|
Re: Motor Speed offset
The first thing to check is mechanical. It is very easy to build the gearbox with a gear backwards (the raised bosses around the bores should be on the bearing side) or with other binding or dragging problems. Sometimes something just doesn't fit properly and binds, even when you've assembled it correctly. We've had binding at the cluster shaft (replaced shaft), with the large cluster gear rubbing the output shaft's rear bearing (replaced housing), and with CIM pinions pushed too tightly against the large cluster gear (solved by rotating the CIM 180 degrees around its axis).
Try backdriving the gearbox by hand (a hub is handy for this) and feel for spots where it sticks. If you find any take pieces in and out and rearrange until you find where it's binding.
Edit: Our "first time" smooth-running success with TB-minis has been no better than 50%. After a particularly bad year of it in 2016, this year we have been verifying that our gearboxes run smoothly before we ever put them under load (that is on the floor) or install encoders.
Edit2: If the gearboxes are OK, check that the belts are lined up and snug and that the idle (corner) wheels rotate freely when not attached to the belt, and that the direct drive (center) belt is no harder to backdrive than your initial tests.
__________________
If you can't find time to do it right, how are you going to find time to do it over?
If you don't pass it on, it never happened.
Robots are great, but inspiration is the reason we're here.
Friends don't let friends use master links.
Last edited by GeeTwo : 08-02-2017 at 16:35.
|