After complete BB failure we needed to switch out two small CIMS from our drive, we had the free weight and motors so we decided to put in the Large CIM and FP as well. Due to planning ahead and some quick CNCing we will be able to make the two new gearbox plates during the fix-it window.
Luckily, the new motor mounts for the arm were made as a precaution before ship.
Awesome! Thats the fastest remade gearbox i’ve ever seen
But a question… why did you opt to use a big cim instead of another small cim? For the extra low end torque?
The efficiency and horsepower are greater on the small cim… but like I said the big cim does have a heftier grunt (torque) at the low end.
-q
Keep it thin your bound to win… Right? (That is pretty sweet by the way)
Well… I have to be honest… It was designed before ship one day when I was bored… It has holes to mount any of the 3 of the following; 2 small Cim, one big and one FP. So it was a perfect fit. Two of these were CNCd this week during the fix-it window.
Also, we originally had two small CIMs (see here; http://www.chiefdelphi.com/media/photos/27694), but we needed to free up two small CIMs for the arm. We replaced those with the big CIMs (we weighed in at 93 lbs at our first regional, for the 5’ class). We realized we had the weight, and the free FP motors so we decided to add those in as well. We already had to CNC new plates in the fixit window, my as well get the most kick out of the gearboxes.
And I got a comment on being “spoiled” by Northrop Grumman and their CNCs and how we were “cheating the system” in reference to this repair. Nearly all of our CNCd parts (except the wheels because we had so many; Northrop did those) were made by a father and son pair who just learned how to machine last fall at a local community college. Both new gearbox plates were made in the fix-it window specified by the rules as well.To top it off, the son is a sophomore and the father is a Dentist. So, in regards to all teams, don’t make an assumption about any team unless you truly know the facts.
EDIT: We have matched the free speeds of the motors (28T on big, 14T on the small CIM and the AM FP planetary) but were wondering if the fact that their power curves were different makes a difference. Anyone have any experience with this? The main issue I’m worried about is FP burnout.