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JBrown83
(@jbrown83)
New Member
Bad Finish Between Layers

This is my first post on the forum. I just got the I3 MK2 last week and I have done many of the test prints that were loaded on the SD card. I had good success with all of these prints so I jumped into printing some tooling for work. The first 2 prints I have done now have had the same issues (see attached). The layers have voids and they are very brittle at this point. This brings me to the conclusion that my files must have some issues or my print settings need to be adjusted. I am new to printing so any help is appreciated.

I printed these with PLA with 5 solid layers on the top and bottom, 15% rectangular fill. I thought my live z adjustments was off so I did another test print and it was perfect. Could this be an issue with Slic3r? Does anyone have any suggestion that I can try?

Thanks in advance!

Thanks, Jason Brown

Posted : 27/02/2017 3:07 pm
christophe.p
(@christophe-p)
Member Moderator
Re: Bad Finish Between Layers

increasing the number of perimeters would probably help here.

However the picture suggest you are experiencing occasional under-extrusion, does the spool rotate smoothly during all the print ?

I'm like Jon Snow, I know nothing.

Posted : 28/02/2017 1:06 pm
JeffJordan
(@jeffjordan)
Member Moderator
Re: Bad Finish Between Layers

hi jason,
here are a few suggestions:


1st: the little fingers look somehow brittle, maybe you need to increase the temperature about +5 or +10°C, so that you'll get a better layer bonding (and nothing breaks off).
2nd: the walls of the fingers look quite irregular above the base. check the zip-ties of the bearings of the y-carriage. furthermore you can try to reduce the print speed. also check the bearings of the x-axis.
3rd: check that the extruder springs are well adjusted. spring length should be around 13mm. and that the extruder pulleye is in perfect condition (and not loose).
4th: check the filament: does it happen with another spool as well ?
5th: increase the infill to about 30% and use fast honeycomb as pattern.
6th: do you use z-hop (lift in case of retraction) ? try a value between 0.5 and 1mm.

dem inscheniör is' nix zu schwör...

Posted : 28/02/2017 3:42 pm
JBrown83
(@jbrown83)
New Member
Topic starter answered:
Re: Bad Finish Between Layers

Hi Christophe.p the spool wasn't rotating smoothly it seemed that the roll was rolled overlapping threads. I printed a new spool holder and it seems to have fixed the problem. The thing is I still am getting the same results between layers but not as bad.

Thanks, Jason Brown

Posted : 04/03/2017 4:17 am
JBrown83
(@jbrown83)
New Member
Topic starter answered:
Re: Bad Finish Between Layers

Hi Jeff, I checked most of your points above and found the pulley on the y axis was loose and the belt on the X was loose and was slipping. I adjusted these but I am still getting the same results but not as bad. It seems to print 10 or so layers good then I get some separation again. I have checked with another spool and I am getting the same result as well. On your 6th topic I use the standard setting so I think it is retraction. I will try the zhop and see what happens.

I have been reading on the live Z because I am not getting a good first layer as well. Could this be causing a lot of my issues with layer separation? It seems that the first bead is good then it bounces back and forth with a few good lines then a few bad. This makes me think that your 1st point make sense because it preheats at 215 then it cools down to 205 during the print. If the nozzle is still hot when the first bead is being laid down and looks good then the tip cools down and the bead gets worse. I will increase the heat and will see what happens.

Thanks for your advice I really appreciate your time!

Thanks, Jason Brown

Posted : 04/03/2017 4:33 am
JeffJordan
(@jeffjordan)
Member Moderator
Re: Bad Finish Between Layers

I have been reading on the live Z because I am not getting a good first layer as well. Could this be causing a lot of my issues with layer separation?

💡 bad first layer bonding to the pei sheet is responsible for many issues (print won't stick, warping etc.), but not for this problem. 😎

the bonding between the layers is mainly influenced by the temperature and sufficient extrusion.

dem inscheniör is' nix zu schwör...

Posted : 05/03/2017 10:51 am
JBrown83
(@jbrown83)
New Member
Topic starter answered:
Re: Bad Finish Between Layers

I tried all of the suggestions above and it seemed to be working really well until for some reason I had a jump in the Y axis. I checked over everything and I don't see anything that looks to be wrong. Below are a few pictures of the layer shift.

Thanks, Jason Brown

Posted : 13/03/2017 10:26 pm
christophe.p
(@christophe-p)
Member Moderator
Re: Bad Finish Between Layers

There are several thing to check:

Check that the pulleys didn't get loose (that can happen with vibration)
Check the pulley tension. Is the selftest with 3.0.10 firmware ok ?
Check that the spool holder is really smooth
Check that the cable management, especially the one behind the x carriage is well positionned, that it does not goes down from the rear of the carriage. If the cable can touch the bed or printed parts when the extruder is on the front side of the bed, it can produce this kind of issue by catching the printed parts. The new cable management from MK2S seems really better for this topic !

I'm like Jon Snow, I know nothing.

Posted : 14/03/2017 6:40 am
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