T-Slot Cutters

[FatherWes]

I did a search here and it came back with zero results. If it has been discussed, please point me in the right direction... Otherwise:

I'm looking to cut a t-slot. The slot I'm hoping to duplicate has a "TEE" section 1.156" wide (the bottom of the "T") by 0.218" deep. The throat is 0.750" wide by 0.187" deep (the top of the Tee is 0.187" below the uppersurface). The Tee slot itself should therefore be 0.406" wider than the neck (meaning the T-cutter needs to be able to cut a slot 0.203" deep.

This T-slot is in the Slide, Compound Rest Tool Post of my Atlas 618 lathe. I contacted Clausing to ask if they still made the part (M6-303). I received a very nice reply saying they no longer make the part, but supplied a copy of the original manufacturing drawing (see attached).

The only place I've found selling T-slot cutters is Amazon (shipped direct from China). Unfortunately, the t-cutter only extends 4 mm (0.157") (18mm cutting diameter, 10 mm shaft). I might be able to narrow the shaft of the cutter to allow the slightly deeper cut (I'm sure that'll void the warranty!!) and I think I could probably make that work.

I am surprised that I cannot find anyone else that sells these. Nothing at Busy Bee, nothing at Accusize. Where else can I check? Or are these cutters also called something else?

Thanks in advance. Wes

 

[RobinHood]

KBC sells T-Slot cutters.

Results Page 2 :: KBC Tools & Machinery

www.kbctools.ca

 

[eotrfish]

Woodruff Key Cutter
Try KBC

 

[Xyphota]

That is a pretty high aspect ratio tee-slot cutter, I did a quick peruse on your behalf and didnt see anything. Are you making the tee-slot nut as well?

I used one of these cutters a few weeks ago on some cold rolled 1018. It took about 45 minutes to cut a t-slot 4 inches long, so it was perfect for some podcasting haha. This cutter is a bit taller and the shoulder isnt as deep but maybe it'll get you in the ballpark.

https://www.amazon.ca/dp/B00N40DL6S?ref=ppx_yo2ov_dt_b_product_details&th=1

 

[Dusty]

KBC sells T-Slot cutters.

https://www.kbctools.ca/products/pg/2?Keyword=T-slot cutter[/U

@FatherWes for what its worth I totally adree with @RobinHood, couple of years back I cut three 10" long T-slots in a cast iron plate for a friend. First I ran the proper sized end mill followed by the correct T-slot cutter from KBC. Very pleased with the T-slot cutter end results and finish.

My only advise is plan the job out meaning end mill to T-slot cutter, above all don't get rammy with the project.

Steady as she goes matey!

 

[FatherWes]

Thanks for the tip. KBC looks like a great resource - I knew there had to be a supplier in Canada somewhere!

And searching for 'key cutter' gives me a better fit for depth and width of the bottom of the tee. ( I had tried searching for a key slot cutter previously, but what I found was held on with an exposed nut below the cutting flutes (so it could not cut a flat bottomed slot). The ones on KBC site look like they should do the job perfectly!

Thank you all!

 

[trlvn]

On Youtube some years ago, MrPete222 had a video series on machining a replacement compound. I know it was for an Atlas but I can't remember which model. You might pick up some tips there.

Craig

 

[Dusty]

On Youtube some years ago, MrPete222 had a video series on machining a replacement compound. I know it was for an Atlas but I can't remember which model. You might pick up some tips there.

Craig

@trlvn Hey Craig is this the video you were speaking too?

@FatherWes FYI

 

[Arbutus]

Its not that hard to make a useful cutter from O1 or A1.

Turn from solid (not brazed) and cut the flutes on the mill to form the correct rake and clearances. Cut a minimum of 8 teeth. Touch up the cutting edge on a diamond wheel. Heat treat and temper. Its a 60 minute job!

 

[trevj]

Thanks for the tip. KBC looks like a great resource - I knew there had to be a supplier in Canada somewhere!

And searching for 'key cutter' gives me a better fit for depth and width of the bottom of the tee. ( I had tried searching for a key slot cutter previously, but what I found was held on with an exposed nut below the cutting flutes (so it could not cut a flat bottomed slot). The ones on KBC site look like they should do the job perfectly!

Thank you all!

Just about any city has Machine tool suppliers. Aside from KBC Tools (which I like), Thomas Skinner and Sons, Sowa Tools (mostly sells to trade, but you can occasionnally talk out of a catalog), and a couple other outfits, have very extensive catalogs of tooling available. And any can organize a custom ground tool, if nobody supplies the dimensions that you need.

Also gonna point out, that Woodruff Key cutter, is a different built beastie, than a Tee Slot cutter. The Woodruff Key cutter uses a curved shank which thins considerably near the cutting teeth, and is really only meant to withstand the cutting forces of being fed in to a shaft to the prescribed depth, to match the key it is for, on one side.

A Tee Slot cutter uses a straight shank, that matches the width of the slot, that the Tee is going in. You mill the slot to width and depth, (plus a little deeper, usually), and then you are stuck essentially taking it on faith, that your machine and set-up, are going to be up to the task, as you pretty much do all the undercutting in a single pass through the work. The straight shank of the Tee Slot cutter provides a lot more support for the cutter.

You can, as suggested, make your own two or more tooth cutter, for use on a mill, or tee slots can be done on a shaper of appropriate stroke. Mount a hinged flap behind the cutting tool, so it swings out of the way on the stroke, and drops down at the end of stroke, to make the cutter ride over the top of the work, on the return, thus preventing a hang up from the shape and location of the slot.

 

[Chicken lights]

Just about any city has Machine tool suppliers. Aside from KBC Tools (which I like), Thomas Skinner and Sons, Sowa Tools (mostly sells to trade, but you can occasionnally talk out of a catalog), and a couple other outfits, have very extensive catalogs of tooling available. And any can organize a custom ground tool, if nobody supplies the dimensions that you need.

Also gonna point out, that Woodruff Key cutter, is a different built beastie, than a Tee Slot cutter. The Woodruff Key cutter uses a curved shank which thins considerably near the cutting teeth, and is really only meant to withstand the cutting forces of being fed in to a shaft to the prescribed depth, to match the key it is for, on one side.

A Tee Slot cutter uses a straight shank, that matches the width of the slot, that the Tee is going in. You mill the slot to width and depth, (plus a little deeper, usually), and then you are stuck essentially taking it on faith, that your machine and set-up, are going to be up to the task, as you pretty much do all the undercutting in a single pass through the work. The straight shank of the Tee Slot cutter provides a lot more support for the cutter.

You can, as suggested, make your own two or more tooth cutter, for use on a mill, or tee slots can be done on a shaper of appropriate stroke. Mount a hinged flap behind the cutting tool, so it swings out of the way on the stroke, and drops down at the end of stroke, to make the cutter ride over the top of the work, on the return, thus preventing a hang up from the shape and location of the slot.

Sowa sells to the public no problem, but I’m lucky enough to deal with a local store.

 

[PeterT]

A Tee Slot cutter uses a straight shank, that matches the width of the slot, that the Tee is going in. You mill the slot to width and depth, (plus a little deeper, usually), and then you are stuck essentially taking it on faith, that your machine and set-up, are going to be up to the task, as you pretty much do all the undercutting in a single pass through the work. The straight shank of the Tee Slot cutter provides a lot more support for the cutter.

I've never heard that before, but admittedly I have not done much. You're saying the initial slot mill surface becomes a bearing surface for the Tee slot cutter shank? If so, I'm a bit suspicious. The surface of majority of cutters does not look well finished (ground) in that area. The schematics I've seen show slight clearance. How would you do a finishing pass with nil clearance?

 

[trevj]

I've never heard that before, but admittedly I have not done much. You're saying the initial slot mill surface becomes a bearing surface for the Tee slot cutter shank? If so, I'm a bit suspicious. The surface of majority of cutters does not look well finished (ground) in that area. The schematics I've seen show slight clearance. How would you do a finishing pass with nil clearance?

No, said no such thing! A Tee Slot Cutter shank fits in the slot. It provides more support to the cutter, than a Woodruff key cutter will.

If I said "My finger will fit in the hole", that has no implications of a bearing fit! Try not to read too much into something simple.

The shape of a Woodruff Key cutter shank, is an arc segment shape, to provide clearance on a generally round work of the appropriate size for the key used. A Woodruff Key cutter is the wrong tool for this, aside from that a Woodruff key cutter only cuts on one edge (the outer diameter) and a Tee Slot cutter uses alternate teeth sharpened to provide the correct width of cut.

Pull up a picture of a Woodruff cutter, and it is considerably narrower, with subsequently less support for the cutters, where the shank meets them

 

[trevj]

Sowa sells to the public no problem, but I’m lucky enough to deal with a local store.

Good to hear. The outfits that I dealt with that used a Sowa catalog, were not Sowa, nor was there a place that called itself that, that was available to me in Edmonton, at the time.

 

[PeterT]

No, said no such thing! A Tee Slot Cutter shank fits in the slot. It provides more support to the cutter, than a Woodruff key cutter will.

Forget the woodruff key cutter, not relevant. How can the slot provide support to the T-slot cutter shank if its not in contact? If the slot is 0.001" away from the shank, then it may as well be on the other side of the room from a support standpoint? Am I missing something you are trying to convey or maybe its just semantics?

 

[trevj]

Forget the woodruff key cutter, not relevant. How can the slot provide support to the T-slot cutter shank if its not in contact? If the slot is 0.001" away from the shank, then it may as well be on the other side of the room from a support standpoint? Am I missing something you are trying to convey or maybe its just semantics?

Again, you seem to be trying to read between lines I did not write. I said nothing of the slot providing support. I said the SHANK supports!

The straight shank of a Tee slot cutter provides support, by being at or very near, the diameter equal the width of the slot itself. Support. Stiffness. Resistance to flexing, ability to transmit torque, not breaking when loaded up with cutting forces. Clear enough? A 1/2 inch straight shank provides better support to the working cutting edges of a Tee slot cutter, than a very reduced, say 1/4 inch diameter shank at the join to the actual working bits of a Woodruff Cutter of similar dimensions.

A Woodruff key cutter (dragged in to this conversation a few times, earlier in the thread) has relatively, a much narrower shank for a given diameter, and thus, LESS support for the extended cutting edges it must drive. That is how Woodruff cutters became involved, and why I suggested that they are a poor choice for a tee slot! And why the are relevant to the conversation.

Clearer than mud now?

 

[RobinHood]

Maybe a picture will help explain how the tool shank itself helps “support” the cutter...

Look at the size difference of the shank material to which the cutter head is attached. In all cases, the cutter is 1.25” diameter. Only the width is different. None of the shanks will ever touch during machining; if they do, you have a big problem and will very quickly bust off the cutter head. Granted, the T-slot cutter could withstand the largest side force because of its sheer size difference (compared to the thin section of the #610 for example).

And here are 1” T-slot cutters by two different manufacturers (& the 5/8” from above for comparison). Again, the shanks are massive as the tool is designed to more of less hog out the slot in one pass. Maybe a little side step to finish, but not usually.

Edit: wrong dimensions (5/8” iso 7/8”)

 

[trevj]

Thank you. I didn't think I was being all that cryptic, or unclear, but yes, this is EXACTLY what the whole point was!

 

[Arbutus]

There's nothing to stop you taking several depth passes with a thinner cutter or a cutter with a slightly smaller shank, say 1/2" instead of 5/8". This allows some side adjustment. Find the nearest cutter with a smaller diameter and 'creep up' on the job. After all a Tee slot does not need to be precise within a thou, so chip away at it.

A one pass cut to mill that tee slot is going to stress every part of your machine!

 

[trevj]

There's nothing to stop you taking several depth passes with a thinner cutter, a cutter with a slightly smaller shank (say 1/2" instead of 5/8") on a cutter with a smaller diameter and 'creep up' on the job. After all a Tee slot does not need to be precise within a thou, so chip away at it.

A one pass cut to mill that tee slot is going to stress every part of your machine!

The mills I used, certainly had no major issues, nor would I expect any on my little Centec, provided I did my part, and buttoned down any sources of slack or opportunities to have the cutting forces throw things about, leading to very uneven cutter loading. And then, likely a wreck.

Throwing the power feed lever on the mill, for the first time for a pretty big Tee Slot, was a bit of a nerve wracking moment. When it was over, pretty much everyone wondered what they were worked up about...