[LeeWay]

I am considering several different ways to design or implement a tool turret on my new lathe project seen here.

I did do a little research on an air operated turret that is locked back in place with close fitting dowel pins. There are a couple designs for those floating around.
Not having a larger lathe or an accurate on yet sort of makes this complicated even more.

I considered building one complete with a pawl and ratchet type locking mechanism. Not nearly as complicated, but not a rigid either as with the multiple locking pins.

I got to thinking that a rotary table might work if I added a ratcheting ring and pawl. Due to it's gearing, the stepper should be pretty strong itself and with a spring loaded pawl, there should be no wiggle in it when cutting.

Has anyone used such a rotary table for a lathe turret?

I may just initially use gang tooling. This would allow me to build a turret. The ratchet mechanism added to a rotary table would still need fabbed, but I could likely make that on my mill.

Thoughts and other ideas are sought.

[phomann]

Hi Lee,

My prototype 7x14 lathe came with a 4 post toolchanger.

http://www.homanndesigns.com/ToolChangerProject.html

It it driven by a reversible AC motor. It rises up off the locking pin and start to rotate, The is a loud click about every tool position from a pawl (I guess). once it is past a tool position the reed switch is activated. The motor is then reversed. It rotates backwards until it hits the pawl then lowers onto the locking pin.

I'd advise against this type of changer for the following reasons.

1. Long tools such as boring bars are problematic as they hit the AC motor or possibly the work piece.
2. There is the possibility for swarf to get under the mechanism when it is raised and rotating. This will stop it seating properly.

A vertical rotating changer seems the best option.

Cheers,

Peter.

[LeeWay]

Peter, that is one I haven't seen before. Thanks for posting. I tend to agree about the functionality of just the standard tool post. Even though it is 4 position, I often had trouble with clearance and only two tools mounted.

I would like to be able to use 4 tools minimum. Thinking about using a 6" rotary table. That may actually be too big though. I haven't worked out the final height yet for the cross table surface. I have to mill the parts flat and remove the dovetails off the bottom of that cross table.

Since I am going to setup initially with gang tooling, I think a 4" rotary table would leave me some room to mount another tool or two on that table beside the tool changer.

For my main production parts that I make in brass, I only need 3 tools. Center drill, drill and cutoff tool. I might like to knurl these little parts too, so there is the 4th.


I was thinking that on a ratcheting design, it would need to turn in one direct for tool position and then turn back to lock the pawl tight. The little tool changer you show does that. I am thinking that a macro in Mach 3 might give me the same functionality. I haven't researched that part yet. Mach is usually a learn as I go thing. Research what I need to do when I need to.
Thanks.

[hesham morsy]

:wave:
http://www.cnc-projects.de/index.html


http://translate.google.com.eg/trans...ial%26hs%3DDtw


http://www.dumpstercnc.com/projects/...ed_lathe_2008/

[svenakela]

Wohooo!

I still get surprised how nice setup people build. The Dumpster lathe is one a piece of machine!

@Phomann, a CNC lathe can move the tool post away before changing, and your solution is so nice and simple for that purpose. I like that it can be built around standard parts.

[H.O]

I'm sorry for not contributing to the thread but holy cr*p, that dumpsterCNC lathe was one nice looking machine. I hope it performs as well is at looks. Never seen it before - very nice work indeed.

[phomann]

Wohooo!

I still get surprised how nice setup people build. The Dumpster lathe is one a piece of machine!

@Phomann, a CNC lathe can move the tool post away before changing, and your solution is so nice and simple for that purpose. I like that it can be built around standard parts.

Hi,

The problem is that a long tool bit (boring bar) hits the tool changer motor. (Doesn't matter where the changer is positioned)

Cheers,


Peter.

[hesham morsy]

:wave:

http://www.issintl-inc.com/latheturret/
plans
http://www.cnczone.com/forums/showpo...7&postcount=13


http://www.cnc-projects.de/Downloads...r-komplett.zip

[svenakela]

Hi,

The problem is that a long tool bit (boring bar) hits the tool changer motor. (Doesn't matter where the changer is positioned)

Cheers,


Peter.

That's not a problem on the tool changer I'm thinking of, there's a lot of space for the motor. The tool post sits much higher than yours, it seems.

[LeeWay]

Thanks for those links. Good stuff. I had seen some before, but not the Dumpster lathes. Those are very nice.
I am curious if these was any resonance or vibration on his slant bed lathe?
I didn't see much on it to dampen those.
Thanks guys. Keep the info coming. Seeing lots of new stuff.

[truckwiz]

Hi,
I'm thinking about building a lathe like this one, how hot would you have to heat up a weldment to destress it from welding it together?

Brian

[LeeWay]

I am not sure at what temp to do this at. I was thinking about 750 F just from memory though. That isn't always accurate. Sometimes not even close to accurate.

There is another build log here where I think this was discussed.

http://www.cnczone.com/forums/showthread.php?t=51688

Somewhere toward the end of the build so far.

[BobWarfield]

A couple of thoughts.

First, gang tooling is faster and easier to build, though less nifty than a turret and requires some savvy programming. It seems particularly ideal when you have minimal clearance on a small lathe.

I have some notes on gang tooling here:

http://www.cnccookbook.com/CCLatheCNCGangSlide.html

Second, be sure to check out Widgitmaster's article on adapting a Hardinge turret top to his lathe:

http://www.cnczone.com/forums/showth...t=lathe+turret

Those turret tops are used on the Hardinge CHNC lathes, for example, so they make a fine starting point for a nice turret. Rather than raising the turret, the locking pin can be driven by air pressure, which is what Widgit shows in his manual lathe version. A compressed air lock and a stepper-driven rotator and you'd be in business.

I was able to get a Hardinge turret like that on eBay for $75, but I still haven't put it to use. Very nicely made!

Best,

BW

[LeeWay]

Thanks, Bob.
Especially the PDF. Lots of tool holders there.
I actually ordered a QCTP from Enco. I will use it and then build my own center drill holder and drill chuck holder. My production parts are very simple.
Center drill, peck drill and then the cutoff tool turns the rest and cuts the parts off.
The QCTP should give me lots of flexibility for turning other stuff. That should get me up and running.
I will then later decide whether a turret is even needed. I have about 5" of travel on the X, so should work decent for a small lathe.