Barróg - Featherweight Lifter Build Diary

[Ocracoke]

What are common ways to mount these gears to the axles, and how to mount the axles to the bulkheads? What steps can I take to avoid the gears from misaligning? Should I use bearings and, if so, what kind?

There are two kinds of shafts. There is a dead shaft, where the shaft is static and the gear slips around the shaft or has bearings inside the shaft to allow it to roll and then there is a live shaft, where the shaft is mounted by bearings on either end and the gear is fixed to the shaft. In Kaizen and Jibril, the axe is a dead shaft but in Jibril's drive system, it is a live shaft.

The material that the shaft is mounted in is important too. HDPE deforms way too easily (though I will confess, Kaizen's axe was a dead shaft in HDPE with a cap on one end to prevent it falling out).

The gears I have come with grub screws in them which I drill a indentation into the shaft and then threadlock them in. If yours haven't, I suspect welding it would be the best option.

Given your design, I would go for a live shaft for your first stage, mounted on flange bearings (https://www.gearsandsprockets.co.uk/...lock-bearings/ for example) and then perhaps a dead shaft for your final stage to the arm but, weight allowing, pillow bearings might work here.

What would be the recommended way to machine these parts to minimize loss in strength while improving weight efficiency? Should I use the 10mm rods, or go up, or even down?

10mm rods are OK in my opinion, depending on what it is made out of. I would have said a lathe to remove some of the bulk from the gear hubs would have been the way to go on losing weight.

Always make a cardboard or wooden template first and its a case of just being precise with your markings. Noting I have never done a chain drive, the sprocket and chain needs to be perfectly aligned so I would mount your motor with the sprocket on first, measure from the edges of your robot as to where the sprocket is horizontally and then mount your second sprocket on the subframe to line up with the depth of your first sprocket.

So if, after being mounted, the motor sprocket, from the far left edge of your robot, is say 280mm in, the second sprocket also needs to be 280mm in. I am sure others who have done a chain drive before can advise further.