Know now why Beall mandrel won't seat fully in my MT-2

[Jamie Straw]

It took awhile to figure out, but I now know why the Beall buffing system mandrel doesn't seat fully in my Jet 1236 Morse taper (headstock). All of my drive centers have an area at the end of the taper where the diameter is smaller, like a rabbet at the end (see picture below). Inside the Morse taper, if probed with a dowel, the wall narrows via a bevel. Obviously, the rabbet on the drive centers clears this bevel and allows them to seat fully. Since the Beall is tapered all the way to the end, it bumps against the narrowing wall just a tiny smidge before the mandrel fully seats. So, there's just a little bit of play. I guess I'll have to grind down the butt end a little bit to solve it. Any tips?

[Calipers are there only to keep the drive center from rolling]

 

[Zach LaPerriere]

For what it's worth, I really like the "Hold Fast Long Buffing Adapter" that threads directly onto the headstock spindle. I think it's a bit longer, too, which is pretty nice for getting further from the headstock.

 

[Bill Boehme]

Just put it on the grinder and grind away whatever is preventing it from seating. I had to do that with the taper adapter on one of my drill chucks.

 

[Jamie Straw]

For what it's worth, I really like the "Hold Fast Long Buffing Adapter" that threads directly onto the headstock spindle. I think it's a bit longer, too, which is pretty nice for getting further from the headstock.

Oooo, thanks Zach, I'll check that out!

 

[Jamie Straw]

Just put it on the grinder and grind away whatever is preventing it from seating. I had to do that with the taper adapter on one of my drill chucks.

Yep, I'll do the drill chuck first -- trial run. You guys have me really paranoid about doing anything to a mandrel for those Morse tapers -- I might leave a molecule or two out of place and precipitate total ruin.

 

[Bill Boehme]

.... I might leave a molecule or two out of place and precipitate total ruin.

One molecule (or ping) only is enough to precipitate total ruin.

 

[Hy Tran]

FWIW, some MT-2 accessories for tailstocks will seat nicely, but won't auto-eject when you crank your tailstock all the way back. I just found that out. In that case, that's because the MT-2 item is shorter than the tailstock expects it to be. This is also a relatively easy fix. Turn an extension that fits in the hole in the narrow end of the MT-2 item, so that when you crank the tailstock back to auto-eject, your turned extension hits the stop on the inside of the tailstock and pushes your MT-2 accessory out of the tailstock.

Make your extension a jam-fit in the MT-2 accessory.

Sorry, no picture. I may try to sketch something and edit my post later to show you what I'm talking about.

 

[john lucas]

You are right. My drill chuck morse taper had a tang and it wouldn't work in my Delta midi. I cut the tang off. Worked fine in the Midi but then it wouldn't self eject in the Powermatic. I drilled and tapped the end and put a 1/4x20 screw in with a custom made aluminum washer to extend the tang about 1/2". Works fine in both now.

 

[Jamie Straw]

One molecule (or ping) only is enough to precipitate total ruin.

ROFL!!
[Oh, I need 10 characters. There.]

 

[Bill Boehme]

ROFL!!
[Oh, I need 10 characters. There.]

I feel confident that we can round up at least ten characters on this forum.

 

[Owen Lowe]

Yep, I'll do the drill chuck first -- trial run. You guys have me really paranoid about doing anything to a mandrel for those Morse tapers -- I might leave a molecule or two out of place and precipitate total ruin.

I’ve resorted to grinding a taper or two to shorten also; just make sure there are no burrs on the unground/shortened portion that mates with the lathe taper and you’re good to go.

 

[Hy Tran]

Do you use the drawbar or tailstock pressure on the buff?

Post-modification, are you using/making a drawbar to hold the mandrel in, or do you bring the tailstock up to apply pressure? (I'm assuming you're using a single wheel-at-a-time buff, and not the Beall-3-buff system).

 

[Jamie Straw]

Post-modification, are you using/making a drawbar to hold the mandrel in, or do you bring the tailstock up to apply pressure? (I'm assuming you're using a single wheel-at-a-time buff, and not the Beall-3-buff system).

This is the 3-wheel buffing system, mandatory tailstock support (they provide a divot for it to go into). I'll grind the mandrel down a bit. Shouldn't need a draw bar once the mandrel fits, methinks.

 

[Jamie Straw]

Fits in new spindle!

I received the new spindle yesterday, and though it's not installed yet I did a test-fit of the Beall mandrel in it, and it seems to seat fine. So, it would appear the original spindle for my lathe is just a little "short" from tip to the interior beveled area. OPCAAW buddies are coming over soon to put in new spindle and, just for the heck of it, replace the bearings.

 

[Dean Center]

I received the new spindle yesterday, and though it's not installed yet I did a test-fit of the Beall mandrel in it, and it seems to seat fine. So, it would appear the original spindle for my lathe is just a little "short" from tip to the interior beveled area. OPCAAW buddies are coming over soon to put in new spindle and, just for the heck of it, replace the bearings.

That's what you get for being so nice. Great service!