Here are the COTS parts that we used this year (some of these parts are available from other sources):
Colson Performa (4" x 0.875", 1/2" Hex Bore) 217-4049 Qty 1 $9.99 ea
Flanged Bearing 13.75mm (1/2"ThunderHex ID) x 1.125"OD x 0.313" WD 217-4006 Qty 2 $3.99 ea
Flanged Bearing 0.375" ID x 0.875" OD x 0.280" WD 217-2733 Qty 2 $2.99 ea
64t Aluminum Spur Gear (20 DP, 1/2" Hex Bore) 217-3575 Qty 1 $14.99 ea
32t Aluminum Spur Gear (20 DP, 3/8" Hex Bore) 217-5455 Qty 1 $8.99 ea
30t Aluminum Spur Gear (20 DP, 3/8" Hex Bore) 217-3210 Qty 1 $8.99 ea
15t Steel Bevel Gear (12DP, 3/8" Hex Bore) 217-3344 Qty 2 $14.99 ea
Versa Planetary Gearbox 7:1 ratio + 9:1 ratio 3/8” output shaft Qty 1 $61.96 ea
Mini CIM Motor 217-3371 Qty 1 $24.99 ea
Versa Planetary Gearbox 4:1 ratio, 3/8” output shaft, CIM adapter Qty 1 $50.97 ea
9015 Motor (am-0912) am-0912 Qty 1 $14.00 ea
100T 48DP Acetal - Brass insert A 1T 2-Y48100 Qty 1 $7.98 ea
30T 48DP Acetal - Brass insert A 1T 2-Y48030 Qty 1 $5.18 ea
Potentiometer TT Electronics 4.5 - 5.5 Volts 858-6127V1A360L.5FS Qty 1 $12.32 ea
Bearing Ball Store:
1/4” Delrin Bearing Balls Pack of 300 Qty 1 $28.00 ea
These Delrin bearing balls are cheaper if you buy them in higher qunatities. We bought a case of 1000 this year which was enough for 10 modules when we added it to what we had left over from last year.
I did not include the hex shaft or Churo shaft stock to the COTS list. I also did not include the nuts and bolts. I assume you can handle that.
Including the motors, this works out to about $290 per module.
A few notes:
- The CAD model shows using a 775 motor. We used a miniCIM with a 3:1 geabox for the drive motor this year instead of the 775s. We used 775s last year and we experienced some issues so we switched to the miniCIMs this year. The price list above reflects that switch.
- We also added encoders to the drive gearboxes this year, but we had a bunch of those laying around, so we did not have to buy those and I don’t have a receipt. Since these are optional, I left those off the list.
- We added powerpole connectors to the motor wires. I did not include the price for those.
- you will need a PWM cable to connect the steering encoder (potentiometer) to the RoboRIO. I did not include that cost as the length will be dependent on the robot design.
The rest of the parts shown in the CAD are custom waterjet cut parts. I did not attempt to cost the raw material needed for this.
Let me know if you have any questions.