Author Topic: Cast White Metal Bearing  (Read 1162 times)

Offline Anzaniste

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Cast White Metal Bearing
« on: October 26, 2014, 05:05:20 AM »
  Oh how the devil do I insert a photo?? I can grab the link or grab the HTML?BBCode but I don't seem to be able to do any thing with them :doh:


image by Anzaniste, on Flickr

Ohh, it's dead easy, just the same as it was in 2011 when I last posted a photo!!!!!!! I just pasted the HTML/BBCode into the text and bingo the piccie appeared when I posted.

Simples! :worthless:


This is the magneto drive shaft bearing off my Anzani engine.

The broken off bit is left hand thread. Needless to say when I removed the brass collar that was screwed on I didn't know it was left hand hence the break.😞
It is about 35 mm long and the diameter of the parallel bit is 20 mm approx and it carries a shaft 15mm diameter.

I need to make a replacement and I want to make it in a similar manner to the original. I know for a one off it probably makes sense to machine from solid or to machine one from a lump of bronze but I really want to make a casting and machine it.

I tried to make a silicone mould but it wasn't succesful for a variety of reasons the principal one being difficulty of de-aerating the resin before it went off.

My proposed method is to make a two part mould out of a couple of chunks of ally that I have in stock.

I propose to spigot the two pieces of ally bar with a shallow spigot then bore one piece to make the parallel bit including a slight angle to permit separation from the mold, this will be through bored to allow molten metal to be poured into the mold.

The other half I intend to machine a triangular pocket to produce the flange and bore a recess to produce the tapered bit. I will add a short bit onto the taper for a chucking allowance.
The mould cavity will be carbon blacked to ensure release ( or would Zebrite work).

The two halves of the mould will be clamped together, preheated and the metal poured.
 
Simples.
 
Or is it? Any advice or suggestions will be great fully received.

Oh, I forgot to say that I started this thread off 'cos I couldn't find any tool geometry, feeds and speeds data for machining white metal!

I really do want to make it a machined  casting so sensible advice about alternative materials or machining from solid will only confirm what I already know; Iím mad.
Well this is MadModder isnít it.
« Last Edit: October 26, 2014, 05:50:35 AM by Anzaniste »
Scrooby, 1 mile south of Gods own County.