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orac conversion help please
Posted: Tue 09 Sep , 2008 12:04 pm
by Bert
dear triac whizz sorry for being a pain as iam new to emails and forums
got wife to upload photos
63 volts dc comes into board and goes into the 24-80volt gecko conection an is working and has a large capacitor across this supply
a 24 volt supply comes into board and that goes to the regulator and other components to reduce voltage to 5.05vdc
and this goes up sheilded wire to the gecko and conects to the comm as i understand it should be +5 v dc
pic bellow
on this machine one gecko is used and one rs 4 phase driver
on the conector that looks white i have traced from bob through resistors up yellow and white wires back to gecko drive
they are direct with no extra wires or componets in these lines
the green and blue go staight to rs 4 phase driver board
pic bellow
this is the board that has had extra resistors fitted
i have conected this up to a spare gecko and stepper and got it to move nicely with mack3
hope this has helped
cheers bert
p.s. previous owner had put a stepper behind spindle drive motor and fitted an electro magnetic clutch and fitted a dremel on another axis above chuck
and used it to divide s well as turn bits
cleaver man butt poor instalation and he took what he had done to machines and why to his grave

orac conversion help please
Posted: Tue 09 Sep , 2008 12:12 pm
by Bert
dear steve
i have putt some pics on now
no extra wires have been fitted resitors are just in line
do not know what a star point is
i work on lorrys for a job and sometimes they have a earth terminal that looks like a star butt i bet i am wrong
cheers bert
orac conversion help please
Posted: Thu 11 Sep , 2008 10:50 am
by Bert
hi triac whizz and everbody else
finaly got my finger out and wired up bob to a machine
set up port / pin got x axis to move but machine gave heavy rumble sound and it sounded like a bearing fault
checked axis by hand and it move freely transfered wiring to other axis stepper and still had rumble and all movment stopped after few seconds
sloted in another gecko and tryed on both axis all ok
checked wirng to see if boards were wired the same the only thing i could see diferent was phase c and d wires were reversed
concluded that it was probably trying to go both ways at same time and i had cooked the gecko
the next day i fitted two gecko's and moved both axis in manual and a mild step motor tune
bench tested burnt out gecko after moving wires it was still alive
refitted it into machince it still works
thanks for reading
bert
ps got a book from maplins electrical about power supplys
larger bob in previous pics has been modified to take in 24v and regulates it to 5 v to power bob tested it on orac power 24v power supply and a 28v power supply and it always gives a 4.97 v reading
Posted: Thu 11 Sep , 2008 12:55 pm
by Triac whizz
Him
Good to see you're getting to grips with the stuff.
p.s. previous owner had put a stepper behind spindle drive motor and fitted an electro magnetic clutch and fitted a dremel on another axis above chuck
and used it to divide s well as turn bits
yeah I've had that idea in my head for ages, but it hasn't escaped yet

It'ld be interesting to see your setup on that one day..
set up port / pin got x axis to move but machine gave heavy rumble sound and it sounded like a bearing fault
could have been acceleration set too high in Mach.. but then...
dear triac whizz sorry for being a pain as iam new to emails and forums
got wife to upload photos
we were all new once..... I hope the missus showeed you how to upload the piccys then
orac conversion help please
Posted: Thu 11 Sep , 2008 23:51 pm
by Bert
hi triac whizz
with your kind help i now have carrages moving
i think i have a parajust unit fitted to control spindle speed on one machine and it does work in manual control and wires apear to be in origional locations not that i realy know were they were in first place
can this be conected to run of mack3 if so do you know how
on other machine a altivar 11 vfd is fitted all wiring is still in place although it does go through an origional circuit board and looks like it exits board on ribbon cable and goes to bob
and also wires from spindle speed sensor go straight into bob so i presume it will be fairly simple to set up in mack3
any ideas will be appreciated
bert
ps have got spare altivar on way to me to install if parajust will no play ball
will get more piccies soon of clutch arangment and stepper location

Posted: Sat 13 Sep , 2008 20:45 pm
by Triac whizz
I think parajust canbe made to work, I seem to remember there was some issue with those units....
probably better off using the alivar as it's more modern
you will need a speed control board (mostly likely) unless you have a board with everything on it.
They're not very difficult to plumb up, getting the dialed in speed to match the actual is a bit more difficult..
read the manuals & come back with questions, if any

orac conversion help please
Posted: Sun 14 Sep , 2008 10:10 am
by Bert
hi triac whizz
going to research in manuals
the altivar that is still wired in has its control wires going in were other machine ( that is standard ) has the speed sensor wires .

..........hmm
i think that i might set only one machine up for tread cutting and get one machine fully operational as basic lathe ( got urge to make some long curly springs )
i did see a document that said using speed sensor wiring connect green wire to 0v red to +5v yellow to signal
and set mack3 to reconise this as spindle index in ports and pins input input signal tab
and check/ general config index bounce is set to zero......
will have research this further
going to have a small break to tidy up workshop and do some reading
cheers bert
orac conversion help please
Posted: Thu 18 Sep , 2008 19:03 pm
by Bert
hi triac whizz
i am having trouble with caliburation of both axis
i have step and dir pulses set to 1
have tuned in steppers to give sensible speed in jog mode
in the steps per box on the motor tune page i have got it set up to 1012.25
this seems a high setting when i move axis 40mm on screen display the actual measured movment is 40.14mm
i am starting to think i might have set something wrong as its sending me round the twist keep adding and taking away steps and measuring out come
have checked for wear in bed and ball screws ect all look slop free
have watched mack3 training tutorial and read the maual i think i am heading in right direction
any comments would be appriciated
cheers
bert
Posted: Thu 18 Sep , 2008 19:41 pm
by Triac whizz
then steps per mm are 1000 - non negogiable - if it doesn't move exact you're loosing steps
orac conversion help please
Posted: Sun 21 Sep , 2008 9:31 am
by Bert
hi triac whizz
have set both axis to 1000 steps (oops forgot about pitch on ball screws)
wow what a machine did some basic turning with brass and nylon verry good results

but with spindle still in manual control
still waiting for second altivar to arive

do you know if it is posible to screw cut using only the spindle speed feed back
ie manualy set spindle speed at x rpm will mack3 configure steppers to move in relation to the speed sensor reading
having thought about it as cutter loads presure on work spindle will probably slow down and give inacurate cut
do you know what max amp rating resistor should be for the standard stepper
cheers
bert
iam snipping and pruning back old wiring and in prosess of getting limit switches working
orac conversion help please
Posted: Wed 24 Sep , 2008 22:40 pm
by Bert
hi triac whizz and everyone else
done some reading yes i will require a speed control board to convert signal from pc into anolage 0-5 volts for speed signal
i also will need two +5 volt signals one for forward and one for reverse havent checked mack3 yet but i am guesing mack will produce these the same way it does for the dir signal for geckos
have had a look for a digispeed board looks like i will have to have one imported from australia found a complete bob with opto isolators and built in analouge signal in uk will ask if he can produce speed board as a seperate iteam
cheers
bert
Posted: Thu 25 Sep , 2008 7:50 am
by cncbasher
check out
https://www.diycnc.co.uk
for a step direction to analogue speed conversion pcb
orac conversion help please
Posted: Thu 25 Sep , 2008 23:07 pm
by Bert
hi cncbasher
thanks for link just what i was looking for
cheers
bert
orac conversion help please
Posted: Fri 26 Sep , 2008 22:34 pm
by Bert
hi triac whizz and others
time to spend some money to get machine to thread cut
i take it that i can use the origional spindle speed sensor and will only require a digital to anolauge board to control vfd
will i need to get any other component to do thread cuting or is it done in software setup
cheers
bert
Posted: Thu 02 Oct , 2008 14:02 pm
by SimonRafferty
That seems to be the long and the short of it!
The spindle encoders usually seem to have two sensors. One which generates lots of pulses per revolution and the other, a single long pulse. You can ignore the former and just plug the latter into Mach.
In practice, to long as the voltage to the inverter does not change, it's unlikely to slow down in one revolution of cut. The inertia of the chuck etc also helps. Mach will adjust the voltage to the spindle as required to keep it at the required RPM.
Si
orac conversion help please
Posted: Thu 02 Oct , 2008 16:10 pm
by Bert
hi simon
thanks for reply going to order speed board
cheers bert
orac conversion help please
Posted: Tue 07 Oct , 2008 23:26 pm
by Bert
hi everyone
if i start up computer before powering up lathe will i need to use a charge pump
i have puchased a number pad to fitt to front of machine
it does not have a shift key for fast jog in mack3 can i change key used for fast jog to an unused key on number pad
all awnsers will be gratfully recived
cheers
bert
Posted: Wed 08 Oct , 2008 9:22 am
by SimonRafferty
Yes - use a charge pump!
Without it, when I switch on the PC, the spindle drive goes to full speed for about 100ms as well as random blips on the step/direction. The coolant relay stays on until Mach starts. It's about the only safe way to operate with a PC.
Not got a copy of Mach in front of me - but I'd be very surprised if it were not configurable - after all, it's just reacting to a different key code.
Si
orac conversion help please
Posted: Sun 12 Oct , 2008 15:50 pm
by Bert
hi ervery one
i am in prosses of ordering speed sensor and charge pump boards
be back soon
bert
