Spinning Tops

[rwm]

I made a Sherline tool post grinder to modify a reamer:

With the lathe and the diamond wheel running I took .002 off the radius of the end of the reamer for about 1/2".
I reamed a test hole and measured it. I got 0.245". Looks like this will work! I hope .005 is not too much interference for a SiN bearing? If so, I guess I could cut off the tip of the reamer and try again.
Robert

 

[cascao]

Found this sick top

 

[rwm]

This is beefier than the last one.
Wildo- Since you own some professionally made tops and have made your own. What nominal diameter should I shoot for to make the stem? Assume the top is typical size and weight. I am presently thinking about 1/4" is optimal?
Robert

 

[rwm]

Best top yet!

Spins perfectly. This was has a thicker rim with more mass peripherally. The .245 reamer worked perfectly for the bearing hole.
In the end, my cast bronze is pretty nice. I was gratified to find no inclusions or porosity during machining. I have enough left for several more tops.

R

 

[rwm]

This particular top spins forever.

R

 

[Ben Nevis]

Here is another video for some inspiration...

 

[Tozguy]

It is very inspiring and fascinating, thanks.

 

[rwm]

Cool stuff! I thought about making a launcher like that.
R

 

[wildo]

Here's one I wrapped up today. Many days in progress... my first milling on a top, first indexing, first three piece, first copper, first cast iron, and first time using a graver. Needless to say- it spins like crap. But it looks awesome and was really fun to make!

This top is copper over cast iron over a stainless steel stem. It has a ruby bearing.

 

[rwm]

That looks great! I find that my tops with a lot of mill work don't spin great. They must be slightly unbalanced.
Have you noticed that your tops spin better over time? Mine seem to. It may be that the bearing wears microscopically and gets more concentric? Otherwise I can't explain it.
I just got a piece of Damascus steel....
Robert