Aloris BXA 16 turning & facing tool

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I have an Aloris BXA 16 Turning & Facing tool. For those not familiar, it is a double ended unit, intended to right hand turn with one end, and left hand face with the other. Both ends use TPG 322 inserts, with adjustable chip breakers.
I'm looking for other user's experience with this, or a similar tool, in regards to speeds & feeds with different material. I have a PM1440GT lathe, and am most interested in cutting 6061 AL, 304 stainless, and 416r stainless, though info for other materials would also be useful. Any information about preferred inserts would also be appreciated.
Thanks in advance.
 
I have an Aloris AXA 16 tool that uses the TPG 321/322/323 series carbide inserts. Over the 3-4 years I had it and with repeated use, I have to say I'm not impressed with the results. I believe the tool is well made, the problem lies with the inserts (I find TPG inserts, cheap to buy, but the quality fluctuates greatly) being a positive insert, they can dull quickly, all it takes is a slight bump, a little too deep of a cut or an interrupted cut, and the sharp edge disappears.

The tool works well, on aluminum, giving an almost mirror finish, steel and stainless steel, was less satisfactory. I get better results with either negative inserts (TNMG and WNMG) and positive inserts (CCMT), the AXA 16 tool now sets in the drawer, pulled out for an occasional aluminum job 5-6 times a year.

To me, the Aloris -XA 16 tool, to be an expensive tool, severely let down by the available insert quality, I'd never recommend anyone to buy one
 
I own the AXA version of this tool and acknowledge that it is an old design that requires some familiarity to work well. I'll summarize my impressions:
  • It is considered a positive rake tool but only in the sense that it is ground with an 11 degree clearance angle under the cutting edge so you cannot flip it over; hence, only three edges can be used.
  • Mine has a carbide chipbreaker on top and the distance of the edge of the chipbreaker to the edge of the insert can be adjusted; farther for roughing, closer for finishing. You have to mess with it.
  • This tool is not the greatest tool for finishing but it roughs well if you have the rigidity, speed and power to use it. I should think a 1440 would do just fine with this tool for roughing. For finishing cuts, the chipbreaker has to be fairly close to the edge and your cutting speed needs to be high. This means that for smaller work (below about 1" OD), you may not be able to reach adequate speeds to finish well. I can only get 2200 rpm on my lathe and it is almost but not quite enough to finish stainless well.
  • You are going to have looong stringers with this tool in aluminum and stainless steel, especially when taking finish cuts. You are limited by slower feeds in order to finish and you do not have the speed to get a nice finish AND get the material to chip off so you'll learn to live with stringers. Be careful of these when the lathe is running. You will find that this tool will finish better if you increase the lead angle. Yes, I know the tool is meant to cut perpendicular to the spindle axis but when you're trying to save the finish on a work piece you'll do anything to get it and a 10 degree increase in lead angle can do it, especially in SS.
  • I tend to use smaller nose radii with this tool. The only reason for this is that I need to finish with it and I cannot get a decent finish with a large nose radius and hold tolerances at the same time. Large nose radii deflect at smaller depths of cut so you have to know how that radius likes to cut and take the finish cut at that depth. A smaller radius allows you to take finer depths of cut with less deflection, at least in my experience.
That's all I can think of off the top of my head. It is a good tool but it mostly comes out when I have a larger piece of material that is either hard or that I can run slow (cast iron comes to mind).

For aluminum, I would highly recommend a CCGT AK insert in a SCLCR tool holder; it is a vastly better insert for both roughing and finishing.

For stainless steel, I don't know the optimal tool for that but having cut SS with the AXA-16, I would give it a try. SS likes a lot of relief angle at the cutting edge and a TPG insert has 11 degrees of relief, which is a lot compared to most inserts. Here I'm talking about 303, 304. For 416, I only use a purpose-ground HSS tool that finishes better than any carbide insert I've tried.

I would defer to the other (read pro) guys who use this insert in a production setting. They will know the right answers. You have sufficient rigidity to use a negative rake tool, which may finish better for you in SS but I haven't used one; hence, we need to hear from the pros.
 
Hi Mikey
I thought negative rake tools were generally better for hogging material because of the stronger cutting edge whereas positive rake tools give a better finish. Willing to be corrected as my only experience is with positive rake 7deg CCMT and CCGT tools.
These tools do all I could require. Yesterday I was removing 0.5mm cuts in 1020 with no problems at over 200 sfm. Could have gone harder much harder. Produced an excellent finish. I was pleasantly surprised given the material being machined.
Also Korloy CCMT inserts in 0903 and 1204 size are dirt cheap -less than $US20 for 10 on Alibaba. I use grade NC3020 for steel and uncoated ground H01 for Alu. Apart from interrupted cuts they last for ever.
I started off using the smaller size in 12mm SCLR holders on my 8.5x16 Sieg SC4 but now mostly use 1204 size on my 330x1000. Even on the mini lathe carbide performs remarked well if you take the care to get the cutting conditions correct.
I have never understood why people fuzz around with grinding HSS except for specially shaped tools. If your willing to sacrifice tool life for cut quality CCGT H01 inserts will match HSS cut quality even on steel. a downside is that carbide does not like very fine cuts but the sharp H01 format will come close.
Ron
 
Actually, negative rake tooling will produce a good finish but good is relative. We're talking about big cuts on a big lathe. I've only ever used a negative rake tool on my friend's SB13 but that insert put a really nice finish on 4140 with a big depth of cut. I have to admit that I was impressed.

Actually, I have the SCLCR tools, too and agree they work pretty good. A 0.5mm DOC is about the smallest roughing cut for a CCMT insert if you want the chip breaker to work so I'm not surprised it cut well for you but 200 sfm is on the slow side. The cutting speed for 1040 is over 900 sfm and this is the real issue with using these inserts in a hobby shop - inadequate speed.

Cutting speed is really a big deal. I had the opportunity to cut 6061 on a high speed lathe using a CCGT AK insert. As I recall, spindle speed was somewhere near 6K and the cut was effortless and the finish rivaled my best HSS tool. What's more, we were able to hold tighter tolerances because the insert was cutting as it should. Finishing passes were 1/2 the nose radius and we were able to hold tolerances in the 0.0005" range. Not too bad, right?

The same is not true at the slower speeds most hobby lathes run at, especially the smaller lathes. A CCMT insert cuts well in aluminum and many softer steels but it will deflect more at those speeds. If you doubt this, try taking a finish cut on a 3-4" long rod without a live center and see what your OD is like at each end.

I'm afraid I have to disagree with you that an AK insert will match a properly ground HSS tool on a lathe running at mortal speeds. In aluminum, it might be close but even then, my aluminum HSS turning tool will cut deeper and finish finer at the speeds my lathe can achieve (2200 rpm max). I'm not just pulling that out of the air; I tested it, albeit crudely, under 20X magnification and carefully measuring OD's on an unsupported work piece. A 22.51 AK insert is limited to roughly a 0.125" depth of cut. My HSS tool will double that cut without even slowing the lathe down and then take a half thou off the diameter with a mirror finish.

Ron, HSS tooling can be ground right and it can be ground poorly so not all HSS tools are the same; much depends on the skill and knowledge of the person grinding the tool. When the tip geometry is tailored to the material, HSS is a very useful material on our slower lathes. I don't dispute that the modern carbide inserts can work for a lot of folks but for me, I only use them when I can meet the cutting conditions of the material and that is usually not the case in my shop.
 
Mike
Interesting comments- food for thought.
When you say HSS ground right can produce extremely good finishes I cannot disagree. However without a proper tool and cutter grinder one grind to the next will never be the same. Also depending on the skill of the machinist the quality of the grind will vary considerably.
With modern carbide inserts it is my experience that they are all so close to the same that for all intents and purposes they are identical. I can remove an insert and replace and can assume the cutting point is in exactly the same place. Also modern inserts come with various nose radii so you can choose to suit the job at hand. Just continue on with no stuffing about.
On the Korloy inserts I can reduce the DOC to about 0.3 mm before the chip breaker fails to work. However requiring a significant depth of cut means you have to change how you work. Rather than sneaking up on a dimension, measure and use your DRO to make sure your last cut will still be > 0.3mm.
Maybe I am not so good at grinding but I am still surprised how good a finish I can get with carbide. How good a finish above a mirror surface do we really need.
I still have no reason to believe I made the wrong decision going with carbide from the start. I have learnt more by just getting on with the job without having to worry about whether my tool was cutting properly.
 
You'll get absolutely no argument from me, Ron. Any comment I make is just a personal observation and/or opinion. I fully agree that inserts enable consistency and that once you know how your inserts cut, you can achieve good accuracy. I am in no way implying anything about your choice of tooling. In fact, I think a very large proportion of hobby guys do exactly as you are doing - using SCLCR tooling and are happy with the result. I'm one of them but only when they provide an advantage.

With regard to HSS tools, I don't use a tool and cutter grinder and seem to bumble along okay. I grind tools for each material class I work with and they perform well for me. It brings to mind a quote from Paul Thede or Racetech who said, "The best you've ridden is the best you know." A well-ground HSS tool can work really well; in my hands on my lathe with me operating it, my tools will outperform carbide in most cases. Obviously, this is not the case for everyone.
 
Positive rake triangular inserts work well for light roughing and finishing of parts of small diameter, thin walled tubular parts, long parts held with the tail stock and any setup with less then ideal rigidity such as deep boring.
Not so good for heavy roughing or interrupted cuts or tough abrasive materials, given a stout setup and machine there is no reason no to run them a 600 SFM or more in 6061 aluminum, say 2500-3000 Rpm's at 1" diameter WITH COOLANT, without coolant the chip will become unruly leave the machine and chase you around the shop, clamp down chip breakers rarely work well in this material, insufficient feed rate will also cause a troublesome chip. If the chip curls off before reaching the breaker it may as well not be there.

For 304 SS 200-250 SFM will work well, around 750 Rpm's at 1" diameter, as mentioned without coolant beware of the chips as they are deadly sharp and difficult to break.

I have nearly zero experience with 416 SS but do a bit in 440C but have never used a TPG insert with it.

Good Luck
 
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