3D Printing 3d printing a fin can/retainer for long-burn motors

[Javacat1]

Hey y'all. I'm looking at 3d printing a fin can and a screw-on retainer for a 38mm minimum diameter I'm planning. I'm hoping to launch on motors like an H45, hitting ~0.8 mach. I've successfully printed retainers previously like for my scale Black brant V, but not anything like this design. I've been using PLA+, which has pretty much only gotten minor warping of single lines outside the main geometry, and minor soot collection from the backblast on the pad. Since this piece will be around an active motor for longer (separated by the cardboard body tube for the fin can), have you guys encountered anything I should worry about with regards to potential warping/damage? I've seen the Limit thread on here, and I have significantly thicker fins (I <3 airfoils) and planning on going slower, so I don't believe I'll be encountering most of the issues in that post.

 

[cwbullet]

Just an FYI: If you get warping with PLA+, it is often poor adhesion. Look at the build plate or your Z offset.

 

[PhilC]

I moved away from PLA derivatives to PETG about 18 months ago. PLA seems to deform over time, possibly due to water ingress. PETG also seems to be stiffer which may increase the flutter speed. I've recently made a 29mm min diameter with printed fin can so I'm equally interested to learn what others think.

 

[cwbullet]

I moved away from PLA derivatives to PETG about 18 months ago. PLA seems to deform over time, possibly due to water ingress. PETG also seems to be stiffer which may increase the flutter speed. I've recently made a 29mm min diameter with printed fin can so I'm equally interested to learn what others think.

It does, but PETG is also more sensitive to UV light so coat it.

 

[Javacat1]

Just an FYI: If you get warping with PLA+, it is often poor adhesion. Look at the build plate or your Z offset.

Oh yeah I’ve gotten that lecture from friends of mine who’ve printed far longer than I have. I may not have been super clear in my post: Print came out fine on the plate, only warping I noticed was more or less a single line I probably should have cleaned off got minor warping because of the backblast on the pad. I do have some PETG I’ll be getting soon that I’ll try out based off of what people have told me.