Making insert holders for my lathe

[jumps4]

I have started making several different style carbide insert holders for the cnc lathe. i wanted long slender inserts to keep down the number of tool changes i would have to do so i chose vnmg inserts, they are 35 degree angle and 3/16" thick. so i needed tool holders. factory ones are 60 to 100 dollars each and they are too big for an axa tool post. i'm making lefts right and centered out of A2 1/2" square tool steel and also making some from mild steel as one piece to fit the quick change tool post. i have finished one 1/2 holder all but heat treating, 5 more to go.
steve

 

[Rbeckett]

Lookin good there Steve. Are those inserts readilly available and fairly cheap? I have seen some that were unreasonable and I never did figure out why they were so much more than other very similar configurations. Any idea why they are so different in price? Thanks for the pics.
Bob

 

[jumps4]

I watch for old stock or lots on ebay, these are $7 to $14 each to buy them from a supplier. I gave $24 including shipping for 10 of them and they have 8 cutting edges each. the tool holders are 3 degree negative rake so all the edges can be used.
steve

 

[Metalmann]

Looking great, Jumps.
One thing I noticed, don't you have the diamond tip hanging out too far? It should be supported closer to the end. You may be busting inserts at the screw, with that much overhang.
Especially, if you plan on doing any interrupted cuts. IMO.

 

[jumps4]

it does look like it is out too far but in pic 9 if you zoom in you can see that it is under the end of where the insert is supported the edges around the inserts do not make contact they are below the surface anyway.
steve

 

[jumps4]

I put the 1/2" tool holders on hold for a while and now i'm making one piece axa too holders for the new inserts. here are a few pics of the beginnings and a vix of the zx45 cutting the bulk out before dovetailing. this 1" 2 insert carbide endmill i bought is just great, if i need metal out of the way fast i'll grab it first every time. cutting the center out of the three parts took a little over an hour total but the dovetailing goes a lot slower.

[video=youtube;UpCWdcNt7QE]http://www.youtube.com/watch?v=UpCWdcNt7QE&feature=youtu.be[/video]

 

[jumps4]

I have all 3 dovetails cut out now and they fit perfectly
that was a pain in the...
the rest of this should go a lot faster
steve

 

[Ray C]

Looks real good. Are you going to black oxide them? That would be a nice touch. I use the Caswell stuff. Works great and I have parts several years old and the finish is holding up fine.

PS: Why was it a pain? Whenever I dovetail cut, I assume it's going to take several passes. And for the center cut, I'm usually inclined to use a 3/8 or 1/2 carbide and make a couple passes. Saves a lot of strain on the machine.

What kind of metal stock do you have? If it's 1045 or 41xx, yeah, that stuff fights back.

 

[jumps4]

i'm not sure what the metal was it was a piece of scrap i pulled out of the dirt with an 1/8" of scale on it.
the center took minutes to remove with a 1" 2 insert carbide endmill
i think my dovetail cutters i bought off ebay were for wood or something they didnt have a brand on them.
see this thread for details http://www.hobby-machinist.com/showthread.php/9584-are-dovetails-a-pain-to-cut
steve

 

[Ray C]

Gotcha... Yeah, dovetails are a little dicey and HSS dulls quickly -especially if you're working with higher carbon stock. I have a carbide insert tool and it's better on the pocketbook in the long run. I tend to spin fast and cut light -but different machines likes different things.

Looks good. Nice job.

i'm not sure what the metal was it was a piece of scrap i pulled out of the dirt with an 1/8" of scale on it.
the center took minutes to remove with a 1" 2 insert carbide endmill
i think my dovetail cutters i bought off ebay were for wood or something they didnt have a brand on them.
see this thread for details http://www.hobby-machinist.com/showthread.php/9584-are-dovetails-a-pain-to-cut
steve