Tool holder opinon

Considering a Quick Change Tool Post Set, AXA to use on my SB9 l415-AV instead of the lantern. I see these for sale however, I have not read anything about their quality or accuracy etc.
Any input/advice would be appreciated.

Here's a link to e recent thread where I had some of the same questions
http://www.practicalmachinist.com/vb/south-bend-lathes/qctp-overkill-249509/

Rick

A QCTP can be an advantage in some cases. I have a 9 Jr and I continue to use the lantern tool post for it. I have a 9-C and I still use its lantern tool post as well. My Heavy 10 came with a lantern post (which I still have) but I purchased a Phase II wedge-type QCTP for it. My son has a 9-A at his business and it has a Phase II QCTP.

The QCTP is more rigid in supporting the tools than the lantern style holders and you can use larger square bits. If you do a lot of repetitive operations, the QCTP can save you some time. For example if you need to turn a piece to diameter, knurl it, and part it off you can set each tool block to the correct height and then just change blocks for each operation. The wedge type QCTP will hold tool position very accurately if you make sure you keep the mating surfaces clean.

On a 9" lathe, I find the QCTP to be in the way fairly often and it limits your ability to "get in close" for some operations. You'll find it banging into the tailstock quite often, for example. This is less of a problem on the bigger lathes.

I'd say that you should consider getting one if you think that's what you want but DO NOT get rid of the lantern holders because, especially on a 9" lathe, you will find cases where you just about have to use the lantern holder in order to be able to get the tools in where they need to be.

Avoid the bargain price piston-type QCTP's because they are not as repeatable for tool location as the wedge-type. You can always hope for a bargain on an Aloris but I've been quite happy with my Phase II equipment.

I've got a related question no one could answer on another forum. I got the QCTP (not the expensive aloris one) and it holds the bits in a horizontal position.

I noticed in South Bend's "how to grind lathe tool bits" bulletin 35, that their illustrations all show the lantern toolpost with a holder that holds the bits so they are pointed a bit upward toward the work.

They also give all the dimensions you need to grind the bits. Now the front clearance and back rake will be different if you grind the angles the same, depending on whether or not the bit is in a lantern or QCTP like the ones I just described.

Are there adjustment angles available anywhere so I can grind my bits properly for the QCTP that holds bits horizontally? I don't think this question has ever been asked.

Thx

Dave

The AXA size posts tend to be a bit large for a 9" SB. You might take a look at this: Omni Post - The quick change tool post system for your lathe!. More compact, and reasonably priced for made in USA. Also, Dorian does make a smaller, less expensive version of their toolpost, and I believe Aloris does as well.

Regarding back rake; the lantern holders had it built in, but you lose that when you go to a quick change. If you want back rake, you have to grind it in yourself. You can cut without any rake on the top of the bit, it may take a bit more effort from the machine. Most of the time, I don't grind any rake on top, just side and front clearance, and it gets the job done.

Paul

Paul, and the front clearance angle would be lower too on QCTP because the bit is already pointing further down. I think what I'll have to do since no one has ever done this is determine the difference in angles and draw up some new templates to use for every bit using a QCTP. It would be interesting to see if anyone has ever done a scientific sort of test to see what if any effects a few angle differences have on rake and clearance.

I think it's basically a tradeoff, being less rake and clearance means a stronger bit that won't wear or spring as much but less benefits with other performance

I have one of the lightweight anodized aluminum A2Z tool posts on my 10K. It's not a bad compromise (or addition) between an AXA and a lantern.

It's quite a bit smaller than the AXA so it doesn't get in the way very often.

It's more rigid than the lantern, but certainly not up to the standards of an AXA/Aloris full sized QCTP, but for $100 it is a useful addition to the smaller SB lathes.