Welcome! Log In Create A New Profile

Advanced

i've got wobbly cubes

Posted by muntahunta 
i've got wobbly cubes
September 02, 2015 07:40AM
as a few of you may know by now, i've had a lot of problems and finally got over the majority of them...

Now im faced with wobbly cubes... yeah.

Take a look.



Any ideas?
Re: i've got wobbly cubes
September 02, 2015 08:18AM
Check your belts are tight and any backlash you can tighten in your axis. Also just curious try sliceing it with cura and see if it looks the same.
Re: i've got wobbly cubes
September 02, 2015 08:20AM
I am using cura. i've found a possible solution in prusa i3 upgrades for z wobble, anyone ever used these?

[www.thingiverse.com]
Re: i've got wobbly cubes
September 03, 2015 05:08AM
Congrats to the first successful prints! grinning smiley
If you have z-wobble, did you remove the upper bearings of the M5 leadscrews?
The z-axis runs better without the upper bearings.
From the pictures, I´d say you have backlash in your belt(s) and print the outer perimeters to fast.
-Olaf
Re: i've got wobbly cubes
September 03, 2015 06:08AM
Well, congrats too though, if you're using a flange nut type, maybe can try this one instead of using nut with springs [www.thingiverse.com]
Re: i've got wobbly cubes
September 03, 2015 08:08AM
YAY!
Those little Z axis mounts have increased the quality by a LOT! ( i also tightened the X axis belt.I cant tighten the y axis though as it has nothing extra for me to grab hold of haha.
check out the pics. still a few things nagging me, like theres seems to be too much extruded on the corners (not sharp corners) but the extruder calibration is perfect, as at the steps per mm on all axis.
The bottom layer sometimes struggles to stick, though thats probably a bed levelling thing.
and theres sometimes a slight bump in the Y axis of the print, but nothing too major... im happy with the print but would love perfection haha. its what we all strive for.

Thanks for all the help so far guys smiling smiley
Attachments:
open | download - 20150903_125406[1].jpg (429.6 KB)
open | download - 20150903_125421[1].jpg (428.8 KB)
open | download - 20150903_125431[1].jpg (437.8 KB)
open | download - 20150903_125441[1].jpg (526.4 KB)
open | download - 20150903_125449[1].jpg (555.2 KB)
Re: i've got wobbly cubes
September 03, 2015 12:40PM
Congrats solving the problem! It has been improved a great deal. I was under the impression that I had the same problem, though not nearly as badly as this. But it turned out to be the stepstick for the extruder motor. I used the 8825 without decay hack. After some research it turned out I was using A4988 stepstick which already included the 'decay hack', the R4 resistor was already bridged, with a 0 ohm resistor. Anyway, now when printing lower layers than 0.3mm it looks much cleaner now, and no z wobble either. Now other problems are rearing their ugly faces but I'll soon fix them. I've ordered an aluminium print bed carriage plate, which should better stabilize the Y carriage. There's some resonance and the bearings are not tight enough.

I was just experimenting with smaller layer heights like 0.1mm and noticed that you also should set the first layer height with a lower layer and the Z offset should be perfect. When you print a test cube, include a perimeter of 1 layer high. You can measure how high it prints. Adjust your Z offset by the amount it's off. If the Z offset is too low (the nozzle has too much space between it and the bed) the deposited filament doesn't make much contact with the print bed, it also creates too much space for the filament to warp and curl.
Re: i've got wobbly cubes
September 03, 2015 01:01PM
well i've started to print stuff now and its coming out fine (though when i changed to black it was extremely shiny so i dropped the heat to 190 and its fine... but half way through a print (2nd time this has happened now) the wire on my heatbed has snapped. the wire is long enough, doesnt snag on anything, but just going back and forth so many times causes it to snap. any ideas?
Re: i've got wobbly cubes
September 03, 2015 02:13PM
Quote
muntahunta
well i've started to print stuff now and its coming out fine (though when i changed to black it was extremely shiny so i dropped the heat to 190 and its fine... but half way through a print (2nd time this has happened now) the wire on my heatbed has snapped. the wire is long enough, doesnt snag on anything, but just going back and forth so many times causes it to snap. any ideas?

This happened to me once, luckily I was printing in PLA with no heat to the bed. Probably a bad solder job, did it snap right where you soldered it to the bed?
Re: i've got wobbly cubes
September 03, 2015 02:26PM
it snapped once (it was presoldered by the chinese) and then i soldered it and it snapped at the start of the insulation wire.

unfortunatly when my heatbed gets decoupled, it turns off the hotend too... if there was a way to fix that I wouldnt be so bothered.
Re: i've got wobbly cubes
September 03, 2015 02:37PM
It never happened to me yet (fingers crossed). Soldered wire gets very brittle, so try to fix the wire farther along to the heated bed with a cable tie or kapton tape. Only use fine stranded wire. If it has coarse strands, try RC car wire instead, it's purpose build for high current and motion.
Re: i've got wobbly cubes
September 03, 2015 02:39PM
seems to be one problem after another. ive done a temp fix with tape xD this is until my new soldering iron gets here tuesday, chinese didnt make it easy to solder with a 30W gun.
Re: i've got wobbly cubes
September 03, 2015 02:57PM
Electronics is another hobby of mine, so fixing the cable to relieve the solder joint of mechanical stress is something I do without thinking smiling smiley
Also making sure the moving wires bend along a wide angle instead of bending along a sharp angle. Some extra length can help and some heat shrink tubing, though I do it without that.
Re: i've got wobbly cubes
September 04, 2015 04:01AM
Silicone insulated multi strand wire is the answer.
A decent solder job is mandatory too.
If soldering takes too long, the solder will creep deep into the wire. Use a hot air gun to preheat the bed.
-Olaf
Re: i've got wobbly cubes
September 07, 2015 06:07AM
Somebody should model a little stress relief clip for the soldered joint area. It would hold the wire straight outwards for an inch or so.
Re: i've got wobbly cubes
September 07, 2015 06:24AM
not a bad idea.... i may have a look at this. my soldering iron came today so all is good grinning smiley
Re: i've got wobbly cubes
September 07, 2015 03:33PM
@RRuser: agreed, I soon will design one that can be fixed to the heated bed corner. I need one as I swap my prusa i3 3 point wood y carriage plate to an 4 point aluminium one, the wood is too flexible and 3 point is easier to level but the unupported corners make it vibrate too much. I currently use the unused heated bed corner hole with a cable tie.
Re: i've got wobbly cubes
September 08, 2015 02:53AM
Quote
RRuser
Somebody should model a little stress relief clip for the soldered joint area. It would hold the wire straight outwards for an inch or so.

Good idea regarding the stress relief, but you have to avoid creating a longer lever to the cable tension.
-Olaf
Re: i've got wobbly cubes
September 08, 2015 04:03AM
Just use a longer cable or a more flexible one. Mine is with a u bend back to the frame to the side. The force is in the same plane as the motion of the print bed.
Sorry, only registered users may post in this forum.

Click here to login