johnsmachines

Actually, I had some spare space on the tree which I used to make some more small gears, and I had some PLA T. Rex’s, so I added one.

And this was the cast result, in bronze.  Yet to be cleaned up, tree bits ground off, and polished..

 Again, the gears are close to perfect.  I like bronze.

And the gears have a short length of shaft, printed in PLA and cast in bronze, which I will be able to hold in a chuck for tidying and turning.  Lesson learned.   Think ahead, how the cast part will be machined….

And at our society Zoom meeting, Frank M  asked about the colour of burning Borax.   I could not remember, so took a shot today…

I would describe the colour as white-gold, with a touch of green.  Like a volcano.   Maybe I overdid the Borax?

Oh.  And I had a brainwave.  When degassing the investment mix with negative pressure, add some vibration.  I tried applying my sanding machine once, and filled the room with old fine sawdust.  But for this session, I placed the vacuum pump on the vacuum chamber, and could hardly believe the volume of air which came out of the mix.  The best degassing to date.

and it takes less bench space.   A no-brainer.  Try it!