Sold 3D PRINTED FIN CAN FOR BT-70

3D PRINTED FIN CAN FOR BT-70

This is a test print that perhaps someone can make use of. I was very pleased with the fin can design and the print quality. It appears to be quite light and strong due to the airfoil shape and sparse fill. The fit is a little snug. The ID measures about the same as the tube OD, when it would have been better to have about .010” clearance for glue. I corrected that on subsequent builds. It has one boss threaded 6-32 for a 1010 rail lug. Sell $10 including postage to continental US. (Note to self: BT70 Fin Can 02).

Single Span: 2.5”
Number of Fins: 3
Outer Layers: 1 X .4mm
% Fill: 20
Fill Pattern: Grid
Weight: 34g
ID to Tube Clearance: Zero
Color: White

If it's a test print, don't sell it. Sample it to whoever wants it. After they cut the tolerance let them judge it and talk about it. It looks great, you may be on to something profitable...

That sounds good. Postage should be at most $4.00, so I'll let the first two go for $4.00 each shipped. The next one (labeled BT70 Fin Can 03) I increased the ID .005", it is better but still a spec on the snug side.
Single Span: 2.5”
Number of Fins: 3
Outer Layers: 2 X .4mm
% Fill: 20
Fill Pattern: Grid
Weight: 43g
ID to Tube Clearance: .005"
Color: White

The fill on BT70 Fin Can 03 is 30%, not 20%. I also thinned up the "can" portion as it was thicker than needed to match the strength of the fins.

Did you design the file?

Yes, I designed the file. It is a scaled down version of a design I was working on before 3D printers became all the rage. Back then, I purchased a 2D CFD program from Apogee. I wanted to make a carbon fiber fin can for my Thundercloud rocket that would work just as well as the original plywood fins (shown in my icon photo), but be stronger, lighter, and move the CP back farther. The design that evolved from playing with the simulations is not far off from the fin can that I printed.

FYI, the first two fin cans are sold! I have a third (BT70 Fin Can 04) that I tweaked a little more and am very happy with. The fit over the tube should be perfect with epoxy or wood glue. The can thickness is .125" thick at the lug boss, so a 1/8" spacer will work nicely for the forward lug. The fins are about .300" thick at their widest point for strength. I will offer this one for $10 shipped to continental US.

Single Span: 2.5”
Number of Fins: 3
Outer Layers: 2 X .4mm
% Fill: 30
Fill Pattern: Hexagon Honeycomb (axis symmetric)
Weight: 37g
ID to Tube Clearance: .010"
Color: White

The third fin can has been sold.

Would you consider making a few for 1.25" OD and 1.5" OD tubing?

I would probably do that. Is this for low power or high power? Please provide any relevant details, especially the exact type of tubing and manufacturer that it needs to fit. Is a 6-32 thread for a 1010 rail button ok? I can also do four fins instead of three if you prefer.

Thundercloud said:

I would probably do that. Is this for low power or high power? Please provide any relevant details, especially the exact type of tubing and manufacturer that it needs to fit. Is a 6-32 thread for a 1010 rail button ok? I can also do four fins instead of three if you prefer.

Click to expand...

Private conversation message sent. Thanks.

Did this item sell? Can I mark it sold?

Chuck, yes it did sell, so please mark it sold. I cannot seem to do that anymore. Under Thread Tools all I get is:

Marked sold.