DIY QTC for HF 8X12" Lathe??

[scubasteve_911]

Hello,

Can anybody tell me if someone has created a QTC mechanism for their mini-lathe and documented it well? I don't really want to spend 100$ on something that I could machine for much less and get the satisfaction out of..

The tolerances don't really seem critical for it, so it seems like a promising project

Steve

[ToyMaker]

this is the best (and easiest) one I have seen on the 'net.
http://aardvark.co.nz/pjet/qctp.shtml

robotic regards,

Tom
= = = = =
"While he sees his refusal to show weakness as his greatest strength, his refusal to show anything but strength is actually his greatest weakness."
- - Roberta Proctor

[scubasteve_911]

Thanks Tom!,

That does look very easy to do, but I'd be concerned about available clamping force. I wonder if it would be rigid enough for most jobs?

You gotta love the simplicity though! I'm thinking of making it now

Steve

[in2steam]

I just paid 149+tax and shipping on a wedge type phase II tool post kit(4 or 5 holders) from enco, and still have to get the satisfaction of modifying it to fit two seperate lathes. I looked into the project a bit, even went as far as cutting up some steel I have into a proper size for spare holders. If I were to make one I would pattern it after a Myford style with the multiple angles, otherwise a typical aloris style would be second. The big problem was by the time I bought the steel(using steel of questonable origins may cause difficulties) and would get it heat treated like a purchased one it would have been more costly then just buying a finished one. I am not sure I would waste time on building one without harderning it, although some have made them work they were on larger lathes were there was more surface area to spread the forces out on. I have since decided that once I finish the mods for the 9x20 post, I will make the steel I have into spare holders which you can never have enough of, on my shaper which has to be the cheapest and easiest machine to make that on as all I need is a piece of HSS. I have not seen anyone make a wedge style post yet, the way I figure its worth the difference in price of about $50 either way and what little time I have left is better spent on other projects.
chris

[scubasteve_911]

Very true about the nearly negligable costs involved, but I think hobby work really isn't about getting things done cheaper.. It's about getting satisfaction out of doing things, but there is definitely a tradeoff between doing what you really desire and what you need to get the job done. I'm taking 16 courses as a part of my final year in electrical engineering, so I guess time isn't a luxury.

I have searched quite a bit for quick tool changers that'll work well with my machine. I have found two solutions, neither of them are particularily attractive. First, is

http://www.littlemachineshop.com/pro...ProductID=2461

This is constructed out of 6061-T6 aluminum, which I don't believe is the right material for something like this. It will fit the lathe without a hitch, but it only holds 3/8" tooling and will probably scratch and wear easily due to it being aluminum. I don't think anyone can dispute this, aluminum is simple not even close to being ideal for something like this.

My second solution was promising due to the quality of the construction and the price being nearly equivalent to LMS.

http://cgi.ebay.com/6-12-PISTON-QUIC...QQcmdZViewItem

But, it needs to be modified in a huge way to get it to fit, as detailed here..

http://www.fignoggle.com/machines/8x...Phase2QCTP.htm

It seems like a ridiculous modification, something I would do if I bought something that didn't fit the job and I really wanted to make it work.

Not to bash LMS, but I have found much better prices from Discount Machine Shop for exactly the same products. In some cases, the same product for 2X the money of LMS. I would really prefer to get the best bang for buck from DMM, but I might have to resort to inferior aluminum QTC that is probably marked up a significant amount.

Steve

[in2steam]

My only grip with aluminum is that it could bend and deform, otherwise taig uses aluminum for there tool post and I have never had a problem and they can take quite a good cut. People often forget we cut steel with aluminum on a regular basis, even the HSS cutting tools. I would think for longevity hardened steel would be the best choice, also as far as mods go removing any kind of metal seems to me a bad idea, I would go for the ones that don't require that or as little as possible, then again I need to make my QCTP work with a 9x20 stud and a regular t-nut tool slot so I am not moding the post itself.

chris

[pastera]

I made my own piston type QCTP for a 7x12 lathe. You will need access to a mill to do the dovetails.

The parts were done in Alibre, so scaling it up or changing would not be an issue.

I paid about $30 for the materials and still have enough to make 3-4 more tool posts (You can never have enough tool holders!!!!). If you have a full scrap bin your cost could be nothing.

Aaron

[itowbig]

[QUOTE=ToyMaker;340636]this is the best (and easiest) one I have seen on the 'net.
http://aardvark.co.nz/pjet/qctp.shtml

robotic regards,

Tom




I just made this one out of steel and the center part is good and sterdy
but the part that holds the cutter is really hard to clamp so im going to make one out of aluminum and keep the center steel as it is really strong no flex what so ever. i bought a qctp and i hate it there is so much flex in that thing.
i'd rather use the one that came with my machine and just use shims.

[RotarySMP]

I was going to make my own, but ended up buying a Phase II AXA wedge type. I'm really glad I did, as Shars has tool holders for about $12 each, and I now have about 17 tool holders. It would have taken me for ever to make the holders.

The repeatability of the AXA design is great for my CNC machine.

[DonF]

http://www.lathemaster.com/QUICK%20C...POST%20SET.htm

Its out of stock at the moment but I have never heard anyone complain about it for the 8x12/14

[DonF]

Another 8x12 mod - QCTP looks like a simple way to mount a standard qctp on the 8x12/14

I wanted to get the bolt on lathemaster QCTP but they say they "Should" have some in December - its out of stock now

[jpelosi2002]

The lathemaster is the cat's meow for the 8 X series lathes. I have one on my Lathemaster 8x14. It works wonderfully and took 3 minutes flat to install. Plus the tool holders are modified to help bring 1/2" bits down to center with some room to spare. In my mind there's no other alternative that can come close for quality, fit and value for the price of the Lathemaster post. Besides, with the cost of raw materials and shipping charges these days your savings would be minimal if you made your own.