TCP 5-axis kinematics

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23 Jul 2018 10:20 - 23 Jul 2018 10:30 #114694 by jsskangas
Replied by jsskangas on topic TCP 5-axis kinematics
Hello Andy

First look mu kinematic file.(XYZBCsmkins.c)
There are two M128 and M129 command that switch between two different kinematic model.
Switching can be only done in B0. C0. position.
Both kinematic models works as they supposed to.


Problem is that, some how axis or joint loses it's position during sifting between these two kinematic models.
Between several shifts I managed to get 5mm error to X axis.
Problem is not mechanical or HW related.
I have been running lot higher pulse rates(servo encoder pulses) in 3+2 axis works than in 5 axis.
Last edit: 23 Jul 2018 10:30 by jsskangas.
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30 Jul 2018 09:21 #115111 by andypugh
Replied by andypugh on topic TCP 5-axis kinematics
This has been sat in my "to answer" pile for a week, and I haven't managed to find the time to look at it in detail.

It sounds like your forward and reverse kinematics might not give _exactly_ the same result. Have you checked this?

I think it is possible to run the kins function from the command line. But I can't recall how one does that.
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07 Aug 2018 11:12 #115738 by jsskangas
Replied by jsskangas on topic TCP 5-axis kinematics
Hello

Thanks for answer. I need to check kinematics one more time.
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24 Aug 2018 14:54 #116549 by Spetrov
Replied by Spetrov on topic TCP 5-axis kinematics
Hi, jsskangas, I tried your kinematics and got an error(on photo), could you help me please?


Even when I compiled your file, I had errors. I myself was able to correct them, but I could be wrong.

Warning: Spoiler! [ Click to expand ]
Attachments:
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25 Aug 2018 05:43 - 25 Aug 2018 07:33 #116570 by jsskangas
Replied by jsskangas on topic TCP 5-axis kinematics
Hello

Yes there seems to be error that has occurred during packing or uploading.
I will take new files.

There is still error at least in forward kinematics.
This is not usable yet.

I will correct kinematics, but at the moment it will take at least 3 weeks until I get fee time for this.
Last edit: 25 Aug 2018 07:33 by jsskangas.
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08 Sep 2018 07:58 - 08 Sep 2018 08:06 #117213 by jsskangas
Replied by jsskangas on topic TCP 5-axis kinematics
Hello andy

I did look into Kinematics, if you look in to exel and use "dxb" at 0.0 value, forward and inverse kinematics are ok.
I removed baxis offset support from kinematics, and still have same behavior

Error must come from somewhere else.
Attachments:
Last edit: 08 Sep 2018 08:06 by jsskangas.
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11 Sep 2018 14:20 #117332 by andypugh
Replied by andypugh on topic TCP 5-axis kinematics
I wonder if you are not using the correct combinations of motor-pos-cmd, pos-cmd, motor-pos-fb and pos-fb pins in motion, so that a homing offset is being added more than once?
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22 Sep 2018 14:14 - 22 Sep 2018 14:21 #117867 by jsskangas
Replied by jsskangas on topic TCP 5-axis kinematics
Hello

Homing works well, it is dead on every time when homed.
This error is not homing error, it is not misplaced zeropoint.

if I use only 3 axis kinematics zeropoint will stay on its point.
if I use 3+2 axis machining axis wont drift.

If I change between kinematics, axis will drift.

Somehow this lost of position is related to shifting between 3+2 and full 5-axis kinematics.
I will make video when I have next free time.
Last edit: 22 Sep 2018 14:21 by jsskangas.
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10 Oct 2018 17:22 #118643 by jsskangas
Replied by jsskangas on topic TCP 5-axis kinematics
Ok, I found error.

Kinematics are ok and switching between kinematics works well.
X axis offset is not supported at the time.

Problem was lost encoder pulses.
Im running 8000 pulses per mm.
This was too much for hardware to handle.

I need to drop my encoder count for this hardware, sadly.
I would have liked to get everything out from machines accuracy.

Im running 6i25 and 7i77, currently Im not using filtering to get better encoder count rate.
I have 8000count per mm but now Im going to drop it down to 2000 per mm.
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11 Oct 2018 20:04 #118684 by andypugh
Replied by andypugh on topic TCP 5-axis kinematics
OK, I wasn't even considering hardware problems....
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