Head stock center to small Help

Chuck Thoits

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Ok so I get the PM 45 all set up and wired. I put the head stock spur center in it slides all the way in to the caller and stops. It seems to need to be about a 1/4" longer to tighten up so it wont spin. It is as if the head stock is worn out:dunno:
I have checked the size it is an MT #2 the center is a jet MT#2 and the old one that I took from another PM 45 is to small also.
Has any one heard of a head stock shaft wearing out? Is there a way to shim it?
Is there a #2 spur center that is just a bit longer? How much bigger is a MT#3 and does any one know where to get one?
With out the center it is going to have to stay as a salad bar.
 
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Hi Chuck

I've heard of MT3 on lathes, but they are not common, as far as I can tell. :huh:

How about the tail stock, doe the drive, or live center fit into it correctly?

Grizzly has the >> Sorby Steb Centers in a MT3 << $80 :eek:

But really the way you might want to go is with an adapter sleeve.........

mt3_to_mt2_adapter.jpg<< Linky Pic

$6 and you are good to go with the drive center and such you have....... ??:dunno:
 
Ok so I get the PM 45 all set up and wired. I put the head stock spur center in it slides all the way in to the caller and stops. It seems to need to be about a 1/4" longer to tighten up so it wont spin. It is as if the head stock is worn out:dunno:
I have checked the size it is an MT #2 the center is a jet MT#2 and the old one that I took from another PM 45 is to small also.
Has any one heard of a head stock shaft wearing out? Is there a way to shim it?
Is there a #2 spur center that is just a bit longer? How much bigger is a MT#3 and does any one know where to get one?
With out the center it is going to have to stay as a salad bar.

Chuck, it sounds like a call to Powermatic "Technical Dept" might be in order. The last time I talked to them with a question on an older tool, they still had a couple of guys there that had been there a LONG time and were very helpful and able to give me the information I needed.
 
Uh-Oh! :eek: Does this mean a spindle replacement is necessary? :(
Well I am hoping that That I can have the MT#2 built up and then turned down to fit. Travis can this be cone? It only needs to be about 2 thousands bigger than it is. Or maybe if there is a make of MT#2 that is just a 1/4" longer than the Jet one it might work.:dunno:
 
Chuck,

I think Travis might be familiar with a process where your center taper could be built up by "spraying" metal on and then, depending on how much was applied and how good the surface came out, it could be either turned down (roughing it close to size) or ground down to the desired size and taper dimension, or using both methods could be used for a super "micro" finish. If this is done properly it could end up being better than original.

I have done it with good results. You're going to need to find someone with a good lathe that has a taper attachment and a tool post grinder for this. And they will have to be familiar with and have the tool for the process.

I definetly would not use welding to build up the taper as that would do more damage than good and you may end up with a hard and soft surface which could be difficult to impossible to turn down.

Keep us posted on your outcome.

Aloha, Tony
 
Chuck, can you determine if it is the taper in the headstock that is oversize or the center you have that is undersize,

Some male morse taper fittings do not have enough front 'over-run' of the Gauge size and if the socket taper has had to be reamed to clean out any scalding due to poor fitting center then they won't engage.

SIZES (opens PDF file attached to this post (page 2)


· #1 is 0.475"
· #2 is 0.700" This is the nose diameter at the open end of the socket, and approx. 1/4" from the front of the male center.
· #3 is 0.938"
 
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Do you know anyone/anywhere you could borrow anything with #2 taper? Tapers don't generally wear out. Not so much your going to be 1/4" deeper. I would try another taper before I did anything. Or if you have calipers or Mics' I would check the shaft of the center. Just sounds suspicious to me.
 
I'm with Jeff... something isn't flushing here.

I've never seen a MT "wear out". Either the center is not a true #2 MT or someone did some serious damage to the spindle. I'd verify the dimensions are correct with a set of calipers and get a definitive answer. If it turns out to be the spindle, the only way to correctly fix it is to replace it.

Mike
 
Jeff, Chaz, Mike,

Chuck stated that he tried more than one MT2 center, "I have checked the size it is an MT #2 the center is a jet MT#2 and the old one that I took from another PM 45 is to small also.".

Chuck, I would think you could test those centers in the tailstock to verify the fit. That would pretty much tell the story. Perhaps someone over-reamed the spindle, possibly trying to correct damage.

I responded to your question of building up the taper. But, I believe you need to replace the spindle to make things right again. You should be able to find one, somewhere.

Aloha, Tony
 
There is something fishy as if a center slipped enough to be that oversize the damage would be obvious.

There are some other standards out there that are very close to the MT one of which is the Brown and Sharpe series. I wonder if it could have been a special or if some one could have bored it out to use some existing tooling.

I can't remember right now if the BS is just a little larger or just a little smaller than the MT2

I have some BS collets and I will check against the MT and see how they fit in a MT2..

I don't have a BS spindle as the collets were bought by mistake at a flea market..

Garry
 
Tony I called the machine shop today and they don't know any one doing the spray thing any more. So I told the guy there what the problem is/was and his first response. It's a tapper fit shave the shaft.(stupid):doh: Ok so he left that out but you could hear it in his voice. So I get home tonight shave an 1/8" off the end of the shaft and tada works like a charm.:thumb:
I still think I am going to get a better spur than the jet, but it was free.:thumb:
 
Chuck,

I take it that you "shaved" the collar of the taper shaft, right? Pictures would sure help us to understand this.

Glad you got some of the problem solved. Maybe a different brand of center will have a design that will work better for you.

Aloha, Tony
 
Chuck,

I take it that you "shaved" the collar of the taper shaft, right? Pictures would sure help us to understand this.

Glad you got some of the problem solved. Maybe a different brand of center will have a design that will work better for you.

Aloha, Tony

So I get home tonight shave an 1/8" off the end of the shaft and tada works like a charm


Meaning the end of the taper that goes into the shaft If I understood this right.
 
So I get home tonight shave an 1/8" off the end of the shaft and tada works like a charm


Meaning the end of the taper that goes into the shaft If I understood this right.
Yeppers, sounds to me like it's a solid spindle, and the live center was bottoming out in the hole. At least that's my guess.

Whatever it was, I'm very glad to see you got is sussed out, Chuck. That lathe looks like it's ready to get dirty.
 
I shaved the head stock shaft not the spur. Vaughn I had to get it dirty to find out if it was going to work. I can stall the shaft now with out the spur spinning in it. The belt slips in the clutch but thats what it is for.
It is a hollow shaft how would you punch the spur center out if it was solid:dunno:
 
It is a hollow shaft how would you punch the spur center out if it was solid:dunno:

The Nova DVR has a solid spindle. Some people use a nut on the spindle to force a spur off. Others just put the spur in their chuck.
I don't like the idea of a solid spindle, and it is a major reason I would be reluctant to get a DVR. I'm just sayin' it is done.:huh:

Edit: I should correct myself. I think the spindle may be hollow, but since it is inline with the motor which has a solid shaft, it may as well be solid. I believe Bill Grumbine's ex-Poolewood lathe also had a solid shaft. I know he could not apply vacuum through the spindle as you would on most lathes.
 
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