New parting tool holder for 0xA QCTP.

David Kirtley

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Dec 17, 2012
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Well, I really didn't like the angle of the parting blade in the tool holder that came with the 0xA tool post. It means each time you extend the blade, you have to find new center height. The angled holder is also lower. I had to mill the corner off of the stock 0xA holder to even be able to get it down to center height and I had to turn the compound slide at right angles to the bed so the holder could go low enough because it hit the top of the compound otherwise. Overall the original holder made parting unpleasant.

I figured I would go ahead and make a new holder. The new one is out of 12L14 steel. It has a few odd facets on the corners because the material was scrap and already had them. I did make one mistake. I milled the dovetail a little wide. Some quality time with a ball pein hammer fixed that little issue. I still might make a few changes. I am considering cutting it back a little to give a bit more room for parting larger pieces. Not sure yet.

I have yet to make an adjuster post for it. Right now it just has a cap screw with a washer that doesn't really work that well. All in all it was a fun project for a Saturday afternoon. Note the test parted pieces of steel next to it on the headstock. Nice and rigid. The clamping bar started out as a piece of 1/2 inch round 12L14 (I think. It was just laying on the bench with other scrap). It probably took the most time of the project. I even broke down and used a hacksaw to cut the bar off. That is really unusual. I just didn't feel like messing with getting out the portable bandsaw with a metal cutting blade and the vertical saw has a carbon steel blade on it right now. The project could have possibly taken less time had I bothered to sit down and plan it out. Instead it was all cut to fit. I don't know if I should tell this but I actually did not use a single measuring device for the whole project. Just used relative sizes of tools and did a lot of test fitting. To be fair, this isn't my first rodeo. I made about a dozen tool holders for my A2Z CNC toolpost that the 0xA is replacing. That got the routine pretty well established for making them.

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Here it is in place on the lathe. Isn't that an ugly adjuster screw? I will have to do something about that later. If I had milled the slot just a tiny bit higher, I would not need an adjuster at all. Oh well. I might make a pretty brass one. Yay, now I don't have to readjust the compound slide to be able to part things off. That was just really annoying. Also, when I part off thick stock, I like to part about 1/2 an inch at a time and then extend the parting tool so it is not extended that far at the beginning to keep it from deflecting. Also my cross slide doesn't have enough travel to start with the blade fully extended to cut thicker stock anyway. Cutting in steps was pretty much impossible with the original parting tool holder because of the angled blade.

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The back of the holder. The evidence of the beating it with a ball pein hammer to close up the dovetail has been milled off. Don't ask and don't tell should probably apply. Pretty good surface finish on the offcuts. They were a off a piece of steel I had laying around. Probably 12L14 steel also. It is nice and rigid and doesn't chatter at all. Still needs a little file work to pretty it up. I will probably do it some day when I am bored.

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I am going to be especially glad I went ahead and made it when I am using the lathe next week. I ordered some stock that should come in Monday and I have 40 bushings to make for another project.
 
Well, as long as I was at it, I figured I might as well finish it up.

Ready for business:

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The business end:

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Notice my patented Channel-lock knurling? Not many people can get that right. Have to have just enough tension on the pliers. It's a feel kinda thing.

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See? Not hiding anything on this side either.

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It looks like it's working well for you. Nice job.
 
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