Saturday, September 11, 2010

Making the 1" Tailstock Die Holder

This is a side tracked project made necessary while I was doing the job for a good friend of mine (see my post under "A Job For A Bro... Part 1").  The previous tailstock die holder I made was for an English made die.  The set of taps & dies I bought subsequently (M1 to M12) have smaller diameter of 1", which is too smaller for the holder.  So a new one is in order.

With the previous experience of making one, I started off rather well and quick till I had the problem of the stock being pulled out of the 3-jaw chuck while boring.  I started drilling from drill size of 4mm to the biggest my 3/8" jacob chuck can take (10mm).  The boring bar was next but I couldn't proceed as when the boring tool went into the hole, the stock came off.  It didn't happen the previous time.

Yesterday night, while I was in my dreamland, an idea suddenly hit me; why not drill & tap the 3/8"-24 hole for the morse taper adapter first and have the stock mounted on the spindle directly?  I'm sure those experience machinists or hobbyists would have done that from the start but hey, my proficiency is in the use of my Casio FC-200.  There are many advantages doing that, I reasoned.  For one, I wouldn't have the problem of the stock flying out of the chuck.  Two, I'll be assured of concentricity.  Three, my alignment will be perfect (or close to).

This morning, I woke up at 6.30am to get ready to work.  The idea works!  Not only the experience with the boring operation changed for the better considerably, I'm also able to turn to the entire length of the body of the holder - sweet!!!

Some pics are attached below.

The holder-to-be with the #1 MT adapter mounted in the spindle and the draw bar tightened (not shown).

The 25.4mm hole bored to 9.5mm deep.  The smaller internal hole was bored to 13mm to allow stocks to pass through the biggest tap in the set - 12mm.

The exterior of the body was turned down to approximately 34mm.

I was trying to "personalize" the holder, following Luiz Ally's demonstration on YouTube.  This Brazilian gentleman is really a master craftman. You should see his work.  Do a search for "Tryally" on YouTube.

But looking at what I did from the pic, you can see that I failed badly in that department...

Test fitted with the M5 die.  The holder is almost complete.  3 more holes to drill and tap; 2 to hold the die using the 2 dimples on it's edge and 1 for the split.  I should be using either 10-32 or M5 screws, turned to almost a point at their tips, as that are the 2 sizes I've the drill for.  I'm leaving the holes till tomorrow.  Arranged with Mike of to pick up the rotary table so that I can drill the 3 holes right where they belong.

Frankly, despite the failed attempt to personalize the holder, I still feel rather proud of the result I get.  The dimensions of the part are very much closer to what I'd in mind, compared to the first one I did.  This one looks much better too.

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