Want to mill T slots, need suggestions please.

Dhector

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My plan in the next couple days is try to machine t slots for an angle table I'm trying to make. I have a piece of steel and I am currently milling the .625 groove to depth, just started so it will be at earliest tomorrow night before I attempt the t slots. I have a couple woodruff key cutters and plan on using them, when the .625 grooves are cut to depth.
I read to cut one side at a time, but cant do that with the tools I have. I would have to cut both sides of the T at the same time, with the .625 center already cut to depth. I know I'm in over my head, but am I seriously in over my head???? Like it will be too hard to do what I want to? Would love to tell you what steel it is, but as usual, I dont have a clue. I have a 9x49 MSC mill, no Schooling, just self taught, aside from what I've learned here.
Would a mister be sufficient? I realize chip removal is paramount so I might even hook up an air source if you think it would help. Any input is appreciated. I'm going to give it a try no matter what, but if there is anything you think I need to know about before I start, i would really like to hear what you have to say. Thank you.

I've been taking pics, but dont want to post until its finished. I bit off a lot more than maybe i should have but i like the challenge!!! If and when i finish it i will post pics. Thanks again.
 
They make different size woodruff cutters . If you can , rough it out with a smaller cutter and then step up . Chip removal is a must as is cutting oil .

Hope you have a power feed . :)
 
They make different size woodruff cutters . If you can , rough it out with a smaller cutter and then step up . Chip removal is a must as is cutting oil .

Hope you have a power feed . :)

Actually I read earlier about cutting one side and I think it may have been a post from you. It was an old thread, dont recall when, and maybe it wasn't you that posted to cut one side at a time but either way thanks. I do have a power feed and plan to go slow. My woodruff key cutters are different thickness, and one is guessing. 200 smaller than the other. Figured to go small and then larger already just to reduce load. Cutters came with the mill, I didnt buy them, but they are new.

So a mister may not be enough? Use air and oil is the way to go? Please elaborate, I'm am very green at all this. Thank you for you reply.
 
You need to evacuate the chips in the cutters teeth , and , you need cutting oil also . I usually just brush it on an use an air hose to clear the chips . There's nothing wrong with cutting both sides at the same time , as long as your mill can take it and your table doesn't jump . If you have a semi-loose table , it can get interesting fast . :D
 
Also , if it's a G job , you can machine L shaped channels and run bolts down into the plate , then machine the flat . More than 1 way skin a cat .
 
A real T-slot cutter is not the same as a Woodruff cutter. Woodruff cutters cut only on the periphery, while T-slot cutters have alternating teeth that cut on the top, bottom and periphery. T-slot cutters usually have a thicker or larger diameter neck vs a Woodruff cutter of the same diameter and the latter will deflect more as a result. T-slot cutters also usually have higher vertical height vs a Woodruff cutter. Looks like this:

TS109.jpg


Personally, I would just buy the T-slot cutter you need. Actually, I would buy two and keep one as a back up in case the first one snaps, which can happen. I would also use a collet to hold the cutter to minimize run out and reduce stress on the neck.

The one time I had to cut T-slots in steel, I cut the same T-slot twice on the same work piece; once with Woodruff cutters and then with a T-slot cutter after I broke two Woodruff cutters in the slot. Broke the first T-slot cutter cleaning up the mess made by the broken Woodruff cutters and wound up using my backup to finish. That's how I learned the difference - by screwing up, as usual.

EDIT: Not disagreeing with you, Dave. I just had a very clear lesson learned and thought I would share.
 
Lol . A woodruff cutter is not the correct tool to use for the job , but that's what he stated he had available .

We ran torpedo trays years back with slots out the butt , and we busted many of cutters . This was on larger solid mills , flood coolant , the best of tools . I threw out an alternative way to approach that job when he runs into trouble . :big grin:

Personally , I would search the Bay for an existing slotted table and avoid some headaches , but learning on the job is fun . The cutter probably would run him half the cost of the table . ;)
 
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Funny but if I ever need another T-slotted table I've already resolved to do as you say and go buy the damned thing or make it out of aluminum!

Dhector, best of luck with this. Do let us know how it works out for you.
 
Over the years I've cut a number of T slots in both steel and aluminum. As mentioned by Mikey the best route is to invest in a couple T slot cutters. I have found the best course is to start by making multiple passes to create a full width, full depth vertical slot. Then use a smaller size T slot cutter for the initial horizontal slot. I cut a short distance, back off the cutter, lube, vacuum, and reengage.

I use plenty of cutting oil and continually vacuum to evacuate chips. Evacuating the chips is key to making a clean slot and not damaging the cutter. Most often the cutter breaks because chips get wedged in the slot, carried around, and recut several times. In this case eventually the slot becomes so jammed with chips the cutter is wedged and eventually snaps. By backing off, lubing, and continually vacuuming the chances of damaging the cutter are minimized.
 
Have at it, it is likely that you are not trying to make time on the job so proceed slowly.
A good deal of flood coolant would make this much easier but you probably do not have that option.
 
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