Losing position & cutting slower than before.

[williams_architectural]

I have a PRT Alpha. Problem #1:I've been cutting decorative scrolls with no problems. I started a new sheet and was drilling for screw holes and the machine sounded like it was struggling when jogging in the Y axis to the next hole. It then lost position. Material is .09 FRP plastic, 1/4" plastic cutting bit set at RPM speed @ 16,000 with X,Y & Z at 2.5" persec. X,Y jog speed @ 6" persec. & Z 3" persec. I then decided to re-tighten the X & Y motors. Gears are also greased regularly. Problem #2: I then drilled out the holes with no problems. I then began cutting out my scrolls. Now when the Z travels down and begans cutting the material it then hesitates for about two or three seconds before continuing to cut the pattern. Also when it comes to corners it nearly stops or slows down very slowly through the corners then speeds back up. It didn't do that before and I've been cutting several sheets for the past few days. I keep the tolerence @.0005

Any ideas?

William

[ron_moorehead]

Check your ramp values. I had a cold in my computer and had to reformat the hard drive and reloaded the shopbot control software and picked the values from the setup files in the shopbot program and it had the ramp values set to low and would slow down to a stop at each turn and the Z would also travel down and then set there a few seconds before it would cut.

[williams_architectural]

Thanks Ron,

I've never checked my ramp values or haven't for a while so how do I do that? Step by step please.

William

[williams_architectural]

Also I have a PRSstandard and not a PRTalpha. I still get that confused if I haven't thought about it for a while.

[ron_moorehead]

Start your shopbot control software and then click on the Values word on the menu at the top, then clcik on Ramp Valus on the drop down menu. I have attached a photo showing what my ramp values are.

Hope this helps...


3679

[williams_architectural]

That was the problem Ron. Somehow the setting was set @.05 don't know how but it was.

Thanks alot,
William

[ron_moorehead]

Glad I could be helpful.

[stopngosigns]

Another Satisfied customer. I just purchased my Alpha and was having a similar problem when cutting out circles using the CC command and the program would just lock and I had to do a hard shutdown of the program. After resetting the ramp values, everything is great again. Thanks for the post. My problem arose after I forgot to remove the clamp from the bit when zeroing the bit and started the spindle (not a good idea by the way) for the second time in as many days. The only plus was that I didn't have to replace the clamp and lead line this time. Things went screwy after that but looks like your post helped.

Thanks again,
Corey

[wberminio]

Corey
If you have a spindle(NOT a Router)-you donot have to use the clamp for for z-zeroing.
Just set your plate under the bit and run your routine.

Erminio

[ron_moorehead]

Are you using the current Shopbot control software? Version 3.5.12. I also just had my ramp values rest them self again, this last week after the control software crashed, maybe a bug?

I see they have a new version out now 3.5.14