Tee Slot Cutter

[Chip Hacket]

I currently have this slide arrangement for adjusting the track tension of my rover project. I'm sure you will agree it's not the most elegant solution. It worked fine for proof of principle, but I think tee slots may be better for this application? The socket head cap screws are 5/16 so I began the search to find a suitable tee slot cutter. It appears the smallest shank diameter available is 1/2". I have a small Taig milling machine with ER16 collets which only go up to 3/8. Do you guys have any ideas for a better solution? My guess is the high cutting forces dictate the need for a thicker shank. Do you think I could turn one of these down to a 3/8 shank? Thanks in advance for your help.

 

[pontiac428]

Take an end mill of the size you want the base of the slot to be, and grind an annular reduction (neck) to your slot width minus clearance. Now you have a t-slot cutter!

 

[GeneT45]

Take an end mill of the size you want the base of the slot to be, and grind an annular reduction (neck) to your slot width minus clearance. Now you have a t-slot cutter!

I have done this a few times, and it's the way to go if you're in a hurry. However, often a "proper" T-slot cutter will be cheaper (and better) than the more versatile endmill that you sacrifice by making one. I'm all about hacking up cutters to do my bidding, but I must admit that I have occasionally fallen prey to the "do it yourself for twice the price" syndrome.

GsT

 

[pontiac428]

If you have an EM with a biffed up end, you can get away with a flat bottom and flat top edge if you grind a slight draft toward the center for clearance like a slot cutter. If you have a decent setup, you can grind reliefs and cutting edges on the top and bottom faces of the t-slot, which will allow more speed but accomplish the same thing. Of course, the turn-key route with the ol' credit card gets the job done too. I'm not sure if this is a case for twice the price, more like scrap to salvation as I see it.

 

[GeneT45]

. I'm not sure if this is a case for twice the price, more like scrap to salvation as I see it.

Indeed! It all depends on what's in the scrap pile and what you can do with it! I can pretty easily rehabilitate an EM with a biffed up end, and those that are large enough to convert to t-slot cutters are well worth doing so (usually) - unless they're just too large to be generally useful. I'm not at all meaning to be critical of your original suggestion - it's obviously a workable solution. Just noting that that it doesn't always work out to a cost savings.

I'm probably not the king, but I am well established in the royalty of doing things yourself the more expensive way...

GsT

 

[benmychree]

Another possibility is a woodruff keyseat cutter, but they are all 1/2" shank also.

 

[Chip Hacket]

Take an end mill of the size you want the base of the slot to be, and grind an annular reduction (neck) to your slot width minus clearance. Now you have a t-slot cutter!

Great Idea! Thanks. I'll show the results when I get a change.