Farm Boy cam

[Boot]

I machined the major dia. of the cam lobe in the lathe plus bore and turned smaller dia. Now I put the part on my rotary table and cut the 220° .250 radius. How do I connect that to the major dia. and get the lobe right. How wide do I make the lobe and what radius do I put on each side of it to get it right. I am confused and stomped. Thanks , Boot

 

[kuhncw]

Hi Boot,

I'm looking at the drawing for the Farm Boy cam. It looks to me like the major diameter is 0.670 based on the 0.335 radius dimension. The 0.250 radius wraps 220 degrees around the cam, as you said. When you reach each end of the 220 deg arc, you would move the cutter in a straight line. The width of the lobe takes care of itself as it is determined by the tangent cut at each end of the 220 deg arc. I'm not sure what you mean by "what radius do I put on each side of it to get it right". If you mean the points where the straight cust intersect the nose, just round the sharp corner slightly with a stone. I hope what I've said makes sense. If not, ask again.

Good luck.

Regards,

Chuck

 

[Boot]

Thanks Chuck. That's exactly the answer that I wanted. I didn't know if that cut would be at an angle or straight off the piece. Next time I get in my shop , time is limited at this time of the year, I'll give it a try. I understand your explanation completely. Thanks , Boot

 

[kuhncw]

Glad to help out. Please keep us up to date on your build.

Regards,

Chuck