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Posting Leader
Posted 19 September 2024 - 12:50 PM
Just in case you wondered...
Some guys like to use the bushings made from bearing bronze. These are turned on a lathe or screw machine from round stock, usually Amco-18.
If you are restoring an old slot car and can't find the right size oilites, you can get oilite round stock and machine them yourself.
Available from McMaster-Carr
Oilite style
Graphite impregnated style
Age scrubs away speed!
Posted 19 September 2024 - 01:45 PM
I got a few lengths of bearing bronze rod years ago. I turned some gram guide weights with some of it because it was about the correct diameter. It turned nicely, but I never thought about it being oil-filled. I was more impressed with its more orange-like color than the yellow of brass.
Headmaster of the asylum
Posted 19 September 2024 - 01:58 PM
Oilites were developed by Chrysler in 1930. The Wikipedia entry on the material is a good read.
Oilite
Gregory Wells
Never forget that first place goes to the racer with the MOST laps, not the racer with the FASTEST lap
Posting Leader
Posted 19 September 2024 - 04:39 PM
As the Wiki entry shows, there are different grades of oilite. You don't need anything special for the rear axle on a slot car. Especially if you are going to douse it with oil at every break. For a motor, you might want to go with more graphite content, since those bushings are oiled more sparcely (or you risk getting oil on the comm, which is not good).
Graphite is a natural lubricant, so where the bushing is going to be run dry, more of that is a good thing. One mistake I see with rear bushing/axle installation is that the builder thinks that minimal clearance between the axle and the bushing bore is important, when too little clearance will actually prevent an adequate amount of oil to flow in. Ideally, the axle should be "floating" on a film of oil, and not touching the bushing at all. But that doesn't actually happen. So carefully matching the weight of the oil and the clearance between the axle and bushing is paramount.
Grand Champion Poster
Posted 20 September 2024 - 05:15 AM
Oilites were developed by Chrysler in 1930. The Wikipedia entry on the material is a good read.
Oilite
This was Mura's source for oilites. They had to be ordered in multiples of 100k... with a 250k minimum, if I remember correctly.
Click HERE to contact Sonic Products. The messenger feature on my Slotblog account has been disabled.
Posting Leader
Posted 20 September 2024 - 09:40 AM
Damn, Phil, you start early just like I used to when I was working. I know you used to supply axle bushings made from bearing bronze, I would assume Ampco 18. If you ever wondered how those bars were made and why they had the spiral pattern on the outside.
Continuous casting:
Back at CWM we did a lot of aerospace parts. One part in particular had tiny 941 grade oilites (I don't capitalize oilite, since that is a Chrysler trademark) in it, cast in place. We ordered them 500,000 at a time, enough for a week's production. About $5K per order. (a penny apiece) We also made a radar gimbal mount, fully assembled, ready for the sub-contractor to assemble into their full unit, which used a tiny 1.25mm O.D instrument grade ball bearing. Those we ordered 300,000 at a time, and came in an armored car. IIRC an order cost near a million bucks in 2005 money.
