Joystick Upgrade

This blog covers a minor upgrade to the joystick bearings.

Overview
The pivot for the joystick had small lateral movement after the pivot bolt was tightened, a check revealed that the spacer tube had cut into the nylon washers as a result of trying to remove all that movement, so the builder pleads guilty to creating the issue.

The idea below came in one of those "I wonder" moments that resulted in four [4]  plastic tube connectors being purchased on a hunch it would redress the issue.

Installation

Tube Connector

The front stick was chosen as the guinea pig and was disassembled for the upgrade, checking showed the opening in the torque tube was 35 mm and with the inserts [bearings] installed a packer of 3 mm was required.

The tube connector rear attachment was removed by cutting with a razor saw by mounting in a lathe chuck then in a series of operations rotating the chuck to each cutting point, finally the resulting bearing was sanded on a flat surface on 80 grit paper to remove all the flash. Finally the existing 1/4'' hole was enlarged to 1/2'' using a step drill to allow the bearing to fit over the joystick mounting tube and associated welds.

Cylinder is waste from component on right

The overall length of the 9 mm OD spacer tube was set at 32.5 - 32.3 mm ensuring the assembly could not be locked at assembly. These were re-manufactured from 5/16'' x 0.035'' wall 4130 tube reamed 0.25'' through in the lathe. 

Installing spacer washers

Note: The brass spacers were replaced with steel to ensure that the edge would not deform when tightened fully and were oiled at installation. 

The spacers are AN4 area washers with thin double sided tape applied onto one face, fitted at the inside face of the torque tube with the tape preventing rotation while fixing them for assembly.

Note: Tacking with a brazing / silver solder would be the ultimate solution

Front installation

The working faces were coated in Labelle 106 PTFE grease before assembly and using a 1/4'' guide pin a AN4 bolt fitted, torqued ensuring the spacer tube was fully bearing on the washers to lock all three [3] components into a single assembly.

Rear installation

The rear opening was smaller so the bearing faces were sanded to create the correct overall length and the spacer tube length adjusted to the correct length.


Comment
It looks right and the finished stick assembly is rock solid with no play noted on any axis.

Happy Puppy....!