Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: makcnc on March 24, 2016, 10:47:04 AM

Title: about the dual lathe spindle
Post by: makcnc on March 24, 2016, 10:47:04 AM
hi there
it took alot of time to get back
i'm very happy to join the masters again
here is the new subject
i'm working on a lathe machine and dream to make it with dual spindle
and here is the problems to discuss :
1- auto close chuck
2- the second spindle picking from the first one
3- the cad cam process to achieve ::) that
i have some ideas to talk about bur let's begin from the beginning
by experiences
Title: Re: about the dual lathe spindle
Post by: makcnc on March 24, 2016, 10:50:19 AM
hope the great masters to join and enrich this discussion

 
Title: Re: about the dual lathe spindle
Post by: makcnc on March 24, 2016, 11:07:06 AM
some thing else :
i reed about the g14 code which make mirroring to the g-code automatically do any body know about that and how to activate it in mach3
hope these links help:
https://diy.haascnc.com/g14g15-spindle-swap
http://www.cimindustry.com/article/metalworking/understanding-two-spindle-turning-technology
Title: Re: about the dual lathe spindle
Post by: mc on March 24, 2016, 01:20:11 PM
I'm certainly not the best to talk about this, but I'd say it's not going to work well with Mach3. Mach 3 only supports one spindle, so without some form of logic external to mach, be that a more mechanical/electronic or processor form, along with various macros to control things, it won't work.

I'm sure Mach 4 could manage it, although probably not the Hobby version, however it would be best to post over on the Mach Yahoo Group, as Brian is more likely to respond over there than on here.

Regardless, I'd say you're going to have to do a reasonably amount of custom configuration/programming to implement all the typical dual spindle functions.
Title: Re: about the dual lathe spindle
Post by: makcnc on March 25, 2016, 06:51:45 AM
thank you mc for your contribution
Title: Re: about the dual lathe spindle
Post by: magicniner on March 25, 2016, 06:40:51 PM
I'm sure Mach 4 could manage it,

:-D When it's fully baked :-P
Title: Re: about the dual lathe spindle
Post by: magicniner on March 25, 2016, 06:44:06 PM
The first thing you need is multi-spindle CAM, then you can look at how that might work with the various control packages, LinuxCNC is likely to be a better fit than Mach4 but unless some developer is actually cutting parts on a dual spindle machine support might be sketchy at least.
Title: Re: about the dual lathe spindle
Post by: makcnc on March 26, 2016, 06:19:46 AM
thank you very much
it is a good help
but there is a member whom has made it
and here is his vedio
https://www.youtube.com/watch?v=xyirJ8cPgQo
Title: Re: about the dual lathe spindle
Post by: mc on March 26, 2016, 07:20:16 AM
If you look at that posters other videos, and some of the titles/comments, I'd guess he's using some form of external controller to slave the secondary spindle to the first, and the secondary spindle linear movement is treated as a B-axis.

Using that technique it is doable using any lathe controller, however you're not getting independent spindle control. You always have to have the primary spindle running when you have the secondary spindle running. It will work for most things, although it will use more energy having the primary spindle always running.
And you'd need added complexity if you want to offset the spindle alignment, like in that Hass manual with the example so jaw chucks can interlock/overlap.
Title: Re: about the dual lathe spindle
Post by: magicniner on March 26, 2016, 07:25:32 AM

but there is a member whom has made it


He is using a PLC, essentially a PLC is an industrial automation computer and you would need to know what functions the PLC deals with, what software was written to do this and how the automation is handled from within Mach3, he's using Modbus to communicate with the PLC but his G-Code will have to include stuff to initiate this.
None of this is standard CAM output, you would be able to write your own Post Processor for a CAM system to support the hardware.
I think there are more learning curves in there than you might thnk ;-)

 - Nick
Title: Re: about the dual lathe spindle
Post by: mc 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.
Title: Re: about the dual lathe spindle
Post by: magicniner 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.
Title: Re: about the dual lathe spindle
Post by: Hood 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
Title: Re: about the dual lathe spindle
Post by: makcnc 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
Title: Re: about the dual lathe spindle
Post by: makcnc 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
Title: Re: about the dual lathe spindle
Post by: mc 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
Title: Re: about the dual lathe spindle
Post by: makcnc 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
Title: Re: about the dual lathe spindle
Post by: makcnc 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