Originally Posted by MechanoMan  The Sherline can handle this.
It is not right for the center drill to wobble. Are you sure you started it at the basic center of rotation?
I have had trouble where the tailstock isn't pointing dead center into the axis of rotation. You can kinda adjust the brass shim on the tailstock-to-rail mount.
You cannot use the tailstock with the parting tool, at least you're not *supposed* to be able to do so by the book. Because the compression causes it to collapse onto the parting tool when the last bit of material gives way. If you keep tailstock pressure minimal this may not be a problem, but the disc needs to be able to fall away.
A SteadyRest will stabilize the 5" stock for end cutting.
Make sure the tailstock is not fully retracted to the ejection position, pull back the jaws of the 3-jaw chuck so they fall below the surface, LOOSEN THE TAILSTOCK OFF THE RAIL, hold the tailstock wheel in your right hand for linear resistance and turning resistance, and *gently* tap the chuck with a hammer. It will stay.
It's not normal. Either the center drill hole was not completely on center (may have moved accidentally), or your tailstock chuck is not pointing towards center. Or your center drill sucks.
No such thing as too sharp.
The coiling "swarf" is desirable. If you are getting chips, you may be turning too fast on the motor or not feeding it fast enough to keep the coil continuous. If it's not coil-swarfing, vibration may occur.
I'm not sure why you're enlarging a previous hole by choice. The bit is more stable on one big drilling operation. |
Thanks for the reply...
I have never checked the tailstock to headstock centre, the Sherline is still quite new and I would have assumed it to be correct. Will check by chucking up a dead centre and have the live centre in the tail stock.
Yes, use the Steady Rest - that makes more sense than using a live centre on the tail stock. I do understand that it's not safe to run the parting tool too far when using a tail centre.
"Center drill sucks" - shouldn't be, the chuck and center drill are both from Sherline. I assume that the center drill is OK to mount into the Jacobs chuck ??
Re: drilling a large hole. You mention to just use the final drill size rather than starting with a smaller drill. mmmm, OK - so need to ramp up the sizes.
Sorry to say that I don't have a bandsaw, so I am using the lathe to dimension stock.