[skyguynca]

I am doing a cnc conversion for my g0704, I am also replacing the spindle motor with a 2.8hp 130vdc max 2.6hp 111vdc continous DC motor with a encoder on the shaft. I am going to use the DG4s from cnc4pc to control that spindle motor.

I am using 3 KL23H2100-50-8B
570 oz In. Hybrid Stepper Motor
1.8° /200 Steps Per Rev.
5 Amps Current ( Bipolar Parallel),
8-wire, Bi-polar or Unipolar
1/4" dual shaft

for my X Y and Z axis also with encoder for closed loop.

Using 8070D - Digital Bipolar Stepper Motor Driver 32 bit DSP to control each stepper.

Now I calculate the servo motor for the spindle comes out to 17.8 amps at 130vdc, but most likely will only run at the continous rating of 111vdc at 15.2amps or below, and the steppers max 70vdc but more than likely less than 60vdc.

I have a 1500va torrid with two input coils and 4 output coils, on the website it shows 115vac input on two coils, two 58vdc @ 12.9amps, one 18vdc@2amps and one 12vdc@2amps. It also states it can be 115vac or 220vac.

So if I use 220vac will the output voltages be twice what is shown instead of 58,58,18,12 vdc will I get 116,116,36,24vdc?

Will I have to make two power supplies, one for the spindle 111vdc and the steppers 60vdc ? or if used on 115vac can the outputs of to 58vdc be wired in series to get the 116vdc ? If on 220vdc can the 36 and 24 be wired in series to get the 60vdc for the steppers?

[john-100]

the two primary windings (input coils) have been wound so they they are identical and can be connected in parallel when connected to a 110V supply or
connected in series when connected to a 220V supply so the output voltages remain the same

yes the two 58V secondary windings can be wired in series to get a 116V AC output, when rectified the DC output will be 1.4142 X 116 = 164V
you will need to check the transformer data to check on the transformer regulation
large transformers output is likely to be about 106% off load so the expected 164 V DC could be about 174V with no load
do you have a link to the transformer data ?

you need to use the 58V outputs in parallel to power the stepper drivers
the 12V & 18V outputs are low current windings

you will need two transformers one for the stepper motor and one for the spindle motor

John

[Al_The_Man]

If the spindle motor is DC brushed, look at the KB/Baldor either SCR or PWM.
No spindle transformer needed.
Al.

[skyguynca]

Thanks for the info John, that is what I thought, I just wanted to be sure.

Wiring it for 220 should use less amps from the buildings load right?

Luckily they had another one of the AN-15458 - 1500VA Transformer, the last one available so I bought it right after I saw your reply...well now my power needs are almost done, just some caps and bridges and I am there!!!

Thanks again.

[skyguynca]

I found this motor pretty cheap, yeah I know I will have to watch the brushes and replace them from time to time but for the package is it small, 2.6hp continuous and only $45 each. I already have the DG4S-16035 DC Servo Drive for 160vdc and 35amps and the 180vdc braking box too. I have a bunch of the AMT-102v new encoders so using that, it should allow me to use a 1.89 gear down to bring spindle speeds to 3200rpm max, almost double my torque and allow me to do rigid tapping too.

If I go with the scr or pwm then I loose that ability.

[john-100]

Hi Skyguynca

with a 230V mains supply the current will be half of the current taken from a 115V supply

( on a larger scale thats why they use high voltage transmission lines to carry the power from the power station to reduce the current in the cables )
http://en.wikipedia.org/wiki/Nationa...Great_Britain)
the 400KV lines are not far from my location

now I've looked at the data for the transformer and the transformer regulation is approx 4% ( output off load 104%)

the 58V AC output is 60.6V off load
rectified DC = 60.6 X 1.4142 = 86V
since this is over the 80V limit for the stepper drivers if I assume the motors are not connected and the drivers are taking almost no current

check your local supply voltage ,if it measures close to 110/220 you may be just on the 80V limit ,
the 0.65V voltdrop across each of the 2 conducting diodes in th bridge rectifier may be enough help you to be within the 80V limit

one way round the problem is to wind an extra few turns of wire around the transformer to give you 5 to 8V
that can be wired in anti phase with the 58V output to give you 50 to 55V

as a test to work out how many turns you need for the extra winding ,
wind a test coil of 10 turns over the existing trinsformer winding and measure the voltage out of the DIY coil

if its 1V and you need to reduce the tranformer output by 3V
you need to add a 30 turn coil using the same size of wire as use for the 58V winding

connect the new 3V winding in series with the 58V winding and if you have them the correct way round you should have 55v
if you have 61V reverse the connections to the DIY 3V winding




Attachment 202580


Attachment 202586

Attachment 202582




http://www.farnell.com/datasheets/1662153.pdf bridge rectifer data



John

another diy psu :-

Untitled Page

[skyguynca]

OK, so I think I got it figured out John, see if this works.

for my bridge rectifiers just plan on using KBPC5010 / 50 AMP ,1000V for both power supplies, I have quite of few of these lying around I got for free.

for the spindle motor supply 110 parallel, output 58v in series to get 116v and using two FAO582F200EH1H CAP TECH 5,800uF 200V Aluminum Electrolytic Large Can Computer Grade capacitor (found at FAO582F200EH1H CAP TECH 5,800uF 200V Aluminum Electrolytic Large Can Computer Grade capacitor 2020001768) in parallel to smooth out the voltage.

for the stepper supply 110 parallel, doing the wire wraps as you suggested but both 58v in parallel and using one 36D212G150BC SPRAGUE 2,100uF 150V Aluminum Electrolytic Large Can Computer Grade capacitor to smooth out the voltage (found at 36D212G150BC SPRAGUE 2,100uF 150V Aluminum Electrolytic Large Can Computer Grade capacitor 2020001576)

Will this work to give me my power needed for both the spindle , stepper drives and steppers without blowing anything up??

[john-100]

Hi Skyguynca

do yo know what is the supply voltage to your workshop? have you measured it

if its 110V the stepper drivers and spindle servo will be running very close to the limit

in my case the my 240V (+ or - 6% ) supply varies between 243 and 248 V

(on paper my supply has changed to 230 V +10% -6% to keep keep the bureaucrats in europe happy )

in the morning I'll check my calculations and add some diagrams

John

[skyguynca]

it varies from 112 to 120

[john-100]

[Hi Skyguynca

with the 120V mains you need the transformers to have a 54V RMS output for the stepper driver and 108V RMS ( 54+54V ) for the servo driver

the off load DC voltage = transformer output V RMS X 1.4142 X 1.04

( root 2 = 1.142 your transformer off load V = 1.04 X full load voltage { 1.04 = offload v/ full load v} )


minimum voltage reduction required

for the stepper motor drivers you need to reduce the transformer 58V by 4V to 54V

off load DC = 54v X 1.4142 X 1.04 = 80V


for the servo transformer o/p 108V

off load voltage = 108 X 1.4142 X 1.04 = 160v


I'd reduce the supply a little more
with stepper psu transformer o/p 52V DC off load = 1.47 X 52 = 76.5 V
with servo psu transformer o/p 104V DC off load = 1.47 X 104 = 153V


ATTACH=CONFIG]202728[/ATTACH]

John


PS

don't forget to connect the mains to each transformer via its own fuse

with a 1500 va transformer connected to a resistive load you would expect the 115 V supply fuse to be 1500/115 = 13A
because of the surge current charging the psu capacitors the fuse needed is more likely to be 20A

[skyguynca]

Thanks for the help.

Did I figure out the right size caps to use for each one?

[john-100]

Ho skyguy


I've not been able to find the data on either capacitor to find the ripple current rating

the servo amplifier manual indicates you need a 2000uF 160V capacitor for the 160V servo power supply

my initial calculation is you need a 8000uF 80V capacitor for the stepper motor supply


depending on the stepper motor current settings the 5800uF 200V capacitor may work



for the servo power supply over 80V

capacitor for servo motor current of 20A = 20 X 2000uF = 40000uF

number of 5800uF 200V capacitors connected in parallel = 40000/5800 = 7


John

[skyguynca]

What is the "servo amplifier manual"? can I get a copy?

I am just winging it from articles I have found on the internet and using that math. I am ok in reading schematics and soldering up circuits and some trouble shooting but
design work is outside my knowledge.


Thanks for all the help

[john-100]

Hi skyguy

I found this one :-
Attachment 202796


now my brother has gone home and I've looked at page 17 again
the 2000 uF should of been multiplied by the motor current in amps !

if the motor current is 20A then you need a 40000 uF 200V capacitor
or 7 X 5800uF 200v in parallel

20(A) X 2000uF = 40000uF number of 5800uF capacitors = 40000/5800 = 7

John