Changed lead screw, no change!

[H500]

It not a given that the speed will be better by making the TPI change. For a given motor & drive voltage, the power is more or less fixed.

The best way to squeeze out more performance is to replace the lead screws with ball screws. They're much more efficient. You will likely get 2 to 3 times more speed.

[ger21]

It's probably resonance, like I mentioned before. A lot of people running that combo have similar problems.

Couple things.
Make sure the pulse width is set to 2 or 3 in the motor tuning. Run the driver test and make sure you get good results. Make sure the screws are not binding at all. You could also try changing to 1/4 or 1/2 stepping and see if that helps.

As was mentioned, you can try Mach2, and it may work better for you on the slower PC.

[grahamshere]

i ger21, sorry didnt get back to your reply, got stuck building a fence. Any way when you say pulse width is that step pulse or dir pulse, I know both are at 0 at the moment. Thanks Graham

[ger21]

Both

[grahamshere]

Thanks ger, well I have my y and z axis traveling at 100" per, but cant get the x past 20" per,I think it has somthing to do with the belt drive? 100" per is way to fast for this machine, way too much whip. but 60 would be good, what happens when each axis is set at different speeds, I use the y raster when cutting in cut3d. Graham

[Regnar]

grahamshere, I have a simular setup and can get 50ipm out of my consistently good 60 ipm is kinda pushing it. What helped me to push it past 20ipm was making sure that nothing twisted when changing directions.

The motor mount was a huge colprut of twisting and it seemed like when It twisted the motor gear would skip or loose a tooth and slam right into frozen.

Another problem I had was the coupler with two bearings wedged into it. Mine had a slight hump in the middle so it would push the belt either to the left or right depending on what direction the belt was traveling.

Pretty much my solution to all of this was to build a box for everything and not use bolts sticking out. It doesnt look that great but atleast it can move pass 20ipm. Here is my build log.Regnar's Build (Now with Video) If you watch the first movie you will see what I am talking about.

[grahamshere]

Thanks Regnar, I can see the same things happening with mine, the motors twist or move a bit every time it changes direction as well as the belts move to the right and left, I was able to adjust some of that but not fully. Plus i descoverd that my x axis are not pararrel to each other, one is .1" off at one end, do you think this would cause it to bind? I wonder which plans you made your first machine from. thanks for your help , maybe ill change some of the things as you did and see if that helps. Graham

[Regnar]

Although ever little bit helps I dont think .1 in the leadscrews will matter that much. Now if it was .1 difference between the 2 rails then I could say that yeah you might be onto something. I say this because the original plans call for you to use 1/4 brown board to mount the nuts to. I believe that would probably bend in the direction of the .1 error before it started to bind. You will be amazed how much the motors can push and pull and put up with. Now I also forgot from my original build that when I attached the acme nuts I had just alittle thread from the bolts sticking into the leadscrew nut. I ran a tap threw them acouple of times and they ran alot better but I ran into whipping then so that is when I scrapped everything. Best I ever got with the original setup was 26 ipm y 16 ipm x and z I didnt really pay attention.

Right now I am in the works for getting rid of the belt I have order a single axis drive from ebay and will be picking up another motor soon. I hope this allows me to move with the same speed and realiabily of my y and z axis.

[grahamshere]

Thanks again Regnar for your info, as it stand now im getting 100 imp for jog and 60 imp on cutting with the y axis, its just the x thats slowing things down. z is fine at 40 imp.I rather not have a belt drive on this but ill just keep working on the x till i build a new machine. Graham

[justCNCit]

I can't believe you said .1", its hard for me to believe you are trying to build a machine with that much play in it - my rail alignment is something like within a tolerance zone of .007".

I must be missing something here because .1" is like a barn door open in anyones world, even woodworking. Thats a full tenth of an inch, even bigger than a sixteenth.