2 things:
1> the screws that came with the cim-sim are too long for the 550s and will cause binding. you’ll need to shorten them to avoid binding (at least we had to)
2> We’ve found that, while very good, the Andy Mark gearboxes require that you grease them, break them in for 1/2 hour, take them apart, clean them, and then rebuild and regrease them. if you don’t you’ll end up with menal filings within the gearbox and that will cause more torque loss and greater gearbox heating (and possibly more noise).
This is great advice. We’ve been doing this with all of our AM boxes since the Toughbox was introduced in 2008. Usually, we’ll assemble them, run them for a bit on a bench switching between forward and reverse periodically, crack them open and check to make sure everything plays well together. Usually we can hear a difference after just a few minutes of run time.
Our team received two additional Toughbox kits last week from AndyMark, built them up over the weekend, and then got to testing them this evening. When we tested them, we got a grinding noise in both of the new boxes. When we opened up both boxes that the team put together, we discovered that the short shaft in both were machined incorrectly. The length is correct, but the hex length is too long (longer than spec).
We took a picture of the new shaft, and an “old” shaft that we pulled out of a “good” Toughbox, and will be contacting AndyMark tomorrow. Guessing it is a bad batch of shafts. Will pass on what we find out from AndyMark.