Repaired the collet alignment screw, Bridgeport clone

[Winegrower]

For awhile several of the R8 collets were hard to get in and/or out, interfering with the alignment screw. I watched Mr. Pete and H&W videos and started in. First problem was no spanner holes in the nose like in the videos, just a radial 1/4” hole in the side of the nose piece.
I have a terrible tiny collection of spanners, none fit, but fooling around awhile it seemed like it was stuck on pretty tight. I did remove the setscrew at the back of the quill without losing it. But no luck with what I could find laying around, and it looked like some past work had smeared out the spanner hole and I didn’t want to make it worse. So I put a hole slightly (0.002) larger than the nose piece in some scrap aluminum plate, turned a 5/16” cap screw down to make a peg for the spanner hole and tapped it into the side of the plate and added some handles. It installed as intended, but still the nose was quite tight. In the process I happened to think maybe it was a left hand thread. Bingo. Spun right off. Duh. Later I saw it written “Bridgeport is RH, clones are LH”. Sort of hard to believe as a blanket statement, but…

The apcollet alignment screw protrusion was mushed over, like maybe the collet was not tightened enough at one point and tried to spin. A little file work took care of it, re-assembly was easy, and it all works as it should now. And if itvever sticks again, I’m prepared.

 

[graham-xrf]

Now that you know it comes off LH thread, don't you think that biggest-ass-spanner de scaffold pipe(s) is being a bit "over-prepared" ?

I have also recently had a couple of encounters with LH threads initially unsuspected to be so. Darn mower motor speed governor lever screw AND a left handed 1/4 x 28 UNF on the roller drive pulley. I was lucky not to take them to the point of destruction!

Nice fix on the BP clone!

 

[jwmelvin]

You could modify your tool to be half the size and fit on and off like a normal spanner. Looks good though.

My clone (Millport) has a RH thread, fortunately because it never occurred to me that it could be LH. I removed my collet alignment screw and have been much happier since.

 

[Winegrower]

You could modify your tool to be half the size and fit on and off like a normal spanner. Looks good though.

Now that you know it comes off LH thread, don't you think that biggest-ass-spanner de scaffold pipe(s) is being a bit "over-prepared" ?

Ha ha, exactly right, guys. It was completely unnecessary. And I don’t think it was all that tight to begin with. It was frankly quite embarrassing when it started to move.
With what I know now, I think I could take it off with a 1/4” dowel pin and bare hands. But the great thing is I learned how easy it will be to get the spindle out for new bearings one of these days.

 

[markba633csi]

Just as embarassing, getting something set up in the hydraulic press only to find that it just comes apart so easily a few taps with a hammer would have done it.
Looks like somebody before you was brutallizing on your depth stop there- with pliers apparently. Don't ya hate that? Knuckle-draggers I'm sure
-Mark

 

[brino]

I have also recently had a couple of encounters with LH threads initially unsuspected to be so.

It was frankly quite embarrassing when it started to move.

I remember when my Dad and I broke off two wheel studs on my brothers old (and wrecked) 1970 Chrysler Newport.
The wheels on one side came off easy, the other side we broke two studs before it occurred to us they were left-handed on that side of the car.
Truly Sinister!

-brino

 

[Winegrower]

Looks like somebody before you was brutallizing on your depth stop there- with pliers apparently. Don't ya hate that? Knuckle-draggers I'm sure

Agree, and don’t know why that would have been necessary. But you should see the table…it looks like they were routing out PCBs using the table as the backing surface. Looks horrible but it has never actually been a problem in use. So I smile a little bit inside when somebody anguishes here over a tiny nick or ding.

 

[markba633csi]

Yep, that's the best part about used machines- the dings are already there so you don't obsess over them
-M

 

[mmcmdl]

Myself and my co-workers find left hand threads amusing watching some of our new hires . Actually , it doesn't matter as to what hand they are . We have top and bottom hot air pipes over and under every die on the lines . They seem to get the bottoms loose and always have issues with the tops . We tell them righty tighty and lefty loosy . They always return with " I just took these off by turning them this direction " . Hey , flip the pipes over if you want .

 

[finsruskw]

Can someone walk me through replacing the collet alignment pin on my Jet JTM-2?