Hello dear friend @kampen ,

You could create Two (2) versions of this Brush Assembly:

• The Full Builder Friendly Version (like the one I have corrected)
• The more Complex Engineering Version, as long as all components remain constant.

Both versions must be completely independent from each other's.
Clear Titles on the Header for each.

And again, the Brush is our Point of Reference, when calling a "View" of any of its individual components or for the whole assembled set.

Like I wrote before, the Dimensions depends on each builder's setup, basically their ID on their Commutator Diameter...as their Inner Rotor OD.
Plus their Brush size that they have available.

Therefore, the Builder's Version could have Dimensions, as long as everyone understand these measurements are purely 'RELATIVE'.

Regards

Ufopolitics

@ All, 

I have completed a new revision of the Rotor Brush Assembly – Complete Dimensions for Fabrication drawing.

This version now includes the fabrication dimensions for the major components, including:

• Dual-function torsion spring pin
• Torsion spring
• Upper and lower brass brush holder plates
• Carbon graphite brush
• Second attachment bolt
• Assembly views with the main reference dimensions
• Exploded assembly with numbered parts
• Brush tension adjustment procedure

My intention was to make this drawing as simple, unified and builder-friendly as possible so that anyone reproducing the machine can fabricate the brush assembly without having to search through multiple forum posts.

• Carbon brush: 11 × 11 × 20 mm
• Brass upper plate width: 22 mm
• Brass plate thickness: 6 mm
• Hole spacing: 32 mm
• Mounting holes: Ø4.2 mm
• M6 × 1.0 spring pin
• M4 × 0.7 attachment bolt

This provides all the explicit fabrication dimensions visible in the rendering.
Below are the dimensions shown in the fabrication drawing. 
All dimensions are in millimeters (mm).
1. Dual Function Torsion Spring Pin (made from regular M6 bolt)

[th]Feature[/th] [th]Dimension[/th]
Overall length	40.00
Slotted top width	4.00
Reduced diameter (spring section)	Ø3.60
Smooth spring area length	12.00
Threaded area	10.00 (M6 × 1.0)
Rotor plate area	18.00
Head diameter	Ø8.00
Rotor plate hole	Ø6.00

---

2. Torsion Spring

[th]Feature[/th] [th]Dimension[/th]
Active coils	6
Free height	22.00
Wire diameter	Ø1.20
Outside coil diameter	Ø8.00
Leg length	20.00
Push-end angle	60°
Inside bend radius	R0.85
Push-end height

3. Brass Brush Holder Plates
Upper Brass Housing Plate (Bent)

[th]Feature[/th] [th]Dimension[/th]
Overall top width	22.00
Side height	10.00
Plate thickness	6.00
Hole diameter	Ø4.20 (M4 clearance)
Hole center distance	32.00
Hole center to edge	11.00
Bend angle	90° each

Lower Brass Housing Plate (Flat)

[th]Feature[/th] [th]Dimension[/th]
Length	22.00
Thickness	6.00
Hole diameter	Ø4.20 (M4 clearance)
Hole center distance	32.00
Hole center to edge	11.00

---

4. Carbon Brush

[th]Feature[/th] [th]Dimension[/th]
Width	11.00
Height	11.00
Length	20.00

Material: Copper Graphite
5. Second Attachment Bolt

[th]Feature[/th] [th]Dimension[/th]
Head diameter	Ø8.00
Head height	3.50
Thread length	12.00
Thread	M4 × 0.7

---

General Drawing Notes

• Units: Millimeters
• General tolerance: ±0.10 mm unless otherwise specified.

---

Key Fabrication Dimensions

• Spring pin length: 40 mm
• Spring pin reduced diameter: Ø3.6 mm
• Rotor plate hole: Ø6 mm
• Spring OD: Ø8 mm
• Spring wire: Ø1.2 mm
• Carbon brush: 11 × 11 × 20 mm
• Brass upper plate width: 22 mm
• Brass plate thickness: 6 mm
• Hole spacing: 32 mm
• Mounting holes: Ø4.2 mm
• M6 × 1.0 spring pin
• M4 × 0.7 attachment bolt

This provides all the explicit fabrication dimensions visible in the rendering.

As always, thank you very much for your guidance and expertise.

Best regards, Alex