What's new
What's new

10L toolpost tee nut?

Sea Farmer

Diamond
Joined
Mar 25, 2006
Location
Cape Cod, Massachusetts
The quick-change tool post (Phase II) on my Heavy 10 backs off under anything more than the lightest cuts. I'm using the bit of flat stock that comes with it as a hold down nut. Not really a tee-nut, as its not tee-shaped.

So is making a real tee-nut, with a center that projects through the center slot to the bottom of the tool post, the answer? Seems like it would provide more bearing surface and greater thread depth for the hold-down bolt on the tool post.

I note my Holdridge Radius cutter has two bolts that attach to the hold down nut, and it doesn't budge a bit. But the tool post holder only has the single central bolt.

So anyone deal with this issue by making a proper tee nut? Design ideas beyond the obvious (duh, its shaped like a tee)? :D
 
I recently bought a phase II and there is no way the supplied flat stock will fit in the compound T slot without machining. Just not possible - it had to be machined to a t nut shape before I could use the phase II.

How are you securing the phase II without that piece being machined?
 
The one on my SB13 (BXA size instead of AXA size but otherwise the same) is rock-solid. I'd try a proper T-nut. Measure the slot, subtract some for clearance, machine, install...

John
 
So is making a real tee-nut, with a center that projects through the center slot to the bottom of the tool post, the answer? Seems like it would provide more bearing surface and greater thread depth for the hold-down bolt on the tool post.

:D

I don't think I'm understanding you correctly, but if the tee-nut "projects up through the slot" it will hit the bottom of the tool post and defeat it's purpose. Sounds like something weird is going on here. The thicker center section of the nut allows for greater thread engagement so the thread doesn't strip, that's all! Maybe a picture of what you're doing would be helpfull.
 
The tee nut doesn't project all the way to the top of the slot. It should stop ~ 1/16" short. That way, the base of the toolholder sits flat on the compound, and you get the thicker section for thread engagement.
 
I recently bought a phase II and there is no way the supplied flat stock will fit in the compound T slot without machining. Just not possible - it had to be machined to a t nut shape before I could use the phase II.

How are you securing the phase II without that piece being machined?

The tool post was supplied with a piece of flat stock drilled and tapped for the central post. It was too wide so I milled it to size. But its not a proper tee nut--just a bit of flat stock about 1/4" thick, that engages perhaps 2 threads.
 
On mine, the top of the compound was worn slightly dished from years of rocker style tool post use, and gave clamping problems. Hold a straight edge on top to check.

What does it have for a washer and nut to lock the tool post? soft or hard?

wawoodman describes a proper T nut shape.

Bill
 
That 1/4 flat stock is not enough meat or thread. I suspect it's bowing when you tighten the center nut on holder which in turn allows it to slide back. Just not enough engagement in the t-slot.
 
The cheap quick change tool post on my Heavy 10 is only secured with the piece of flat stock and I've had no trouble with it. I think hitandmiss may be on to something with his suggestion to examine your compound.
 
Not to hijack, but the thread is timely. Just machined the base on the PII AXA that came in last night for my 9A...perfect fit into the compound (with .280 off each side, before notching)- but when I fitted the post to the base and tightened it down, it kept spinning...

Scratched my head for about a minute before I realized that I'd run out of threads- and needed to add a washer up top under the main nut. Guess the "depth" of the compound on the 9A is relatively small. Only alternative is to lengthen the threads- but I don't see how a single washer will compromise rigidity. If I'm wrong on this, please let me know...

I had initially thought "why mill a "T", and not just make it flat stock", and realized that had I done so there would be very little "meat" left for the post threads.
 
^^ maybe a silly suggestion but did you perhaps reverse the post bolt?

IIRC one end is threaded for only ~1/2" and the other end threaded for about 1"
 
^^ maybe a silly suggestion but did you perhaps reverse the post bolt?

IIRC one end is threaded for only ~1/2" and the other end threaded for about 1"

Lol no, I'm capable of silly mistakes and have made many of them but not this one somehow.

I'll just make a proper tee nut that has more thread engagement than the flat stock that came with the thing.
 
SouthBend compound slots are nicely sized to match standard flat stock so screwing and gluing two pieces together is the easy way to make a proper full length T-nut. Sizes in the back of How To Run a Lathe.

Except nobody in their right mind uses a T-nut in this situation anyway. Do the job properly and permanently fix a stud in the middle of the full length nut. I either use alignment pins and silver solder or screws backed up with high strength loctite. Whilst you are in "do it proper" mode check the top of the compound for flatness as advised by hitandmiss. It won't be flat so rectify that first. Then check the underside. That will be bent too so some careful filing needed to get it right without upsetting the T geometry. Might as well check the tool post base whilst you are at it. Don't see Phase 2 over here in the UK so I don't know if the centre portion of the tool post is relieved to ensure that it doesn't try and hold on a very narrow ring round the centre if things aren't perfectly flat. Typically a sorta square shape like that should have a relief circle covering about half the bottom area i.e. radius half the side length of the square. If it hasn't been relieved put an ally washer about 3/16 thick underneath with the necessary relief, approaching 1/16 deep will be fine. If it does have the relief put a stiff paper or thin alloy washer underneath. Two or three times the thickness of normal photocopier / printer paper is fine. Probably last a couple or three years but keep some spares for when it gets tatty.

Lastly don't over tighten. If you need more than 20 ft/lb you have problems. So check again.

Swopped out my Heavy 10 for a Smart & Brown 1024 years ago so I don't have a built up T-nut and stud assembly to photo. Did find I have three one piece machined ones on the shelf left over from the still born "Clives Perfected Rapid Interchange Tooling System" project. So if anyone in the UK cares to offer a a couple or few drinking vouchers for them PM me.

Clive
 
Last edited:
^^ maybe a silly suggestion but did you perhaps reverse the post bolt?

IIRC one end is threaded for only ~1/2" and the other end threaded for about 1"

Not silly...bolt bottoms out in the compound and draws the nut up tight, still need a washer topside to have enough thread to get it tight. Unless there were variations in the thickness of 9A compounds from the factory (and no one else with one has needed to do it) either I got a post bolt short a couple threads, or perhaps the top surface of the compound had been resurfaced at some point (though it sure doesn't look it!).
 








 
Back
Top