Looking to link the carriage to the headstock spindle

[MR.20C]

I am in the midst of trying to figure out how to do this. I would like to have the headstock spindle (linked ) to the carriage on the bed. I was sent an E-mail from a member of another forum and had mentioned cnc-ing this lathe. My thinking is this: If I can get 2 servo motors linked together through processing unit for both and manipulate that through software I think the possibilities are almost limitless.
Are any of you familiar with servo motors/processing units and software as far as cnc conversions. I know this can be done but my problem is i don't know what I am looking for and am not educated in this area, as far as what power to look for in a servo motor, what processing unit would work. I have an X axis (headstock) and a Y axis (carriage) I also could add a third probably to the in-feed to the material Z axis (cutting tool or router.
I can have my machinist make the necessary parts- that is not the problem, what is , is where to go? I originally was going to do this mechanically linked , and may still have to do that , but this idea has sparked my interest.
If any of you have any knowledge about this I would really appreciate any feedback you can give me, at least I will have a place to start.
thank you,
Brian

[MR.20C]

Here is the lathe: Oliver 20C pattern lathe, I have totally refurbished this lathe from the ground up , including the drive system for the headstock (transmision is in the belly) any help would be appreciated.
THANK YOU
Mr.20C

[Al_The_Man]

In a manual lathe this is done with back gears for threading, which I assume you want to do with a CNC lathe.
It is normally done by fitting an encoder on the final spindle shaft, and the Z axis motor is geared off of this encoder, it is done in this order, because the spindle is usually not so precisely controlled as a servo.
To achieve this, you need a controller that has the gearing capability.
Incidentally this encoder is also used with the X axis infeed to provide CSF by increasing the speed of the spindle accordingly.
One method is to pick up one of the Legacy motion card from ebay like Galil and use the basic communication s/w, this is the cheapest, but does not have fancy HMI etc.
Al.

[MR.20C]

Do you need more photo's of the headstock ? I really need some help on this. I don't know where to start- honestly.. I am not comp illitereate but I do need to know what i have to have to make this work. Do you have a diagram (rough of coarse) of what motors/encoders/controllers on the setup ?
Thanks
Brian

[MR.20C]

Originally Posted by Al_The_Man In a manual lathe this is done with back gears for threading, which I assume you want to do with a CNC lathe. It is normally done by fitting an encoder on the final spindle shaft, and the Z axis motor is geared off of this encoder, it is done in this order, because the spindle is usually not so precisely controlled as a servo. To achieve this, you need a controller that has the gearing capability. Incidentally this encoder is also used with the X axis infeed to provide CSF by increasing the speed of the spindle accordingly. One method is to pick up one of the Legacy motion card from ebay like Galil and use the basic communication s/w, this is the cheapest, but does not have fancy HMI etc. Al.

Al,
I want to do twist rope and maybe some other things - no metal threading.I do column work (large) column work I might add. 24" in diamiter and up to 105" long. I would like to be able to flute twist on this lathe.
thanks
Brian

[Al_The_Man]

You may get away without a variable speed spindle motor, I see you have a (1ph?) AC motor with belt reduction?
If you can use manual infeed on the X then you would need just a Z servo motor, otherwise one on each.
Here is a link to some of the animated applications using Galil, especially the flying rotary shear similar to what you are looking for.
http://www.galilmc.com/support/motioncode/index.html
Al.

[MR.20C]

Originally Posted by Al_The_Man You may get away without a variable speed spindle motor, I see you have a (1ph?) AC motor with belt reduction? If you can use manual infeed on the X then you would need just a Z servo motor, otherwise one on each. Here is a link to some of the animated applications using Galil, especially the flying rotary shear similar to what you are looking for. http://www.galilmc.com/support/motioncode/index.html Al.

Thank you for your help Al - I really appreciate your input! the headstock spindle and the travel on the carriage must be linked. My drive system is not 1ph it is a Baldore induction motor: 220V 3 phase - 3 hp f class. My lathe is controlled by a Yaskawa Variable frequency drive rated for 7hp-3ph. I don't think what your proposing will work correctly, although I am really not to sure where you are going with this thought?
This is all new to me Al , I understand the process, but I do not understand what application will work better,and thank you for the hyperlink but I don't know what application will work, for instance- i don't know what a Z servo will do- ?what I do know is that I need one to move the carriage down the bed, and the other to turn the Headstock spindle, what servos or axis is all new to me. I can have my machinist make any gear/part that I need and then attach it to the headstock spindle for linkage with the servo / step motor ( i don't understand the difference between the two- maybe you could elaborate on that), anyways ~ as well as the carriage gear for the travel on the bed. would both servos be able to accomplish this in sync to do a helical pattern and any others that I would be capable of doing such as a leaf pattern? the third part in this is the stops for the carriage. Example:
I have an 8' column 20" in diameter. I know I want to do a helix flute (twist) on this column , but it needs to be a "Stop Fluted" column - the profile stops 1~2" away from either end instead of carrying the profile all the way through the entire length. that is another process in this that would have to be implemented. I look forward to hearing form you,
Thanks again Al,
Brian

[Art Ransom]

First step is what is your long term goal. If like me you want it for the long run then you need to start from scrach. If you want a CNC machine for routing flat work and also be able to do lathe then my machine is what you want. Also I would hate to see you ruin the beautiful Oliver. If this is just a low use machine then get a book by Taton Press called Router Magic and it will show how to make a manual machine to do the job.
To cut wood cleanly the cutting tool must have a high cutting speed. This is acomplished by your Oliver by spinning the wood at a high speed but requires a masive machine to withstand the torque. My machine uses the cutting speed of the spindle and doesen't spin the wood a high speed and therefore doesen't need the mass to keep the stock from walking across the shop.
There are a lot of other considerations and I would be glad to discuss them with you. You can call me 972-227-2741 from 0800 to 2000 7 days. As complex as the project seems all you have already passed the hardest part in that you have the desire to get it done.

[MR.20C]

Thanks for getting back to me. I don't think I made my statements very clear. The carriage has a wide verity of cutting tools and the router is not used for any of that process (rounding) the only reason I want the router is for fluting and some design work. 2 axis I believe. As far as ruining my Oliver - that will never happen I just spent over a year refurbishing it. I have replaced the old Babbitt bearings with 4 high speed/ high thrust bearings and a new index wheel. The drive assembly has totally been repositioned and redesigned.
Hand sculpting is only done on fine areas of detail , such as rings or curves. I enjoy that part very much and is very creative individually for me. I do not want my router doing this. I have included the forum where this whole refurbishing process on the Oliver 20C .
Art, do you have any idea of what I would need- step motors/ encoders/cards and software? Just some place to start.
thank you Art.
Brian


here is the thread : http://www.sawmillcreek.org/showthre...ghlight=oliver

[Art Ransom]

I suffer from Oliver envey! Here is the manual solution I use with my Powermatic.
http://www.turningaround.org/7LargeColumnBase.htm
Use the same idea but add gearing so that the Oliver can run the router back and forth. You could make the frame so it attaches to the Oliver and have the carrier asembly swing back out of the way when not in use.

[MR.20C]

Art,
That's a neat concept, and reminds me of the legacy ,however, that is not the direction I want to go. i definitely want to bring this Oliver out of the prehistoric age and up to modern standards - as your lathe that you built is and can handle fluting through todays modern technology. I'll keep prodding here - Thank you,
Brian

[Al_The_Man]

Originally Posted by MR.20C the headstock spindle and the travel on the carriage must be linked. My drive system is not 1ph it is a Baldore induction motor: 220V 3 phase - 3 hp f class. My lathe is controlled by a Yaskawa Variable frequency drive rated for 7hp-3ph. I don't think what your proposing will work correctly, although I am really not to sure where you are going with this thought? This is all new to me Al , I understand the process, but I do not understand what application will work better,and thank you for the hyperlink but I don't know what application will work, for instance- i don't know what a Z servo will do- ?what I do know is that I need one to move the carriage down the bed, and the other to turn the Headstock spindle, what servos or axis is all new to me. Brian

You have to decide whether you want to go mechanical or electronic, the link showed examples of almost exactly what you want to do, electronically i.e. Synchronize the carriage movement to the spindle rotation?
I am assuming that what you want to do is very little difference from threading in a CNC application.
As I mentioned earlier, an encoder on the spindle would be used to electronically gear the carriage (Z axis), if neccessary with live tooling.
This would exactly replicate the mechanical method but implement it electronically.
Even with using the Galil and programing with native commands is not a trivial undertaking, as will be the case with any other electronic method.

Originally Posted by MR.20C I have an X axis (headstock) and a Y axis (carriage) I also could add a third probably to the in-feed to the material Z axis (cutting tool or router.

BTW, in CNC terms, the X axis is the cross slide, (radial to the chuck) the Z axis is the carriage (axial to the chuck) and if the spindle is used as a rotating axis or is referenced to the Z for example, it is the C axis (rotates around the Z)
Al.