February 4, 2018
Description
I was looking for something to impress my brother-in-law for Christmas. He always seemed inordinately pleased with the gear systems I had given him before, so I was looking for something more elaborate. I liked the asymmetric planetary gears by faggahz, and the eccentrically cycloidal drive model by otvinta3d, but neither seemed to quite do it. So of course the logical thing to do is to connect them together. I made extensive use if the customizable involute spur gear by artanian and would like to say I made it through logical design processes and that it worked perfectly the first time, but that would not be correct. So exactly how much of this did I do? I designed the transmission and the support structure, both of which I thought came out pretty well.
I of course designed this to print on my machine, which does outside measurements pretty well, but tends to make inside measurements a little small. Since the tolerances on everything are a little tight, you may want so subtly adjust the size of a few components if it doesn’t work for you. Ring 2a, Hold 5, and all the axles are good candidates for this. It uses 6 #4 x 0.5 inch flat head bolts with nuts to hold the supports to the base. You could glue them in place, but then you wouldn’t be able to take it apart if it needed repair.
Assembly tips:
Adjust the contact layer to spread as little as possible while maintaining a good bond (this is a nuisance to clean off gears).
Print one of most things but two of “Support5,” “Clip4,” and “2_peg” (so a total of four pegs).
Make the planetary gears first; these fit most closely and it will tell you if you have to adjust sizes. They should all snap in at once. They should also be capable of rotating without the square support (Hold5). There are several ways they can be inserted, but only one were the support lines up with all the holes (the side of the support against the build surface goes away from the gears). The pegs join all the gears to the support except “Planet 7” (the small one).
To make the transmission, insert “Small_axle_ext” through the 10 tooth gear (pliers may be necessary). Insert the washer one end and the same end through "Hold5" into "Planet7." Insert the plain end of “Bottom axle 1” into the 27 tooth gear (I glued it, but it may not be necessary). Engage the 27 and 10 tooth gear the drop “Brace 2a” over both axles (snap it onto the smaller one). Place “Spacer1” on the larger axle.
Place “Wheel2” between the two “Support5’s” (the washer-like bearings go on the inside). Place this assembly over “Bottom_axle1” and secure with “Clip4.” The full assembly can then be attached to the base with the 6 nuts and bolts. Insert the plain end of “Top axle 1” into “Spinner 3,” glue if desired. Engage “Pinion2” to “Wheel2” and pass the axle through it. Secure the axle with the other clip. Place “Bridge3” over the protruding struts of the supports and ring gear (should be a good friction fit). And you should be done.
License:
Creative Commons - Attribution
Harfigger
