Hehe triple-hybrid test assembly: CAD printout, pen lines on paper, some actual components. This could be an art form.
Conversation
The first complex thing I ever built was a model kit glider ~1988, that came with 1:1 scale drawings. This now-vintage one. I built it by using drawing itself as the construction template, with nails on a board,. It was all balsa wood cut-and-glue pieces. 1:1 is a great hack!
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One minor problem I have to solve now is to make a passive roller out of this wheel. It has a 3mm d-shaft hole to press fit on the shaft of an N-20 moto, which is how I’ll use it for the 4 drive wheels, front and back, but the middle 2 wheels need to be passive free rollers.
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First thought is to try and drill out the D into a 3mm circular hole, and put a circular shaft into it supported by a fork. But I don’t like destructive mods. Alternative is to use a round shaft with a D-end, and cantilever other end in a sleeve.
There’s just so many details.
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Sketched out wire harness problem. I need to solve for A and B and make 4 of these.
Current solution: A and B both 9-pin DuPont wire-to-wire connector pairs. So would need to cut off the connector that came with the sg90. The red cable needs to route through aluminum struts.
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Thought of using ribbon cable for this (initially thought 18 conductors together for 2 drives on one side). suggested IDC punch down connectors for ribbon end. Not sure what it would mate to on board end… wires soldered onto an IDC header?
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thought this was overkill and just shove 9 separate wires through. He also suggested USB for the red interconnect, though it’s not meant for this use case.
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One interesting thing… the orange stepper female 3-pin futaba connector is what’s needed at the board end. The cable is even long enough and fits through aluminum strut. I may be able to just make A/B a 6-conductor problem instead of 9.
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And for the 4+2 N20 problem, the cables at either end are not long enough but together the should do the trick. Remember this sketch is ~ to scale. If so, no red cable/connectors may be needed at all.
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