Starter brush holders - what is the metal?

[AdminJeff]

Does anyone know what material the starter & generator brush holders are made from?
It sure acts and feels like Aluminum to me, but I'm not sure which alloy. It appears different suppliers used different metals.

One of them seems MUCH better made and sturdier and heavier than all the others but I cant quite make out the Vendor name.

I'm investigating having a high-quality reproduction made. My initial supplier feedback looks quite promising using both casting as well as precision CNC processes.

This one is obviously Stewart Warner and is also very well made:

I'm not looking for opinions on why or why not, just on what the best alloy to use might be.

AdminJeff

[speedytinc]

Cuts, grinds & drills like aluminum. Does not deteriorate like pot metal.
Consider 6061-t6. Cuts fast & well for CNC machining.

[Kevin Pharis]

Modern alloys will easily mechanically outperform any original casting material. Consult with your potential manufacturer as to their most common materials. Most likely billet machined will be 6061 and casting A356

[Ken Buhler]

Send some to a metallurgist for assay. They will tell you the exact percentages of all contents.

[Jerry VanOoteghem]

Originals are most likely die cast from Zamak, or similar.

https://en.wikipedia.org/wiki/Zamak
https://decoprod.com/design-support/zamak/

You might want to look at lost wax investment casting for new ones.

[TRDxB2]

Does anyone know what material the starter & generator brush holders are made from?
It sure acts and feels like Aluminum to me, but I'm not sure which alloy. It appears different suppliers used different metals.
One of them seems MUCH better made and sturdier and heavier than all the others but I cant quite make out the Vendor name.
I'm investigating having a high-quality reproduction made. My initial supplier feedback looks quite promising using both casting as well as precision CNC processes.
This one is obviously Stewart Warner and is also very well made:
brushholder Stewart Warner.jpg

I'm not looking for opinions on why or why not, just on what the best alloy to use might be.

AdminJeff

You might try to trace the manufacturers name with a piece of paper over the letters & rubbing over the letters gently with a lead pencil. Also might this be an old brush & the manufacturer is no longer in business?

https://en.wikipedia.org/wiki/Brush_(electric)
Carbon brushes are available in four main grade categories: carbon graphite, electrographitic, graphite, and metal graphite.
Exact composition of the brush depends on the application. Graphite/carbon powder is commonly used. Copper is used for better conductance (rare for AC applications). In order to maximize electrical conductivity and green strength, highly dendritic (electrolytic) copper powder is used.[5] Binders, mostly phenol or other resins or pitch, are mixed in so the powder holds its shape when compacted. Other additives include metal powders, and solid lubricants like MoS2, WS2. Much know-how and research is needed in order to define a brush grade mixture for each application or motor

This link describes several compositions of brushes & uses https://www.repcoinc.com/about/blog/Wha ... sh-bd.html
Metal graphite carbon brushes for electrical motors are often made from natural graphite and fine metal powders. Copper is the most common, but silver, tin and lead are sometimes used. Metal graphite brushes are ideal for many applications due to low resistivity.

[Jerry VanOoteghem]

Does anyone know what material the starter & generator brush holders are made from?
It sure acts and feels like Aluminum to me, but I'm not sure which alloy. It appears different suppliers used different metals.
One of them seems MUCH better made and sturdier and heavier than all the others but I cant quite make out the Vendor name.
I'm investigating having a high-quality reproduction made. My initial supplier feedback looks quite promising using both casting as well as precision CNC processes.
This one is obviously Stewart Warner and is also very well made:
brushholder Stewart Warner.jpg

I'm not looking for opinions on why or why not, just on what the best alloy to use might be.

AdminJeff

You might try to trace the manufacturers name with a piece of paper over the letters & rubbing over the letters gently with a lead pencil. Also might this be an old brush & the manufacturer is no longer in business?

https://en.wikipedia.org/wiki/Brush_(electric)
Carbon brushes are available in four main grade categories: carbon graphite, electrographitic, graphite, and metal graphite.
Exact composition of the brush depends on the application. Graphite/carbon powder is commonly used. Copper is used for better conductance (rare for AC applications). In order to maximize electrical conductivity and green strength, highly dendritic (electrolytic) copper powder is used.[5] Binders, mostly phenol or other resins or pitch, are mixed in so the powder holds its shape when compacted. Other additives include metal powders, and solid lubricants like MoS2, WS2. Much know-how and research is needed in order to define a brush grade mixture for each application or motor

This link describes several compositions of brushes & uses https://www.repcoinc.com/about/blog/Wha ... sh-bd.html
Metal graphite carbon brushes for electrical motors are often made from natural graphite and fine metal powders. Copper is the most common, but silver, tin and lead are sometimes used. Metal graphite brushes are ideal for many applications due to low resistivity.

Brush HOLDERS. Not the brushes.

[Dan McEachern]

Jeff- take one to a scrap dealer/ scrap yard and have them shoot it with an ZRF gun. That will tell you the alloy rather than sending one to a testing lab. Even if you have to pay them some $$$ to do it. My guess is aluminum, similar to the magnet support spools for the flywheel.

[AdminJeff]

Jeff- take one to a scrap dealer/ scrap yard and have them shoot it with an ZRF gun. That will tell you the alloy rather than sending one to a testing lab. Even if you have to pay them some $$$ to do it. My guess is aluminum, similar to the magnet support spools for the flywheel.

that is an interesting idea!

[AdminJeff]

You might want to look at lost wax investment casting for new ones.

I had a lead on this as well! Its pretty interesting. The molds are expensive ($1000's) no matter which casting process is used. The CNC process doesn't incur that...

[Jerry VanOoteghem]

You might want to look at lost wax investment casting for new ones.

I had a lead on this as well! Its pretty interesting. The molds are expensive ($1000's) no matter which casting process is used. The CNC process doesn't incur that...

I think the wax can be 3D printed now, cutting down on mold costs.

[Allan]

If wax molds can be printed in multiples, that should bring costs way down. Previously, a wax mold was cast using an original part as a pattern. This wax casting is destroyed in the metal casting process, so the whole pattern making process has to be gone through to make subsequent castings.

Allan from down under.

[AdminJeff]

Mystery solved - at least for this particular one!! I'm sure its whatever scrap metal they could find 100 years ago, all melted down.