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Fin can CAD file for 3D printing

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spyfly

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Hi,
I have a friend who works with 3D printing. They have some pretty exotic materials (carbon fiber, high temp type blend of materials with high strength) he volunteered to print me a fin can, so I was thinking of taking him up on his offer...

Only problem is.. I don't have a design file that we can use (and I'm no good with cad programs) so I'm looking for a 54mm or 3" fin can cad file that we can use as a design start in this project.

Anyone got one?

Thanks
 

JumpJet

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Tell me what you are looking for exactly and I can draw one up for you and supply you with an STL file for printing. If the fin can slides over the 54mm tube tube I need to know what the OD of the tube is since the 54mm should be the ID of the tube. Give me some dimension of the fin and if you want then to be flat, airfoiled or double taper like a Nike Type fin and I'll draw something up for you.


John Boren
 

spyfly

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Fantastic!
Thank you John!
I will pull together a paper drawing with the design I'm looking for.
I will message it over to you sometime next week.

Thanks so much
Martin
 

spyfly

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Also,
Since we have so much experience on this forum let's talk about the design in general.

Initial design thoughts:
- 4 fin design to get enough fin area with a as short fin span as possible for stiffness.
- use "fillets" to stiffen up the fins.
- air foil for leading and trailing edge.

Other thoughts?
 

ttabbal

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I would consider knowing the line thickness the printer uses. Then make the walls a multiple. For example, mine lays down 0.6mm lines. So if I make things 2.4mm thick, the printer can easily make that happen. If I ask for 2mm, something has to give.

For the CAD guys, I'm curious how you would make a fin can. I'm still learning 3D CAD and haven't come up with what I think of as an elegant way to make them, keeping them at the right angles etc..
 

spyfly

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Great comment on the line thickness. I'll track that down.

Thanks
 

new2hpr

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Before you get too excited about maybe trying a machbuster or similar MD design, the "exotic" carbon fiber 3d printing will be NOWHERE near as strong or stiff as epoxy/fabric layup carbon or glass. Probably not even as strong as plywood.
-Ken
 

spyfly

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Yep, well aware that they are much less strong then composites. Still very fun to get access to the high end stuff and try to design something interesting.
 

djkingsley

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I would consider knowing the line thickness the printer uses. Then make the walls a multiple. For example, mine lays down 0.6mm lines. So if I make things 2.4mm thick, the printer can easily make that happen. If I ask for 2mm, something has to give.

For the CAD guys, I'm curious how you would make a fin can. I'm still learning 3D CAD and haven't come up with what I think of as an elegant way to make them, keeping them at the right angles etc..
I make thin wall parts fairly often, and as you surmised sizing to multiples of your expected line thickness is the first step. Then you can play with the extrusion multiplier to dial in the print, the multiplier can/will change with material.

I usually print a partial part and do some destructive testing to make sure the thin wall portions are properly bonding.
 
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