A rather neat machining trick

[Brian Rupnow]

When I designed the hexagon shaped manifolds for my twin steam engine, I wanted them to have "domed" ends, so I designed them that way. Now it's true,--You can do some things on the computer that are almost impossible to do in "real life". The hex rods were drilled out full length to 1/4" inside diameter, then a brass plug silver soldered into each end. I have tried shaping a dome on the end of stock with a file, but was never terribly successful. Then I remembered the 1/2" hand held belt sander that I seldom use. It removes a lot of stock very quickly. I ran the lathe at about 200 rpm and with the running belt sander in hand I shaped the dome "freehand". It went very quickly, and gave excellent results. It worked so well that I considered it worth posting about.---Brian

 

[arc]

Now that's a good idea. I've got one of those little belt sanders, I"ll try it out.

 

[bazmak]

Brian ,i put a rad/dome on my buffers for the simplex using my homemade
ball turner.It worked well.Have you given it any thought or have you not made one yet.Apart from engines it nice to make some tooling then get use out of it

 

[Brian Rupnow]

I made a Steve Bedair ball turner a few years ago. I made a couple of balls to convince myself that it would work, then it hung on the wall for two years. I ended up giving it away because I never used it. Later I made a ball turner using a boring head mounted in my tailstock chuck. Made a couple more balls, then sold my small mill and the boring head went with it. I don't make enough balls to bother having a ball turner.

 

[charlesfitton]

Pfffffttttt

If I were using that argument, I should give away my whole shop.....

 

[rlukens]

I've machined ball ends on my lathe with a carbide rounding over bit in a tool holder. You're limited to fractional sizes but you have a ready made radius cutter. I've used them in milling also.

 

[Brian Rupnow]

I have a few different HSS corner rounding endmills. I will try one on a piece of the brass hex material and see how it works.

 

[lathe nut]

that is a good idea, going to have to fine one somewhere around here, thanks for the tip, love that engine.

 

[Hopper]

The trick to using a file on the lathe is to keep the file moving at all times. Use long strokes of the file just as if you were filing a stationary job in the vice.

 

[mu38&Bg#]

I have a few different HSS corner rounding endmills. I will try one on a piece of the brass hex material and see how it works.

This will work just fine. I've used wood router bits for this purpose. It's just a form tool after all, so keep the limitations in mind.

 

[Brian Rupnow]

Today I got around to trying a rounding over endmill in my lathe to put a radius on the end of a piece of brass stock. It worked like a charm. The only downside to this is that although you can put a nice radius on the stock in the lathe, you can't really do a curved "dome" because you are limited to the radius built into the cutting tool.

 

[lathe nut]

Thanks for the post, neat idea.

 

[bazmak]

If you have a set of carbide woodworking router bits,then make a holder to accept them and they work well,rad,cham,OG etc.I use them all the time in the mill