cobalt

Turntable bearings huh. Have lots of turntable fans around here. Bearings are the biggest improvement they made in TT design as far as I am concerned since the early days.

The previous bushings used a special alloy bronze we called bearing bronze I used to cast for large compressors and military application. Not sure if you can cast it anymore due to the lead content.

Goughary

Hear you go:

cobalt

Interesting explanation I know of Sintering. You use this for turntables?

I was talking about this;

Bronze Bars C93200 (SAE 660) are high quality smooth machine finish stock for general utility bearings and bushings and which are highly resistant to impact, wear and corrosion. It is a general purpose bearing alloy possessing good anti-friction properties, ample strength and hardness, adequate ductility and excellent machinability. It is used as bearings, bushings, light duty gears and sprockets, impellers, wear strips, plates, automotive fittings and washers. It is used extensively in pumps, cylinders, machine tools, earth moving machinery and a myriad of general purpose applications.

Doesn't require lubrication for this type of application other than some grease. I cast large bearing blanks in a similar alloy years ago but the lead content became a problem with OSHA for us. There was a kit sold by automotion or one of those companies back in the 80's and 90's that sold machined stock out of this material it was a nice one time fix.

Goughary

Cool stuff. So how do we make a set of the correct sizes now? I have access to a specialist machine shop...so if I had designs and a specific material spec, I could see about making them...

cobalt

I guess we can reverse engineer it. The older clusters had larger bushings these are thinner. I was casting large 60 pound bushings. I have access to a foundry that can cast brass, bronze, elemental copper, heat treated and non heat treated aluminum alloys and hopefully I will soon have them casting aluminum based Magnesium alloys. Possibly Zirconium based in the future if I can get the standard alloys to run without issue. However something this small would probably be cheaper to just machine out of bar stock which is readily available. As you know the elevated cost of copper has sent the cost of brass and bronze through the roof. No doubt we can do it the question is can it be done economically.

DobermanDad

Could this also be done on a lathe?

I made the spacer for my alternator fan out of billet with a lathe.

cobalt

Don't see why not. Mine is still awaiting me to wire it up.

DobermanDad

Think i may try this. Gonna have to find some bronze at my local materials shop.

Why bronze? Is there a specific reason.

mystert

The wall thickness of the bushings looked to be too thin to machine and then press into the sleeve. With bronze being such a soft material any misalignment when installing would cause it to bend and buckle. You could always press in a larger one and then open the ID to the proper size on a lathe or with a long reamer and a hand drill.

onceover

Anyone have dimensions for the bushings? I'd like to give turning these on my lathe a go.

Goughary

I wish the brake bushings were a little less rattly- has anyone ever checked to see if the bronze bushings from the earlier pedal kits work for the clutch in our car? The new plastic brake bushings fit terribly and the clutch bushings are good enough, but a bronze kit for both would be nice

r-mm

Hey there kids I’m coming to this thread years later looking to rebuild the pedal box in my ‘91 C4. Where does a man look for the latest and greatest bushings roll pins etc?