I've been having printer grief so I'm taking a stress break but i just thought I'd catch you up on stuff .
This is the final version gearbox with optional mono shock mount .The mount is a draft print so its a little rough but you get the idea .
These are the jigs for modifying the front spool and creating the axle for gear 2 that has a cross pin and screw hole to drive the chain sprocket .
First the front spool jig . You insert the spool , place the lower part in a a vice , then cut flush with the far end , file the flat on the cut away section and lastly drill a 2.5 mm hole through the guide hole in order to tap an M3 thread to fit the front sprocket .
Second is the 5 mm axle for gear 2 that needs two 2.5 mm holes drilled for the gear cross pin and the M3 hole for the rear chain sprocket , again you insert the 5 mm steel rod and clamp in a vice and cut flush with the jig end then drill the two 2.5 mm holes through the guide holes and then tap the one for the sprocket .
Lastly i found a part that can be modified easily to make half of the front spool , it just needs a hole re-drilled from 3.5 mm to 5 mm , otherwise its virtually exactly the same other than a larger set screw thread size and that's a good thing in my book ! sorry about the lousy pictures , its on the left , the one on the right it a very worn and damaged original , its from the FTX Vantage and easy to find part No FTX6273 , its surface hardened but it drilled easy enough , i did it on a lath but i can easily make a drill jig if needed as it does need to be drilled true or i guess i could mod them as its very quick and easy but that bumps the price ....
