Poor layer quality on multi-part prints

[joboman]

I've calibrated my machine to get amazing prints for single parts. When I try to have multiple parts printed at once, my layers aren't smooth and i get striations and basically very minor layer alignment issues. Not happy about this at all, I've taken off the arms and joints and made sure everything is clean and proper. Am I the only person experiencing this? How can I resolve this? Thanks guys, this is driving me crazy.

This is a Rostock MAX v2 with the u-joint style arms.

[mhackney]

More information needed... What filament? What slicer? What slicing parameters? What hot end?

It would also help if we saw how the parts were oriented on the bed during printing. The deep striations look odd in this orientation and I don't see how the gear in the upper left is printed unless it is tooth down.

Simple answer to your question, many get much better results than what I see there. "clean" joints and arms does not mean "no backlash" so you do need to make sure there is no movement/slop in the joints. Also the carriages need to be adjusted properly and don't overlook making sure the hot end is secure and not moving around a little.

[Polygonhell]

The parts are printed with the face on the inside of the cube down, so it is just Layer alignment.
How much slop is there in the platform?
Have you tried single pieces at various positions on the bed?
How fast are your rapid moves?
At the end of the day, if it's mechanical it's going to be something sloppy or something binding that is causing the poor alignment.
It's most likely not showing up on single part prints because the head doesn't move the same way, so it's either location of the parts on the bed, or the motion between them.
It does look like you are overextruding to me, that can also cause this effect, how many perimeters, and how much infill are you using?

[joboman]

Hey guys, thanks for getting back to me. Some of the requested info..

1.75 mm ABS from seacans
simplify3d 0.15 mm layer height @ 230 C
I have elastics on the arms to prevent backlash
the gears and the motors don't move at all, no looseness
print speed is 60mm/s, 30mm/s for perimeters
travel speed 250mm/s
2 perimeters, 15% infill
iamge attached of how parts look like on the bed

[JFettig]

Do you have it set up to print multiple layers per part then go to the next or one layer per part before moving to the next?

It looks like what I've experience when I told S3D to print 1-3mm on each part before moving onto the next - the part would cool too much before it received the next layer so it would have shrunken previous layers then the next layer was larger, it would be more like a hose-barb look where the layers would be large and tapered to small at the interval I was printing.

Do you have cooling turned on? As in layer speed adjustments? Maybe its too extreme or not enough?

[brianmichalk]

This is still a problem. When I print single parts, they are excellent quality. Multiple parts seem to have an occasional problem that kind of looks like under extrusion. I'm trying to add a picture, but it's not inserting after uploading.

[rootboy]

This is still a problem. When I print single parts, they are excellent quality. Multiple parts seem to have an occasional problem that kind of looks like under extrusion. I'm trying to add a picture, but it's not inserting after uploading.

I was having that problem the other night until I figured out that I was exceeding the file size limit (without being told that I was).

[brianmichalk]

I am still having problems, and the problem may be a strange batch of plastic filament in my case. I printed with some black, and for whatever reason, it plugged up my nozzle. Normally I print with Orange ABS+. Another symptom is the EZStruder would slip, causing under extrusion. So, I cleaned that out. After studying the issue, I've had to bump up my hot end temperature to at least 260. That has solved most of my problem. This is strange, because I've used 240C for the better part of a year without issues. I have two hot ends. One brass and one hardened steel. They both exhibit the same behavior, so I'm sure it's not the temperature sensor.

[buggy]

Ive had almost the same exact issue with my prints, tried forever to figure it out to no avail. Decided i was going to set my esteps for my extruder back to the stock 80 do a test print to compare quality and to my amazement my print was almost perfect. I calibrated my esteps back when i built my printer almost 2 years ago and never thought to change it again. give that a try and see if it helps

[IMBoring25]

It's the axis steps per mm that shouldn't change from 80. Extruder steps per mm should be determined experimentally during calibration because there are many variables. 80 should not be correct for the extruder, which should be calibrated experimentally. You probably have problems elsewhere that happen to be opposite in sign and approximately the same magnitude.

[rootboy]

I have to agree with Buggy. When I get a plugged nozzle and/or stripped filament, the first thing that I do is to dial down my extrusion by 5%. That almost always fixes it.