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Author Topic: Problem with Router not cutting consistently  (Read 8583 times)

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Offline Hood

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Re: Problem with Router not cutting consistently
« Reply #10 on: April 10, 2009, 09:33:58 PM »
It wont be offsets if each time is different, more likely it is losing steps due to motors being tuned too high, try lowering the accel a bit in motor tuning, remembering to save each axis as you go.
Hood
Re: Problem with Router not cutting consistently
« Reply #11 on: April 10, 2009, 10:58:20 PM »
I will try this and let you now thanks
Re: Problem with Router not cutting consistently
« Reply #12 on: April 11, 2009, 11:42:55 AM »
the accel is set at 180 do you have a suggestion what to change it to   also should I change the velocity from 250

Offline Hood

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Re: Problem with Router not cutting consistently
« Reply #13 on: April 11, 2009, 11:52:46 AM »
Its hard to tell, especially as I have always had bigger/heavier machines and they are set in metric. For my stepper Bridgeport I cant actually recall the exact accel but I think its something like 50mm/s/s so for your imperial that would work out around 127in/s/s.
 These numbers are however meaningless as they are on two totally different machines, different drives, motor weights types of axis etc etc etc.
 What I would do is drop the accel by half and see if it makes a difference, if it does then start increasing again until you find the sweet spot.
Hood
Re: Problem with Router not cutting consistently
« Reply #14 on: April 12, 2009, 05:15:14 PM »
I adjusted the accel to the sweet spot of 125. This improved the running of the router a lot. And seemed to improve the cut a little. but we are still having a problem I am going to post some more pics to try to explain the problem where it stands now. I cut it out of black poly on my milling machine and the lastest cut for the router I did in wood to show you the contrast. You can see in the pics that sum edges line up good and the others are smaller.
« Last Edit: April 12, 2009, 05:18:08 PM by cut2spec »

Offline Hood

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Re: Problem with Router not cutting consistently
« Reply #15 on: April 12, 2009, 05:33:45 PM »
Have you checked to make sure your steps per unit are set correct?
Hood
Re: Problem with Router not cutting consistently
« Reply #16 on: April 12, 2009, 05:50:05 PM »
That is where we are. But we are having trouble figuring this out. Are 1" gear has a 16 pitch but we don't know how many pulse per rev are steppers are. How do we determine our pulses per rev

Offline Hood

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Re: Problem with Router not cutting consistently
« Reply #17 on: April 12, 2009, 06:15:19 PM »
Steppers will usually be 200 steps per rev but less commonly also come in 400 steps per rev. You will also then need to take into account the drives as they will most likely have some sort of divisor. They could be full stepping, half, 4, 8 10 or more microstepping.

One other thing to look at is see if you have backlash enabled, if you do make sure it is set up right or better disable it as a test.
Hood
Re: Problem with Router not cutting consistently
« Reply #18 on: April 13, 2009, 10:56:19 AM »
Backlash was not enabled.  Our steppers are 200 and our drivers are set at 1/8 so we calculate 1600 pulses per revolution.  Since we are using a 1" gear, 16 teeth we calculate that we are traveling 3.1415 inches per revolution.  We then calculate that our steps per inch should be at 509.3108.  Are we on the right track?  We'll run a new part and see what we get with this setting.

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Re: Problem with Router not cutting consistently
« Reply #19 on: April 13, 2009, 01:24:14 PM »
That sounds about right.
Hood