Live Axle how to

[daniel_dsouza]

Hello everyone,
Our team has always used the kitbot drivetrain, and therfore has no experience with live axles on a drivetrain. I want to try and CAD a design to present to my team leaders, who have expressed a desire to change from the kitbot drivetrain. However, I can't figure out what parts to use...

I have heard that a hex axle is usually better than a rounded one, mainly due to the complexity of securing something to a round shaft. However, I can't figure out what parts I absolutely need or where to get them. (besides AndyMark)

Is far as I know, the kitbot had only one bearing to a wheel, and that was just pressed in. How should I attach bearings to the structural part of the drivetrain?*

What hardware should I used to attach wheels and sprokets to an axle?*

If our team decides to use a version of the design for the season, then will posting it on CD count as "open sourcing" it?

What are your opinions about direct drive for the center wheel (6wd) vs. linking it with a chain?

Is there anythign you wish you had known before making a live axle drive system?

*pictures would also be apreciated

Thanks in advance for answering a rookie's questions.

[EricH]

You guys are from Chandler, AZ... I would suggest a weekend road trip to Kingman, AZ. FRC 60 is one of the originators of the West Coast Drive. That was 7 years ago.

For a few answers: The hex axle is more common, but not for the reason you say. It's for reduction of stress when transferring power. You can use a round shaft, but you'll need some form of keyway; keyways like to act as stress concentrators. That can be pretty bad for the axle, maybe not immediately, and maybe not if your axle is properly sized, but potentially after an event, or during one, say during finals matches...

The Kitbot has 2 bearings per wheel, IIRC. If you only have one, there can be a bit of a problem. Typically, bearings are pressed in.

Hardware: clips on the end of the shaft, setscrews, it varies by design.

[robodude03]

Originally Posted by daniel_dsouza

Hello everyone,
Our team has always used the kitbot drivetrain, and therfore has no experience with live axles on a drivetrain. I want to try and CAD a design to present to my team leaders, who have expressed a desire to change from the kitbot drivetrain. However, I can't figure out what parts to use...

Have you taken a look at the kitbot on steroids presentation by 1114? You can do a lot with the standard kitbot drivetrain without having to go with a complete new setup. However, if you are looking to move to a new system, look into contacting a local veteran team as EricH has suggested.

[ajlapp]

There are some off-the-shelf chassis systems with both live and dead axles....Perhaps these will help you understand how to best design your own chassis.

221 Robotic Systems

Andymark