Topics

1

General Mach Discussion / lathe threading problem

« on: October 18, 2016, 03:07:57 PM »

Hi
i have a problem with my denford orac cnc lathe that i hope the people on
this forum can help me solve this problem
the lathe was converted to mach 3 about 3 years ago and has been a very reliable machine
until easter sunday this year when it decided that it would no longer do external or internal
threads , but still works very on normal turning jobs
the machine is using mach 3 version 062
i have tried a new cnc4pc spindle index board but this has not solved my problem as well a
few other ideas found on internet , the latest being a proximinty switch which i bought from
cnc4you this gives a very stable spindle speed but still no threading .
the problem when threading it is not picking the pitchin the same every time so all it
ends up with is alot of grooves
i have changed to a new copy of mach 3 on about 6 times just in case the program is corrupted
but still no joy
i have been stuggling with this problem for 7 months and have now run out of idea's so please
can anybody help me
thank you
robert

2

General Mach Discussion / spindle speed problem

« on: May 10, 2016, 11:20:30 AM »

i have a problem with spindle speed not being shown in S true speed readout box , on start up of the spindle using the M3 command in a program the spindle starts up and the true speed readout shows the spindle speed but then goes straight down to zero , because of this happening the lathe will not thread . i have been trying to solve this for weeks even buying another spindle index board but this has made no difference . can anybody please help me solve this problem . this machine has run perfectly over the last 2 years with no problems
MACHINE
Denford Orac cnc Lathe
mach 3 turn version 062 with the standard lathe screen
using parallel port
stepper motors 10x microstepping with 4.2A stepper motor driver
C3 index pulse board - settings - output TTL & active low
slotted disc on spindle has 1 slot x 12mm wide

3

General Mach Discussion / toolpost help needed

« on: January 14, 2015, 11:36:06 AM »

hi
i am in need of some help i have just made an 8 station indexing turret for my denford orac lathe at the moment this turret is being indexed manually until i can find the spare time to convert to stepper motor drive .
today is the first time i have used this  but it is not using the correct tool offset number on a tool change , i have enclosed the program i was using when this was happening
the program uses 2 tools , when using tool T0101 it was finding the correct tool 1 offset but when it was was using the other tool T0705 it was using 07 as the tool offset , has anybody any idea's as why this is happening
robert

4

Share Your GCode / Internal Threading

« on: July 31, 2013, 06:17:56 AM »

i have a denford orac cnc lathe that has just been converted to Mach 3 , this is using a licenced version of mach 3 . i have only just started to use this machine after a few problems which with help from other people has now become a reliable machine.
my problem now is internal threading which no matter what i do to alter the code it is still working as though it is cutting an external thread , everthing is working ok with the threading movements
i am including my code below for people to look at to see if they can pick out what i am doing wrong
thank you in advance for all your help
robert

5

General Mach Discussion / spindle speed problems

« on: February 26, 2013, 07:55:04 AM »

i am in the process of finishing a total refit  of a 1983 denford orac cnc lathe , all the electronics ,stepper motors & main spindle motor have been replaced with new upto date items .
everything has gone fairly easy until recently when i am trying to set up the spindle & i can't get anything to work properly.if i am in manual mode & using the mdi line put in m3 s500
what i get will something like
S true = 1750 rpm
s box = 500 rpm
but the spindle speed using a hand held tacho = 800 rpm
i have tried the spindle calibration screen , it starts the spindle at 250 rpm & stops at this 30 mins so i stop it because it is going knowwere
everything else is working fine , stepper motors , homing switch's
machine spec
parallel port board , 2 stepper drive boards , spindle board (step & direction converted to 0 to 12v for inverter control ) all these items came from www.diycnc.co.uk these are the system 4 system on his website  , the spindle inverter is an imo idrive - idx 1hp , the motor is a dual voltage 3 phase 3/4 hp 1370 rpm , it has a cnc4pc c3 index pulse board settings are active = low
output = ttl
the spindle index disc has 4 slots with the largest being 12mm wide
i have spent the last 2 days changing settings & try again still no joy
please has anybody any ideas as to what i am doing wrong or something i am overlooking
i am enclosing my xml for you to have a look at to hopefully see my problem
robert

6

General Mach Discussion / problem with my cnc lathe

« on: February 07, 2013, 02:09:59 PM »

hi all
this my first post , but have been a watcher for a few years trying to gain some knowledge
i have a denford starturn 4 cnc lathe that has been converted to run mach 3 while still using the steppers & driver cards . the machine has been running reasonably well until this afternoon when i tried to do a manual move with the arrow keys on the keyboard but nothing happened ,so i tried another keyboard but still no movement , i then tried the home x & home z and both axis moved to there home positions . has anybody got any ideas as to what has gone wrong it has got me baffled
robert