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Author Topic: Lathe turret toolchanger  (Read 10891 times)

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Offline DAlgie

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Lathe turret toolchanger
« on: March 06, 2006, 05:36:47 PM »
In the process of converting my 13 by 40" manual lathe to CNC control, I am considering building a turret toolchanger for it. probably a disc type with 5 or 6 tool stations. I would drive this with a geared down stepper motor, and lock it with a solenoid- pin arangement. The pin would also have a microswitch to tell Mach3 that the change is complete and to continue on with the program. Questions are; what capability does Mach3 have for this? I would drive the stepper in certain increments to the next tool needed, this would obviously change as a multiple of the station seperations if the tool needed was not the next one on the turret. Would need to set timing to unlock the pin, determine that the pin is actually unlocked, then drive the stepper to the called out tool station, then stop there and plunge the pin back in and determine that the pin is locked. So, two microswitches for both lock pin positions needing two data pins in the parallel port, and drive the stepper motor certain amounts of steps. Possible? Thanks in advance.
Re: Lathe turret toolchanger
« Reply #1 on: March 07, 2006, 06:37:13 AM »
This can be done and others have done it in the past :) There is some VB that you will have to do to get it running but we will help you with that.
Looks like you are having fun !
« Last Edit: March 07, 2006, 06:37:15 PM by Barker806 »
Fixing problems one post at a time ;)

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Offline DAlgie

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Re: Lathe turret toolchanger
« Reply #2 on: March 07, 2006, 04:45:38 PM »
Great to hear, this was kind of the only real stumbling block to go ahead with it. Attached is a screenshot of the turret disc, I went with an eight position one as it all fit on an 8" diameter disc after all. Time to go find some applicable hardware for it then....

vmax549

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Re: Lathe turret toolchanger
« Reply #3 on: March 07, 2006, 10:52:22 PM »
Dalgie. It looks Good. You might want to take a look at how you are going to tap the holes for the setscrews for the Square toolbits. Please keep us up to date on your project. Thanks Terry

Offline DAlgie

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Re: Lathe turret toolchanger
« Reply #4 on: March 08, 2006, 12:59:44 AM »
Yes, you're right, I'll have to clearance some more above the set screw block area for tapping, I just drew this up late last night in about 15 mins so I didn't do too much thinking.... Got to go find a large solenoid for the lock pin somewhere...

vmax549

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Re: Lathe turret toolchanger
« Reply #5 on: March 08, 2006, 09:25:26 AM »
Have you thought about using a rachet style mechanism to lock the head. It will rotate freely in one direction and lock up solid in the reverse direction.  Just A thought.
(:-) Terry

Offline DAlgie

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Re: Lathe turret toolchanger
« Reply #6 on: March 08, 2006, 12:51:03 PM »
Well, I was sort of copying an italian design we had on our Clausing storm lathe with the lock pin. I have seen the Haas machines, the turret extends a small amount before it rotates, this might be a ratcheting type, not sure if it is bidirectional or not. I had hoped this would be able to be bidirectional so hadn't considered a ratchet, and the Haas type is a bit of a pain to engineer for because the bearing package gets more complex if you want to move the thing in the Z axis direction to unlock at all. Early days though, I'll stare at the solid model for a bit and come up with something as simple as I can yet still be compact and rigid.

vmax549

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Re: Lathe turret toolchanger
« Reply #7 on: March 08, 2006, 02:57:41 PM »
Roller rachet works well

Offline Graham Waterworth

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Re: Lathe turret toolchanger
« Reply #8 on: March 08, 2006, 03:31:17 PM »
Hi,

most turrets move forward to disengage the curvic coupling.  This is like two face gears that lock the turret from moving under cutting load.

Graham.
Without engineers the world stops

Offline DAlgie

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Re: Lathe turret toolchanger
« Reply #9 on: March 08, 2006, 11:47:42 PM »
Hmm, don't understand the roller ratchet drawing you have there. My thoughts on moving the turret disc versus moving a lock pin; the turret and tools attached weigh quite a bit more than just a pin, so you need quite a bit larger solenoid or system to get it to move in any reasonable amount of time. Still, the pin must have a slight taper to actually lock, and this can be difficult to withdraw from it's taper. Thinking of using a large automotive starter solenoid for the pin withdrawal, plenty of power, readily available and cheap to boot...