# Milling Sherline sized T-slots - bit of help required



## David Morrow (Mar 26, 2019)

I'd like to make a new Sherline lathe cross slide and that will require milling a pair of T-slots. I would have thought this would have been pretty straight forward but, the Sherline T-slot seems to be at the smallest end of the T-slot world so cutters do not seem to be readily available. I could cut larger slots but would prefer that the slots stay consistent in size due to my extensive use of Sherline tooling.

One alternative is to take an old Sherline mill X-axis that I have and cut it to length and mill the bottom to remove the dovetail but I'd rather not as I am after a 3/4" wider cross slide than the Sherline has.

I've searched the forum and just about everywhere else but have not found a solution. Can anyone provide a bit of guidance ?


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## petertha (Mar 26, 2019)

I had the same issue on the Sherline rotary table. cant recall if they are 10-32 or so. For what they charge I just bought some. They are not difficult, just a bit fiddly. I cant recall if I checked them for hardening but I rather doubt it.


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## David Morrow (Mar 26, 2019)

Peter, I think you're thinking of the T-nuts. I need to mill the T-Slots. But you're correct on the 10-32 ; Sherline uses 10-32 threads on almost everything.


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## petertha (Mar 26, 2019)

Sorry about that. Should have read more carefully. Small might be getting into the specialty range. Not exactly cheap depending on the material & profile

http://www.harveytool.com/AdvancedSearch.aspx?Search=1&Keywords=t slot
http://www.harveytool.com/prod/Keys...ters---Retaining-Ring-Keyseat-Cutters_79.aspx


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## David Morrow (Mar 26, 2019)

Thanks for those links. I suspect that you're correct - those small sizes really are into the specialty range and the prices show it.


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## goldstar31 (Mar 27, 2019)

Elsewhere here I've been trying to re-educate others by recommending the Model Engineers Workshop Manual by Geo H Thomas. 

In his detailed and pedantic description of making  a rotary table and putting in tee slots, he merely takes a bit of silver steel/ key steel stuff and makes a cutter up and then tempers it.

Cost???  The square root of bug**r-all.  That's how I did the tee slots in a tool and cutter grinder. They were TWO 10" runs for Myford( non standard) tee slots.

Hope this helps

N


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## fcheslop (Mar 27, 2019)

This link may help
http://www.homews.co.uk/page334.html


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## wgpeters (Mar 27, 2019)

Sherline sells a cutter for making compatible t-slots.  But, price is $94.
https://www.sherline.com/product/t-slot-cutter-carbide/


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## goldstar31 (Mar 27, 2019)

fcheslop said:


> This link may help
> http://www.homews.co.uk/page334.html



Harold Hall's description is pretty much what Geo Thomas wrote-- much earlier.

Apart from that- my best wishes to Frazer.

Norm

GHT in the Rotary Table thing also does a quite pretty 'circular' Tee slot which makes a delightful rotary table  on Chaddock's Quorn. Mine, sadly is one peppered with  a ring of holes per DHC.  I should have known better---- hmm.

N


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## fcheslop (Mar 27, 2019)

Hi Norm, the only difference is the webby thing is for free a price that always  has some merit for me
The book you mention is my go to for info despite its age its still relevant or that maybe just my way
Harolds site is a gold mine 
cheers


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## john_reese (Mar 27, 2019)

David,
I don't know the size of T slot you are trying to cut so this is somewhat of a shot in the dark.  Is there a Woodruff cutter the right diameter?


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## petertha (Mar 27, 2019)

Any idea what the stock Sherline part is made from?


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## nel2lar (Mar 27, 2019)

GOLD MINE


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## David Morrow (Mar 28, 2019)

john_reese said:


> David,
> I don't know the size of T slot you are trying to cut so this is somewhat of a shot in the dark.  Is there a Woodruff cutter the right diameter?



I've tried those as well and while some are close in size, all of these cutters seem to be disproportionately expensive for cutting 2 x 7.00 inch long slots. I'm starting to look to alternatives.


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## goldstar31 (Mar 28, 2019)

Two alternatives  are to 
1.  Grind an oversize cutter to the wanted size
2.  Make your own cutter- as suggested to Thomas's or Hall's suggestion.

Of course, you CAN fabricate- which follows what Martin Cleeve did at times.

If you are also following my discussion with Baz.   Cleeve actually fabricatted the tee slots on his Myford faceplate.

I've prattled about these things seemingly forever. 

I'm getting old, a bit blind now and somewhat weary- and am off on holiday now

Norm


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## Baz (Mar 28, 2019)

If you have access to a shaper it is possible to cut a T slot with a left and right hand tool but you must have a runout at the end and the clapper box must be locked otherwise the tool will break on the return stroke. I have an old Perfecto 7” shaper and have done a few this way over the years. As goldstar31 says a few posts back Prof Chaddock done a circular T slot on a piece of 3” dia bar for the workhead on the Quorn cutter grinder,in his Quorn book be gives details of tool shapes required.

Baz


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## David Morrow (Mar 29, 2019)

Thanks for all of the suggestions. After reading and considering them, I think I have a Plan B. 

I replaced the X and Y axes on my old Sherline mill with parts from A2Z CNC several years ago. I think I will use the old Sherline X axis. I'll cut it to length and mill the dovetails off the back. It's so unlikely that I will ever need that part for any other purpose and it has minimal sale value so that makes the most sense for me now.


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## Wizard69 (Apr 5, 2019)

David Morrow said:


> Thanks for all of the suggestions. After reading and considering them, I think I have a Plan B.
> 
> I replaced the X and Y axes on my old Sherline mill with parts from A2Z CNC several years ago. I think I will use the old Sherline X axis. I'll cut it to length and mill the dovetails off the back. It's so unlikely that I will ever need that part for any other purpose and it has minimal sale value so that makes the most sense for me now.


Refactoring old parts is a tried and true method to solving a problem.   If it works for you go for it.

As for your original plan making a cutter really isn't that big of a chore.   However I would go to larger T-Slots and just make the proper T-Nuts for those slots.   Why?   For a milling cutter even a little bit larger shank is likely to last longer.


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## davidyat (Apr 6, 2019)

Don't know if this will help. When I was machining the lathe model from PM Research, they had a face plate casting blank. In order to machine the T-Slots for that small piece, I put an end mill of the proper diameter for the slot into my rotary table on the mill table. Put a grinding wheel that was for carbide in the chuck, lined up everything to the proper depth and slowly moved the table towards the grinder while rotating the rotary table. Milled a straight slot into the face plate a little into the T area, switched to the T-Slot cutter and finished. In the picture, in the upper left part of the plate, you can see the T-Slot that was cut. The face plate is about the size of a half dollar coin.
Grasshopper


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## David Morrow (Apr 6, 2019)

I love it. Brilliant !


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