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Author Topic: about the dual lathe spindle  (Read 3601 times)

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Offline mc

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Re: about the dual lathe spindle
« Reply #10 on: March 26, 2016, 02:26:08 PM »
It could be done without a PLC, and I don't see the importance of CAM. The only added complexity of programming a dual spindle lathe, is turning it on/off, and the part swapping.  The actual turning/machining is just like a normal lathe, except the spindle is on the opposite side, so provided you're proficient in programming a standard CNC lathe, you'd just need to consider the part handover and machining from the opposite direction.

If you're happy to have the secondary spindle slaved from the primary (i.e. as I mentioned previously), then all you need is some method to ensure the secondary spindle is synchronised to the primary, and some method of activating the secondary spindle.

Depending on what spindle motors/drive systems you use, you could probably get away without perfect synchronisation.
If you use servos with toothed belts, then it would have to be near perfect synchronisation. I could think of a couple ways to do this, but my personal preference would be a KFlop, as you could program it to do the synchronisation, and activate/deactivate the secondary spindle via some custom M codes/Macros within Mach.

However, if you were to use DC motors, or even two VFD driven AC motors with the VFDs set via Modbus (so you can set the exact frequency on both) connected to the spindles via a non-timed belt (i.e. V or multi-V), then you should get enough 'slip' in the drive system to handle both spindles being mechanically linked during the handover period. All you'd need to do is have a M-code/Macro to connect/disconnect the secondary spindle, which would be as simple as an extra output switching a relay or two.
Off course, that method would mean you wouldn't get repeatable synchronisation, but depending on what you want to achieve, that may be perfectly acceptable. It would certainly work for the parts in those video.
Re: about the dual lathe spindle
« Reply #11 on: March 26, 2016, 02:33:22 PM »
I don't see the importance of CAM.

There isn't any if you want to manually code parts.

Offline Hood

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Re: about the dual lathe spindle
« Reply #12 on: March 26, 2016, 05:20:08 PM »
This would work well with servos spindles and drives similar to the AB drives I use but probably even the Chinese Delta drives would be able to handle it.
What I would do is have the secondary spindle set up as a follower of the main drive, that way it will be perfectly sync'd. I would then have the secondary control method of that drive as Analogue (if using an analogue  capable controller) or   Step/Dir (if Step/Dir controller) , once hand over is complete I would change the second spindles drive to Analogue mode (or Step/Dir mode).

So  it would go like this.
Part turned in main, second not enabled.
Enable follower mode in second spindle drive and do the swap over.
Change second drive to normal command (analogue or Step/Dir) and turn off main drive then swap outputs to second spindles drive and complete the part.

If you werent bothered about both spindles running at the same time it would be even simpler as no change over of command method would be required, just constantly have the secondary spindles drive set in follower mode.


Hood
Re: about the dual lathe spindle
« Reply #13 on: March 27, 2016, 05:48:00 AM »
hi \friends
a thought about the plc
and the good news is
i think he is using a hydrolic chuck
about the motion planing that could be made by analyzing the pick motion in practice
i think there must be some hand made software to calculate the pick position
i hope the member who made it to share his experiences
Re: about the dual lathe spindle
« Reply #14 on: March 27, 2016, 09:58:46 AM »
is it active in mach3 to use g14
and what is its syntax

and welcome to the masters mc and hood
we are hungry to learn

Offline mc

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Re: about the dual lathe spindle
« Reply #15 on: March 27, 2016, 03:36:57 PM »
http://www.machsupport.com/forum/index.php/topic,31419.0.html

Mach3 doesn't support G14, however it can be done via some custom M-codes and macros.

The basic handover process would be-
Activate/synchronise both spindles
Move secondary spindle to chucking position
Clamp secondary spindle
Un-clamp primary spindle
Move secondary spindle to required parting position
Clamp primary spindle
Part-off
Turn of primary spindle (optional)
Move secondary spindle back to machining position
Re: about the dual lathe spindle
« Reply #16 on: March 29, 2016, 10:19:11 AM »
i have a very crazy idea to activate /synchronize both spindles
and will drew it an solidworks  then upload the photos
Re: about the dual lathe spindle
« Reply #17 on: March 29, 2016, 10:24:43 AM »
but tell now we did not talk about the properties of the spindle motor
and how to calculate the cutting force for the machine