Enlarging Taper in Tailstock Quill--Pros? Cons?

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Utah Smitty
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Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by Utah Smitty » Sun Jul 14, 2019 12:41 am

I just bought an Enco 12x24 belt driven lathe (Model 92010). The specs I read said it had a tailstock taper of MT3. When I got it home and popped the dead center out of the tailstock, I found it was a MT2.. same size as on my SB heavy Ten. This has me a little bummed because I just bought a tailstock turret with a MT3 shank. I also would like to be able to use a larger drill with tapered shank in my late, plus larger, i.e. stronger enters, etc.

I did some research and found that Enco offered this lathe with either a MT2 or a MT3 taper in the tailstock quill.

My question: I can get a MT3 taper reamer for undewr $100... what are some of the considerations I need to consider in enlarging the tailstock taper from Mt2 to MT3?

Thanks for your responses,

Utah Smitty

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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by Harold_V » Sun Jul 14, 2019 1:45 am

The quill may be hardened, so reaming may not be an option. I'd strongly suggest you determine that before you consider the idea.

It is important that you don't change the orientation of the taper. One would think that the reamer would follow the existing hole, but a tapered reamer cuts differently than does a chucking reamer, and is capable of moving the hole, although it's not necessarily true that it will. You can take measures to help ensure that it doesn't. If you approach the task, make sure that you have the quill mounted so it runs dead true, and follow the reamer with a center, to keep it aligned with the centerline of the spindle of the lathe in which you attempt to do the alteration. That means that you most likely will not be able to use the same machine from which it comes.

It's a good idea to determine if the center/tailstock being used for the reaming operation is concentric with the spindle.

H
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liveaboard
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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by liveaboard » Sun Jul 14, 2019 5:48 am

Wouldn't it be better to make a completely new quill?
It seems to me it would only be a little more work than cutting the original one.

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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by earlgo » Sun Jul 14, 2019 8:59 am

If Enco made that lathe with either a #3 or #2, I'd consider buying the #3 direct. Then you would have the option of either quill in your shop.
JMHO.
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Mr Ron
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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by Mr Ron » Sun Jul 14, 2019 1:28 pm

If you have a taper attachment on your lathe, It wouldn't be too hard to make a new quill. I understand Grizzly may have parts that will fit the Enco as the lathes are clones of an earlier lathe.
Mr.Ron from South Mississippi

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rudd
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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by rudd » Sun Jul 14, 2019 2:07 pm

I doubt "call Enco" is going to be a solution. I think that lathe is no longer in production. Some folks think Grizz parts may interchange, some folks think Jet parts may interchange.
For me, centers fail at the tip, so diameter of the shank isn't an issue. Consider that the shank is essentially fully supported in the bore of the quill.
In the way-back-ago folks used MT shank drills that didn't fit the tailstock quill by putting the tail end on a center in the tailstock, and using a slotted piece of flat or a dog on the flat extension for ejection to keep it from spinning. Not ideal, but it worked.

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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by mihit » Sun Jul 14, 2019 2:22 pm

"Don't make what you can buy" - as earlgo said, if you can source the part that's your first solution.

If you can't then making a whole new quill would be my choice.

If you do decide to modify it, I would look for/make a piloted reamer to avoid the potential yaw issue Harry mentions.

armscor 1
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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by armscor 1 » Sun Jul 14, 2019 4:00 pm

I made a new mt3 quill for my lathe and finished the bore with a roughing and finishing reamer. I doubt the quill is hardened, mine was soft, simply bore out the quill and finish with reamers.
You need a lot of pressure on the reamer to remove material.
I made my quill out of 4140 and has performed faultlessly for the past 5 years.

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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by armscor 1 » Sun Jul 14, 2019 7:05 pm

Quill I made.
Honed Tailstock bore to a nice finish, was rough from the manufacturer and machined OD of quill to suit for a good fit.
The centre of tailstock sits 2 thou high, happy with that.
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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by spro » Mon Jul 15, 2019 2:29 pm

Very interesting thread, in that I also have an early Enco 12x36 with the MT #2 barrel taper. They went to MT #3 shortly afterward. I would prefer to have another barrel of MT #3. There must or was a stock of these somewhere.

spro
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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by spro » Mon Jul 15, 2019 11:05 pm

I meant "quill" instead of "barrel" in this thread. The #2 serves well and I have a #2 turret shared from the smaller South Bend. I have numerous MT#3 drills which would have been useful. I think that the boring and pocket for the #3 tang may leave me with neither.

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Re: Enlarging Taper in Tailstock Quill--Pros? Cons?

Post by liveaboard » Tue Jul 16, 2019 4:09 am

mihit wrote:
Sun Jul 14, 2019 2:22 pm
"Don't make what you can buy" -
Exactly the opposite of how I do things.

My lathe has an mt2 tailstock; it's a small lathe so this is ok.
I use larger drill bits by using an adapter.
Ok, I bought the adapter, didn't make it myself.

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