MakerGear Forum

I sculpted a piggy bank for my girlfriend for xmas, split the model in half and printed in two pieces. the front half printed GORGEOUS...then the back piece had weird shifting issues? my only guess is one of the little screws that holds the X and Y motor to the motor came loose...AGAIN...does that look like the issue to anyone else?







i say the little screw might be the issue because its happened more than once with those little screws coming loose. This screw (i was told to get a glue for these screws to keep this from happening but i haven't had time to run to a hardware store this week) i'm assuming this is the problem?



Any ideas?

PS. any ideas what those little bumps are? the front half that printed has NO bumps, its printed amazing i must say. the back is all messed up though. the shifting and those little bumps...ARGH!!!

If you rotate the extruder cog by hand, do you feel any play in it at all? If you do, that's definitely your problem. Otherwise, you are skipping steps for some other reason. Possible reasons might be you are trying to print too fast (what speeds are you using?), or overextrusion might be causing your nozzle to contact the print. Also try rotating your whole extruder in its mount by hand. If it shifts at all off vertical, you may have a cracked mount.

The zits are a perennial issue, you can mess with coast/wipe/restart settings to try to reduce them. Try 5mm wipe, .20 mm coast, -.20 mm extra restart distance in some combination to see if it makes things any better. What I like to do though is use the Choose start point closest to specific location setting in the Layer/Start Points tab, and choose a start point that will collect the seams up into a seam along an unobtrusive surface. If you really want a smooth print, you can prime and sand your part and having them all in one place makes it easier to hide them.

Yes at ine point i think i uad mentioned putting some locktite on the setscrews but you really need to tighten those better. Even without loctite they should not keep loosening up all the time if they are torqued down. The bumps as jin said are another issue and just tuning. Het the skipped steps under control first then dive into tuning. You cant tune when you have mechanical issues. Once you get that under contr then just follow jins advice

@jcz

did you go into detail more about choosing a start point? I'm looking at my s3d settings and optimize start points for fastest printing is checked.

so are you saying you can define a seam? I would love to know more about this, love to see some examples of how this can be useful. This is just something I know nothing about at the moment so it's hard for me to grasp without seeing this in action I guess, I'm still not exactly sure how I would use this.

X\Y axis movement 9600
z axis 1200

I believe the extruder will not move by the way, I can't check it right now cuz I'm doing a test print but I don't believe that the issue Thank God.

Under the Layer tab, the lower right group, Start Points. The third option is Choose start point closest to specific location. The default, 100x 300y is down the middle and way back off the bed, so if your object is centered the seam should run down the "back" of the model. You can change that to put the seam wherever you'd like. A simple way to figure out the coordinates of various locations suggested by jimc is to model a very slim cylinder and drop it in with your model. You can move it around, then double click it to get the exact bed coordinates.

Oh, your travel speed is fine, I use 18000 x/y movement speed. But what is your printing speed (Default Printing Speed at the top of the Other tab)?

jsc wrote:Oh, your travel speed is fine, I use 18000 x/y movement speed. But what is your printing speed (Default Printing Speed at the top of the Other tab)?

Default Print speed. 4800.0 mm/min

i started a new print btw and its...maybe halfway done, i see one more shift again. damn. . .

i'm going to print some test shapes tomorrow and i'll try a print with that seam you speak of JC. looking forward to testing that. \

does that print speed seem ok?

Yes, that's my default speed, too. I suspect you have a mechanical issue. Check if any of the belts are slack.

metrons wrote:maybe halfway done, i see one more shift again. damn. . .

When:

• You ask for help with a printing problem
• We tell you a loose pulley setscrew will cause that
• You show a picture of a pulley with a loose setscrew
• We tell you to tighten the setscrew securely, using Loctite to hold it in place
• You don't do that
• And the same printing problem happens again

Then there isn't much more anyone can say, is there? Your prints will be junk until you fix the problem.

Yeah, Christmas really isn't the best time to make a tool run, but, while you're in the store, pick up a set of fine needle files so you can repair the damage that setscrew has done to the flat on the pulley shaft. The setscrew must sit on a smooth, flat surface, not a bunch of gouges, to prevent any motion.

Please?

Hooray. A patronizing reply. So helpful.