Raising Nozzle When Traveling

[clm7214]

So I'm pretty new at this and I have been printing almost constantly lately (printing ericthepoolboys 22RE) and have noticed that on large prints at higher speeds, the nozzle tends to contact the printed object ever so slightly when traveling. It honestly just grazes, but sometimes is enough to knock a support loose after repeated hits. Not a big deal on quick prints, but on a 26 hour engine block print it really stresses me out. I'm using Simplify 3D and a brand new MakergearM2 leveled and adjusted perfectly. Has anyone else had this happen or does anyone know of a way to add a "raise by X mm when traveling" to the code?

Thanks all, and love this forum BTW.

[3dPrintingMD]

Hi and welcome to the forums.

What your looking for is on the Extruder Tab, Retraction Vertical Lift. Most go with 0.20mm.

Please note that when this happens depends on when your performing retraction, which may be adjusted under ooze control on the advance tab.

[Jules]

It happens frequently. Depending on what you are printing, sometimes the edges can warp and curl up. (Depends on a lot of factors, like whether it's an overhang with PLA and there's not enough fan hitting it to cool it off, or if the gap is set correctly between the nozzle and the bed for the first layer, or whether the extrusion multiplier has been calibrated correctly, or whether the filament diameter is uniform. Each of those things can cause over-extrusion or warping.)

Support is particularly tough, because it doesn't have a lot of surface area contacting the bed and it gets knocked loose very easily. Make sure you are using enough adhesive. (And I hope you're using S3D, cause that's the only one I've got suggestions for... )

I like to use a cross-hatched support instead of the default single parallel bands. It's more stable. Set that by using Support Infill Angles of 45° and -45° on the Support tab of S3dD.

Also, if you set a Brim around the part, the support structures will be printed on top of it, giving them a much more stable base.

In S3D, on the Additions tab, check Use Skirt/Brim.
Skirt Layers: 1 or 2 (2 is more stable)
Skirt Offset: 0.4 mm
Skirt Outlines: 15-20 or however many you need to completely capture the support structures.

PLA warps if it isn't cooled off quickly, and any overhanging parts on the back that don't face the fan directly tend to warp a lot. Add a desk fan behind the machine to cut down on that if you're working with PLA. (If not, ignore that bit.)

In Simplify3D, you can force the printer to jump on retraction, (which can help with clearing little bits that stick up), but ideally, you'd probably rather not have the filament warp up on you in the first place - it tends to screw up alignments down the road. (And i'm not sure it helps with support structures.) But, if you wanted to try it.....

In the Extruder tab, set the Retraction Vertical Lift to from 0.3mm to 0.6 mm. And on the Advanced tab, uncheck Only Retract When Crossing Open Spaces. Optional, (because it's really going to add to the print time), is to also check Avoid Crossing Outline for Travel Movements under Movement Behavior.

I put that suggestion last, because although you can make it jump, it's kind of an extreme solution to a problem that can usually be avoided by cooling off the print (if you are printing PLA) and locking down your support structures. (And I find all the hopping around annoying...it makes it noisier, and makes me jittery.)

And I see that someone beat me to it again......damn I've got to stop being so wordy.

[clm7214]

Thanks for the great responses, I'm not sure how I overlooked the vertical lift option. I'm trying out a large brim and adding vertical lift now while printing the model camshafts vertically. I was wondering how to get more stable support structures also, thanks for the tip.