MT3 Dead Center

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Metalman
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MT3 Dead Center

Post by Metalman »

Haven't been here for a while, Hope all and everyone is well.
I have a Morse taper 3 dead center with a damaged point. Does anyone know of a service that can regrind it?
OR: What would I need to adapt it to the spindle of a South Bend 13? I have a 5C collet adapter but never had a way to use the dead center in the spindle. If I could put in the spindle I might be able to regrind it with a tool post grinder (slow).
Ernie F.
chief
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Re: MT3 Dead Center

Post by chief »

Do you know the taper of your headstock?

Some 13" SB's are Morse taper 4, in which case you could buy an adapter, probably cheaper than the cost of grinding the dead center.

From what I've read, other lathes had a different taper, a SB proprietary taper that I have no knowledge of, so I don't know if adapters are available.

I'm sure some SB expert here on the board can jump in and provide more info.

Terry
Technical Ted
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Re: MT3 Dead Center

Post by Technical Ted »

Here's what I made for my SB13. Don't remember where I got the dimensions from, but it works.

Ted
SB13 Spindle Adapter to MT3.pdf
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SB13 Spindle Adapter to 3MT.jpg
Technical Ted
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Re: MT3 Dead Center

Post by Technical Ted »

I turned the OD, then put it in the spindle taper to finish the bore taper. I suggest match marking it before putting it in so in use you always put it in the small way/position.

Ted
John Evans
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Re: MT3 Dead Center

Post by John Evans »

You will be time and money ahead just to replace it . Dead centers are just that dead! A cheap import one will serve just fine. I have Morse 2& 3 straight sleeve adapters that fit a tool holder on my lathe. Those I can hold in the 4 jaw chuck on the work head on my very old B&S #13 grinder. But again for the price of a new one I doubt I would go to the trouble to set up the grinder to do the job.
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Bill Shields
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Re: MT3 Dead Center

Post by Bill Shields »

Agreed on replacement unless you have a friend with a grinder who will do it for nothing.
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BadDog
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Re: MT3 Dead Center

Post by BadDog »

Are you sure you need it? I used to use a dead center just because it came with my lathe and an appropriate adapter. My new lathe did not. Even before the new lathe I had started using a short drop of steel in the 3 jaw. With a small step so it can't be pushed back, and with the pointe turned in place, it's dead true every time, minimal overhang, and you have the jaws to drive a dog. Each time you mount it, if you need it dead on, just touch it up after mounting, and you are guaranteed no runout.
Russ
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pete
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Re: MT3 Dead Center

Post by pete »

Damage probably means rings or a flattened tip that almost guarantees the dead center got hot from lack of lube or being too tight. If so then just regrinding it isn't going to restore that all important hardness. So I'd agree about replacing it, and with a carbide tipped one. I have re-pointed one that wasn't too damaged using carbide, but even then there really, really hard.

If your wanting to use it in the tail stock and hold it in your head stock for just that re-pointing then you need what's known as a Morse Taper to Morse Taper reducing sleeve as John said. https://www.mscdirect.com/browse/tn/?se ... =true&rd=k

For actual use in the head stock I do exactly the same as BadDog does.
Technical Ted
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Re: MT3 Dead Center

Post by Technical Ted »

SB 13's spindle tapers are not MT4. If I remember correctly, the taper angle is either the same or very close, but the diameter is between a 3MT and 4MT. See the attached chart and check the dimensions compared to standard MT sizes.

Ted
SB Lathe Spindle etc Specs 5224.pdf
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BadDog
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Re: MT3 Dead Center

Post by BadDog »

I just realized I likely misunderstood the original post. I thought he was planning to use this in spindle of the SB lathe for turning between centers (generally a live center in ts). But now I see that was not what was stated. But rereading, it's not clear what the application may be, or how important hardness and accuracy may be. If the intent was to use it in a tool grinder, then it seems unlikely to feel the need to be posting that question. Now I find I have no idea what might be a good plan without knowing the application.
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Technical Ted
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Re: MT3 Dead Center

Post by Technical Ted »

I'm not sure what the intent is either. But, I totally understand his desire to repair what he has, by any means available to him with the equipment he has. Hey! This is a hobby member site! We love doing things that take a challenge and hopefully will provide a great pleasure and learning experience as we travel through things. Yep, he could very well just buy new. But, what fun would that be???

Don't know about everyone else, but I am well know for doing things that don't make a lot of sense to a guy who runs a production shop and needs to optimize everything they do.

Have fun. Learn. Enjoy the hobby. I'll help all I can and enjoy every minute of it.

Ted
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BadDog
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Re: MT3 Dead Center

Post by BadDog »

Certainly. But while he mentioned ideas for regrinding himself, it seemed like his main focus was a service to send it out for in a "get it done and move on" sort of approach.
Russ
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