Lines in print. Stepper resolution problem?

Electronics, Components etc
kleingeist
Posts: 34
Joined: Wed May 24, 2017 11:51 am

Re: Lines in print. Stepper resolution problem?

Post by kleingeist » Fri Aug 04, 2017 9:03 am

I got exactly this kind of lines in my old fabrikator. I'm pretty sure that it is caused by the Z bed mechanics not running perfetly smooth or there is some sort of minimal play. Even if you got a perfectly straight rod the bed moves that tiny bit causing a shift in XY or z.

Doug
Posts: 1
Joined: Thu Jun 15, 2017 12:04 am

Re: Lines in print. Stepper resolution problem?

Post by Doug » Sat Aug 05, 2017 12:33 am

Shaking from the spool or changing tension on the filament as it unwinds?

FranJans
Posts: 41
Joined: Wed Jul 19, 2017 10:35 am

Re: Lines in print. Stepper resolution problem?

Post by FranJans » Sat Aug 05, 2017 3:54 pm

kleingeist wrote:
Fri Aug 04, 2017 9:03 am
I got exactly this kind of lines in my old fabrikator. I'm pretty sure that it is caused by the Z bed mechanics not running perfetly smooth or there is some sort of minimal play. Even if you got a perfectly straight rod the bed moves that tiny bit causing a shift in XY or z.
That could be. How can you detect such problems?
The Z rods are bolted at the top end. The bottom end is placed inside a bearing block. This will always have some play. I always assumed that the weight of the table would eliminate this play. The platform assembly weighs several kilograms. It is insanely heavy. However, if the play would do anything that it would mostly effects the X and Y axis. The problem in the print looks like a Z axis issue.

You can see the bearing blocks for the rods at the top if this pictures.
https://fransseo.home.xs4all.nl/Foto's/ ... opbouw.jpg
Doug wrote:
Sat Aug 05, 2017 12:33 am
Shaking from the spool or changing tension on the filament as it unwinds?
I solved that issue some time ago. I even printed spool bushings. Now the rod is always in the centre of the spool. The spool turns really smooth.
You can see the extruder lifting the spool if you don't use the spool bushings. I don't like that ;)
Image

Image

kleingeist
Posts: 34
Joined: Wed May 24, 2017 11:51 am

Re: Lines in print. Stepper resolution problem?

Post by kleingeist » Sat Aug 05, 2017 4:15 pm

That could be. How can you detect such problems?
I gave up on the printer that produced those lines on the print. They drove me crazy and I tried everything possible. Your bed sounds rigid enough with that pre loading mine wasn´t (Fabrikator). Modding seemed to be a dead end for me so I designed my own to get around this.

The error could have been elsewhere. The only thing I did not try was replacing the stepper motors. The mechanics except the bed seemed ok.

I suspect the stepper motors , at least the one in the extruder. *Unsure*

I get pretty much perfect prints now and it is running on a crappy ramps board with A4988 drivers.

FranJans
Posts: 41
Joined: Wed Jul 19, 2017 10:35 am

Re: Lines in print. Stepper resolution problem?

Post by FranJans » Sat Aug 05, 2017 8:17 pm

That is encouraging. :lol:
The lines are truly persistent.
Hopefully I will be finishing the printer in the up coming weeks. Perhaps replacing the tyraps on the extruder with a decent bracket will help.

kleingeist
Posts: 34
Joined: Wed May 24, 2017 11:51 am

Re: Lines in print. Stepper resolution problem?

Post by kleingeist » Sat Aug 05, 2017 8:24 pm

I guess your mechanics are good, judged by you cable management :D

Maybe at least the possible causes are narrowed down a little.

Sorry :P

FranJans
Posts: 41
Joined: Wed Jul 19, 2017 10:35 am

Re: Lines in print. Stepper resolution problem?

Post by FranJans » Sun Aug 06, 2017 9:08 am

I hoop the mechanics are good. It is debatable what good enough should be. The mechanics are absolutely not perfect. For example, the X and Y stepper motor are placed at the bottom of the printer. This is not a small printer so you can image what length of belts I had to use. I already replaced the original fibreglass belt with steel cord belts to reduce the stretch of the belts. I also tried to mount the motors on top of the printer. This attempt failed. I have to redesign large parts of the printer to get this to work. I gave up on this. I already redesigned the electronics, firmware, and a most of the mechanics. :shock: There is no end to this project :shock: :lol:

ronka
Posts: 41
Joined: Thu Jun 15, 2017 4:00 am
Location: Holland

Re: Lines in print. Stepper resolution problem?

Post by ronka » Sun Aug 06, 2017 2:08 pm

In tom's video about steppermotors he had special z motors without bounce in the spindles.
can you check te z motors to see if you can get movement in that direction?

kleingeist
Posts: 34
Joined: Wed May 24, 2017 11:51 am

Re: Lines in print. Stepper resolution problem?

Post by kleingeist » Sun Aug 06, 2017 4:10 pm

What ronka said.

Do you have any photos of the xy gantry?

FranJans
Posts: 41
Joined: Wed Jul 19, 2017 10:35 am

Re: Lines in print. Stepper resolution problem?

Post by FranJans » Sun Aug 06, 2017 8:40 pm

ronka wrote:
Sun Aug 06, 2017 2:08 pm
In tom's video about steppermotors he had special z motors without bounce in the spindles.
can you check te z motors to see if you can get movement in that direction?
Do you mean this video? He doesn't mention it.
https://www.youtube.com/watch?v=bItYRMLGoVc
kleingeist wrote:
Sun Aug 06, 2017 4:10 pm
What ronka said.

Do you have any photos of the xy gantry?
Off course. If you need more photos please let me know.

Old photo
https://fransseo.home.xs4all.nl/Foto's/ ... opbouw.jpg

These are more recent photos
https://fransseo.home.xs4all.nl/Foto's/ ... /XY/44.jpg
https://fransseo.home.xs4all.nl/Foto's/ ... XY/44b.jpg
https://fransseo.home.xs4all.nl/Foto's/ ... /XY/45.jpg
https://fransseo.home.xs4all.nl/Foto's/ ... /XY/46.jpg

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