1 Topic by Dan_E

  • Dan_E
  • Member
  • Offline
  • Registered: 2013-04-20
  • Posts: 37

Topic: Major Layer Offset with SD3 Printer

Just starting out with the Solidoodle 3 printer, Setup is Repetier Host with standard slicer, ABS filament. 90C bed and 195C nozzle.
I had trouble at first even getting the printer to wake up, then got control after finding what com it was on and changing the baud rate to close to 250k, I think 230k was the closest choice on my laptop.
I used a small test model I created in Solidworks about 100mm x 60mm x 45mm tall.
I left all settings at default for this first build, it appeared to slice successfully, and centred the model on the stage.
It began printing and the first few layers didn't adhere well in one corner so it was lifting a bit, but continued to print.
I left it for a few minutes and then noticed that the filament had unraveled from the spool and jammed so the print head was pulled back and I think the belts cogged when this happened so I killed it.
I secured the spool better so it wouldn't jam, anfd then I tried printing the same model again - after about 12 layers the printhead would shift towards the back (y) about 30mm for each successive layer, then shifted in the x direction about 80mm, creating a mess - killed it again.
Is something damaged by the jammed filament spool? Is there a way to recalibrate the x-y positioning?
I read about getting better adhesion by cleaning the bed with acetone so I will try that and leveling the bed to the nozzle plane, haven't done that yet. Before I try the build again I wanted some opinions on this issue.
I must say I didn't expect to have to do so much tweaking as I see in this forum in order to get a good part, but I am willing to learn, and hopefully don't break it before I get it working right. Help is needed!
Thanks in advance

2 Reply by Gordym

  • Gordym
  • Member
  • Offline
  • From: Adrian, MI
  • Registered: 2012-08-10
  • Posts: 317

Re: Major Layer Offset with SD3 Printer

Your problem may be occuring for a couple of reasons. #1, if the corners are lifting on your project, the print head may be catching on the lifted edge, causing the print head to skip. #2, because you had a jam, the belts may have stretched slightly, causing the need to tighten them up a bit. There are instructions here and in the wiki to teach you how to tighten the belts.

SD2
E3D V6
MK5 V6

3 Reply by pcpoirier

  • pcpoirier
  • Member
  • Offline
  • From: Wichita Ks
  • Registered: 2012-10-25
  • Posts: 231

Re: Major Layer Offset with SD3 Printer

I dissolved some small abs pieces in my small acetone bottle(6 oz fingernail polish remover) and now it is actually hard to remove my parts.

4 Reply by Dan_E (edited by Dan_E 2013-04-23 00:41:42)

  • Dan_E
  • Member
  • Offline
  • Registered: 2013-04-20
  • Posts: 37

Re: Major Layer Offset with SD3 Printer

So I am posting some pics of the layering offsets to show how much I am talking about. This was a test square 50mm x 50mm x 10mm high. so 33 layers high at 0.3mm layer. It started printing fine up to layer 20 and then the Y offset about 12mm per layer after that. When it eventually came to the front edge of the bed it stopped offsetting but was bumping against the front stop.
First picture shows the screen slicer finished image how it thinks it printed. Pic 2 is the actual print showing huge layer shifts after layer 20. Belts are tight, pulleys not slipping - what else could cause this?

Post's attachments

IMG_1032.JPG 703.82 kb, file has never been downloaded. 

IMG_1033.JPG
IMG_1033.JPG 1023.69 kb, 1 downloads since 2013-04-23 

You don't have the permssions to download the attachments of this post.

5 Reply by pcpoirier

  • pcpoirier
  • Member
  • Offline
  • From: Wichita Ks
  • Registered: 2012-10-25
  • Posts: 231

Re: Major Layer Offset with SD3 Printer

Your y axis(front to back) is hanging. Most probably the belts are are not the same tightness.
Shut off the power and move the carriage back an forth by hand. it should move freely. If not adjust the belts to have the same tension. Test by pressing the belt in the middle with fingers about half the distance from not touching each other is good.  use the same pressure on both belts. The pressure is the same a squeezing a orange quarter half way.

6 Reply by Dan_E

  • Dan_E
  • Member
  • Offline
  • Registered: 2013-04-20
  • Posts: 37

Re: Major Layer Offset with SD3 Printer

The belts are snug, the rails well lubed and are not binding. I realize this is an unusual problem maybe not seen here before. The Y axix is not hanging as it is jumping FORWARD about 12 mm for eack layer but only after doing about 20 layers mormally.
I guess I'll have to go to the source for this one.
Thanks for your input.

7 Reply by Dan_E

  • Dan_E
  • Member
  • Offline
  • Registered: 2013-04-20
  • Posts: 37

Re: Major Layer Offset with SD3 Printer

Printer is working better now. I recalibrated the trim pots on the Y and X planes (very difficult). Also, I set the baud rate to 250000 as opposed to the previous setting of 230400 (set from PC). Now printed a test block fairly good without major layer shifts. However first layer did not adhere well in the 2 front corners so block has 2 corners slightly lifted. I will now try leveling the platform and spraying the surface with hairspray, also maybe adding a raft to the first layer.

8 Reply by supraflyer

  • supraflyer
  • Member
  • Offline
  • Registered: 2012-09-02
  • Posts: 86

Re: Major Layer Offset with SD3 Printer

I had the same problem and went thru the belt tightening, filament reel sticking and it did not work for me. What I discovered is that in my case the filament was extruding too much and creating a hard blob of plastic that would catch the nozzle and offset the print in the direction towards the door. I had to add a 1mm z offset to my slic3r settings to make it go away. I also calibrated my extrusion rate and corrected the filament thickness.
What I have found is that when changing spools of filament, either color or manufacturer I need to recalibrate the printer. The printer is fine its the diameter and flowrate of the filament that changes. I change the filament diameter in my settings and check the flowrate with a cube and adjust as needed. It only takes a few minutes.
I hope someone else would add to the spool change checks.....

9 Reply by mikefree41

  • mikefree41
  • Member
  • Offline
  • Registered: 2013-03-11
  • Posts: 40

Re: Major Layer Offset with SD3 Printer

I just started up my SD3 and am getting quite a bit of offset in the Y direction, 10mm, each layer and then sometimes not so much but still some. The belt tension SEEMS the same, my fingers aren't calibrated yet. The belts don't line up top to bottom. It moves pretty hard back and forth like dragging it across a saw blade. Are the tension screws supposed to have nuts on them? Right side does, left side doesn't. Motor belt is real tight. Also the tension screws aren't horizontal the belts tend to pull them up. Need to run something to keep the wife happy about buying something foolish.

10 Reply by mikefree41

  • mikefree41
  • Member
  • Offline
  • Registered: 2013-03-11
  • Posts: 40

Re: Major Layer Offset with SD3 Printer

FYI: I solved the Y axis offsetting problem by realigning the pulley's on the cross shaft in the back. They probably shifted during shipping. I also cut back on the feed rate, because I was getting blobs that the nozzle caught on, and caused stepper motors skipping or the belts jumping teeth.

Does anyone know what tension the belts should have on them?

11 Reply by lawsy

  • lawsy
  • Moderator
  • Offline
  • Registered: 2012-08-13
  • Posts: 1,220

Re: Major Layer Offset with SD3 Printer

There is an official Solidoodle video for that on Vimeo.

lawsy's Website