DEWBOT XVIII Drive-Train

1640's Swerve history dates back to 2009 and all of our Robots from 2010 up to now (excluding 2016 - Stronghold_ have been swerve robots. We've always made our own kit and originally our swerve focus made us unique. But the world has changed. A number of excellent COTS swerve drive systems are now available to FRC teams and swerve has become a common feature.

So this year, for the first time ever, team Sab-BOT-age had to go through a make-versus-buy analysis. Using a COTS swerve module provides some very compelling benefits:

• COTS may be purchased ahead of the start of Build Season; and
• COTS may be reused.

Balanced against this:

• Some teams using COTS swerves in 2022 experienced supply-chain delays with spare parts (we can manufacture our spare parts);
• Design & building the swerve modules provide a great education for our students;
• 1640's swerve is very light-weight (4.8 lb); and
• We are very comfortable with our swerve's performance.

The result of our make-versus-buy analysis was the decision to build our own modules again in 2023. But we'll go through this analysis again next fall.

Sab-BOT-age's 2023 swerve design was developed from the post- Hatboro 2022 design. Improvements focused on ease-of-manufacture, ease-of-service, and survivability.

Key 2023 changes were:

1. 4" VexPro Traction Wheels (217-2588) replaced the 4" 80A durometer AndyMary HiGrip wheels (am-2256) we had used since 2013. We like the HiGrips and they're light, but they wear out and replacements require machining before use. The VexPro Traction wheels are used as-is and use a replaceable tread (which 1640 prints using Priline Assure 95A Urethane). AndyMark HyGrip pattern. Tested at Ramp Riot and found acceptable wear rates.
2. Used BI-6127v1a360fs repaced with Calt encoder same cost double ball bearing 10-12bit encoder
3. replaced 15 & 29t AM drive gears bought pinion stock 15T bored to 8mm and broached major time and cost savings and a much better solution - 29t broached ourselved for tight fit on thunder hex shaft.
4. polycarbonate top plate - changed supplier to full .250 thk better faster.
5. 11t timing belt pulley had purchased from si/sdp - prone to cracking during broaching. eliminated a stage of reduction. htd5. 6t-48t stage 1 - hard sure 75d Ninjateck armadillo PU very tough filiment. Changed to 1 piece gear pulley.2 stage with nEO 550. 1100 rpm. 6:48 * 11:60 .ack of commercially available 11t pulley was the motivation.
6. G10 bottom plate

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Casting Carbon Fiber/Epoxy Forks

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