Questions on lost steps.

[southernexplore]

I know this has been asked before but I just finished my homebuilt router and I am having trouble with the lost step bit. I am running Mach3 and PicStep drivers with a 48 power supply. I can run as fast as 180 IPM with the system but it is not consistant, niether is 150 or 125 or 100 IPM. What I mean by that is I can give my machine a G0 command and it will move at say 150 IPM with no problem, give it another G0 command (accelaration set to 1) and in the middle of the command it starts missing steps. Even if I slow it down it does this. It is not consistant enough to pinpoint the problem. It seems like if I can run at 180 IPM sometimes I could slow my max rate down to 125 or so and it work O.K. Does anyone have any tips or things I can try to stop it. I am wondering if it is resonance.
Thanks,
Tommy C.

[ger21]

It sounds like it's not losing steps during accelleration, but during constant speed? Does it do it in the same place on the machine? Is there any binding anywhere, does the screw bind anywhere?

Does it have the same force at any speed, if you put a load on it, can you make it lose steps?

The usual answer is to slow it down. It could be resonance, but resonance usually occurs at a certain speed, not at many different speeds, and not usually apparently random.

[southernexplore]

The screw is easily turned with two fingers throughout its travel so that would ne be it. If I have an axes stopped and I try to stop it as it strats moving I cannot, if I try to stop it after it reaches full speed I still cannot make it miss steps, even at 150 IPM.
At 180 IPM I can make it stop but it does take a good bit of force. I have ballscrew from homeshopcnc and I have THK linear guides on all axes. If I new more about how to use an osilliscope (brand new digital one) I would check all outputs on the drivers but I am not sure how to check that. Do I put the ground on the neg post on the driver and check each phase seperatly? I have not had a chance to readup onthis because I have been really busy doing all the machine work on the router. What is an average rapid speed for a stepper motor system with only 48 volts driving it.
Tommy C.