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mayfieldtm
02-19-2004, 04:39 PM
I've just finished reading "The Amateur's Lathe".

On the subject of Tailstocks and Morse Tapers, the author recommends that the Morse Taper (male) should be wrapped with a single layer of thin writing paper, before inserting into the Tailstock.

He claimed this provided a better friction fit and helped protect the Tailstock from damage in the event that the taper should spin.

Is this a good idea?

I damaged my Tailstock like this, on my old Shop-Task (that I just sold), while drilling with a drill chuck, and since then I have high-anxiety when drilling using the tail.

For my new Lathe, I just bought a ½" "Jacobs Super Chuck" from "Enco" with a real Jacobs Arbor.
This Arbor (Morse #3) has a Tang, which makes me feel much better.
( By the way Enco's sale price on the chuck is just $99. #505-8004 )

Tom M.

yorgatron
02-19-2004, 04:59 PM
i use a trick my dad showed me to help keep the chuck from spinning on the drill press,after you make sure it's clean and burr free rub a little chalk on there,it grabs just enough to keep it from spinning.don't know if that's the right way to do it,but the drill press chuck is still in place some 25 years later and i haven't spun anything in my tailstock lately-george

JCHannum
02-19-2004, 05:01 PM
I have not heard of using a paper shim in the tailstock to prevent slippage. It may help.
The best way to prevent slippage of a Morse taper in a tailstock when drilling is to clamp a lathe dog to the shank of the MT adaptor and allow it to slide on the compound. Even if the adaptor has a tang, most lathes will not hold it without slipping under the stress of a heavy operation such as drilling. They are not designed to handle these loads.
Installing set screws, as some people recommend, creates the possibility of shearing the small key used to locate the tailstock ram.

Bruce Griffing
02-19-2004, 05:45 PM
In my opinion, the tailstock is not designed for high torque. But it should handle normal drilling. I clean the taper with acetone on a paper towel and make sure the taper is clean and dry. Same for the arbor on the chuck. I first make sure that the tailstock barrel will eject the arbor when retracted. If so, I then open the chuck so that no jaws are showing and whack it with a plastic dead blow hammer. Try it a few times. Use the tailstock to eject the arbor right away and begin to get calibrated on how hard it is to eject the arbor. If friction in the tailstock barrel is the only thing keeping the arbor from spinning, it should be somewhat hard to pop the arbor - though it should be done easily with the crank (no extra leverage). JC is correct in that tailstocks I have used do not have a socket for the tang. YMMV.

Carl
02-19-2004, 07:13 PM
I'm with JC, I use a lathe dog also.

Bruce Griffing
02-19-2004, 08:12 PM
It's hard to argue against using a dog. Can't go wrong. In fact I do that also for heavy cuts. But most of the time I don't. Most of my holes are 3/8" or less. Often in aluminum. So I think it depends on what you are doing. My 2 cents.

wierdscience
02-19-2004, 11:15 PM
On a drill chuck if you want to do away with the dog,make yourself a "cup" out of steel to fit on the od of the tailstock barrel and press onto the arbor shank,then drill and ream for a dowel pin to fit up in the tailstock barrel keyway,a 1/4" pin will work up to a 1-1/2" drill.

J Tiers
02-19-2004, 11:48 PM
My dumb question of the day is.....if you don't dog it, aren't you putting a lot of faith in that little bitty pin that holds the tailstock ram against turning?

It could ruin your week if that sheared into the ram and stuck the t/s solidly.......

Bruce Griffing
02-20-2004, 12:23 AM
On my recently acquired Standard Modern, that little thing in the 1.575" barrel is a 1/4" wide by 1/8" deep slot. The slot is engaged by a steel part over 3/4" length. Beefy enough, I think, to drill small holes.

wierdscience
02-20-2004, 12:35 AM
<font face="Verdana, Arial" size="2">Originally posted by J Tiers:
My dumb question of the day is.....if you don't dog it, aren't you putting a lot of faith in that little bitty pin that holds the tailstock ram against turning?

It could ruin your week if that sheared into the ram and stuck the t/s solidly.......</font>

Never had the problem,5hp motor stalled once on a 1-3/8 hole in 316 stainless,adapter slipped right out,I suppose though if it would make you feel better you could make the sleeve a bit longer and use a key,but the dowel pins are pretty tough.When I go to a 1-1/2 or bigger drill I still use the lathe dog anyway.

Mike W
02-20-2004, 01:33 AM
On my lathe, the tailstock barrel does not recess all the way inside. I made a clamp to attach to the end so it sticks out just a little. I drilled and tapped a 8-32 hole in the clamp. I then drilled a little dimple in my chuck arbor just behind the chuck.

When I put the chuck in the tailstock, I finger tighten a 8/32 allen head screw into the dimple. Since I have done this I have never had the morse taper slip while drilling.

Evan
02-20-2004, 03:03 AM
What ever are you guys talking about? On the SB9 tailstock we have no itty bitty pins. The barrel is keyed with a approximately 3.5" long key to a keyslot in the barrel. I don't think that is going to twist off. Even at maximum extension about 1.5" is engaged. I happily drill holes 1" in steel and the MT2 doesn't twist either.

[This message has been edited by Evan (edited 02-20-2004).]

Thrud
02-20-2004, 03:38 AM
Tom
Use of a lathe dog is the proper way to ensure that you do not bugger the drill, the lathe, and the work.

THIS IS NOT AN OLD WIVE'S TALE, IT IS KNOWN FACT FOR THE PAST 100 ODD YEARS.

J Tiers
02-20-2004, 10:27 AM
<font face="Verdana, Arial" size="2">Originally posted by Evan:
What ever are you guys talking about? On the SB9 tailstock we have no itty bitty pins. The barrel is keyed with a approximately 3.5" long key to a keyslot in the barrel. I don't think that is going to twist off. Even at maximum extension about 1.5" is engaged. I happily drill holes 1" in steel and the MT2 doesn't twist either.
[This message has been edited by Evan (edited 02-20-2004).]</font>

Logan has a short key with a pin into the casting (part # LA1095), Atlas has pin, I think. Either would batter the keyway.

One of the few *downsides* of the Logan, if it can be called that.

It is so easy to dog it that..........

JCHannum
02-20-2004, 11:04 AM
<font face="Verdana, Arial" size="2">Originally posted by J Tiers:
It is so easy to dog it that..........

[/B]</font>
Considering the possible problems that can result from not taking the simple precaution of using a dog on larger drills, it is stupid not to do it. At some point, something will give, and damage may occur.

mayfieldtm
02-20-2004, 06:07 PM
I tried a Hot Dog; but, it didn't work.
So then I tried a Lathe Dog, and that works like a dream. Feel much Better, except that I should have figured that out for myself.

Thanks guys.

I rarely drill larger than 1/2", and that’s usually for a starter hole for a boring bar.
Most anything larger, I do in the mill or drill first.

One thing I did learn on my old machine, was to take the time to make sure that drilling is on center, center, center. Especially on deep holes.

Oh Oh, my wife is calling, she wants her Hot Dog back.

Tom M.

spope14
02-20-2004, 11:01 PM
I tried the paper on the taper trick today, but on a Cat V-40 taper in a machine with a slightly buggered spindle (given to the school). It worked like a charm, and helped the tool seat and release much better. I used a sheet of brown paper towel though, much thinner, and more cushion.

The tool stud grabber is also out of sorts, no way to get it right without a total rebuild of the spindle (which i will do this summer). The towel also allowed the grabber to set right and release better. It held quite well, it was tested at 300 RPM, then about 900, 1200, right up to 2500. No wobble whatsoever

Did this doing an engraving job where wobble would kill the tool - single point carbide 60 degree.

Learned a trick today, thanks.

darryl
02-21-2004, 03:39 AM
I've used a paper shim for that, it works fine. I'm not saying don't use a dog, just that the paper does the job of protecting the tapers. Be careful, though, of moisture content in the paper. I've seen it rust.