Each component in the drivetrain category has its own unique tests.
V-wheel
| Test |
Description |
Target |
Tolerance |
| Outer diameter |
Measure the outer diameter of the v-wheel with digital calipers. |
23.89mm |
+/- 0.1mm |
| Inner diameter |
Measure the inner diameter of the v-wheel (where the bearings will sit) with digital calipers. |
15.974 |
+/- 0.05mm |
| Width |
Measure the width of the v-wheel with digital calipers. |
10.23mm |
+/- 0.1mm |
| Smoothness |
Inspect the wheel to ensure there are no eroneous grooves, cuts, or knicks |
No blemishes |
N/A |
GT2 Timing Belt
| Test |
Description |
Target |
Tolerance |
| Length |
Measure the length of the belt using a measuring tape. |
See BOM spec. |
+/- 1cm |
| Width |
Measure the width of the belt using digital calipers. |
5mm |
+/- 0.25mm |
| Pitch |
Measure the distance between one tooth and another one 50 teeth away using digital calipers, then divide by 50. |
2mm |
+/- 0.02mm (1%) |
| Thickness |
Measure the thickness of the belt using digital calipers. |
0.75mm |
+/- 0.05mm |
| Stretchiness |
Tie a belt to a fixture 1.5m or more off the ground. Mark the belt just below the knot and then add a second mark exactly 1000mm below the first. Hang a 10kg weight from the belt (below the 1000mm mark) and measure the distance between the two marks. |
1000m |
+ 10mm (1%) |
| Strength |
Use a tensile testing machine to measure the equivalent hung weight at which the belt will break. |
100kg |
- 20kg |
| Color |
Inspect the belt for any discoloration or markings |
Black, no markings. |
N/A |
GT2 Pulley
| Test |
Description |
Target |
Tolerance |
| Number of teeth |
Count the number of teeth on the pulley. |
20 |
+/- 0 |
| Pitch |
Mate the pulley with a belt and inspect tooth engagement |
The pulley should fully engage the belt’s teeth at all points of contact. |
N/A |
| Tooth width |
Measure the width of the teeth using digital calipers. |
7mm |
+/- 0.5mm |
| Overall length |
Measure the overall length using digital calipers. |
14mm |
+/- 0.5mm |
| Outer Diameter |
Measure using digital calipers. |
15mm |
+/- 0.5mm |
| Hole diameter |
Measure the diameter of the motor shaft hole using digital calipers. |
5mm |
+ 0.05mm |
| Number of setscrews |
Count the number of setscrews. |
2 |
N/A |
| Setscrew drive size |
Use a hex driver to validate the drive size of the setscrews. |
2mm |
N/A |
| Material |
Ensure the material is aluminum and stainless steel and will not rust by holding a magnet to the part. |
Aluminum and stainless steel (no magnetic attraction) |
Weak attraction to stainless steel is permissible. |
Belt Sleeve
| Test |
Description |
Target |
Tolerance |
| Inner width |
Measure using digital calipers. |
7.5mm |
+/- 0.1mm |
| Inner height |
Measure using digital calipers. |
2.15mm |
+/- 0.05mm |
| Outer width |
Measure using digital calipers. |
10mm |
+/- 0.2mm |
| Outer height |
Measure using digital calipers. |
5mm |
+/- 0.2mm |
| Length |
Measure using digital calipers. |
10mm |
+/- 0.5mm |
| Material |
Ensure the material is aluminum and will not rust by holding a magnet to the part. |
Aluminum (no magnetic attraction) |
N/A |
| Sandblasting |
Inspect for thorough sandblasting coverage. |
100% |
-1% |
| Anodization |
Inspect for thorough annodization coverage. |
100% |
-1% |
| Deburred |
Inspect for burrs. |
No burrs |
0 |
5mm to 8mm Shaft Coupling
| Test |
Description |
Target |
Tolerance |
| Inner diameters |
Measure using digital calipers. |
5mm and 8mm |
+/- 0.05mm |
| Outer diameter |
Measure using digital calipers. |
18mm |
+/- 0.5mm |
| Length |
Measure using digital calipers. |
25mm |
+/- 0.5mm |
| Setscrew drive size |
Use a hex driver to validate the drive size of the setscrews. |
2mm |
N/A |
| Material |
Ensure the material is aluminum or stainless steel and will not rust by holding a magnet to the part. |
Aluminum and stainless steel (no magnetic attraction) |
Weak attraction to stainless steel is permissible. |
| Fits motor shaft |
Connect the coupling to a motor shaft. |
The coupling should be easy to connect and resist pulling off by hand once tightened. |
N/A |
| Fits leadscrew |
Connect the coupling to a leadscrew. |
The coupling should be easy to connect and resist pulling off by hand once tightened. |
N/A |
Leadscrew
| Test |
Description |
Target |
Tolerance |
| Length |
Measure the length using a measuring tape. |
800mm |
+/- 3mm |
| Threads |
Thread the leadscrew into the delrin leadscrew block. |
The leadscrew should thread as expected without significant resistance. |
N/A |
| Straightness |
Place the leadscrew on a reference table with a flatness tolerance of 0.5mm per 1m or better. |
0mm deviation |
+ 2mm |
| Deburred |
Inspect for burrs, especially on the cut ends. |
No burrs |
0 |
| Material |
Ensure the material is stainless steel and will not rust by holding a magnet to the part. |
Stainless steel (no magnetic attraction) |
Weak attraction to stainless steel is permissible. |
Leadscrew Block
| Test |
Description |
Target |
Tolerance |
| Size |
Measure the outer dimensions of the block with digital calipers. |
34mm x 20mm x 12mm |
+/- 0.5mm |
| Threads |
Thread a leadscrew into the block. |
The leadscrew should thread as expected without significant resistance. |
N/A |
| Hole diameter |
Measure the hole diameter using digital calipers |
5.25mm |
+/- 0.1mm |
| Hole spacing |
Attach the block to a cross-slide plate according to the FarmBot system design. |
The block should attach without screw/hole interference. |
N/A |