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abraham.m
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Purge Tower Bumps - Crashing/ETC

Sep 29, 2018 11:08 pm

The nozzle sits on the purge tower while loading/unloading filament.

This causes a defect in the surface.

Subsequent passes hit this defect, and can cause the crash detection to trigger, repeatedly.

I suggest lifting the head, or wiping and traveling to the side of the purge block while sitting.

In my case, I may be having issues with overstuffing that are causing the dragging, as shown below.
IMG_20180929_125945.jpg
IMG_20180929_125945.jpg (4.32 MiB) Viewed 471 times
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abraham.m
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Re: Purge Tower Bumps - Crashing/ETC

Oct 02, 2018 6:21 pm

After looking at this a few more days, I don't think it's melting in place as I said.

I am suspicious of a blob forming when the MMU hangs and you 'fix' it.

Perhaps setting the spacing larger on the purge tower would help. As the MMU become more reliable, this is less of an issue, but ALL my towers have bumpy wastelands on top and they aren't helping things.
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PJR
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Re: Purge Tower Bumps - Crashing/ETC

Oct 03, 2018 6:19 pm

I think it's more likely to be over-loading by MMU. Have you tried the latest MMU firmware and calibrating all MMU feeds?

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

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james.s35
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Re: Purge Tower Bumps - Crashing/ETC

Oct 04, 2018 12:45 pm

Peter,
where can one locate the new firmware, i've looked on the GIT but don't see any releases in MM-control-01. Have you been able to build from source
Thanks

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PJR
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Re: Purge Tower Bumps - Crashing/ETC

Oct 04, 2018 3:15 pm

james.s35 wrote:
Oct 04, 2018 12:45 pm
Peter,
where can one locate the new firmware, i've looked on the GIT but don't see any releases in MM-control-01. Have you been able to build from source
Thanks
https://shop.prusa3d.com/forum/assembly ... ml#p110121

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

JVEnterprises
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Re: Purge Tower Bumps - Crashing/ETC

Nov 17, 2018 4:52 pm

Did you ever find a solution to this?

I have a very similar problem where the are small gaps in the extrusion when the filament is first being ejected after a change. These gaps then affect the adhesion of the next level, and it snowballs from there,

I have calibrated the tubes and i believe path resistance is minimal, but there is not way for me to really be sure.

trung.n
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Re: Purge Tower Bumps - Crashing/ETC

Mar 03, 2019 9:27 am

So i've notice if there are gaps in the purge tower if you adjust the so called universal numbers. The loading speed until you get perfect wipe tower changes. Mines is set to 16 but there are so many other variables. But this setting adjust the speed in which plastic is layed down in the tower.

joost.u
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Re: Purge Tower Bumps - Crashing/ETC

Mar 13, 2019 6:31 am

I have the same problem and my theory is that the heat of the nozzle during a filament change makes the top layer of the wiping tower soft.
It deforms and a ridge is formed. After a few color changes the wiping tower get’s knocked off.

I have tried both firmware versions. The problems stay’s.

Regards,
Joost

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PJR
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Re: Purge Tower Bumps - Crashing/ETC

Mar 13, 2019 9:15 am

Other solutions are available:
IMG_20190313_101114.jpg
IMG_20190313_101114.jpg (745.92 KiB) Viewed 121 times
200mm tower with absolutely no problems.

Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss.

joost.u
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Re: Purge Tower Bumps - Crashing/ETC

Mar 13, 2019 9:23 am

So you made a new object and selected:
Wipe into this object's infill
Wipe into this object.

I have tried this but the preview doesn't show wiping and I end up with an extra object and wiping tower.

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