for amps). The reason I am scratching my head is because in Mach, I have the steps per for X and Y set to 4000 and the steps per for Z set to 8000.

Something doesn't seem right because the Z is moving the correct distance so it would seem like the steps per on the Z driver should be set to 1/8(which would be 001 for the dip switches) and I have no idea why dip switch 8 is different - its not even in the documentation. It has been a really long time since I wired this stuff up apparently.

[hoss2006]

That's correct, 101 = 1/4 microstepping and 110 = 2.7 amps
dips 4 and 8 don't do anything.
Are you running a 2:1 pulley ratio on the Z like I do?
that would be why you need 8000 steps/per.
Also, 36 Volts (40 if you adjust the pot on the power supply) can get you 100+ rapids.
Don't go any higher than 1/4 microstepping, torque drops way off the higher you go.
I run 1/2 and there's tons of power for the important part, MILLING.
Hoss

[mrcodewiz]

I thought of that as I was laying in bed last night "DUH! I have a pulley ratio to factor in!".

Would I notice a big difference going to 1/2 steps? When I first got into this, I thought that precision was king and I had to be at .001 or less for everything I did - now I realize that for the stuff I do, speed and repeatability is much more important than being within a thousandth of my design.

I need to order a stepper and driver for the 4th axis I am putting together so I am just going to go to the 36V power supply as well. I may even get another 425oz as a backup. It may be completely unrelated but whenever I start having a problem with the Z missing steps, I can sort of hear the Z stepper 'twitching' when it is at a standstill. I don't think it's moving but it makes sounds. I guess it could be the driver too ... not sure.