Transitron eventually consolidated its manufacturing in New Mexico,
and sold all of its plant facilities east of the Mississippi to
Sparton Electronics.
The Florida engineers spun off their own transformer companies, most
of which are still doing well.
LLoyd
Probably from me -- and this only applies that I am sure of for
the BOSS-3 through BOSS-6 machines. BOSS-8 had moved to servo motors
instead of steppers, and are probably easier to run from single phase
(except for the spindle motor, of course.)
Looking at the manual chapter which you posted a link to, this
appears to be for the later ones, with a single power supply providing
128 VDC for all three axes from a single power supply -- thus it is
probably running servo motors and servo amps (the "Motor Drive Module
Assemblies"). This one will be easier to convert than the BOSS-[3-6]
machines are.
The BOSS-[3-6] machines have a *big* three-phase transformer,
providing lower voltage AC to each axis motor electronics from a
different phase.
Each phase goes through a saturable reactor (mag-amp) and a
bridge rectifier to a filter capacitor to provide power to the stepper
driver for that axis. When stopped and stepping slowly, there is no
current through the control winding of the mag-amp, so the voltage
reaching the rectifier and filter capacitor is reduced to about 50V DC
or less out of the filter. However, when stepping rapidly, a DC current
is fed through the control winding, lowering the inductance greatly, and
getting more of the AC through the bridge rectifier through to the
filter capacitor (and the stepper drivers and motor). This produces an
80V power to the stepper motors to overcome the inductance of the
stepper windings.
The stepper motor machines have big cooling fins on each stepper
motor to deal with the heat from the current. The servo motors are just
plain cylinders with brush caps sticking out.
At least on mine, the contactors are mechanically interlocked.
Actuate one (with a short pulse of AC) and the other drops out before
the first closes.
IIRC, the contactor coils run from 120 VAC (developed from a
large step-down transformer which powers other things as well), and they
are controlled by a 24 VCD coil relay plugged into an octal socket in
the computer rack on the opposite side of the machine itself. (There
are three boxes -- high power on the back, electronics on the right (as
seen from the operator's position, and the interlocked reversing relay
in another box on the side which also contains an outlet for a coolant
pump, and another outlet for an operator's light.
If you are running the spindle motor from a VFD, you want to get
rid of the interlock reversing relay, and give low-voltage commands to
the VFD (easily derived from the relay which switches the reversing
contactor.
I really should scan all of what I have for the older machines
and send to you -- but too many of the pages are too large for me to
scan reasonably, and I'm having problems getting the just acquired SGI
computer (which comes with scanning software) to talk to the SCSI
interfaced HP Color Scanjet 5c. (It is expecting a Scanjet IIc at best,
I think.) The manual has gazillions of fold-out schematics too big for
my scanner.
No reversing contactors should be between the VFD and the spindle
motor. The VFD should receive commands to stop or to run forward or
reverse -- at the 5V or 10V level.
It all depends on which version of the BOSS series he has. If
it is BOSS-3 through BOSS-6, then things are more difficult. If it is a
BOSS-8 or later, things are easier, and match your manuals. And your
chapter 4 is a *lot* shorter than mine. :-)
Enjoy,
DoN.
--
Email: < snipped-for-privacy@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
Nope. One AC supply runs off one 240V phase, a DC supply runs off a
second 240V phase, and the motor runs off all three.
...snip
True, but I still have to rewire the main harness to get both internal
supplies on one phase.
or in
Unfortunately, it's also about four to eight times the cost for that
VFD than what my RPC (locate OUTSIDE the shop, and thus "silent")
would cost.
Oddly... even the folks who sell retro-fit kits for the R2E4,
converting them entirely to new electronics, don't seem to want to
mess with the spindle motor. They sell VFDs. They recommend an RPC
for that machine. (?)
LLoyd
Yep, they are two seperate single phase transformers, they each connect
to your 240V input. They were only connected to seperate phases on the
three phase supply to better balance the load on the three phase and
lower the amperage requirements.
That's just a few wires, 30 min of work.
The used VFDs I got from Iggy for $100ea would do it. New ones for a 2hp
spindle are a couple hundred dollars.
Don't know, haven't seen their retrofit packages.
From Iggy's docs, there is nothing special about the spindle motor. The
speed control setup is funky and probably not worth messing with, but
that in no way precludes the use of a VFD set for simple 60hz output to
power the spindle motor.
I spent some 5+ years doing CNC service BTW, however, the machines I
worked on were generally newer. How far are you from Dallas anyway?
Assuming that it is not like the Bridgeport Series 1 BOSS-3
through BOSS-6. Those have a *big* three phase transformer in the back
power box, with each phase separately feeding a saturable reactor and a
bridge rectifier and filter capacitors. These three supplies power the
three large stepper motors. The power needed by these steppers is
sufficient tha they felt that they needed to spread it out over the
three phases. The actual computer and lower power driver circuits are
all derived from a single phase as you describe below.
Later versions, starting with the BOSS-8 used servo motors, and
were not nearly as power hungry, so they could be driven from single
phase except for the spindle motor.
Unless it is an old stepper motor driven axis machine, in which
case it may indeed be using the full three phases to power those
electronics.
An imbalanced (voltage mode) RPC can fry the power transistors
driving the stepper motors on this old design, so if you use a RPC, you
need to take care to balance it beforehand -- at least with the
BOSS-[3-6]).
Enjoy,
DoN.
--
Email: < snipped-for-privacy@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
you
BOSS-9, Don. Pete was right in all respects, except that the two
internal supplies do run off two phases. But they certainly can be
made to run off one. The BOSS-9 R2E4 is all servo driven, and not
power-hungry, at all.
LLoyd
You can use a series of motors to get the capacity you need. If you
want, you can do a sequenced start where one motor comes on line, use
that one to start the second, the first two to start the third and so
on. As long as the combined HP of the on line motors is significantly
more than the newest one to come online, you can just run the new one as
a pure 3 phase motor. Since you are starting them off the previous
motors, you do not need to mechanically couple them. It does make sense
to couple the first one or two to a single phase starting motor.
The downside of all this is the extra motors, extra switching, extra
space, extra noise, extra power losses, and general hassle. Used 3 phase
motors are cheap. If the windings are ok, the only thing that goes wrong
is the bearings, cheap enough to replace.
Lloyd E. Sponenburgh wrote:
On 2009-01-19, Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:
Absolutely. No need to couple them mechanically.
I have a phase converter with two idlers, which has a lot of benefits
and no drawbacks. My idlers are 10 and 7.5 HP respectively. Using a
lot of 1-3 HP motors would be messy, but not really electrically
infeasible.
What were you quoted on a 7.5 HP motor?
Would you be interested in a new Reliance 10 HP motor?
I do not think that in a HSM context, you need a new motor for an
idler. Even used motors have thousands of hours of service ahead of
them, and phase converter does not load the bearings with anything
besides the weight of the rotor.
--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
Might be, Iggy; How much? (and how to ship economically?)
I love the old RE designs. They last forever. I have a 1968 RE 1HP
TENV motor on a powder granulator that is still running as quiet and
strong as it did new, and it's never had _anything_ done to it.
Are the 'new' ones as beefy as the 60's vintage motors? I re-painted
the '68 one a while ago, and it weighed in at just under 90lb. A new
one on another machine (of other manufacture; I think GE) weighed
about 60.
Yes, I know I don't need 'new' motors, but I can get 3HP NEW Dayton
motors for under $50, and with aggregate shipping, about $10 apiece to
ship. I already have two (only one working as an RPC right now_), and
they work fine with my 2HP spindle motor, even though the rotating
mass on the new motors is MUCH lower than the older designs.
LLoyd
On 2009-01-19, Lloyd E. Sponenburgh <lloydspinsidemindspring.com> wrote:
This is that sort of thing, in a cardboard crate (plywood
bottom). TEFC motor. 10 HP.
$200 plus shipping, it is UPSable. Figure about 130 lbs weight.
This motor was never unbolted from plywood.
As I said, I think that if you look and find a used super cheap 10 HP
motor, for say $40, you will be fine with it for your phase converter
application, essentially forever. And no shipping to pay if you find
locally, at some tired guy's warehouse, hidden in layers of dust and
other crap. Given current economic environment, scrap price and
general fear level, you should be able to do that.
But, if you want new, my offer will stand for a week or so.
I am pretty sure that it is over 100 lbs, with the box but the box is
not much.
I would love to sell this motor to you, but in my honest opinion it is
overkill for what you want. Find some garbage used motors and that
will work just as well.
Just one more disclaimer, the motor I have is under a pile of stuff,
and there is a very small chance that I either do not have it, or it
is not 10 HP, but my memory is pretty good in this instance.
--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
On Mon, 19 Jan 2009 09:13:26 -0600, "Lloyd E. Sponenburgh"
<lloydspinsidemindspring.com> wrote:>Bob, I've got a theory question I might put in practice, if I've got
As far as Im aware..and do this in my own HS...multiple motors simply
add to the capacity.
My big 7.5hp Clausing 1500 didnt want to start on the 5hp RPC, but Id
turn on the MasterMill and the HLVH, leave them running and the Clausing
would fire right up.
Gunner
Clausing
Sure... "no load" is the operative principle, though. Both the other
machines are acting as idlers. If you loaded the first two machines,
I'll bet the third wouldn't start.
LLoyd
Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here.
All logos and trade names are the property of their respective owners.