Shopsmith Forums

Hi, I found each of my Mark V's tailstocks can deflect a tad under hand pressure. The tailstock pipes fit into the 2 honed cylinders pretty snug, but definitely not a force-fit. I started trying some paper shims. There was no way to wrap each pipe with paper and still fit the tailstock in the holes...

Good Point. If you are DRILLING, why are you trying to do it on a lathe(good idea with metal lathe, bad idea wood lathe). Why not use SS in 'horizontal boring) mode? Clamp the miter gauge in position, place the 'blank' against it, add a stop, clamp blank in position & bore away. Only your setup...

First of all, this has been the standard way of boring a centered hole using a lathe for a few hundred years. Secondly, the wood is well supported. I'm using a proper chuck with tall jaws that extend well over half the length of the blank. (Not that it is needed considering we are talking about a sh...

Just WHAT is moving??? Tail stock in frame holes? Tail stock eccentric? Chuck adapter? Chuck? Bit? You people don't listen to well. The alignment is fine. The problem is the combined weight of the chuck and drill bit is causing the tailstock to flex and the tip of the drill bit to dip. If I swap it...

beeg wrote:With "A", it sounds like the bit isn't tight in the chuck or the chuck arbor is spinning in the tailstock.

I was talking in generalities, I haven't had that particular problem with this machine.

Johnathan, it seems like this ought to be quite a bit lighter than the SS 1/2" drill chuck with its 5/8" spindle hanging off the SS tailstock arbor adapter. it looks like the PennState unit might be shorter than the stack of SS units. if so, it would also reduce the cantilever moment even...

And also the implication that it flexes back. Once bent, why wood it flex back? The spinning wood. If the bit touches a 32nd below center, it just cuts a larger than planned hole. But once it grabs the wood, one of two things happen. A. It follows the wood around the circle, weakening and eventuall...

Machine tolerances may allow it to shift position an unacceptable amount but I have a hard time accepting that it bends that much. A 16th of an inch, maybe just a 32nd. It isn't much, but when you need a tight fit it ever bit counts. And of course any flex in the tailstock is multiplied by the leng...

jpg40504 wrote:IS YOUR BIT BENT?????

Nope. But all metal is flexible, which is why shorter drill bits are preferred when doing this kind of work.

Even when I'm spinning round stock 1 1/2" thick, having it hang out 4" without a center to support it will cause it to bend.

I just don't know why the entry point of a drilled out tube would become larger than the end point. I have no explanation for this at all. Not even a guess. Like I said in my original post, it is due to the flex in the tailstock. Instead of being perfectly horizontal, the tip of the drill bit sags ...