pic: FRC971 Spartan Robotics Presents: Renegade

[kevincrispie]

We also worked to make new wheels this season, to complement the new drivetrain.

Tread is attached via zipties.
Wheels measure around 2 inch wide and 3.5 inch tall w/ tread.

Thank you to RC for machining these. They turned out great (so far).

[Sh1ine]

Originally Posted by kevincrispie

We also worked to make new wheels this season, to complement the new drivetrain.

Tread is attached via zipties.
Wheels measure around 2 inch wide and 3.5 inch tall w/ tread.

Thank you to RC for machining these. They turned out great (so far).

Very nice robot.

We also use belts for our drive train. This is our second year using them and as for a a skid steer type drive train is concerned I do not think we will ever go back. We use live axles in our system. It seems like you are using a dead axle system with the sprockets machined directly into your wheels (very cool). I would love to see a up close and personal view of how your power transmission works.

[AlecMataloni]

First of all, Congrats on the win at Sacramento. I'm glad to see you guys coming to the championship this year. I really wish I had seen 971 at St. Louis last year.

Second, I'm curious about the pistons you're using to shift. I've never seen anything like that! How reliable are the "Pancake" pistons? Are there any drawbacks to using them, compared to the standard actuator on an AM supershifter? It looks like they save quite a bit of space and weight. Also, where are they for sale?

[Cory]

Originally Posted by AlecMataloni

First of all, Congrats on the win at Sacramento. I'm glad to see you guys coming to the championship this year. I really wish I had seen 971 at St. Louis last year.

Second, I'm curious about the pistons you're using to shift. I've never seen anything like that! How reliable are the "Pancake" pistons? Are there any drawbacks to using them, compared to the standard actuator on an AM supershifter? It looks like they save quite a bit of space and weight. Also, where are they for sale?

We first used the pancake cylinders in 2010, with the 3 position variety for our PTO, due to the relaxed pneumatic rules. I believe we were the first team to use the flat cylinder line from Bimba.

We used the 2 position ones last year and this year.

They're no more or less reliable than the standard Bimba line of cylinders. They do require different fittings, since they are so small, and must be face mounted.

[AlecMataloni]

Originally Posted by Cory

We first used the pancake cylinders in 2010, with the 3 position variety for our PTO, due to the relaxed pneumatic rules. I believe we were the first team to use the flat cylinder line from Bimba.

We used the 2 position ones last year and this year.

They're no more or less reliable than the standard Bimba line of cylinders. They do require different fittings, since they are so small, and must be face mounted.

Thank you for the information! Do you know the part numbers for the cylinders and the fittings offhand?

[James Kuszmaul]

Originally Posted by AlecMataloni

Thank you for the information! Do you know the part numbers for the cylinders and the fittings offhand?

Check here. We used a .313 long stroke, and I can't remember what bore size we have off the top of my head. Probably 9/16 or 3/4.

[NickCrispie]

Here's a photo of our Robot competing at the Sacramento Regional. As you can see, we made a few changes in between taking our reveal shot and competing at the competition.

We hope to make some improvements and be even better at SVR.

[kevincrispie]

Originally Posted by Sh1ine

Very nice robot.

We also use belts for our drive train. This is our second year using them and as for a a skid steer type drive train is concerned I do not think we will ever go back. We use live axles in our system. It seems like you are using a dead axle system with the sprockets machined directly into your wheels (very cool). I would love to see a up close and personal view of how your power transmission works.

Sprockets (or pulleys I should say, for this is timing belt) are not machined directly on. They are locktighted on the wheel and obtained from SDP-SI. Directly machining those pulleys would take too much out of our resources.

How does the belt drive work for you? Was it hard to do? If so, was it worth the difficulty?

[kevincrispie]

Originally Posted by SuperNerd256

How does the belt drive work for you? Was it hard to do? If so, was it worth the difficulty?

We'll see how it holds up at Davis. It has been working pretty well thus far after the drivetrain was tuned.
The timing belt drivetrain is nice, but it's best to run force calculations to see how it'll hold up. Belt doesn't stretch like chain does, and its quieter and a bit more efficient. It is also lighter. This, coupled with the fact that we have 2 inch wheel means we should be able to get to where we want to go on the field.
The extra traction is useful going up the bridge.