Tee slot nuts - sizing query

[CRB]

No facilities to make them ourselves.

Why not make them?

 

[DanielW]

I need to get hold of some more tee slot nuts for our radial arm hole-chewer. Sizes below are in MM. (May well be imperial??)
No facilities to make them ourselves

You have to improvise if the item/s are imperial or odd sizes?

Block of milled steel to lower half of T nut clamp size drilled and tapped thread size(which can be got anywhere)then a square nut to size of slot and thread size.

You don't even have to weld the square nut to the milled steel block because the moment the bolt starts to clamp the job piece it will lock up

 

[Kent]

Its dumb to make stuff like this yourself even if you have the kit and skills - IF YOU HAVE A GOOD FULL ORDER BOOK!

 

[Pete.]

I Just weld two nuts together normally, assuming there is enough height in the bottom part of the slot- there is on all of our machines.

I would do (and have done) similar myself until I took a class on scraping and machine rebuilding earlier this year. In that class I learned that bowed mill tables can be the result of repetetive tightening, especially over-tightening, of tee slot nuts essentially 'peening' the underside of the tee slot and causing a build-up of stresses that bend the table. In one example the tutor claimed that a table was sprung back flat by running a clean-up pass through the slots with a tee-slot cutter. I can only imagine that using a hex nut in a tee slot with it's profiled face instead of a longer tee with flat faces would result in higher concentration of forces and an exacberation of the condition. I wouldn't do it on that basis.

 

[Windy Miller]

I would do (and have done) similar myself until I took a class on scraping and machine rebuilding earlier this year. In that class I learned that bowed mill tables can be the result of repetetive tightening, especially over-tightening, of tee slot nuts essentially 'peening' the underside of the tee slot and causing a build-up of stresses that bend the table. In one example the tutor claimed that a table was sprung back flat by running a clean-up pass through the slots with a tee-slot cutter. I can only imagine that using a hex nut in a tee slot with it's profiled face instead of a longer tee with flat faces would result in higher concentration of forces and an exacberation of the condition. I wouldn't do it on that basis.

Not that I know anything at all about this, but a good explanation there Pete - thanks Mate! It still amazes me how much knowledge there is on here!

 

[MrFluffy]

I'm with Sparky and Pete on this one, I've seen too many horrible holes in tables caused by exactly the use of a nut in place of tee nuts. The only feasible repair is to cut a section out and insert, its a lot of skilled work so you tend to see the poor machine wearing its scars and people avoiding clamping on that bit of the bed until someone tires of it and scraps it out.
For what they cost, I just bought a ruck of them when i first got my mill, then some to match the slots on my rotab & I have to order some more to match another machine which has come along and needs a different size. I'd make my own, but only if I needed it to finish a job and it couldn't wait.

Curiously the only thing I have I do have to make them for is the shaper, because its so old it has dovetail slots not Tee profile :-)