Team 254 Presents: Deadlift Technical Binder 2015

[Cherry254]

Originally Posted by thatprogrammer

1.How are the carriages driven up and down? They appear to be attached to timing belts through some type of clip?

2. What type of bearings did you use for your elevator?

3. What types of belt did you use in your elevator?

4. How did you install your chain in the tubing?

5. Are you using the talon srx or victor SP?

1. Via HTD timing belts (endless) joined with a custom timing belt clamp that was integrated into the carriage bearing block assemblies.

2. Standard R3 and R4 equiv bearings.

3. 5mm Pitch HTD x 9MM wide

4. We held the chassis vertically and lowered the loop of chain down the end of the tube with the sprockets already on it and slid the shafts through the bearing blocks.

5. Victor SP

From what I can see, you guys have almost all of the robot in CAD before you start making parts for systems other than drive. At what point in the season do you finish drivebase CAD and the rest of the CAD? How many people do you have on your CAD team, and how long do they work to get it done?

Finally, does your team use any type of version control for SolidWorks, either EPDM or workgroup? If so, what type of server/computer does it run on?

It looks like you had no way to adjust chain tension this year. Would you recommend running a chain in tube drive system with no tensioners in a more aggressive game, or would you probably switch back to an adjustable and accessible design?

I've also seen your team run 3mm pitch pulleys off the output shaft of the RS-775 motors many times. Are these pulleys you make yourselves with a press fit for the motor shaft, or are they something else?

What material was used for the friction brakes?

Drive CAD is done early by a group of a few students and a few mentors. It ideally is complete in the first 4-6 days. The rest of the CAD can linger for many more weeks as prototyping continues. Deadlift wasn’t even completed in CAD until the last minute with some parts were designed days before stop build.

We use PDM workgroup to manage SolidWorks files.

Undecided on the chain in tube. An adjustable and accessible design has worked well for us in the past. We didn't like that the chain rattled inside the tube, but otherwise we didn't have any issues with it. Assembly was not difficult and once it was installed we never had an issue.

3mm pulleys are available from WCP. http://www.wcproducts.net/gt2-timing-pulleys

Friction material was from McMaster: High Friction Molded Brake & Clutch Lining Sheet.