Author Topic: New mill, to me that is!  (Read 3670 times)

Offline Hugh Currin

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Re: New mill, to me that is!
« Reply #30 on: June 10, 2020, 04:08:58 PM »
MJM460: That's possible since I can't figure where it came from. Thanks.

Bill: So it is a cnc. Would that be 2 axis? I don't see any motor on the Z.

John mentioned jogging and hard interrmitent use being detrimental. I've run into a conundrum putting a VFD on my lathe which seems to fit this thread. My lathe has a go forward and go backwards lever near the apron. This activates, through a twisting rod, either a go forward or go backwards switch(s) near the head stock and control circuit. There is also a brake and latching switch plus a jogging switch. Now, one of the nice features of the VFD is a soft start, it ramps up to speed and avoids the large inrush current. If I just wire in the 3P power from the VFD this ramp up won't work. When energized the VFD ramps up to full speed but nothing will be connected. When a switch, such as go forward, is engaged it will draw an inrush current starting the motor.

I'm just starting to find ways around this. One option is to wire around the control directly to the motor. I can do without jogging, would miss braking, but really miss the go forward/go backwards lever. I can just ignore the jogging switch. The brake is somewhat redundant. The VFD ramps down speed when asked, but is a ramp down rather than a coast. Thus the brake would be working against the VFD. Probably use the brake switch for "off" and wire this to the VFD to start the ramp down, but latching may require some of the original control. I may be able to wire in the go forward/go backwards switch to the VFD, using ramp up and down for start and stop. Anyway, I'm off to RTFM.

The mill was easy, one go forward/go backwards switch directly to motor. The lathe is proving to be a little more complicated.

Art: I hope you find this of some use and I'm not just drag the thread into a rabbit hole. If your mill is like mine it will be fairly simple to add a VFD.

Thanks.
Hugh

Offline john mills

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Re: New mill, to me that is!
« Reply #31 on: June 10, 2020, 10:54:41 PM »
these functions need to be done by the vsd there should be remote inputs that can control the vsd  and the
functions of the vsd do these functions  .the vsd parameters can then set so all function done by the vsd  should  be able to program the vsd and  the remote control inputs  all the functions done by the vsd.ramp up braking  reverse  ramp down  done by the VSD  no longer done by the original mechanical devices.No switching after the VSD.

Offline gary.a.ayres

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Re: New mill, to me that is!
« Reply #32 on: June 11, 2020, 12:33:54 AM »
Great looking mill!

Offline Art K

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Re: New mill, to me that is!
« Reply #33 on: June 11, 2020, 12:55:46 AM »
Bill,
Yes it is ProtoTrak MX2, the only problem with that I can see is that to save a program I have to save it onto a 3.5 inch floppy drive, I have two formatted discs. On a happy note the Supermax mill at work is 3 Phase and my boss is fine rewiring it to plug into both machines. Saves money for a vise I guess.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Dave Otto

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Re: New mill, to me that is!
« Reply #34 on: June 11, 2020, 01:10:22 AM »
Hi Art

There are emulators that will allow you to use a USB thumb drive in place of the floppy, to the computer it looks like a floppy drive,  but the magic happens in the devise that allows the PC to write to the thumb drive. This may be an option for your controller. My first CNC control (AhHa) used only a 3.5 floppy drive, about the time I built my new servo box and switched to Mach I learned about this option. AhHa has a loyal following and there are still lots of systems in use. I sure don't miss those floppy discs. :Lol:

If your controller doesn't use a PC well all bets are off. :lolb:


Dave

Offline yogi

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Re: New mill, to me that is!
« Reply #35 on: June 11, 2020, 03:59:34 AM »
Nice score on the mill!  :cheers:

There are also external 3.5 floppy drives available that plug into a USB port. I have been using one to transfer programs to my Milltronics lathe without problems. (And you can back up the parameters).


Offline Art K

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Re: New mill, to me that is!
« Reply #36 on: June 11, 2020, 03:59:59 AM »
Dave,
I may have to send off an email to SWI to find out. Although it may not be a problem at all. I am wishing work would slow down enough to catch my breath though. It may be a bit till I can clear up the spot where it will go. I still need it running to figure out how to use it.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Art K

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Re: New mill, to me that is!
« Reply #37 on: June 11, 2020, 04:03:15 AM »
Yogi,
It isn't a PC based system as far as I know. I'd have to check but I don't remember seeing a usb port.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline yogi

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Re: New mill, to me that is!
« Reply #38 on: June 11, 2020, 04:54:20 AM »
The external floppy drive plugs into your computer, then you can keep using floppy discs to transfer programs.


Offline Art K

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Re: New mill, to me that is!
« Reply #39 on: June 11, 2020, 12:40:24 PM »
Yogi,
My desktop is old enough and I have retained the floppy drive. Though I think I've used it a grand total of twice.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline awake

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Re: New mill, to me that is!
« Reply #40 on: June 11, 2020, 01:17:47 PM »
I've run into a conundrum putting a VFD on my lathe which seems to fit this thread. My lathe has a go forward and go backwards lever near the apron. This activates, through a twisting rod, either a go forward or go backwards switch(s) near the head stock and control circuit. There is also a brake and latching switch plus a jogging switch. Now, one of the nice features of the VFD is a soft start, it ramps up to speed and avoids the large inrush current. If I just wire in the 3P power from the VFD this ramp up won't work. When energized the VFD ramps up to full speed but nothing will be connected. When a switch, such as go forward, is engaged it will draw an inrush current starting the motor.

I'm just starting to find ways around this. One option is to wire around the control directly to the motor ...

Hugh, if I understand correctly (always a dangerous assumption!), a VFD has to be wired directly to the motor. Let me hasten to say that I don't know this from personal experience - just that I've read discussions where people have chosen a rotary converter rather than a VFD precisely because they wanted to keep the original controls. I think this may especially have applied when the machine in its native form included a 3ph to 1ph transformer for some of the control circuitry.

As John says, you can likely replicate some (most? all?) of the controls through the VFD itself.
Andy

Offline Hugh Currin

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Re: New mill, to me that is!
« Reply #41 on: June 11, 2020, 04:09:30 PM »
Art: If I'd only known, I threw out dozens of 3 1/2 floppies a few years ago. I still have one drive but it hasn't been in a computer for years. But for your machine, if you tire of working with floppies or the controller goes belly up, you can replace with a new computer and modern control. You'd be way ahead of the game already having ball screws and motors on the machine. Probably could save the motor drivers. Another possible down side to the old controller is memory. It may not have enough memory for complex parts. Great news about getting three phase power for it. All in all, a great find.

John & Andy: I didn't consider this too much when I ordered the VFD, just made sure it was OK for running the spindle motor. But after some consideration I think you are both right. At the least I'd lose all the nice features of the VFD by just plugging in to the machine with original controls. At worst the inrush currents when the motor started would fry the VFD. But I've found a mode in the VFD which will operate with two switches, one go forward and one go backwards, plus one E-stop switch. I've tracked down the go forward & backward switches in the original control and isolated them. Now I'll track down the brake switch for an E-stop. The brake isn't critical as the VFD ramp down can be much quicker than a coast down, the reason I've previously used the brake. I'll need to move from the keypad on the VFD to all hardwired controls for this mode to work. Thus I need to add a potentiometer, on order, for speed control. This is going to be a nice machine, maybe it wasn't stupid to drag the 2500lb beast from Oregon to Arizona. (Although my wife is convinced of this stupidity.)

Thanks.
Hugh

Offline BillTodd

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Re: New mill, to me that is!
« Reply #42 on: June 11, 2020, 06:14:10 PM »
Bill,
Yes it is ProtoTrak MX2, the only problem with that I can see is that to save a program I have to save it onto a 3.5 inch floppy drive, I have two formatted discs. On a happy note the Supermax mill at work is 3 Phase and my boss is fine rewiring it to plug into both machines. Saves money for a vise I guess.
Art

I have fitted mine, and my brother's, with usb floppy adapters (cheap enough from ebay) they're a bit of a fiddle (they use an obscure German pc app to configure the USB stick as multiple floppies) but work perfectly.

Re Vfd yes these should be wired directly to the motor ( All my machines have VFDs and I've converted several other ones)
« Last Edit: June 12, 2020, 12:56:45 PM by BillTodd »

Offline Elam Works

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Re: New mill, to me that is!
« Reply #43 on: June 11, 2020, 07:41:05 PM »
There are also USB adaptors like Calmotion (which I use on my Haas) and CalMAN (which seem to be little more than a adaptor cable) that adapt between USB and the RS-235 port. Good if your controller does not even have a floppy, or (like Haas) charges an ridiculous amount for a floppy/USB controller card. The configuration is the basic RS-235 settings, the downside is they are slow as you are limited to the RS-235 max transfer rate of 9600 baud. As with many things, speed cost more money!

Saves from having to keep floppy disks around, and you can use the more common (presently) USB stick.

-Doug

Offline Mcgyver

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Re: New mill, to me that is!
« Reply #44 on: June 21, 2020, 01:11:05 PM »
Congrats on a solid looking machine

I'm not an electrician, but I've built RPCs, installed VFDs, wired my shop for 240 and 600V 3P, hooked up tons machines at home and otherwise and some of the info here, not sure its spot on and its not the best area to blunder forth on, damning the torpedoes.  The motor is a 3 phase 3HP, says right on it C.V more less equals HP.  If in doubt, look at the amps and volts:  10 amps x 230 V = 2300 watts.  A HP is about 750 watts so 2300/750 = 3

Your 220/240 in the house is not 2P, its single phase.  230V 3P has 230 between each phase.   A "phase" isn't the wire, its electrical potential between two wires.  When you are looking at delta diagram for example, a triangle....the points are the wires, the lines are the phases.  Don't be tempted to change the motor out - 3P is better.

The common way to get 110 1P on 3P machine is to use a transformer with 2 of the 3P wire into it.  Really no other way, all the 3P wiring I've seen doesn't carry a neutral.   This of course won't work if power by a VFD (you don't have 3P coming in)....but since you are wiring the  VFD from 240 1P, carry a neutral with it then you have 120 1P right there.

You don't want to use controls between the VFD and motor.  However most VFDs have connections for low voltage external controls.  Rewire the mill controls that way and full functionality is maintained.

The delta and Y come into the internal wiring of the motor - whether its hooked up for 230 or 460V.  The motor can be run on either depending on how you hook up it.  It should be standard, follow the diagram inside the peckerhead (yes, that what they call them) and if there's no diagram you can figure it out with a multimeter.  Its always delta for the low voltage connection (230) Y or Star for the high (460)

For your mill,  if you don't have 3 phase, run a 240 1P line.  Get a VFD.  Nowadays its easy to find 1P in 3P out vfds, so one rated for 3HP will do.  You can use 3Pin  to 3P out, but you have to overrate the VFD so the DC bus can handle it - i.e. run 240 1P in to a 3P in 5HP VFD to power a 3HP 3P motor. 

If in good shape, keep the mechanical speed reduction.  I've the same kind of drive on my XLO and its a great drive, superior to a vfd for speed control.  VFD's will reduce the speed with constant torque, but you don't want constant torque on a machine, you want constant HP!  (i.e. torque increases as speed goes down)

One other tip on the USB thing....a floppy emulator can work, but partitioning can trip you up.  You often have to make partitions on the USB the same size as the floppy or the old controller can't read it.  bit of pain went into learning that tidbit :)
« Last Edit: June 22, 2020, 12:40:12 PM by Mcgyver »

 

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