Miniature Sherline CNC Cam Grinder, Part 2

Grinding a cam for a model internal combustion engine can be a tough job. Using a computer controlled cam grinder is an attractive alternative to hand filing cam lobes, assembling multipart camshafts or building a complicated mechanical grinding machine. Joe Martin has created a CNC (Computer Numeric Control) cam grinder using mostly off-the-shelf Sherline machine tool parts along with a g-code program he developed himself. This video details the production of a cam for a Howell V-4 engine being produced by the Joe Martin Foundation Craftsmanship Museum. To learn more about the engine itself go to www.CraftsmanshipMuseum.com/HowellV4.htm. For more about Sherline miniature machine tools visit www.sherline.com. This is part two of the video. Each half is about 9 minutes long.

Category:

Autos & Vehicles

Tags:

• cam
• grinder
• grinding
• CNC
• Sherline
• model engine
• camshaft

[emmon72cz3x]

The closeup shows a discontinuity on the trailing surface of the lobe. Does the grinder leave the surface at any time during the cut? Does the program acount for a progressive depth of cut?

[craiglibuse]

@emmon72cz3x We are starting with a round blank and grinding away the material not needed. Because the depth of cut is fed in manually the same program is used for each pass; therefore, the lowest part of the cam is the first ground. The top of the cam lobe will be the last part formed. --Joe

[gearhead944]

Nice setup. Why not grind after heat treat?

[craiglibuse]

@gearhead944 The blank is heat treated first and then ground.

[TheElsyd]

Did the cam made in the video work OK in the engine?

[gwheyduke]

Great video.  Very slick set up with the

sherlilne!

I hope you consider doing a build article

in Model Engine Builder magazine?

Like to see how you built the grinder.

[haxanthrobo]

Oh man, thats neat!

[Axbent]

Super! Goes to show the enourmous versatility of this modular machine tool! We have lots to be thankful for the products Mr Martin put on the market!