1 (edited by jevans3d 2015-11-25 19:09:34)

Topic: CTC Dual, layer issue?

HI all,

New here and after some advice on a problem I just cant figure out.

All my prints are printing fine, abs works great, no curling issues at all. But i recently printed a string of taller models (lightsabers hilts) and the all have layer separation (not so bad its ruined the print) at exactly the same level on each print, even dofferent models.

Ive tested it with a simple cylinder and got the same layer issue at the same height again, and I used different slicing settings.

Printer is a ctc dual running sailfish 7.4 and repg.

2

Re: CTC Dual, layer issue?

Do you have an enclosed chamber? With ABS, little ambient temperature changes can cause faults in your prints.  As well, as ABS cools it, it shrinks. Sometimes if the heated bed is not hot enough your base will shrink enough that it can pull layers apart. If the print is big enough, this can happen even with a heated bed.

This could be a temperature problem if you are printing at too low a temperature.

Finally, I have also seen where in a larger print you might be maxing out the capacity of the chip on your motherboard. If that is the case, when you reach that point anything can happen. What I have seen most commonly is that the printer will skip or pause for a few seconds while more gcode is loaded before it continues. Just a few of my thoughts to try.

Solidoodle 4-Mostly stock running off headless Raspberry Pi with Octoprint

3

Re: CTC Dual, layer issue?

Hi Morganism,

Thanks for the reply. I'm wondering if it may be the chip capacity then. As its only one layer and is approx 4 inches up the models. That little pause would cause the previous layer to cool too much for proper layer adhesion wouldn't it?

Having said that I'm not in a full enclosure either. But its only on tall prints always 4 inches up that this happens. I'm printing at 240. started lower but slowly increased it to stop earlier layer issues lower down the model. The current issue is much worse than the earlier ones but still not a major issue. Just chasing perfection.

4

Re: CTC Dual, layer issue?

Just an fyi. The CTC uses a mightyboard which uses a 2560 chip. That chip is twice as fast and twice the capacity of the chip used on a RAMPS 1.4. I have a CTC and have printed many objects that go above 4 inches. However I use exclusively PLA, PET+ and PETG. I won't use ABS due to the fume hazards and the issues with layers. I have never had any separation.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

5

Re: CTC Dual, layer issue?

I don't have any layer issues below 4 inches and its just that one single layer, any thoughts what it could be then? I actually get much worse prints with pla.

Here is one of my ABS prints. I think its pretty good isn't it? But you can see that layer on top I mean on the keys. They broke off when assembling the hilt so glued them back on.
http://soliforum.com/i/?aV1p8qh.jpg

6

Re: CTC Dual, layer issue?

Is the layer separating or missing? You should really try to watch the printer when it gets to this point. It could be your bed moving to far, could be a temp drop could be many things but the first step is to watch the printer behavior when the problem usually happens to see if you see or hear anything different from previous layers. Even it happens at the exact same layer on every print then it is a mechanical problem and you need to watch for anything odd at the point it happens at. Set an alarm or something to remind you to start watching it from about 2 minutes or so from the time it happens. You could even do two different prints and see if it happens at the same layer count in the software for each print. Looks like a mechanical issue so go from that angle for now..

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

7

Re: CTC Dual, layer issue?

Thanks Carl, I'm doing another print now so will set an alarm to check it and hopefully have some further info to go on.

8

Re: CTC Dual, layer issue?

Right, random update. I timed it twice and the issue that occurred non stop didn't occur again. Weird. So I started another print and left it, I came back to find it had totally failed at the problem level and i had a birds nest of filament. So... I then watched at the right time and this happened again at the exact same level. Only thing is is didn't notice any weird mechanical jerk or anything etc. The layers just started to stop sticking and just got worse. What could be causing this at the exact same level? But now... just this one model segment. The other psrts that are just as high (but narrower) don't have the issue any more after changing to white abs.

9

Re: CTC Dual, layer issue?

Possible wiring issue. When it gets to that height, see if the extruder wires are getting tangled or at a strange angle. Many 3D printers will print just fine for small things at a few inches but the full range of motion doesn't happen until you use up the full build space. On my SD2, there is a nice bend in the Z rod and all is good until you get there and things turn sloppy.

SD2 Expert stock, ABS fume fan,
XYZ DaVinci 1.0 stock ABS, Simplify3D
QUBD Two-Up PLA, new 3D printed X gantry, Y idler, flex z coupler, extruder mount, E3D Lite