Ok, back on track with the Coke Bottle engine.
What I'm doing here is roughing out the parts. Meaning I'm going to skim cut to clean up as much as I can without going right to size. That will be done later as the parts are put together for a trial fit.
The first pic shows how I chucked up the rough casting for the part known as the "inside head" this part mounts between the frame and the cylinder assembly. I used two 1/4" HSS tool bits as parallels and the tailstock to push against the part to ensure I was as close to square as possible. After the chuck was tightened the two pieces of HSS tool stock was removed. Why? Saftey reasons. You don't want them flying out while maching and hit you in the face. That would ruin your day of fun machining.
![](http://www.kingstonemodeleng.com/Madmodder/inhead1.jpg)
Then I just cleaned up the diameter and shoulder. No set dimension here. Just enough to get to a nice clean surface. This will allow me to turn the part and insure it will be square for the next operation.
![](http://www.kingstonemodeleng.com/Madmodder/inhead2.jpg)
The part has been turned and chucked on the surface I just turned. Now I'm going to face and turn the OD of the part. Again to just clean the surface.
![](http://www.kingstonemodeleng.com/Madmodder/inhead3.jpg)
And there is the rough turned part. All the diameters and shoulders are now square to each other making the machining to finish size easier and more accurate.
![](http://www.kingstonemodeleng.com/Madmodder/inhead4.jpg)
Next I've decided to do the other cylinder cover.
Pics to come soon.
Bernd