Charmhigh forgets component rotation sometimes

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Brian Silverman

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Jun 6, 2024, 3:17:45 PM6/6/24
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Hi,

I have a new-to-me Charmhigh CHMT48VB (builtin touchscreen computer), running the Charmhigh software. On my first run of multiple boards, I ran into a weird problem: it seems to not rotate components sometimes. Once it does this, all subsequent boards will have the same component(s) not-rotated, until I go back to the main menu and load the job again, and then these components work fine. I've seen various reports here and on the eevblog forums that sound like the same thing, but never any details. Anybody know how to avoid this? I'd be happy to learn something like "don't single step through an even number of components" to avoid this problem.

I did not take video, so I don't know if it's not rotating them, rotating them too much, or rotating for the camera and then rotating back. I suspect it might be related to single-stepping through the job in some way. The list of components on the screen still shows the correct rotation, even when the machine is acting like there's a rotation of 0. These are all 0603 capacitors and resistors, so I would not notice if they were 180 degrees off.

I ran some boards with various 0603 placed by the machine, and it was definitely easier than placing all the components by hand. I could deal with rotating random components by hand, but it'd be nice if the machine just did it...

I'll do some experiments if nobody has a solution, and report back. Figured I'd ask first in case somebody else has already been through this.

Thanks,
Brian Silverman

Вячеслав Буренков

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Jun 8, 2024, 5:57:15 AM6/8/24
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Hello. I have a CHM-T36VA, the same problem - repeated failure to rotate some components 180 degrees. I swapped the installer's heads in the program, 1 <-> 2, the second turns correctly. Such magic.
четверг, 6 июня 2024 г. в 22:17:45 UTC+3, Brian Silverman:

Tõnis Kuik

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Jul 28, 2024, 7:52:47 AM7/28/24
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Hi!
My CHMT48VB rotates components at wrong angle very rarely and quite randomly but on the one board design it places two components always at wrong angle - one 0805 resistor with 90 degrees and one diode with 180 degrees error. Editing components properties does not change anything. I remember that i changed diode from one feeder to another before this happened but the resistor feeder remained same as generated earlier. So i leaved this problem unsolved as i make this affected board in very small quantities and only two components needs to corrected manually.

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Hank Kauffmann

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Jul 28, 2024, 11:58:45 AM7/28/24
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The root cause is the programming has no acceleration curve and it is harsh in its movements.

There is a problem around parts at an orientation of 180 degrees. If the vision system thinks it needs to +5 degrees to be corrected, it won't adjust by 5 degrees but will spin it by -355 degrees instead. The speed of the spin can dislodge the part enough so it doesn't also spin -355 degrees and ends up being placed crooked.

The solution for non polarized components like caps and resistors is to edit the file so they are placed at an angle of zero degrees. Any correction to orientation will be minor and the problem won't happen.



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Hank Kauffmann
HW Development team lead

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