View Full Version : Turning a spherical bowl-any tips

10-30-2007, 01:55 PM
Hi all, this is my first post here and I am looking for some help please, I am making some cylinder head inserts for a two stroke engine on my old harrison L5 lathe (from England). I am not that experienced at turning but am learning all the time. I would like to know the best way to turn the combustion bowl, i have calculated the dimensions i need to give me the correct head volume, the radus of the bowl is 26mm in this case, I have ground a tool to form the bowl but am not having much success, any help would be appreciated.

10-30-2007, 02:11 PM
You should look at post on this site called making internal hemispheres.
Jim Sehr

10-30-2007, 06:46 PM
I think you'd probably have the best luck with a radius turning attachment. The commercial ones are big bucks, but there are lots of ideas and plans for building your own. Search the archives here for "radius turning" or similar and you should get some good hits.

10-30-2007, 07:14 PM
to do it the most accurate way ..
rough it out on the lathe undersize

then move it on to the mill

and do it like this


all the best.mark

10-31-2007, 10:17 AM
thanks for the replies, I`m now making a radius cutting attachment for my lathe