4mm Z distance lines (compressed layer)
Although not so obvoius they are there at a fixed interval in Z.
I tried to recalculate from where this 4 mm comes from.
If I know it would be easy to solve 😀 .
Happens with all filaments also on long objects all around so it must be in the Z system.
Screws are checked and the regular 4 mm distance makes it repeatable and not random.
Vcore 300 with Ventermechs + Orbiter 2.0
Where to look first?
Paco
16 Replies
ratty-blush•2y ago
4mm sound like 2x2mm which then would point to the Belts, how tight are those? Belt artefacts often come from to hard tightened belts
optimistic-goldOP•2y ago
It was hard to make the lines visible in a picture. So in the picture you look at Z from left to right. I forgot to mention. Where left is the top and right hand side is the bottom. So I imagen this is not belt related. Correct me if I am Wrong.
ratty-blush•2y ago
then it is even clearer, Z-Wobble, something is binding on your leadscrews probaply, clean and lubricate would be my advise
optimistic-goldOP•2y ago
OK,
1] Cleaned the spiral shafts
2] Checked the star drives of the Ventermech to run smoothly.
3] Spiral shafts are not constrained at the top and can move freely in all directions.
4] Put everything together again and lubed the stardrives and spirals shafts again.
5] Performed by G-code Z travel of 40 times 300mm up and down to break in again the Z units.
6] Checked all the screws in motor couplers, the three pillow balls and the printed arms to be secured and tightened correctly.
7] Printed a 20mm cube.
Problem persist all around the cube at 4 mm intervals as shown in the picture.
By observation……….
When I move the bed in Mainsail Z by 1 mm the motors a ¼ turn.
When I move the bed in Mainsail Z by 4 mm the motors turn 1 full turn.
Printing 0.2 mm layer height means 20 steps for 4 mm travel of Z.
Why just at this point the Z just gives this tiny artefact which you can feel with the fingernail.
Paco
ratty-blush•2y ago
V-Cores have TR8x4 Lead Screw AFAIK. So a defect every 4mm over the whole Area should be an indicator, that the problem seems to be in the part running on the screw, not the screw itself as this would then change depending on the height. Maybe consider a Upgrade to 3.1 with the ingenious Old Ham Couplers
genetic-orange•2y ago
Mechanical misalignment on Z axis
optimistic-goldOP•2y ago
@escrich could you be more precise please what you have in mind?
genetic-orange•2y ago
I had same problem, more or less, and I was certain about everything was right from mechanical point of view, but at end, the solution was to loose all the screws and start tightening one by one with X axis at different heights in order to have everything really aligned, at end it was the solution, from motors , couplings, leads, linear rails, to the last moving part
@jupacreations Which leadscrew limiters are you using?
genetic-orange•2y ago
No ones
optimistic-goldOP•2y ago
Initial none to have no restiction that the lead screws are forced or damped. I do not care about the sound and the clicking of the star drives.
I am stumbed about the exact 4 mm and no one can give a technical explanation why, only PLEASE TRY THIS ;-). I appreciate all the comments do not get me wrong.
I printed a 0.4 mm wall cube the lines at 4 mm almost gone. Will print a 0.8 mm wall cube too.
Experimenting along. I have 82A flex filament in to print top restictors. I keep you informed.
@jupacreations The TPU wiggle woggle leadscrew limiters control only the most excessive leadscrew movements....highly recommended......and yes I am a bit stumped at what you observed too, specially as you say they stayed at 4 mm spacing regardless of print size.
optimistic-goldOP•2y ago
I will experiment untill it is gone.
First wil start again to rebuild all to non 1PZ with venter mechs and wiggle woggles in TPU.
That will be my base. If then the problem persist.........who knows rebuilding the frame to 3.1 openfront and see if the suggested option will work. 🙂 I have the profiles ready to swap.
It is clearly not the extruder problem which recently was highlited by Mr Mirage C. As that would be irregular on large prints as that shows under and over extruding on large objects. Why at exactly 4mm this happens?
The bed is going down for just taking an other step down the spiral shaft and the mechanics do not know the difference if it is 4mm or not. Might it be electrics where the step pulse is just shorter and we do no not make a full step of 0.2 mm or the energizing of the motor coils for holding the 4mm step is a fraction to late and we do not have a full step? Who knows.
One thing to be careful of is the Dual Axis V-Pivot must not have ANY slack in the mechanism. The first one I did in PETG deformed/distorted a little with the bed temp and developed some slack in it. One rotation of the leadscrews is 4mm and if there is any slack in that mechanism....
optimistic-goldOP•2y ago
I know all limitation of the 1P Z system. The 4mm is also with the standard RR pillow ball and pins and venter mechs. 😦 The picture at the begin of the thread is from that RR original set up with venter mechs. I can change from regular to 1P Z in 8 minutes if I need 🙂
OK. Or not OK.
Did some more trouble shooting this week.
Installed top TPU 85 shore dampers instead of free wheeling spiral shafts.
lower print speed of 30 mm/s
I changed my Z to fixed spreadcycle too.
Tightened and checked all X and Y gantry screws again.
Bought Prusa matte black PETG to have good comparising filament.
Changed from SuSi to Ideamaker back an forth.
Checked Extrusion Muliplier and moved from 1 to 0.9
The exactly 4mm Z distance lines keep coming back in razor sharp or faint vision but they are there every time.
They always start for the first at 3 mm in to the print height.
Heater and bed are PID tuned several times.
Installed ADXL345 and ran the input shaper macro.
I am slowly running out of options.
optimistic-goldOP•2y ago
