On a recent ball, I have noticed that when drilling the thumb hole (1 5/16" for Vise IT installation), there was a pretty pronounced "bulge" in the wall of the hole, between the filler material and the core.  Not sure if it's a dull bit, some play in the drill press, or just the different density materials relaxing after drilling?

I have seen this before, but not to this extent...  this one even did it a little in the fingers (31/32" hole).  I had to go back in and try to sand/smooth out a bit.

Related (I think) is a similar situation where the top sleeve of the Vise-ITs have all been very tight when initially drilling the thumb hole.  I have to work out a bit in order to get the ring to slide in with little effort (therefore the thumb slug will go in with I it having to force).  I though maybe the tolerances were off a bit on the bag of sleeves, but I bought a second bag and saw the same thing.
Would a slight wobble (I can't see/detect it visually) and/or a dull bit cause a hole to be slightly smaller and/or not perfectly round?

Anything to look for or try?  I have an older Delta press.
Thanks!

Scott

My driller cuts the top rings for IT in half.  Not sure if Vise now sells shorter top rings or he still does this.  He found the full length ring wasn't needed and led to problems when the ball swelled filler material, etc.

What size pilot hole do you use?

you can use whatever bit you like. obviously the bigger the better as the IT bit doesn't have to do as much work. I normally do a 7/8" bit.

Would a slight wobble (I can't see/detect it visually) and/or a dull bit cause a hole to be slightly smaller and/or not perfectly round?

Anything to look for or try?  I have an older Delta press.
Thanks!

Scott

Quote from: Strapper_Squared on November 22, 2016, 11:07:46 AM

I found that I get a little chatter if using a pilot...

I'd be checking your drill, if the hole isn't round and your getting chatter on a pilot hole that sounds like something causing the bit to wobble or the ball isn't locked down good.

So You either got something loose, the tool or the ball is moving.

I'd also check for your speed and/or feed plus check the point on the bit too