i have not read all posts here but i noticed something interesting
regarding Z-Axis wobble
After fixing the power supply which killed my internet connection i tried to print the
circuit print cover and saw on thingiverse something interesting
Please look at the third picture of the series where you can see from above
the wobbles in the z axis. Interesting for me was that it seems the wobble get
stronger the higher the extruder gets
I was prepaired to print a z-motor holder next because i have similar problems
but not that heavy.
Actually what i did next was to remove the filament spool from top of the machine
and mounted it on external spool holder not connected to the printer
Maybe the filament spool on top of the printer leads to extruder offset. Stronger
the higher the printed object gets?
Here are the results with external spool holder
(Sorry for picture quality but this is hard to get with my cam)
Now i’m not sure how much better it can get with z-motor holder.
I noticed the slight transparent blue is not delivered with constant coloring
and this can be seen already on spool
However i’m surprised how much effect it had in my case. I’m using original printer design
no modifications - except the spool put aside (and forgot the IKEA mirror)
If you already know this or it doesn’t work for you or admin knows better - never mind
This was the second printed part for me and I just wanted to report this
no longer shake me up the the z axis again
have a nice print
br
Johann
You get indeed very good Z axis results. However, if it is not too much trouble for you, I would totally recommend you to try out a printed Z motor mount which keeps the motor in place. I have the spool on the spool holder and I get way better results with the other Z motor mount.
One (not very related) question I have: Do you have a fan on that points at to you extruder (especially the white insulator)?
(and yes, I didnt have the correct length bolts and didnt feel like sawing them off, so I made do with extra nuts and even hotglue for the switch. Hey, it works ).
For the record, I installed a longer rod for the filament and it currently holds 6 rolls and some rolls of tape.
I am actually more laughing about the hot glue on the endstop
You should also get yourself some flex couppler.
~ Tectu[/quote]
lol, yeah those bolts were too short to put a nut on, but they go through the PLA all the way, so the switch is fairly firm (certainly better than the stock setup with only 1 bolt!), at least after I glued the bolts in place :). It was all meant as a stop gap solution until I got around buying the correct bolts, but its been working perfectly fine for weeks. Not many things you cant fix with duct tape, hot glue, and well, a 3D printer :p.
Can you elaborate on the flex coupler? Have a link?
Something like these. They are stiff in rotary direction, but allow to compensate a wobbly Z axis.
I use them myself (not exactly these, this is just a quick Google link. Mine are two-staged and are more flexible, but that doesn’t really matter here, I guess).
Note that there are also printable versions of these flex coupplers. But as some kind of mechanical engineer, I don’t really approve them. Howerver, that does not mean that they do not do a good job
I am using my printer without the top nuts and I moved the top bracket for the bearing up so the z-axle is only standing on the coupling on the motor end. The top end can move around a little but that is no problem. The idea is that now the axle will move side ways and not the extruder so it will improve even more. I found this on the reprap forum if I remember it right and it is working just fine. Give it a try, it is easy to do.
I’ve tried that : it worked but the threaded rod was vibrating. So I removed the lower nut and kept the upper one but not too tighten up.[/quote]
Ok, vibration is not good indeed, if it only circles around it is not a problem. The explanation of these guys was that the sideways movement of the axle is a good thing since it can not put any force on the extruder construction any more and also not on the motor mount so the motor movement will not push the extruder up and down every time it moves sideways a bit. It will look odd for the less experienced users they say Removing the bottom bearing and nut will do the same I think.
Vibration on a 3D printer is not good at all!
Use the ‘Vibration Limit’ setting in Slic3r to suppress that. Limiting the acceleration in the ‘speeds’ settings will help as well.
My printer does not vibrate a bit.
[quote=“johann”]
The slots are full of this addon PLA blobs and there the layers get really ugly
,
Has anyone an idea how to minimize this ?
I used standard ini file for print
br
Johann[/quote]
I think you should try to adjust the retract value for the extruder. I noticed some blobs with my printer as well and I have a feeling that many things can lead to blobs. I did the extrusion calibration and it seems to produce a lot less blobs now as well.
I have already removed some of this blobs but there is still plenty of them
and not easy to remove. Hard to believe this is with standard ini or maybe
it’s the PLA i’m using? (Which is also standard anyway)
Thanks
Johann
Btw. nice z-axis design @snowleopard
Don’t know exactly where I did see the value but it is some where in there. Others mentioned that it was always after retract and spooling forward again and another person mentioned that since he made changes to the construction so that it did have much less volume inside he could lower this setting a lot so it seems that this value has a lot to do with this. i can have a look tomorrow if you can’t find it.
But the temperature will influence it as well. Different colors need different settings. I don’t have them but there are some other threads on this forum.
).
