Hello All,

Hello dear friend @kampen ,

Ok, so, the ONLY thing I was still not happy with the latest NEW DESIGN...

Was the Line from 1-1 to 1-1 that was on the BACK SIDE of PCB...

I did not liked it, simply because it was too close to ALL HALF the Connectors where we bolt to Commutator.

As there was a high risk to make a short somewhere ...

So, what I did...Is to set this same Line, BUT ON TOP:


And you can see it now on the UPPER HEMISPHERE (Two Upper Quadrants) that goes from the 1-1 on LEFT (12:00 O'Clock)  to the 1-1 on RIGHT (6:00 O'Clock)

As there are NO CHANGES ON THE BACK OF PCB LINES, except the 1-1 to 1-1 Line is no longer on the back end (See Image below)


I made a very short video explaining this small Mod (Modification):



Regards to All


Ufopolitics

Reply to Message # 815

This correction makes good engineering sense.
Moving the 1–1 to 1–1 trace from the back side to the front side is a good improvement because it reduces the risk of a short near the commutator bolt/pad region.
My comment
The new layout is cleaner and safer for three reasons:

• Better clearance
  The previous rear-side 1–1 line was too close to many commutator connection pads. That is risky, especially with vibration, solder, carbon dust, and possible small alignment errors.
• Lower short-circuit risk
  By moving that trace to the front side where there is more open space, the design gains more insulation distance from the crowded bolt/contact area.
• Easier visual inspection
  The 1–1 connection can now be checked directly on the front layer, making continuity testing and troubleshooting easier.

Recommendation
I would keep this change.
Before finalizing the PCB, I would still verify:

• Minimum clearance between the 1–1 trace and any unrelated pad: ideally 3 mm or more.
• No trace passes under metal washers or screw heads.
• Add solder mask between all pads/traces.
• Keep the 1–1 trace wide enough for current.
• Perform continuity test:
  
  • Output 1 must connect only to all #1 pads.
  • It must not connect to #2–#8.

Final opinion
This is a better final layout. It is safer, clearer, and more manufacturable than having the 1–1 joining trace on the crowded rear side.

Kind regards, Alex 

Subject Ref.:  Dimensions Added to the 4-Layer PCB Design Rendering

@ All and dear friend Ufolpolitics,

I have completed an updated engineering rendering of the 32-Segment Bipolar Commutator Driver with the principal mechanical and PCB dimensions now embedded directly into the drawing.
The purpose of this version is to move beyond conceptual visualization and begin establishing a preliminary dimensional framework for future CAD development and manufacturing evaluation.
IMAGE:
The drawing now includes:

• PCB outer diameter: 160 mm
• Inner diameter (brush sweep area): 95 mm
• Dual 32-segment commutator layout
• 4-layer PCB stack-up visualization
• Mounting bolt circle dimensions
• Output terminal dimensions and pitch
• Assembly height references
• Bearing and support structure locations
• Preliminary electrical specifications (300–400 VDC / 5 A design target)

Please note that these dimensions should be considered as engineering estimates and design targets, derived from the information Ufopolitics has shared so far.
Final manufacturing dimensions will still require verification against the actual commutator assemblies and brush geometry.
The objective is to provide a practical starting point for CAD modeling, manufacturability studies, and future prototype construction while maintaining compatibility with the latest commutator and PCB concepts.
As always, comments and corrections from Ufopolitics and other builders or guests are greatly appreciated.



Best regards, Alex (user: kampen)

Hello All,

Hello dear friend @kampen ,

Great images as always!!...The Engineering approach!

Now, I will refer on this post about our possibilities of Commutators Building...

I have made some CAD's design of a 32 Elements Commutator for another Builder Member here, and an old friend...a while back:


Now, this CAD corresponds to the "Typical Method" to build commutators, which consists on:

• Making a 'Specific' Copper EXTRUSION BAR, which contains the 'DUCK TAILS' and adjusted to the ID and CAD Plans.
• Setting ALL Copper elements fixed into a Mold, then drop the Paste- Semi-Liquid Mica or Phenol, or Bakelite,
• Then run it through a Vacuum Chamber Process to ensure the Mica Paste would penetrate all inner spaces where the "Duck-Tails" are.
• Then take it to an oven and at very high temperatures to fuse-cure and solidify the Insulator element.

This is a very, very costly (expensive) process, even more when this COMPLEX mold Design, plus Copper Extrusions have to be made from scratch...

My old dear firend recently contacted me a few days ago...they want it $1600.00 USD for JUST TWO Commutators!

That is $800.00 USD per commutator!!...That is an OUTRAGEOUS PRICE!!

And the place that builds them is located in India...

He told me the guy at the factory went into a momentary shock, when he told him that the commutators were designed to be Stationary...

The point of this, is that since these commutators designs are NOT based on the "TYPICAL" way that they are built for over 100 years...

Bringing these designs to ANY Commutator Manufacturer would throw them out of their 'Comfort Zone'...then they will end up charging us a fortune to build these design from scratch.


And...So far the Commutator design I have shown, based on starting from a Copper Tubing, ending with U SHAPED ELEMENTS, requires a LOT of Machining and Cutting, Filing, etc Work, therefore, NOT everyone could build one on their Garages...at Home:


I design it, simply because I could build it, However, its design is NOT Robust nor Lasting...

It is just made to PROVE A CONCEPT.

After the Concept is proven, then I can sit it as a 'Relic' which brought us wide open to a New Methodology.

However, I have been working on my mind on a NEW WAY to put together a New Commutator Design which is MUCH EASIER to Build...

As it would be a very long lasting model, because it starts with SOLID Copper Square Bars...which will need to be cut to identical size, plus drilled precisely.

But will bring many new advantages and new features, that any existing commutator have, which are:

• Adjustable Inner Diameters (ID)
• Much easier to 'round' inner surface (Still a Lathe would be required here to do this operation)
• Air Gaps will be 'TRULY AIR FILLED GAPS', because the way to hold together these 32 Bars is through:
• Two POM (or any other material that stands heat and is NOT Brittle) Slim Rings (Top & Bottom), secured by bolts-washers-nuts.
• These OPEN AIR GAPS will keep cooling ventilation circulating at all times.
• Keeping Copper Elements at Room Temperatures.
• Since Elements are made of SOLID SQUARE BARS, Heatsinking would be much easier.
• The Double Contacts at 1-1 and 8_8, would be made WITHOUT AIR GAPS, but a Solid Copper Block that have the size of Two Elements.
• This feature (having ALL Four (4) Main Double Contacts as One Single Element) would:
• Minimize the Air Gaps to only 28.
• Make the Brushes run smoother through these Transitions.
• Lesser wear, less friction.
• Lesser Gap Jumping.

The Manufacturing Process here would NOT Require anymore:

• To make specific Copper Extrusions...
• To make a New Complex Mold from scratch....
• To run the assembled mold through a Vacuum Chamber.
• To use an OVEN at Higher Temperatures to fuse-cure the Insulating Material.

Therefore, ANY Machine Shop would be able to make these commutators from scratch, without the need of an Expensive High Temperatures Resistant Mold, which needs to be built from scratch.

There is just one 'HINT' for the Machining Process of these Copper Elements once Bolted Together to cut, rectify JUST the ID...

They CAN NOT BE MOUNTED ON THE POM or ANY other Plastic Insulator to be Machined...because they may crack or melt during the inner Lathe cuts.

SO, another 'JIG' needs to be build, made out of Steel or Aluminum, just to hold together ALL Elements secured in place...to be cut by the Lathe.

This 'JIG' would have a CENTER SHAFT to be mounted easily centered on Lathe.

Now, because of the very wide Inner Diameter Spec's of ALL these Commutators, the "ARC" to be cut from a SQUARE Surface would be really MINIMAL.

Meaning that 'Cutting-Rectifying Time' on Lathe would be also MINIMAL.

I will make this NEW COMMUTATOR DESIGN on 3D Maya and displaying here sometime...but, by now, you all have "an idea" how they would look like.

Stilll working on the 2D CAD of the PCB, Front and Rear Views...

Regards to ALL.

Ufopolitics

Reply to Message # 818

Yes, Ufopolitics' analysis is correct.
The CAD shown is a traditional industrial commutator design with:

• 32 copper bars
• dovetail/ducktail retention features
• mica/phenolic/Bakelite insulation
• molded and vacuum-filled structure
• oven-cured insulation
• precision circular machining afterward

That is why a factory quoted $800 each. For a one-off custom stationary commutator, that price is high but not surprising.
Expert advice:
For this project, I would not recommend using the traditional molded dovetail commutator method.
It is too expensive, too specialized, and unnecessary for a stationary experimental device.
Better approach for Ufopolitics' build
Use a layered mechanical assembly, not a molded commutator:

• Copper segments individually cut/machined
  
  • Flat copper tabs or bars
  • No complex extrusion
  • No ducktail required
• Polycarbonate or G10/FR4 support ring
  
  • Much easier to machine
  • Good electrical insulation
  • Good mechanical strength
  • Replaceable if damaged
• Bolted clamping structure
  
  • Copper bars bolted through insulating plate
  • Stainless or brass hardware
  • Use insulating sleeves/washers where needed
• Defined air/insulation gaps
  
  • Do not rely on poured mica
  • Use machined spacing between copper elements
  • Fill gaps later with epoxy if needed
• Stationary design advantage
  
  • Since it is not spinning at high RPM like a motor commutator, it does not need industrial molded dovetail construction.
  • Mechanical retention can be done with bolts, plates, and clamps.

Best practical construction method
I would build it as:
Top insulating plate
Copper segment ring
Spacer/insulation layer
Bottom insulating plate
Bolts through each segment

Materials:

• Copper: C110 copper flat bar/sheet
• Insulator: polycarbonate, G10, FR4, or phenolic
• Fasteners: stainless steel or brass
• Gap fill: high-temperature epoxy or mica sheet inserts
• Brush contact surface: machined/polished copper faces

Important design recommendations
1. Avoid aluminum as a structural conductor near segments
The CAD labels an aluminum ring. I would avoid aluminum near active copper elements unless fully isolated. Aluminum can create unintended current paths or galvanic issues.
2. Use G10/FR4 if heat becomes an issue
Polycarbonate is easy to machine, but G10/FR4 is better for heat, stiffness, and electrical insulation.
3. Keep the brush surface replaceable
Brush wear and arcing will happen. Design copper elements so they can be resurfaced or replaced.
4. Build a small test section first
Before building all 32 bars, fabricate a 4-segment test module and verify:

• brush contact
• insulation gap
• heating
• mechanical clamping
• arcing behavior
• BEMF discharge path

This avoids wasting material.
My conclusion
The industrial quote is expensive because the manufacturer is thinking in terms of a rotating motor-grade commutator.
But Ufopolitics' design is different: it is a stationary commutating distributor.
That means it can be built much more economically using:
machined copper segments + insulating plates + bolted construction
instead of:
custom copper extrusion + molded mica/Bakelite vacuum casting
So yes, Your direction to avoid the traditional commutator manufacturing route is correct.

Kind regards, Alex