Messages

41

Show"N"Tell ( Your Machines) / Re: 1979 Takisawa DTX-1 Turret Lathe

« on: October 29, 2009, 02:09:05 PM »

Thanks for the comments all, I will try to keep posting comments/pics as it comes along.

Hood, The tailstock is powered, hydraulic.  It has ~ 3in of stroke.  I am not exactly sure how it all works yet, but you can basically set the force with a pressure regulator and then run the hydraulics with a solenoid valve.

It will swing 20in over the bed, and there is a 10in gap at the chuck where it could swing something huge, not sure how big.  There is a 2in spindle hole, but with the hydraulic chuck actuator installed it is 1.625.

Thanks you all for looking!
Dustin

42

General Mach Discussion / Re: spindle encoder, VFD, rigid tap, lathe

« on: October 29, 2009, 11:57:20 AM »

Thanks Hood, I realized shortly after posting that a little reading on the rigid taping would've answered that question, I will look into floating tool holders, or just cut the threads with single point tool.

On the gearing in the spindle, there is a high and a low range that is shifted hydraulically via  a solenoid valve.  There are switches that sense lo, hi, and neutral.  The encoder is after the gearshift, so the ratio between it and the motor changes upon shifting.

Dustin

43

Show"N"Tell ( Your Machines) / 1979 Takisawa DTX-1 Turret Lathe

« on: October 29, 2009, 01:00:15 AM »

Hi All,

Just wanted to post some images of the lathe I have been working on for the last few months!  It still needs lots of love, but it is coming along.

Thanks for looking!
Dustin

44

General Mach Discussion / spindle encoder, VFD, rigid tap, lathe

« on: October 29, 2009, 12:16:52 AM »

Hi All,

I am working on a lathe retro-fit and have a few questions about spindle feedback in Mach.  I currently have a little lathe running now on Mach with just a spindle index for feedback into Mach, one pulse/rev.  The spindle motor/drive is a cheap 3HP hitachi, no feedback into the drive.  It works amazingly well for cutting threads...

The big lathe I am working on now has a 15HP DuraPulse Vector drive with the encoder feedback option.  There is a quadrature encoder with an index pulse on the spindle that spins at the RPM of the chuck and there is an auto lo-high in front of that.  I was considering just running the spindle's encoder to the feedback card in the DuraPulse, and the index pulse to Mach3.  I have a few questions about the setup:

1- Is rigid taping on a lathe an option in Mach?
2- Can/should the encoder go to just Mach, just the drive, or both?
3- This is probably more of a question for automation direct, but how will the drive work with encoder feedback after a gear-shift?  I may need to change the way I command the spindle speed based on the ratio between the motor and the drive....  Anybody out there done this?

I am going to try to post some pictures of the machine in the "show'n tell" section if anyone is interested...
Thanks!
Dustin

45

General Mach Discussion / Re: Lathe turret Tool Changer, PLC, VB Scripts

« on: October 29, 2009, 12:06:59 AM »

Thank you for the input, I appreciate it.  I think I might go with the PLC for now, partly just because I want to get more familiar with their operation, etc.  Also, I am concerned that I would not be able to modify the program if I go with the ModIO, is that right Peter?  It is flashed into a PIC and I would not be able to change it?

Hood, you say that you have an AC servo for your spindle, how do you have that setup in Mach?  I was going to go into that here, but it turned into a new topic, called "spindle encoder, VFD, rigid tap, lathe"

Thanks again all,
Dustin

46

General Mach Discussion / Lathe turret Tool Changer, PLC, VB Scripts

« on: October 28, 2009, 12:22:58 PM »

Hi All,

I am working on a Takisawa DTX-1 Turret lathe and am using Mach3 for the retrofit.  I have used Mach on 2 other machines, a small 9X24 lathe and a Bridgeport sized Gorton 1-22 knee mill, but have not needed extra IO.

On this machine there is an 8-position turret (see photo) that I need to get going.  There are at least 9 inputs (8 tool positions and lock/unlock state) and at least 4 outputs (lock/unlock, motor on/off, motor brake on/off, and forward/reverse), just for the turret and things need to happen at specific times.  For instance, the direction cannot change with the motor on, among other things...

I have talked with Peter Homann and he has graciously volunteered to write some custom software for his ModIO card, but I am considering using an Automation Direct PLC instead, mainly so all of the outputs are relay controlled and all of the logic is a nice robust 24V.

So, what I am looking for are some general guidelines on doing this.  I have watched the videos on VB scripting and the modbus, and that all seems fairly straightforward.  Here are specific questions:

1-Would one program all of the timing functions in VB, or would that be done in the PLC "ladder logic" and the VB would just do "something" via Modbus after the M6start?
2-Is Modbus a robust enough interface for a serious machine like this?  With a 15 HP spindle and 2KW servo motors I want this thing under control at all times :-)

Thanks for any help or suggestions!
Dustin
www.protoplant.com