BMI CAD Fin alignment jig

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Well-Known Member
Sep 10, 2011
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This is a well machined unit. Guides fit into base slots very precisely. Pricey unit but it will last a lifetime. This thing is solid. I got the 12 inch deluxe set with 13, 18, 24 and 29 motor mount pins. 4 guides, and 4 clamps. Slots for 3 and 4 fins.

Base plate is 1/2 inch thick, guides are 1/4 thick at slot end, one side flat other offset for thicker fins. Motor pin hole is 13mm all pins fit precisely as well. 13 mm is 2 inches long, 18 and 24 mm are 2 inches + a half inch long base pin, 29mm pin is 4 inches + the half inch long base pin.

I put my assembled 38mm Madcow f-g kit on jig with 29mm motor pin. With fig guides on flat non offset side the fins fit flat on guides. Already see how precisely this jig works because one fin is off a bit from perpendicular. Guides are 3 1/2 inches tall from top of base plate. And 4 inches wide.

Not much else I can add. It's a solid tool that will last. Nice job BMI CAD!
I have had one for many years. Long ago I forgot what I paid for it. It is super fine. you have to keep the slots real clean. I cover mine when not in use. I mounted mine on a folding try table and hang it up out of the way.