Model Engine Maker
Help! => Hints, Tips & Tricks => Topic started by: Brian Rupnow on November 21, 2017, 04:47:56 PM
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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
(http://imageshack.com/a/img922/2842/t6Du2G.jpg)
(http://imageshack.com/a/img924/2434/ZRZGWN.jpg)
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Try turning it with a rounding router bit.
Cuts perfect domes, two tips for about peanuts from China. Free bearing every time ;)
Jo
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Good plan Jo. I've never used a router bit. I guess that would require some type of dedicated holder?
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I've used a corner rounding endmill held in a lathe toolholder.
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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.
(http://imageshack.com/a/img922/2954/rhaZb4.jpg)
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Answer
Grind a HSS tool to your required shape ,then you have it for future use 👍👍👍👍👍
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What stuart says make a tool to whatever shape you need, Ground Flat Stock is easier to shape
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Tidman%20Organ%20Engine/DSC00496_zps5ttyjcwp.jpg)
(http://img.photobucket.com/albums/v156/jasonballamy/Engineering/Muncaster/DSC01263_zpsjrnfnmri.jpg)
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If all else fails, grind up a bit of old file, I'v done that, and clamped it on a steel tool holder in the same way you would clamp a Tungsten Carbide tip.
Ian S C
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Yes Jason
I surgested HSS. As I do not know what gear brain has
The way I do it it is to use gauge plate ( flat silver steel / drill rod / w1 ) use a tapered carbide end mill .
Draw up the shape in fusion 360 up side down with the profile required on the bottom , CAM it up with the bottom now the stock top/ model top , have at it in the concert mill , harden/temper to your requirements
The reason to use a tapered EM is to get the clearance all round just tipping it and a normal EM will not do it
But then again with gauge plate you can file up the contours