another tough tool holder ...

[wquiles]

In a recent thread one of you here was cutting a very tough tool holder, and I even remember Barry saying something that in the past he has ruined some bits cutting some tool holders as well. Well, this is my story ...

I have plans to make a very rigid cut-off tool holder for my Iscar Do Grip cutout blade, the idea being that instead of having the blade being held in a block/holder, and this in turn being held in a BXA tool holder, it will be a single piece design.

Recently I scored a good deal on an used Iscar Do Grip grove/cut-off tool holder with the inserts (I really wanted just the inserts since the price was right), so I decided to "practice" making a single piece for my BXA tool post. Being a name brand holder I expected it was going to be tough, and unfortunately it was!

Here is the Iscar Do Grip tool holder on the left, with my Kennametal one on the right - note how massive the Iscar holder is:

Given those previous threads I decided to try my new 1" Toolmex Carbide cutter, held by my ER40 collet system:

It was a slow process, taking about 0.030" at each pass, but the cutter worked great:

It was also slow since I don't yet have a DRO, so I had to cut, measure, cut again, etc.:

Then, when it came time to work with the 3/4" 60 Deg HSS Cobalt dovetail cutter - everything went downhill, and the dovetail cutter failed miserably:

I had a second, brand new one, so I tried again, this time instead of a slow feed at 1000 RPM, I ran it at about 350 RPM - both times I was using the Kool Mist Clone pretty heavily:

This time, the new cutter, with the slower speed, worked much better, although the cutter is definitely dull now and the very sharp tips are gone (although not damaged like the old one):

and it did fit properly the first time:

Of course now I had to drill a hole for the adjusting bolt, and sure enough, my HDD drill bit just scratched the surface, and same for my premium USA 135 Deg Cobalt drill bits. Luckily I recently scored on a good deal on solid Carbide re-charpened straight drill bits, and those were able to easily cut through this tough holder (carbide drill bit installed on the drill chuck):

Here is a close up of the carbide drill bit:

Tapping was very, very slow, but I was able to get enough for a solid engagement. I now need to get a longer screw (3/8"-24 fine thread), and it will be ready for cutting duty:

To compare how much closer to the centerline of the carriage the new holder sits (less overhang), here the new cutter is flush with the end of the drill rod:

and here my Kennametal is about 1/2" further out:

Now I need to buy another 60Deg dovetail cutter, either solid carbide or with carbide tips, so that I can then work on my cut-off holder project

Will

 

[gadget_lover]

You can get 60 degree endmills that use inserts to do dovetails. I only have HSS dovetail cutters so I seldom tackle hardened steel with them.


Daniel

 

[Mick]

That is a neat way to go, Will
:twothumbs

 

[precisionworks]

Nice mod

The better holders are tough as nails, and most will test over 50 HRc. Conventional coated carbide inserts work OK at that hardness, but cermets are the insert of choice when the hardness exceeds 40, and they cut well up to the 60-62 range. You can usually find a few on eBay at bargain basement prices.

High speed steel tooling can be used to cut hard material, and I've drilled tons of holes in AR400 plate, roughly 40 HRc. It is slow going, running around 15-20 sfpm with heavy flood. Small, fragile tooling like the dovetail cutter, needs to be solid carbide or and indexable with cermets.

 

[Tekno_Cowboy]

So for a sense of scale, what are the shank sizes of both cut-off tools?

 

[StrikerDown]

Nice job will. I found out milling that hard tool holder that carbide is the only way to go and correct size of end mill is important to. Great idea eliminating the extra hardware on the quick change.

My 3" face mill w/carbide inserts was too large and just ruined inserts. When I got a 3/4" end mill it cut like butter by comparison. I does not even seem to have dulled the end mill at all.

 

[KC2IXE]

The type of job where a shaper come in handy - cheap tooling

 

[precisionworks]

3" face mill w/carbide inserts was too large

For a mill-drill, small knee mill, or Bpt, 2" is about as large as the smallish R-8 taper can handle.

type of job where a shaper come in handy

If I had to do more than one, they would go to a wire EDM shop about 40 miles away. Tolerances of .0001" are no big deal on an EDM, and hardness is not an issue as the metal is removed by spark erosion. For that particular dovetail cut it would be a quick & simple job to set up.

 

[StrikerDown]

For a mill-drill, small knee mill, or Bpt, 2" is about as large as the smallish R-8 taper can handle.

The 3" face mill came with the mill so I gave it a try, it works great on aluminum, nice wide swath, higher rpm, and deeper cuts, lots faster facing off a larger piece. Just not the way to go for hard milling!

 

[KC2IXE]

...snip...wire EDM ...snip...

Well, yeah, that'll work too, but I think a small shop like most of us is a heck of a lot more likely to have a shaper - run a nice Stellite tool, and watch the tool go back and forth making chips

 

[wquiles]

Well, yeah, that'll work too, but I think a small shop like most of us is a heck of a lot more likely to have a shaper - run a nice Stellite tool, and watch the tool go back and forth making chips

You guys mean a shaper such as this one on Ebay?
http://cgi.ebay.com/ATLAS-MODEL-7B-7-METAL-SHAPER_W0QQitemZ320405281774QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item4a99a49bee&_trksid=p3286.c0.m14

That does sound like an interesting machine

 

[KC2IXE]

That's a small shaper - that and the Aamco seem to be the most popular. If you have rom for a LARGE shaper, you can often get them for either scpa metal price, or "scrap metal - removal fee" which often turns out to make them free

If you follow Practical Machinist in the Antique section, you'll often see 14-20 inch shapers going free

That Atlas at $700 is kinda high priced IMHO

 

[wquiles]

Given their somewhat "automated" behavior (from what I watched in a couple of youtube videos), would it be "fair" to describe these old shapers as the "CNC" machines of their day?

 

[precisionworks]

I had a pristine Atlas 7-B for a couple of years, and probably ran it less than an hour during that time. The unguarded ram is problematic - if you make the mistake of flipping the on switch while any body part is in the path of the ram, the ram is rather unforgiving - it's on a highly geared down power train with massive torque. The small vertical knee mill (aka Bridgeport) all but killed the shaper, until OSHA came along with the final bullet.

IMO, they are a lot like a boat. It's better to have a friend with a boat than to have your own :nana:

 

[KC2IXE]

There are still a FEW jobs out there where a shaper, and even a planer come in VERY useful (recenty heard of a job where a guy was eating endmills beveling the edge of a plate - someone noticed he had something like a 20 Steptoe in the shop and said "Use that" - went real well)

I forgot if it was kennametal or Valnite who recently ran an applications note for some company that was doing some really odd maching job -one of those "oh yeah, I've heard of them - so that's how they are made" - it was something like a 20 ft planer, and the change of the carbide they were using made the job go from "an insert every 3-4 strokes to 2-3 inserts/day"

A shaper is still pretty much the only way to do an internal keyseat, without a broach, but then again, as you said, better to know someone with one, than to have one. One internet buddy has a nice mint Atlas. He has the space, and he said "it cost me $50"

What always amazes me is that if you have the space, OLD pre-cnc "big iron" is so darned cheap. I can understand why, but I've known one or 2 shops that made some GOOD money by, for instance, buying an old horizontal mill just for a particular job - IF you have the unused floorspace

 

[PEU]

I see one every time I go to my friends at the CNC shop, they use this machine to resurface drilling machine tables.
First time I saw it I tought, why not do that operation on the CNC VMC, the reply was its a few parts every now and then and we have that machine doing the operation since my father ran this shop more than 30 years ago

They also told me that this machine is used to make excelent quality toolholders that are able to repeat to 0.03mm, they know the manufacturer that makes said toolholders (http://www.peyal.com/)


Pablo

 

[wquiles]

Well, thanks to a recent 35% off MCS special, I was able to pick up a very nice 60 deg dovetail cutter:

each of the three tips is at an angle from the centerline of the shaft:

and the inserts have a cutout on the back which matches a dimple in the front:

Now, where is that darn "tough" tool holder again? ... :devil:

 

[precisionworks]

Nice tool. Dorian tooling is top end, as are their tool posts :thumbsup:

 

[darkzero]

Nice tool. Dorian tooling is top end, as are their tool posts :thumbsup:

Nice, thanks for confirming that. :thumbsup:

After moving on from my initial 5 piece generic indexable set, Dorian tooling is all I have been buying with the exception of my threading tools which is Carmex. Unfortunately I had to sell a couple since they didn't work out for me. I have a Travers down the street that stocks Dorian so I choose to support them & stick with Dorian when ever possible. Plus it's great not having to wait for tooling in the mail when needed. I hate waiting yet I love it at the same time.

 

[precisionworks]

That's a photo of an early Aloris AX piston tool post with one dovetail. My AX is the newer version with two dovetails. A very well made post, and usually under $100 on eBay - seems like I paid $65 or $70 delivered. Aloris still sold those through 2003 or 2004, but now makes only the AXA (wedge) which lists for over $300 without tool holders. IIRC, Aloris brought these out in the late 1940's, and continues to specialize in QC tool posts and tool holders.

The story I heard was that a group of Aloris employees formed their own company and called it Dorian. Both are 100% compatible within the same series (A,B,C, etc.) Dorian continued to develop metalworking tooling, and carries a broad product range. Their mill tooling is superb, and is copied by some of the Eastern European manufacturers, like Dolfa (sold by Bison TMX).

If you closely look at Will's dovetail cutter, the inserts are tipped "backwards" (15 deg) so that the inserts shear & lift the chip. Also, cutting forces are supported by almost the full thickness of the insert, meaning that those positive triangles should have long life without edge chipping. Really a well thought out design.