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Giant dovetail cutter

cuttergrinder

Hot Rolled
Joined
Mar 16, 2007
Location
Salem,Ohio
Does anyone know where I could get a 15 degree dovetail cutter that would cut a dovetail 3" deep. Actually not sure if it would be 15 degree or 75 degree. Just depends which way you look at it. The angle needs to be 15 degree off the shank of the cutter. Preferably one with a 2" shank
 
There are indexable dovetail cutters that would cut that size, but I wouldn't use them for finishing. Most of the very large dovetails I used to cut we did on the planer.
 
You'd have to step cut it anyways, because you won't be taking a 3" DOC slice, even as a finish cut. This is why we learn trig.

I dont see why we couldnt take a 3" doc. We will be running these on a 5" boring mill. The material is cast iron and the dovetails are already cast. They just need finished. They only require a 250 finish. We take 10" doc with a 2" endmill pretty regularly when required. You have to take it easy but it does work.

I am thinking about making an insert dovetail cutter. If all else fails we do have the cincinnati 20' planer that we can use. These castings are pretty rough and have a little sand in the casting. They are going to be real hard on high speed tooling. Here is a picture of a cutter I am thinking about making.
 
Any good 'cuttergrinder' could produce the tool you desire.

By the pound, you may not like the price.

I might be looking into a shell mill arbor and a suitable custom cutter. Quite common really.

Your desire to clean up three inches in one pass has limited your options. I can not grasp why you might cling to it.

The total machine work would be done by now if you had put the work on your shaper.

50 inches of clean up....
'doesn't seem like an issue to me.
 
these dovetails are 6 1/2' long not inches. The dovetails are cast but do have about 1/4" of stock. I could grind a high speed cutter but We don't have one 3" thick. Even our 6" shell mills are not 3" thick. I have a plain mill with the 15 degree angle but it is only 2 3/8" thick it would work but I will have to make an arbor as it has a 2 1/4" hole. Also it would need a counterbore ground in the one side so it could be mounted on a stub arbor.
 
The plain mill would also need to be ground so it has clearance on the face which I can do. It was never meant to cut with the face. Putting the counterbore in the one side will be the hardest. I could try machining it with ceramic but the keyway is going to be hell on the ceramic.
 
Many years ago I needed a big dovetail cutter - not that big, but chunky.

I started with a nice piece of steel, welded it to a 40 taper shank then turned it to the 60 deg angle I wanted. Then off to the mill with an indexing head and 3 slots cut in it with the leading face on the centre line. Welded in 3 sticks of HSS and off to the T&C grinder to clean it up.

Worked fine, it's still floating about somewhere. I can't see why a bigger/heavier version wouldn't work and if it needs carbide, so what, braze them in (welding worked but there was some cracking, I just didn't care for a one-off and it was quicker). I'd probably TIG braze them nowadays.

Or just use the planer which would likely be my pick as long as you can set a stop so you don't need to baby-sit it. Slew the slide over, engage the power feed & go do something else until it stops.

PDW
 
Here is the cutter I found

If you think that cutter will live long enough milling out sandy cast iron, then make a split expanding OD stub arbor for it, set it in a cylindrical or cutter grinder that has an ID spindle, use a small cup wheel to make the counterbore, then make a proper arbor to hold it for the milling job.

With a little care you might make the grinding arbor work as the main arbor too, just avoid the splitting and retain the cutter some other way.
 
usually i use 2 dovetail cutters. carbide insert type for roughing and a separate one with brazed on carbide teeth full length of flutes for finishing. not sure where they get them.
.
i have seen carbide insert ones where big inserts damaged the pockets holding them and the angle held was off. too much roughing forces can damage the carbide insert mill. better to take a extra pass even roughing
 
Many years ago I needed a big dovetail cutter - not that big, but chunky.

I started with a nice piece of steel, welded it to a 40 taper shank then turned it to the 60 deg angle I wanted. Then off to the mill with an indexing head and 3 slots cut in it with the leading face on the centre line. Welded in 3 sticks of HSS and off to the T&C grinder to clean it up.

Worked fine, it's still floating about somewhere. I can't see why a bigger/heavier version wouldn't work and if it needs carbide, so what, braze them in (welding worked but there was some cracking, I just didn't care for a one-off and it was quicker). I'd probably TIG braze them nowadays.

Or just use the planer which would likely be my pick as long as you can set a stop so you don't need to baby-sit it. Slew the slide over, engage the power feed & go do something else until it stops.

PDW

I think I would have to baby sit the planer. As far as I know, the planer doesn't have any stops to shut off the feed when it would get to the corner of the dovetail. Though I havnt run the planer all that much. I usually only use it to cut internal keyways in very large jobs that are too big for a key seater and for these, I usually feed it by hand.
 








 
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