Hi, Hotfoot here, the arts centre at Milton Keynes has recently had a
graduate G L lathe passed on to them. I am one of the turning tutors who
helps runs their 10 lathe workshop. Unfortunately when installing the lathe
it has refused to start, it has varispeed fitted, it has on and off push
buttons on the front of the head with a small blue speed knob on the front
side of the head.
It has on and off buttons on the back side of the head along with a large
yellow and red power on and off switch, that you twist. It also had what
looks like a female kettle socket also on the back side of the head.
Does anyone know what this socket is for?
Is it a light socket?
Is it to do with the varispeed?
It runs (not) of a three pin plug so I assume it converts it to Three
phase.
How many safety micro switches is it likely to have?
Should it have a foot safety switch? maybe it wont run with out this?
If anyone can help with any thoughts, information, ideas of who may be able
to help, we and all the turners who use this workshop will be very grateful
(eventually).
And Yes I have checked the fuse, the one in the plug ( 13amp) and the
one in the box at the foot of the head. (glass).
Yours in hope, cos its a brill lathe,
Hotfoot.

Hi Hotfoot,

I'm no Graduate lathe expert but I don't believe they were originally sold
with variable speed drives. Therefore, it's likely to have been converted
at some time after its manufacture. LRE Machinery[1] make (or maybe just
market?) the Variturn system of speed control for these machines; it may be
worth contacting them if it is one of theirs, as they should be able to
advise what may be wrong.

Alternatively it could have been done as a one off conversion by a previous
owner. If it's got a 3 phase motor and a normal mains plug then there must
be an inverter included somewhere to achieve the variable speed operation.
You should proceed with the following only if you are appropriately
qualified and understand where the risks may be. If not, then any
competent firm of industrial electricians should be able to sort it out for
you. If you locate the inverter[2] and note its make/model you should be
able to find documentation explaining what its required inputs are and what
its output is. Then you can trace the wiring and use a multimeter to check
which of the switches is open or closed, and work out if any need switched
to the other position or replaced. Methodically tracing the appropriate
control circuits should locate all the microswitches (if they exist) that
are in the machine. In this manner you should be able to eliminate the
problem.

This, of course, assumes the inverter is working and that may not be the
case. If it's faulty first check it for fuses or resettable trips, then
look at getting a new one. RS[3], Farnell[4], or an electrical
wholesaler/electrician should be able to supply a suitable inverter.

Hope this is of help to you.

Neil

[1] http://www.woodturninglathes.co.uk/
[2] they vary in appearance but here is a typical model:
http://img-europe.electrocomponents....R365168-01.jpg
[3] http://www.rswww.com
[4] http://uk.farnell.com/jsp/home/homepage.jsp


outofthewoods wrote:

Hi, Hotfoot here, the arts centre at Milton Keynes has recently had a
graduate G L lathe passed on to them. I am one of the turning tutors who
helps runs their 10 lathe workshop. Unfortunately when installing the
lathe
it has refused to start, it has varispeed fitted, it has on and off push
buttons on the front of the head with a small blue speed knob on the front
side of the head.
It has on and off buttons on the back side of the head along with a large
yellow and red power on and off switch, that you twist. It also had what
looks like a female kettle socket also on the back side of the head.
Does anyone know what this socket is for?
Is it a light socket?
Is it to do with the varispeed?
It runs (not) of a three pin plug so I assume it converts it to Three
phase.
How many safety micro switches is it likely to have?
Should it have a foot safety switch? maybe it wont run with out this?
If anyone can help with any thoughts, information, ideas of who may be
able to help, we and all the turners who use this workshop will be very
grateful (eventually).
And Yes I have checked the fuse, the one in the plug ( 13amp) and the
one in the box at the foot of the head. (glass).
Yours in hope, cos its a brill lathe,
Hotfoot.

i would suggest that you check the following and only if suitably
conpetant.

if the graduate is fitted with variable speed it probably works with a
dual phase motor powered through an invertor.

1. check the mains plug fuse
2. is there 240V going to the invertor
3. the invertor should make a noise (the cooling fan) when working (if
it is a modern one)
4. is there a digital display on the invertor - is it showing anything
if there is a display the invertors programming may have been altered
by mistake.
5. if invertor working check there is 4 wires leaving the invertor (1
earth) and check the voltages of these.
6. aparently invertors should not work of separate on/off switches in
the power circuit . ie the switch is through the control panel of the
invertor not on the power circuit.
so if there is power coming out then check the power after the switch
that you are using.
if there is no power after the switch - obviously the problem is in
the switch which you could try by passing or changing.
7. also if there is power in and none out of the switch - old pull in
switches have a max current setting which means the trip on the switch
could have gone off and need resetting.
8. check that you are using a suitable dual phase motor and you have
wired the motor the correct way (star or delta)

if you have a multimeter it shouldnt take long to find the problem...

good luck