Auto bed probing and compensation with G29 Development

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1013
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Re: Auto bed probing and compensation with G29 Development

Post by 1013 » Thu Jul 25, 2013 6:06 am

The model is designed to 9.9mm, and it is printing to 9.1mm. I will give it an extra 0.8mm in the hex. (to 10.7)

attached is the updated STL file....please print it and make sure the nut fits snuggly. If so, I will update it on thingiverse.
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Z_NutSpring_1013_M6_loosened_nut.stl
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BotLord
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Re: Auto bed probing and compensation with G29 Development

Post by BotLord » Thu Jul 25, 2013 2:56 pm

Awesome, will start getting it printed shortly!
Running 28 AO-100.5s and 8 Tazs daily @ Lulzbot HQ
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1013
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Re: Auto bed probing and compensation with G29 Development

Post by 1013 » Thu Aug 01, 2013 10:23 am

BotLord wrote:Awesome, will start getting it printed shortly!

Any luck?

jebba
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Re: Auto bed probing and compensation with G29 Development

Post by jebba » Fri Aug 02, 2013 10:48 am

I don't know the full status as I'm not doing it, but I know the parts are printed and it is all assembled. Perhaps just doing the firmware now or something.

1013
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Re: Auto bed probing and compensation with G29 Development

Post by 1013 » Sat Aug 03, 2013 7:39 pm

I was more curious if the oversized hex model I posted was oversized the correct amount for the hex nut, or if I should modify it a little more?


But I do need to post the firmware config file and G-code too.

1013
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Re: Auto bed probing and compensation with G29 Development

Post by 1013 » Thu Aug 08, 2013 10:12 am

Just added the custom G-code and cofiguration.h file to make this mod work to the first post of this thread.

andy
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Re: Auto bed probing and compensation with G29 Development

Post by andy » Sat Aug 10, 2013 8:11 pm

I am trying out this gcode after updating the firmware and fabbing the parts. Am I missing something? It appears that the gocde posted would only go to one place on the bed? I thought the whole point was to probe 3 places to determine the plane. also, does anyone else think the bed is probably a hypar and not flat plane? hypars would need 5 points to determine.

1013
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Re: Auto bed probing and compensation with G29 Development

Post by 1013 » Sun Aug 11, 2013 10:39 am

look at the config.h file. the co-ordinates for the 3 probing points are in there.
G29 goes to those 3 points and probes. the extra Z home call out in the G-code is there in case you are way high up in the z before probing, since the G-29 expects you to be fairly close to the bed.


yes more than 3 points would be better, but 3 is all we get, short of re-coding the firmware.

aadamson
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Re: Auto bed probing and compensation with G29 Development

Post by aadamson » Wed Aug 14, 2013 11:49 am

1013 wrote:The model is designed to 9.9mm, and it is printing to 9.1mm. I will give it an extra 0.8mm in the hex. (to 10.7)

attached is the updated STL file....please print it and make sure the nut fits snuggly. If so, I will update it on thingiverse.
BTW, I printed the first version and no way was a M6 nut going to fit in there... I may experiment with a little heat, but I'll print this one too and let you know.

I ordered M6 brass nuts from mcmaster and just got them along with inserts.

Alan

aadamson
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Re: Auto bed probing and compensation with G29 Development

Post by aadamson » Wed Aug 14, 2013 6:24 pm

1013 wrote:The model is designed to 9.9mm, and it is printing to 9.1mm. I will give it an extra 0.8mm in the hex. (to 10.7)

attached is the updated STL file....please print it and make sure the nut fits snuggly. If so, I will update it on thingiverse.
So I printed this loosened version, it was much better than the original, but it's just ever so slightly too large (nut sloppy in the hex size).

I measured about 10 different nuts from a bag of 50 from mcmaster, they at average were 9.8mm. Taking that extra .1mm and looking at it on the calipers, that would be .05mm on each side... and that's probably going to be about right.

I also tried an experiment and as soon as I got about 40 layers up (higher than the thickness of a single nut, I dropped the nut in there while the printed part was still hot. After taking if off the glass, that nut is much better than the one next to the window.

If you could mod this part for 2 things... first that .1mm smaller diameter, and second, not so much of a taper on the nut at the window. I found that with the 1/8" rods in that there was too much play with that nut as it wasn't quite down into the hex... Either that or move the 2 spacing rods slightly closer together.

I'm happy to try this again, if you can make some changes to help.... printed on a printer that taper on the one nut probably is lots different than the high quality part that you printed on the production printer... between round extrusion and the taper, there just isn't enough to get a good bite, even if the size of the hex were perfect.

Alan

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