# QCTP  base question



## litewings (Jan 29, 2020)

Received  this QCTP with my PM1340GT lathe. A little concerned about the attaching base not being the size  and shape of the tool post. A lot less contact on the compound that has me wondering about uneven wear/damage to the compound over time. I dont have a mill, or I'd build a new base. Is this a commonly seen type of attaching base?


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## Bob Korves (Jan 29, 2020)

Make your own t-nut to fit the compound rest.  Make sure that when it is pulled up by tightening it down that the top of it does not rise above the compound rest, or it will not hold the tool post down to the compound.


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## wrmiller (Jan 29, 2020)

No, I've not seen a t-nut like that. You say that you don't have a mill, but do you know someone reasonably close who could machine one for you?


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## litewings (Jan 29, 2020)

I don't have anyone around that I know of besides machine shops in the business. Will have to give them a try to see how much $ to machine a T-nut. This nut I have is just strange. No clue what the notch is for on the one edge. Tool post otherwise seems good so far.


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## francist (Jan 29, 2020)

Looks like it was made on a lathe -- a perfectly good way to make one if you don't have a milling machine on hand. As for the notch, maybe they made a mistake with the hole placement but decided to use it anyway? It happens...

-frank


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## ErichKeane (Jan 29, 2020)

A common 1st project is to make one of those on a lathe.  All you need is a hunk of material as wide as the T-slot (minus a little, or filed to a little less), then turn down the center boss and thread it.  Consider that as a next project!


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## Cadillac (Jan 29, 2020)

If it’s a flat piece without ledges. Chuck it up in the lathe on edge take a cut, flip it make a parrallel cut, get to your width and done.


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## Tozguy (Jan 29, 2020)

That round T nut with the notch in it is from a four way tool post. The notch is to clear a detent that indexes the tool post in each of the four positions. The detent also captures the T nut so that is does nut slip out of its channel. It will work fine for your QCTP if the bolt is the right size. Is there a corresponding hole in one of the lips on your compound?
A rectangular T nut blank was supplied with my new QCTP but I used the old 4 way T nut until I got equipped to mill the blank.


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## middle.road (Jan 29, 2020)

litewings said:


> _Received  this QCTP with my PM1340GT lathe_. A little concerned about the attaching base not being the size  and shape of the tool post. A lot less contact on the compound that has me wondering about uneven wear/damage to the compound over time. I dont have a mill, or I'd build a new base. Is this a commonly seen type of attaching base?


Did you just get the machine and the QCTP from P-M or did you score them used?


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## erikmannie (Jan 29, 2020)

Bob Korves said:


> Make your own t-nut to fit the compound rest.  Make sure that when it is pulled up by tightening it down that the top of it does not rise above the compound rest, or it will not hold the tool post down to the compound.


I did a deep cleaning on my PM-1030V today and I saw that I have just about stripped both of these T-nuts due to me overtightening the 
nuts on top.

I learned that you only need to loosen these nuts just enough to allow the compound rest to rotate (this, of course, when you want to rotate the angle of the compound rest). 

So I will have to make some T-nuts, as well.


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## Tozguy (Jan 30, 2020)

Erik,
Not sure that you and Bob are talking about the same T nuts.
The two nuts holding the compound to the cross slide are high wear items. Mine were upgraded to grade 8 nuts and bolts. The heads of the bolts had to be machined to fit in the cross slide and slide easily in the round channel. Even though the nuts are never tightened to extreme, grade 8 bolts have closer fitting  threads and wear much less.


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## litewings (Jan 30, 2020)

_Is there a corresponding hole in one of the lips on your compound?  _No there isn't. I do have the standard tool post also and plan on trying that t-nut bolt combo in the QCTP.  Haven't measured the bolt yet to see if its compatible.

_Did you just get the machine and the QCTP from P-M or did you score them used?   _Bought both new from PM

The round nut ("O" nut?) works but has less than half the contact surface as a full size t-nut has. Afraid over time it could deform the compound. And the OCD in me just doesn't like the way it looks.


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## ErichKeane (Jan 30, 2020)

I'm not sure I would be too worried about it, but if it concerns you, they are easy enough to make on the lathe 

I'm surprised that is the TNut that came from PM... Even the cheap Chinese tool posts come with what is just a fairly sizable hunk of steel with a bolt hole and oversized T area.


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## Tozguy (Jan 30, 2020)

Being a belt AND suspenders man myself I get the OCD thing, But if the bottom of your tool post is perfectly flat (worth checking) then the area of contact as outlined with a black marker in the photo is entirely adequate. There is no deflection of the compound because there is clearance between the parts.

Note that a full contact T nut would only add contact at a distance from the bolt. There is a corresponding decrease in holding pressure in proportion to the distance from the bolt due to deflection of the T nut.

The conversion from a four way holder to a QCTP on my compound required that a new bolt be fitted to the original T nut. The shoulder on the original bolt did not work with the QCTP. But I eventually ended up using the bolt and T nut blank that came with my QCTP.


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## middle.road (Jan 30, 2020)

litewings said:


> _Is there a corresponding hole in one of the lips on your compound?  _No there isn't. I do have the standard tool post also and plan on trying that t-nut bolt combo in the QCTP.  Haven't measured the bolt yet to see if its compatible.
> 
> _Did you just get the machine and the QCTP from P-M or did you score them used?   _Bought both new from PM
> 
> The round nut ("O" nut?) works but has less than half the contact surface as a full size t-nut has. Afraid over time it could deform the compound. And the OCD in me just doesn't like the way it looks.


I would contact P-M and ask them about it and see what they say. They may not have seen the T-Nut when it came through their shop.
It should be a full square matched to the compound IMO.


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## bakrch (Jan 30, 2020)

My PM1236 (Chinese) came with the same base for the QCTP. My guess is that it's standard.


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## Latinrascalrg1 (Feb 1, 2020)

Look at this members recent thread, post #6, and see if there is anything recognizable!


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## darkzero (Feb 1, 2020)

bakrch said:


> My PM1236 (Chinese) came with the same base for the QCTP. My guess is that it's standard.



Yep my PM1236 also came with a "round t-nut" with the QCTP that was included with the lathe. It didn't have that slot though & was in addition to the 4 way tool post & t-nut. I never used it though & sold that QCTP w/ the nut right away but it should work perfectly fine. Don't need to make a new one if you don't want to.

IIRC they include these cause they're quick to make but mainly to get the customer started so they can use their lathe right away. I could be remembering wrong though but that's what I recall. Not all people will already have a mill so this is a great courtesy which they don't have to do.


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## LEEQ (Feb 1, 2020)

I have that t- bolt on my G4003. It was holding the bxa piston, Now I have it holding a bxa wedge. It works fine. I don't have a peg or detent in the hole in the compound and get along great. Try it out before you give up on it. You may discover it's more than enough before you find an easy avenue to replace it. OR, and I'm just throwing this out there, Buy a mill because this part needs made and you want to mill it. (to be fair I never said I was a good influence)


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## Titanium Knurler (Feb 1, 2020)

litewings said:


> I don't have anyone around that I know of besides machine shops in the business. Will have to give them a try to see how much $ to machine a T-nut. This nut I have is just strange. No clue what the notch is for on the one edge. Tool post otherwise seems good so far.



Litewings, I have a PM 1236T that came with a similar T-nut.  It worked fine but I pretty quickly changed to a Dorian QCTP and machined my own T-nut but you don’t have a mill or a nearby machine shop so this does not seem to be an option for you.  If you really want a “conventional” T-nut you can have Aloris make you one for you.  I am not sure of the lead time or cost.


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## litewings (Feb 1, 2020)

_*"Buy a mill because this part needs made and you want to mill it. (to be fair I never said I was a good influence)"*_ 

This was one of my first thoughts, because this makes it a "need", not just a want right?
I've had a few hours of use with the "O" nut QCTP and it works fine. Just looks unfinished. Pretty sure it will eventually get replaced.

Thanks for everyones input


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## Tozguy (Feb 1, 2020)

Or do the milling on your lathe


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## LeChuck (Oct 31, 2020)

I bought my QCTP from PM and I wish it had come with that round nut, which would mean I could actually use the QCTP. Same situation here without a mill or anyone I know with a mill, and I got the rectangular hunk of steel. Looks like being able to reuse the T-nut from the regular tool post would be ideal, but I haven't taken it apart to look yet. Looks I might have to live with the 4 way tool post for the time being. Apparently PM was selling a kit with a milled nut but I was too late on that.


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## ErichKeane (Oct 31, 2020)

LeChuck said:


> I bought my QCTP from PM and I wish it had come with that round nut, which would mean I could actually use the QCTP. Same situation here without a mill or anyone I know with a mill, and I got the rectangular hunk of steel. Looks like being able to reuse the T-nut from the regular tool post would be ideal, but I haven't taken it apart to look yet. Looks I might have to live with the 4 way tool post for the time being. Apparently PM was selling a kit with a milled nut but I was too late on that.


With the 4 way post, you can put an end-mill cutter in your lathe chuck (dial it into a 4 jaw!), clamp the T-nut to the 'side',and use your cross-side to mill the nut.  Otherwise, if you get measurements, I'm sure a post in 'can you make this for me' would get a response.  You live in Arizona so I'm sure there are a half dozen members within short distance of you that would help out.


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## LeChuck (Oct 31, 2020)

Oh, I didn't think of that, thanks. I don't have a 4-jaw chuck. I might get one, but I can also try using the stock chuck. I wasn't aware of that forum, I'll check it out too.


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## ErichKeane (Oct 31, 2020)

LeChuck said:


> Oh, I didn't think of that, thanks. I don't have a 4-jaw chuck. I might get one, but I can also try using the stock chuck. I wasn't aware of that forum, I'll check it out too.


Do you have a collet chuck?  Endmills don't like being held 'off center', so unless it is pretty close you're likely to break it


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## erikmannie (Oct 31, 2020)

LeChuck said:


> I bought my QCTP from PM and I wish it had come with that round nut, which would mean I could actually use the QCTP. Same situation here without a mill or anyone I know with a mill, and I got the rectangular hunk of steel. Looks like being able to reuse the T-nut from the regular tool post would be ideal, but I haven't taken it apart to look yet. Looks I might have to live with the 4 way tool post for the time being. Apparently PM was selling a kit with a milled nut but I was too late on that.



Hopefully, when you remove your 4 way tool post (leaving the T-nut and bolt in there), your new QCTP toolpost will fit right on.

When I did this, my new QCTP T-nut bolt happened to thread into the T-nut that came on the lathe.


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## SLK001 (Oct 31, 2020)

Forget needing a mill.  A HACKSAW and a FILE is all you need to fit YOUR compound.  You can also use an ANGLE GRINDER to cut it to size.


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## LeChuck (Oct 31, 2020)

I do not have a collet chuck. I just got this lathe last week. Just finished the VFD conversion this past weekend and DRO and tach install, and received the QCTP and cutters in the mail yesterday, was bummed out about the t-nut as I was hoping at least for that round nut. Going to move the lathe into final position today. No extra accessories yet. I have an ER32 collet chuck for my wood lathe, but haven't made the expense for the metal lathe yet. I think I want one for what I will be doing (mostly pen making), so this might just tip the balance. I was looking at the ER40 collet from Shars. Are there others for the D1-4 mount?


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## LeChuck (Oct 31, 2020)

SLK001 said:


> Forget needing a mill.  A HACKSAW and a FILE is all you need to fit YOUR compound.  You can also use an ANGLE GRINDER to cut it to size.


Maybe this will be the *one* time when I'm able to saw something straight and true by hand, but I doubt it


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## Superburban (Oct 31, 2020)

That looks just like the nut that came with the tool post for my shopfox gunsmith lathe (G4004g clone).


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## LeChuck (Oct 31, 2020)

erikmannie said:


> Hopefully, when you remove your 4 way tool post (leaving the T-nut and bolt in there), your new QCTP toolpost will fit right on.
> 
> When I did this, my new QCTP T-nut bolt happened to thread into the T-nut that came on the lathe.


That would be fantastic and uncharacteristically lucky on my part but I'll try it.


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## erikmannie (Oct 31, 2020)

LeChuck said:


> I do not have a collet chuck. I just got this lathe last week. Just finished the VFD conversion this past weekend and DRO and tach install, and received the QCTP and cutters in the mail yesterday, was bummed out about the t-nut as I was hoping at least for that round nut. Going to move the lathe into final position today. No extra accessories yet. I have an ER32 collet chuck for my wood lathe, but haven't made the expense for the metal lathe yet. I think I want one for what I will be doing (mostly pen making), so this might just tip the balance. I was looking at the ER40 collet from Shars. Are there others for the D1-4 mount?



So your QCTP toolpost arrived without the nut? I would expect that a nut would be part of the deal there. I think that if you call the supplier, they will send you that nut.

I would guess that there was a nut to begin with but that it got separated from the QCTP toolpost somehow.

I often buy nuts & bolts on eBay; I like to select ones with a high hardness rating (e.g. Grade 8 or 10.9). I am sure that you could find a flanged nut there.


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## LeChuck (Oct 31, 2020)

It's from Precision-Matthews. It came without a round nut as shown by the original poster but with a chunk of steel that I need to mill to make the nut, with the bolt going through already. I already contacted them about it. They were polite but indifferent. They are out of stock on the already-milled nut and did not offer to make and send one.


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## ErichKeane (Oct 31, 2020)

It's really common to get an unmachined toolpost nut. Aloris even charges extra (despite you dropping a grand on a tool post!).  Presumably PM knows the dimensions of their lathe enough to do it for you, but *shrug*.

That said, if you WANT a round nut (they tend to hold worse, but would work presumably), you have a lathe  easy enough to turn one from dimensions.


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## erikmannie (Oct 31, 2020)

LeChuck said:


> It's from Precision-Matthews. It came without a round nut as shown by the original poster but with a chunk of steel that I need to mill to make the nut, with the bolt going through already. I already contacted them about it. They were polite but indifferent. They are out of stock on the already-milled nut and did not offer to make and send one.



I just finished milling a T-nut for my new lathe. Personally, I would not have attempted it without a milling machine.

My T-nit was straight on all 4 sides. I don’t know how a rounded side on 2 sides is a benefit.

Short of you using this as a fine excuse to acquire a milling machine, I am sure that if you ask someone here to make it, then somebody will as it is a very straightforward job on a mill.

In any case, I think you will find that your new QCTP stud threads right into your old T-nut.


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## LeChuck (Oct 31, 2020)

Thanks all. There are a bunch of options here so I'll see what I can figure out. I don't need an excuse to get a mill but a bunch of money  (that and the fact that it's already enough of a pain to get a lathe into my garage...)


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## SLK001 (Oct 31, 2020)

LeChuck said:


> Maybe this will be the *one* time when I'm able to saw something straight and true by hand, but I doubt it


That's what the FILE is for.  Or, use a belt sander to straighten things up.  It isn't all that important that the edges be straight and true - it just has to fit into the T-slot on the compound.


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## LeChuck (Oct 31, 2020)

True, true. I have a 12 inch disc sander and (mostly) 90 degree jig that I use for pen blanks.


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## LeChuck (Nov 2, 2020)

Well, this isn't going to be the nicest piece of steel you've ever seen. Literally a hack job. But it fits and works well. So QCTP issue resolved in my case. Not a fun Sunday though.


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## mikele1 (Jul 16, 2021)

Hey it works! Nice job!  I'm going through the same thing myself right now and ran across your post.


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## SLK001 (Jul 17, 2021)

Just make sure that the top of the T-nut is below the base of the compound when tightened up.  Otherwise, you won't be able to get a secure tool post and it may even slip on you.  This happens more than you might realize... "_My QCTP nut is tight, but my bit still moves when cutting..._" is a title often seen in machining forums.  It is fixed by taking off a small amount off the top of the nut.  The tool post has to bear _entirely_ on the top of the compound, *not* the top of the T-nut.


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## Christianstark (Jul 17, 2021)

Does not look like a hack job to me. For not having a mill, that looks fantastic, and I bet you learned some things along the way. Bravo!


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## oregontripper (Jul 17, 2021)

Have an impending 1440GT and PMs BXA QCTP. Hoping it arrives not looking like it is from the scrap pile. $$$$


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## aliva (Jul 17, 2021)

On my King 12x36 the nut is very similar.  The notch on my corresponds to a hole in the compound , a steel pin is inserted preventing the QCTP from sliding  in the slot.


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## SLK001 (Jul 17, 2021)

aliva said:


> On my King 12x36 the nut is very similar.  The notch on my corresponds to a hole in the compound , a steel pin is inserted preventing the QCTP from sliding  in the slot.



That's odd... Sometimes you WANT the QCTP in other positions in the slot (ie, not always in the center of the slot).


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## Christianstark (Jul 17, 2021)

SLK001 said:


> That's odd... Sometimes you WANT the QCTP in other positions in the slot (ie, not always in the center of the slot).


I think you can defeat it in those circumstances.


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