Mach Settings for G540

[ianober]

I have a G540 running Keling 425 oz. steppers. I have Mach3 configed through the XML file supplied. I am curious about speed though. I am only able to get about 125 ipm movements before the motors stall. I am using 1/2-8 5 start screws and DumpsterCNC antibacklash nuts. I have heard of others with the same mechanical setups claiming to get 250 ipm rates but I am doubting this. In the motor tuning I can always get the motors to run faster before stalling for some reason, something like 150-175 ipm.

Any suggestions?

[ger21]

What voltage are you using, and what is your acceleration set to?

Most people use 380 oz motors with the G540, as they'll perform quite a bit better than the 425 oz motors, which have much higher inductance.

Do you mean 1/2-10 5 start? There is no 1/2-8 5 start.

[ianober]

Sorry Gerry, yes, 1/2-10 5 start screws. Did you want to know the voltage off the power supply? I believe it is running at 48V but I will have to verify. I bought a control unit pre-made so the assembler did the adjustments. I have the motors set to 3 amps and my acceleration is at 10.

[ianober]

I will try messing with the acceleration to try and get more performance out of the motors. Not sure that will help much at all though. I also adjusted the trim pots on the motors the other day and made sure that those were good to go.

[Logon_Bob]

Noob here as I have just got my machine running. There's my disclaimer. :-) , but this machine is Stupid Fast, meaning faster than I want or need to go and similar to yours.

Are you working in inches? Don't know if verified movement yet, or if you tell Mach to move 1 inch, does it move one inch. You may have entered wrong step info.

Config/ Native units - select inches - Warning says not for changing units but for motor tuning.

2 - Your 1/2-10 5 start is the same as 2 turns per inch.
3.- So in Full Step your 200 step motors must do 400 steps per inch ( Mach unit )
4- G540 is 10x micro stepping, so 10x 400 is 4000. 4000 is entered in the first box of motor tuning, Steps per unit.

In Ports & Pins - There is the first Default box Kernel of 25000hz. I don't know enough yet to tell what you can do here but in Default 25K With your setup Mach will limit out at 375 IPM at 4000 units. This must be how fast the computer can actually talk to Gecko because I tried the next box of 35K and got a higher limit but I don't need to go that fast, back to 25K until I understand what that really does.

Now, my machine is similar. cncrouterparts 380oz motors on Y & Z with their custom cables ( nice & excellent service BTW ) and built in motor resisters. Both will run at limit of 375 and not even thinking about quitting.

X - I needed a Dual shaft motor to run both sides, cncrouterparts doesn't do Dual Shafts so I picked up what might be the same motor you have, 425oz Keling. They have more than one model, nameplate is down and I can't see it. 2.5 amp 6.x inductance if that helps.

3:1 belt reducer to xl Belt, so that's 1.07 inches per turn. I only have one side hooked up and it should rack on me but doesn't. I can lean ( straight arm ) the side not hooked up and she will push me out the way at 800 IPM. For fun at 36K Kernal, I quit at 1103 IPM and still going like the energizer bunny, have not missed a step yet.

OH, Power supply is the same 48v 7.5 amp but fully turned up my meter says 44v unloaded, 38v's with all 3 motor locked at rest. I would ***** but I am so damn happy with Gecko and this setup I can't see straight for the smiles. First time with quality stuff. 10 years with 80oz 12v supply that will stall if you look at them the wrong way.

What else to look at. Dumpstercnc nuts. Same here, my second order. OH, my Y&Z are 3/8-8 4 start but that is the same as you, 2 turn/inch. I love my Dumpster's but they are critical to alignment. You only get a couple of degrees off the drag goes way up. You should be able to turn somewhat easily with your thumb and index finger motors off. Dumpstercnc also can run a tad tight depending on the leadscrew. He does that because mfg's tolerances, some perfect and some tight but never loose. Here with motors disconnected you should also be able to turn with thumb and index finger. Can't help here, it's feel. You certainly can't give em a spin but you shouldn't have to grap a handful to turn them either. There are instructions on how to match them to YOUR leadscrews on his site IF you feel they are a bit too tight.

Put a meter on your power supply and see if it's putting out what it is supposed to or close. Other than that, I can't believe you would have bad wire connections on all three motors unless maybe a bad ground effecting all three. Oh, wire gauge?

I assume the slides are reasonable drag wise???

About all the help I can offer, hope it is all correct or the experts are going to get me.

edit: Acceleration: I only run at 20. My router is sitting on two commercial steel desks back to back, this thing at 90 will take off shaking the table, 20-30 is plenty for me.

regards
Dan