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View Full Version : How hard is it to mill a QCTP holder



Chris165
02-12-2012, 06:44 PM
I am running a cxa system on my lathe which will hold 3/4" tools. Got a good deal on a lot of valenite 1" shank toolholders and would like to get the $17 imported standard blocks and mill 1/8" off the top and bottom to make an oversize toolholder instead of $80 for one pre made. How hard is it to mill the tool blocks? Are they hardened steel or just black coated regular steel?

PixMan
02-12-2012, 06:55 PM
Mill the 1/4" off the bottom and backside of the tool holders rather than tooling blocks, especially if they are the No.2 style that have the V-groove along the bottom.

This preserves your tooling blocks for the time when you might acquire more properly-sized 3/4" tools. It also retains the structural integrity of the block, while a 1" tool holder milled down to 3/4" square just becomes it's own little brother. Milling the block you lose a few threads from the clamping screws, and weaken the support underneath.

Both are of about the same hardness, BTW, but by milling down the the tool holder shank you can use a lead angle carbide insert face mill rather than the solid carbide end mills you'd probably blow through by milling inside the block's slot.

That's my 2 worth.

Dr Stan
02-12-2012, 06:57 PM
2X on what PixMan said

lane
02-12-2012, 06:59 PM
They are not hard . Some may be tough, but can be milled.Why not just mill the bottom of the 1 inch tool bit shanks save money nothing to buy . they are not that hard either. Carbide cutter will shim them down to size easy

PaulT
02-12-2012, 07:02 PM
My experience with the cheapo import holders is that they are a low grade mild steel. Machines pretty easy, don't expect a good surface finish though, its junk steel.

Chris165
02-12-2012, 07:06 PM
That sounds like the way to go milling the toolholders. I do need extra holders anyway because I only have 2 right now and at $17 every tool can have a holder. There was also a 1" x 12" boring bar in the deal so can the sleeve be removed form a standard boring holder or just bite the bullet on an oversized boring holder? I am using a micro mill with carbide em's so is it still going to be easy.

hsm'er
02-12-2012, 07:34 PM
Yes, the sleeves can be removed. They're there so the holder fits two different size bars.

PixMan
02-12-2012, 07:48 PM
If you buy tool holder blocks from Tools4Cheap.net (http://www.tools4cheap.net), they are quite hard, and very high quality for a very fair price. I have a video on YouTube where I mill 4mm off the bottom of one of Jeff's "CA" size blocks with a 45 lead face mill. No doubt, it's HARD.

I can imagine that the look-alikes sold by CDCO and Shars for a buck or two less are much softer. Buy the good stuff; do this right as it only costs once. The ones sold by Jeff @ Tools4Cheap use high-quality screws and adjusters, and the holders are just a little bigger and stronger.

http://youtu.be/WjmQl9ke7I8

Boostinjdm
02-12-2012, 09:22 PM
I don't know about shars blocks, but the phase 2 ones are hard as hell. I tried to add a few set screws to my boring bar holder and it's eaten 3 taps so far.

Steve Steven
02-12-2012, 09:40 PM
If you buy tool holder blocks from Tools4Cheap.net (http://www.tools4cheap.net), they are quite hard, and very high quality for a very fair price. I have a video on YouTube where I mill 4mm off the bottom of one of Jeff's "CA" size blocks with a 45 lead face mill. No doubt, it's HARD.

I can imagine that the look-alikes sold by CDCO and Shars for a buck or two less are much softer. Buy the good stuff; do this right as it only costs once. The ones sold by Jeff @ Tools4Cheap use high-quality screws and adjusters, and the holders are just a little bigger and stronger.

http://youtu.be/WjmQl9ke7I8

I can tell you that the AXA holders from CDCO are VERY hard, I broke a NEW 1/2" carbide end mill with two passes trying to cut it down to fit his grandfathers homebuilt lathe (more on that in a separate thread, its QUITE impressive). I tried two of them, both were hard. Not what I expected.

Steve

gnm109
02-12-2012, 09:51 PM
If you buy tool holder blocks from Tools4Cheap.net (http://www.tools4cheap.net), they are quite hard, and very high quality for a very fair price. I have a video on YouTube where I mill 4mm off the bottom of one of Jeff's "CA" size blocks with a 45 lead face mill. No doubt, it's HARD.

I can imagine that the look-alikes sold by CDCO and Shars for a buck or two less are much softer. Buy the good stuff; do this right as it only costs once. The ones sold by Jeff @ Tools4Cheap use high-quality screws and adjusters, and the holders are just a little bigger and stronger.

http://youtu.be/WjmQl9ke7I8


The ones I got from CDCO are rather hard. I opened two of the #200 (BXA) up from 5/8" to 3/4" so that I could use some 3/4" tools that I acquired. HSS end mills wouldn't do it. I had to use a carbide end mill to do the job. I took 1/16" out of the top and 1/16" out of the bottom of the slot. They fit nicely on my 13 X 40 lathe.

Carld
02-12-2012, 11:42 PM
The same here for the CDCO tool holders. I have a Phase II BXA tool post and bought some spares from CDCO. I decided to machine one for some 3/4" cutters and it was not easy and I had to use carbide to machine it.

I took the metal off the bottom of the slot and some out of the back. It worked out pretty good and I use it more than I thought I would and not just 3/4" cutters. I have a home made boring bar holder that has a 3/4" tongue on it and will hold a 1 1/2" bar that I can now use.

The only thing bad about the CDCO holders is the set screws so I bought a box of them to change them out and have spares.

PixMan
02-12-2012, 11:54 PM
I've seen but not cut the CDCO holders, and in addition to using poor-quality set screws they also seem to have sub-par adjusters, some with drunken threads. I'll never buy from anyone but Jeff Beck.

Carld
02-12-2012, 11:56 PM
Hmm, I haven't noticed that problem on the ones I have. It's just a set screw that can be replaced anyway.

lakeside53
02-13-2012, 12:00 AM
Mill the tooling, not the holder. Easy...

gnm109
02-13-2012, 12:07 AM
Hmm, I haven't noticed that problem on the ones I have. It's just a set screw that can be replaced anyway.


No problem on my CDCO holders with the adjusters either. Some of them had OK set screws and some didn't. I just bought a box of good ones from McMaster-Carr and changed out the weak ones. For $9.00 or $10.00 per holder, they are fine for me.

.

Spookydad
02-13-2012, 01:15 AM
Some of my CDCO adjustment screws are the "drunk" ones. It was driving me nuts until I looked closely at what was going on.

EVguru
02-13-2012, 05:56 AM
A 1" square tool might even be big enough to mill the dovetail straight into!

brozier
02-13-2012, 06:21 AM
What I've done on oversize tools is mill a quarter of the shank away so you are left with a shank which has a inverted L-shape.

e.g. the OP could leave the Top and Left hand side of the shank at 1" but machine a 1/4" x 3/4" section off the bottom right hand corner, along the full lenght of the shank.

This means the tool fits in the holder snugly but you get the benefit of extra rigidity. means removing less material too. :D

Cheers
Bryan

hareng
02-13-2012, 09:22 AM
I wouldnt fancy milling most of my turning tools.
The ones i did bring down in size were done on the lathe.

Have done 6 of those BXA so far and confirm they are tough. A top class ripper cutter wont do two holders.
What i have found to work is those Seco Multi master cutters and holders, one interchangeable cutter will do posts without a mark on them.

The knurling tool holders are quite hard and very hard towards where the knurls are.

Boucher
02-13-2012, 10:20 AM
There is a lot of variability in hardness in both the tool holders and the quick-change blocks. My Sandavik holders machined easily and the Dorians were very hard as were Dorian QC blocks. The CDCO blocks are not all soft so start with carbide. I have cut Dovetails in 1" Sandavik Bars to fit directly on my AXA post. You lose the in-out adjustment so you need to give some thought to where the Dovetail is located. The tool post manufacturers make oversized holders they are more expensive but worth it. I have a lot of the CDCO which work ok for the intended purpose. Both Aloris and Dorian have specialty holders that work much better.

Chris165
02-13-2012, 06:32 PM
I hate to mill the toolholders but it seems easier than milling the tool blocks. And I will get some tool blocks that do not have screw problems. Thanks for the warning on the tool blocks, I would have hated to end up with a bunch of poor quality blocks.