Problem printing large extruder double helix gear

Hi,
Has anyone any ideas what I can do to correct this print problem. I originally had this problem on both gears when I printed on the same time but have successfully printed the small gear on its own. Ive re run the stl file through slicer again but it keep shifting over on X axis at the same point each print as you can hopefully see in the picture.
Thanks
Tailzer

That looks like Y-Axis slipping moving towards the Y Axis sensor so it comes back further each time because it didn't go towards the sensor(left side) each time

Check the Y Axis belt is properly running and tide up correctly

That looks like Y-Axis slipping moving towards the Y Axis sensor so it comes back further each time because it didn't go towards the sensor(left side) each time

Check the Y Axis belt is properly running and tide up correctly

Look more like Y-axis - would make sense, more material added, more mass to move

Here you see the effect of a one-notch Y-axis belt slip



Erik

ok will check that but I dont understand why just this print and why at that height everytime?
Thanks

Hi Tailzer, it looks like both your Axi are slipping from the picture.
Check the belts as they are either to slack or to tight....
When the Y-axis moves look at the belt as it leave the motor. If it starts to Hump Up as it leaves the motor pully then the belt is a fraction slack.
In Slic3r, make sure that there isn't a tick on the Wipe on Retract box.
If you have increased the speeds then slow them a fraction.

My belts here are tensioned ok, but the wipe on retract is such a violent movement that it kills a print here.

Also (from experiance) before printing the gears check your Z is correctly Square, as I print them initialy and they wouldnt work, yet looked ok.
The Z axis had slipped a fraction when I lifted the machine to put it in it's box.

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Quote
Tailzer
ok will check that but I dont understand why just this print and why at that height everytime?
Thanks

Have anything heavier printed ok?

Erik

How do you have the y-belt attached to the plywood rib? If you still have it jammed in the slot, then the most likely cause is that the belt is slipping in the slot. I recommend using Matt's y-belt fasteners, along with my spacers to adjust the belt tension. Links to both at [github.com].

If you are already using this or a similar solution, then try increasing the Y motor current to 1000mA if you haven't already done so.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Im still on the belt jammed in the plywood. Have just printed the belt fastners and will now print the spacers. I just dont see how the weight of that gear would affect it as other things ive printed are heavier like the coat hook.

Ive also done a much bigger multi part print that was higher than this and that was fine. fickle beasts these printers!

I have adjusted the speeds to some discussed on the forum so maybe thats not helping either.

Anyway I will update the parts and try again.

Thanks to all for the amazing rapid replies, what a great community we have here!!

:O)

What was the head temp?

If the head got stuck on the part as the Y-Axis came past this can have the same a effect...that happening 5 times will also give you the same result...

head is at 195

Quote
Tailzer
Im still on the belt jammed in the plywood. Have just printed the belt fastners and will now print the spacers. I just dont see how the weight of that gear would affect it as other things ive printed are heavier like the coat hook.

It's not just weight that matters, it's also acceleration. Unfortunately there is still at least one bug that causes excessive acceleration in some prints, see [forums.reprap.org].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Mmmm that is fine temp...

That part is also only 4mm thick when done but on your picture it looks a lot thicker, like the Z axis is moving up too much...

is your Z-Axis compensation correct? On the picture it looks like it is compensating more on the one side than the other..

Also if your Z-Axis compensation is not right it can press the head into the part too deep causing the slippage on the X and Y axis...

Since this is a circle you are printing which uses the X and Y axis in conjunction to get a circle it was only exploited now...

That is why it looks like it is twirling up and higher on the one side than the other. I guess...

Edited 1 time(s). Last edit at 05/20/2014 09:01AM by KaGen101.

As dc42 says, it's acceleration that can cause the problem, and causes it to slip at the same place. Putting a cable tie around the belt (or a couple), as per the instructions if you haven't already, helps a lot, and should at least get you printing: [reprappro.com]

And there's some more info in the troubleshooting section: [reprappro.com]

Ian
RepRapPro tech support

Are you using DC42's firmware, which fixes the worst acceleration bug? If not, that could well be the cause - the bug causing an excessive acceleration at the same place in every print. You can usually hear the "bang" when it happens. Also don't have "wipe while retract" enabled when you slice the part.

Dave
(#106)

Hi
I finally got a bit of time to try again. Ive upgraded to DC42's firmware and tightned the belt. Just finished the print and its perfect (after recalibrating the bed etc).
Have printed Matts adjusters along with the spacers but not had time to install yet.
Thanks for all your inpu again, one happy printer now
:O)