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SB 9 With Phase II QCTP Parting Tool Problem

processhead

Plastic
Joined
May 23, 2018
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I am trying to setup the pictured parting tool fixture on my Phase II QCTP installed on my SB-9. The problem I am having is adjusting the parting tool to the centerline of the work.

The second picture shows how the parting tool cutting edge is above centerline when at its lowest adjustment point. (chuck removed and a center inserted for illustration).

What am I missing here? How do I lower the parting tool, short of grinding it down? Also, when extending the tool for making deeper cuts, it just increases the tool height further.

Thanks for any solutions or suggestions you can offer.
 

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Well that Phase 2 part number is an Aloris AXA size, which I would have assumed should be in range for a SB 9. But though you look set up correctly, it appears the AXA size it too tall, you are bottomed out on the adjustment range.

If you put a #1 holder in (250-101), how far are you adjusted down to hit center line ? Optimally, you want all your holders somewhere in the middle of the adjustment range on tool post.
 
A quick solution for parting tool, going to need to grind that cutting edge down to use the same tool and parting blade.

If your #1 holders can go low enough, might go this route.

I think there is a sub AXA size from Aloris, not sure Phase 2.
 
Thanks for the reply.

I haven't had any issues using a 101 tool holder, but need to check which end of the range I have it set to.

Something I was checking today were the distance-to-centerline from various points on compound base. There was one that didn't seem right, and I need to follow up on it in the morning.

It has me wondering if I have all the correct components? http://www.wswells.com/data/spec_sheet/5224.pdf
 
do yourself a favor and take a 2-3" diameter disk of metal, about 1" thick, chuck it up and face it flat, then flip it around and turn it to the standard dimensions for the circular dovetail post that goes in the hole on the cross slide. but relieve the middle portion such that when you clamp it into the hole, it only contacts the cross slide around the perimeter of the disk.

drill and tap the middle of it for a bolt to hold your QCTP.

put the compound rest away and only bring it out when you need it again.

enjoy successfully parting metal on a SB9, perhaps for the first time in its history.
 
do yourself a favor and take a 2-3" diameter disk of metal, about 1" thick, chuck it up and face it flat, then flip it around and turn it to the standard dimensions for the circular dovetail post that goes in the hole on the cross slide. but relieve the middle portion such that when you clamp it into the hole, it only contacts the cross slide around the perimeter of the disk.

drill and tap the middle of it for a bolt to hold your QCTP.

put the compound rest away and only bring it out when you need it again.

enjoy successfully parting metal on a SB9, perhaps for the first time in its history.

This sounds like an attractive solution.

Based on the measurements I took, it appears the compound and base are from another model and add height. The added height places the parting tool above centerline with the 107 toolholder and the QCTR.

Regular cutting bits in the 101 tool holder work fine.
 
Thinking about this more, the dovetail round post can be the nut, separate from the slightly concave disk. You dont need to start from solid and remove half a pound of steel.
 
Thinking about this more, the dovetail round post can be the nut, separate from the slightly concave disk. You dont need to start from solid and remove half a pound of steel.

That makes the project sound even more attractive. I was thinking about all the material that would have to be removed to turn the dovetail stud from the same full diameter stock.
 
Taking Johansen's recommendation and following his good verbal directions I was able to turn the pieces to solve my parting tool alignment problem. This also allowed removing the compound feed from the cross feed. Guessing this will provide a more rigid setup than the original tool rest.
Thanks for the suggestions.

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This is the main reason I don't use this type of parting tool holder. Every time you put a grind on it- even if you do it without removing it from the toolholder- you need to reset the height because you've shortened it and lowered it at the same time.

I much prefer a tool block with parting blade and GTN inserts. Set and forget, just adjust stickout for the diameter of your part.

Search results for: '404-0402 set'
 
do yourself a really big favor and switch the whole compound rest to one for a 9" machine, the one you have appears to be from a 10k

the only functional difference is the 10k rest base is about 1/4" or so thicker so you're not only limited severely with you parting tools, but also every cutting tool, as your centerline currently is probably only around 3/4" above the top of the compound rest top, once you factor in the tool holder you can likely only use a max 1/4 bit in your holders
 
I might be a little late to the game here. I also have a SB9 and had problems parting.

Turn your compound to 0 and the tool holder should have clearance to drop lower and get the tip at centre.

Firstly, regrind the tool bit or an area near the tip to almost 90 degrees. The problem you likely are having is that it has way too much angle and it digs in and stalls the spindle, chatters like mad or generally pisses you off! The base of your tool holder has the needed angle of around 7 degrees. You'll find that this is about perfect for a tool with the 90 degree angle.

Second: I found that on a wimpy flexible SB9 a much thinner parting tool helps tremendously to not load the lathe as much and eliminates chatter. I can crank away with the chips coming off at a very fast rate. *You have to almost flood it with oil as you cut. Left hand oiling while your right hand is feeding the tool. Or use the powered crossfeed. Another help is to tighten the gib screws on the crossfeed to eliminate any unwanted motion.

I use a T shaped 1/16 wide tool from this company. ICS Cutting Tools
On larger diameters initially keep the tool stick out at a minimum and only enough to cut the part diameter say 1/4 inch deep.. This wards off flex and potential chatter. Cut until the tool holder is about to touch the stock. Then pull the tool out another 3/8 inch and resume cutting, Repeat as needed. As the tool holder base is angled, when you cutoff the now different diameters you'll have to reset your tool point height for that diameter to keep it on centre. This applies to the part in process. Remember that as you pull the tool out to go incrementally deeper in a large diameter the tool also goes uphill and above centre.

Try these suggestions and you should be parting like it's nothing. **With the 1/16 wide tool don't try grinding a side angle on it so the cutoff nub stays with the stock in the lathe. The 1/16th tool is too weak to do this and it will flex towards the cutoff part. Grind it straight and live with the nub.


edit:
Last week I parted off a 3 inch bar of 4140 with no problem. It took a while, but it worked just fine.
 
To get the present setup to "work", if the compound has a slot for attaching the QCTP like a SB, all you have to do is loosen the QCTP from the compound rest. Make a shorter "nut" or cut the side off the present one. Now slide it towards the left side so the tool holder part is sitting over air and re-tighten. It will look/feel a bit off being off center but you can then lower it even more to match the cutting tip to the center of your work. You may have to straighten the compound angle to make it work but that is no big deal.

FWIW

-Ron
 
LOL!

Wait until you ALSO discover how much nicer it can single-point threads and take heavier plain-turning and boring removal rates with the sloppy compound clear TF off the lathe!
:)

Nice to OWN a compound. Now and then one has a steep taper to do.

But they began life as an "accessory" and not all lathes ever put to hard work EVER owned one, their life-long.

:)

Good point.

I also recall a similar explanation from neanderthal mach. His post is a little long and hard to read, but the core of that particular point is in the last paragraph of what he wrote:
Operational considerations of compound rest

My own South Bend was set up more as a manufacturing lathe with a turret tail stock, and cross slide had no compound rest:

223.jpg 10.jpg

I did loose some rigidity going with a taper attachment set up, mostly notable when parting off:

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And coincidentally, note the dial indicator on tool holder. I was incrementally cross feeding and down feeding toolholder :D. I was missing the previous set up for better weight and rigity, and wishing I had it on. Using lathe unpowered like a shaper, I was making replacement square drives for a clutch assembly on another machine. Just driving the carriage right into work, one slice at a time:

113.jpg 114.jpg

Anyway, that would have been easier without the compound rest.
 
This is the main reason I don't use this type of parting tool holder. Every time you put a grind on it- even if you do it without removing it from the toolholder- you need to reset the height because you've shortened it and lowered it at the same time.

If your HSS parting tool is propery shaped why would you be re-grinding it as opposed to re-sharpening it with a stone? Resetting the height is a matter of twisting the knurled nut. That is one of the main benefits of a system like this right?
 
If your HSS parting tool is propery shaped why would you be re-grinding it as opposed to re-sharpening it with a stone? Resetting the height is a matter of twisting the knurled nut. That is one of the main benefits of a system like this right?

If you chip or break the cutting edge might be a while hand stoning it out :D. Just refreshing an unbroken edge its fine. But grinding goes a bit quicker whether chipped edge or not.

I don't see an issue with checking and setting height though, just takes a minute. I use hss parting blades myself, but I do have the insert type as well. I can see some advantage in using it like he mentioned, instead of adjusting, just pop a new insert in. But I'm not high speed production and find hss convenient enough.
 








 
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