Since writing the first few blog posts I’ve had several other folks who purchased this same gimbal, the GB004 from Famous Hobby, reach out to me with their own struggles. It’s good to have the opportunity to put our minds together as we work through this build.
I’ve made progress but I’ve also had a few setbacks, three of which I’ll touch on here.
1. I cannot get the roll support bar to align through all degree’s of roll
After repeated attempts to get the carbon-fiber roll bar to align with the four guide wheels I became convinced that there was something wrong with the carbon fiber piece — that it wasn’t perfectly round. So I decided to test it using a bit of geometry (or pseudo geometry).
I traced the outline of the arc then used a compass to make bisecting lines throughout the arch. I was looking to see that they would all intersect at one center point. Then I would measure to make sure that point was equidistant to each section of the arc. I should be able to put the compass on this center point and trace the arc perfectly.
With my crude tools for testing I believe it’s close enough to show that the arc is perfectly round.
Spending a lot of time thinking through this I realized that I was approaching the alignment all wrong. I should have attached the roll bar first and adjusted the other elements of the gimbal to match the roll bar. I also noticed that the tube running up and down was turned 1-2 degrees out of center and it was also set to the wrong depth.
Once I made these adjustments the roll aligned MUCH better.
2. The roll mechanism doesn’t roll smoothly, I think there are wrong size washers
The wheels that the roll bar ride on do not roll smoothly. I wasn’t sure if I needed to add grease, if the wheels were just too tight and needed to be sanded down a bit. Upon really close inspection I noticed that one of the wheels would spin more freely than the others. Looking at the washers I noticed that one of them was slightly smaller than the others.
I contacted Famous Hobby and they agreed to send me a set of new washers. I requested 12, they should be arriving shortly and I’ll let you know if that improves the movement of the wheels.
3. The motor wires on the 8017 broke loose.
I highly recommend that prior to doing any work on your gimbal make sure that the motor wires are securely glued down using epoxy glue. Only after a little bit of work the tiny wires broke loose. Because they broke off right at the winding point around the stator there was no chance of reconnecting them with solder. Famous Hobby was gracious to replace the broken motor.