New style QCTP for an Atlas lathe

Very nice!
A couple newb questions though. First, how did you make the eccentric shaft?
And second, I'm not seeing how the cam functions in the assy. I mean I know the eccentric pulls/pushes the brass shaft. But if the hole is big enough to slip the cam thru, what is holding it to allow it to move the shaft?
Thanks,
Wes
 
WesPete66 said:
Very nice!
A couple newb questions though. First, how did you make the eccentric shaft?
And second, I'm not seeing how the cam functions in the assy. I mean I know the eccentric pulls/pushes the brass shaft. But if the hole is big enough to slip the cam thru, what is holding it to allow it to move the shaft?
Thanks,
Wes
Click to expand...

Yes I should take it back apart and take some more photos. After I bored the hole in the the steel body and brass plug I took a 3/4 end mill and relieved one side of the hole in the brass plug about 1/16" so as the cam turned in the bore it would not jam. The cam simply pushes to the rear or the front and one side of the 3/4 hole is relieved. As for making the cam I should be telling you I four jawed it and then re-cut it I did not. I put a 1/16 shim under one of the jaws on my 3 jawed chuck I then machined the cam part to 3/4" . I then took the shim out and machined the bearing surface and the top part for the handle it really works good and I dont have to change chuck ( lazy ).

The top bearing surface is 3/4" OD the bottom of the shaft is 5/8 OD this allows wiggle room to drop the cam in then you install a 3/4 x 5/8 brass bushing in the bottom to fit the bore and make the shaft fit nice and tight to the body. The (hat) at the top allows you to tighten the whole thing down to the compound but the handle remains free. This also stops the cam and the shaft from moving out I sure hope that explains it!! Ray
 
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