Is there a kinematics calibration guide?

I was meaning what was the problem you were having with Z clearance, but then I
viewed the thread in a browser and saw the picture.

I could make a version that’s longer to give more clearance at the top of the
router, but before I do that, how big of a problem is this?

currently it requires ~2.5" from the bit about 3" up from the sled (allowing for
~5" of router/mount diameter

another option is to mount the bars a little high, this will introduce the
potential for pendulum type errors (as the sled swings at the beginning and
ending of a cut or as the bit hits denser wood), but I suspect that a little
error here won’t hurt too badly

@gero how much error were you seeing from your offset mount?

I can likely design around it (unless you start selling larger kit will gladly buy one), I think now that I’ve got the z design worked out, I could just move to a bosh router which is about an inch smaller than the rigid which would be about the right amount of clearance to fit your design. I can also increase the number of clamps and reduce the size for the same amount of stability.

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It might be getting late where you are, but is there a chance you could .zip up your groundcontrol.ini and attach it to a post here? I’m interested in looking at the settings. Thanks :smile:

I’ll put it up tomorrow for you.

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If you can design around it, that would make the tests more useful to others. If not, let me know and I’ll make a custom set for you (how much clearance do you need from the bit?)

I never did any cuts with the offset mount. Currently my sled is taken apart waiting for the top-mount to arrive. (departed NY 30th)

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Do you have your old .ini file? Seems odd to me that deleting the .ini file solved the problem… if so, then there might be a software bug somewhere.

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@Onelonedork, you don’t happen to have a copy of the deleted ini file do you? I was hoping maybe you renamed it. Just trying to track down what the issue was. It sounds like something may have been calculating the rotation radius incorrectly.

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Maybe we should have GC save a couple most recent versions, changing either on startup or shutdown (to avoid losing them when making multiple changes during the run). Opinions?

I just realized, your print.log in the GC folder would also have this data. If that is around you can send that to me as well.

While helpful here, I think the likelihood that this is needed is very low. If we did something like this, the best option would be to dump the ini file into the log every time. But I think we already largely have that.

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I’m looking for this, no joy. I do see log.txt, though?

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Sorry yes, this is what I meant

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groundcontrol.ini (853 Bytes)
Here’s my ini file, my log file is 35mb, i’ll see if I can upload it and post it via g-drive. I deleted my original ini and redownloaded 1.00 before I started over yesterday, so i’m not sure if it’ll have what you need. But anything I can do to help.

On a side note, my home position is still about 59mm off from the center of my workpiece, I wonder if I still have calibration issues.

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Here’s the log file https://drive.google.com/open?id=1u4_SbFbJr3qpG5xw2V2AXmZxYaTnlS70

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off to the side, or off vertically?

I just centered it and remeasured. Horizontally it is dead on 4 foot on each side. Vertically it is 26 1/4 inch from the top and about 22 inches from the bottom (little hard to measure with my z upgrade).

The groundcontrol.ini file has the default value of 463mm (18.22") for ‘motoroffsety’, the distance from the top of the workarea to the center of the motor shaft. Could it be that this dimension is different, smaller, on your setup? It can be difficult to measure…

I’ll double check as soon as I’m done with this next test cut. Thanks!

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If I remember right, the center of the shaft is 30mm above the surface that the motor bracket is mounted to - it’s easier to measure from there down to the plywood :wink:

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Mine is a bit different considering my z-axis upgrade. It’s actually much easier to measure to the top.

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