3D Printing Fin cans

[cwbullet]

Is there any interest in fin cans?

I have started testing some fin cans. If I print extra, what size tubing do most want to see on printed for?

 

[Arnie]

4 inch Quantum tube adaptable

 

[cwbullet]

4 inch Quantum tube adaptable

That one might have to wait till January. I have to tube in my larger printers.

 

[hball55]

My experience may be an outlier, but I launched a minimum diameter 54mm rocket on an I65 motor, and right from the start things went bad. The motor warped the fins, two in one direction and the third in the other direction. The rocket corkscrewed violently and got an altitude far less than simulated.

When I recovered the rocket, the fin can resembled a boat motor prop, except for the fin warped in the opposite direction.

 

[GlenP]

Centuri Screaming Eagle fin can.

 

[cwbullet]

My experience may be an outlier, but I launched a minimum diameter 54mm rocket on an I65 motor, and right from the start things went bad. The motor warped the fins, two in one direction and the third in the other direction. The rocket corkscrewed violently and got an altitude far less than simulated.

When I recovered the rocket, the fin can resembled a boat motor prop, except for the fin warped in the opposite direction.

What material? Did you fly it naked?

 

[hball55]

What material? Did you fly it naked?

Not sure what material it was, PLA? It was one of Landru’s (additive aerospace) early items. Yes, it was naked, no paint or finishing epoxy.

 

[cwbullet]

Not sure what material it was, PLA? It was one of Landru’s (additive aerospace) early items. Yes, it was naked, no paint or finishing epoxy.

PETG and it is not a great filament for Mach especially if sustained.

 

[hball55]

PETG and it is not a great filament for Mach especially if sustained.

I doubt the I65 motor gets a rocket anywhere near mach.

 

[cwbullet]

I doubt the I65 motor gets a rocket anywhere near mach.

Are you sure? Minimum diameter and long thrust and low weight could do it. I have a 54 minimum that his 685 mph. That is close enough to heat up the fins and I am not the lightest builder. I am sure someone can do it.

 

[Landru]

Are you sure? Minimum diameter and long thrust and low weight could do it. I have a 54 minimum that his 685 mph. That is close enough to heat up the fins and I am not the lightest builder. I am sure someone can do it.

I have personally done M1.3, and have reports of successful flights to M1.6 without any distortion. Time above Mach is obviously an important variable. So far I'd say PET fin cans are a great success in the vast majority of cases.

 

[cwbullet]

I have personally done M1.3, and have reports of successful flights to M1.6 without any distortion. Time above Mach is obviously an important variable. So far I'd say PET fin cans are a great success in the vast majority of cases.

That makes sense. Friction creates heat and the longer the exposure to the heat, the more deformation you will get. An I65 might not reach Mach, but it will have a longer exposure to heat and friction.

 

[thzero]

I have started testing some fun cans.

Fun cans!!

 

[DarthMuffin]

Is there any interest in fin cans?

I have started testing some fun cans. If I print extra, what size tubing do most want to see on printed for?

Around 2" diameter. I'll find a BT to fit what you make. I want something smallish for a 29mm motor but a fat enough tube to fit a JLCR in is my only requirement. My Cheetah is a 1.9in tube I believe, and that's getting about minimum size to fit one.

I have a Prusa Mk3 and I might try to find something, but I'm not a great CAD designer. Nor have I tried exotic filaments like PC yet. So pre-built would solve headaches.

Don't care what they look like, I'm function over form.

 

[hball55]

That makes sense. Friction creates heat and the longer the exposure to the heat, the more deformation you will get. An I65 might not reach Mach, but it will have a longer exposure to heat and friction.

I believe it was the flames at ignition since the rocket started corkscrewing less than 50 feet off the rod. Thrust hit the blast plate and deflected up and warped the fins. Probably should have had the rocket on a standoff further from the blast plate. Only problem, is there’s so little length of rod to get up to 30 fps and the I65 being so low thrust, I was courting trouble from the start. I was able to cut the fin can off and replaced it with an Acme fin can. The rocket flew better the next time, just not on an I65.

 

[cwbullet]

Around 2" diameter. I'll find a BT to fit what you make. I want something smallish for a 29mm motor but a fat enough tube to fit a JLCR in is my only requirement. My Cheetah is a 1.9in tube I believe, and that's getting about minimum size to fit one.

I have a Prusa Mk3 and I might try to find something, but I'm not a great CAD designer. Nor have I tried exotic filaments like PC yet. So pre-built would solve headaches.

Don't care what they look like, I'm function over form.

I have one that size. I can upload it to Thingverse next week if you are interested.

 

[cwbullet]

Fun cans!!

Don’t search for that on google.

 

[beeblebrox]