Also have seen this issue on some printrbots, just not as pronounced. Anyone have a solution?
mmark
June 22, 2015, 1:52pm
5
Thanks for you reply,
I’ve checked my cura settings and the filament diameter - everything seems correct.
try to extrude 100mm manually and measure the real amount of filament extruded
I’ve had the same problem and I’ve reduced it, originally, using Simplify3D software. However, it is still there.
I’ve read somewhere it has to do with the threaded rod. Mine is pretty wobbly so first thing is to try to make the z screw the most straight it can be.
What layer height are you printing at?
I’ve had this problem before, and I think the reason Antonio_Bencini is mentioning it is because it becomes more pronounced with over-extrusion, which it looks like you have a little of. I find that I run an extrusion multiplier around .898 and I get much less of it. The last time it was bad on one side for me, it was because my Y belt was loose, so that would be my next step, to double check the x and y belts, as well as the stepper mounts. I have wobble in my Z-screw as well, but those things usually take care of it. The next step would be to adjust the layer height to something directly calculated from the steps and pitch of the acme screw. I know for my Simple Metal it works out to something like .1975 or something like that. I think you’ll see the most improvement by fixing the over-extrusion though.
Hi Mark
You say this is getting more pronounced over time, so I guess we’re looking at a little Wear and Tear here as well as a few other things. I also have a Jr v2 (amongst others) and it’s a good printer when on form.
You may want to print something to keep the Z rods from moving as the Z goes higher. The 8mm rods are fine but they can flex as there is more torque on them.
Tighten all the screws. If you find one a bit loose in the wood, treat the threads with wood glue, screw them as far as they will go and then, when it dries, turn it a bit more - it should help the grip again. If you think the wood maybe too worn, and you have access to a laser cutter, the complete DXF are available on youmagine.com , as are lots of PB original wood plans.
The Z screw is a 3/8" ACME screw. I’m sure there are some tables that will tell you the optimal layer height.
As mentioned before, check all the belts. Tight but not overtight as the motors will suffer, especially on the Y and X when they bend round the bearings.
Ian
mmark
June 24, 2015, 2:40pm
11
Don’t you check the stepper calibration if you measure your prints?
mmark
June 24, 2015, 2:41pm
12
I’ve noticed the same with mine actually… I think its time to replace the wooden thing witch Printrbt supplied me with - any good alternatives?
mmark
June 24, 2015, 2:44pm
14
mmark
June 24, 2015, 2:44pm
15
mmark
June 24, 2015, 2:50pm
16
Hi, thanks!
Is there for both a good alternative?
Cheers!
What happens if you go up to a 0.3 layer height, is it more or less visible?
Edit: This is not in response to the Video:
That is one way, but with different filaments you always have slightly different diameters. I was referring mainly to slicer settings, where the extrusion multiplier is. In cura, it’s called the “Flow Multiplier”. I would recommend printing something like a 10mm cube and reduce the multiplier by .02 over a few prints and see if that helps. If you are over extruding, and you calibrate the printer steps for x and y with a test print, the values will be inaccurate. I run test prints with the filament until I start to see evidence of under-extrusion, then back off a little.
mmark
June 24, 2015, 3:10pm
20
looking at the Octo’s in that video my problem should be underextruding… Wil try non the less!
mmark
June 24, 2015, 3:11pm
21
If you are over extruding, and you calibrate the printer steps for x and y with a test print, the values will be inaccurate.
Buy a proper z couplers from printrbot. It will fix the majority of your problems.
mmark
July 5, 2015, 1:34pm
23
Hi everyone; thanks for the replies! The problem was the wooden coupler and the nylon nut-thingy. After a year of printing it is worn out causing clearance - the rod could move how it want to move.
I ordered a better coupler.
Not really sustainable quality parts Printrbot…
