8 station turret

[Bert]

Oh the joy's of cnc world

I have read many posts about the denford 8 station turret and have even found the origional wiring diagram on this site.
But found it all a bit hard to work out

With more modern electronics how hard would it be to get it working

I would like to possibly make a very simple to put together circuit/ relay board

some of the wires are marked up with 5v 12v and 24v

in order for it to work what does it need and why and what happens during rotation

It was working before I got my hands on it but the way it had been done was not very good and I have now removed all old electrics and attempting to make a better job of it

bert

[Steve]

The turret works with 24V connected in one polarity to index the turret. When it is in the correct position the polarity is reversed and reduced to 12V. The 12V is applied to the motor all the time when the motor is in position holding it against the ratchet. Cutting forces are applied against the ratchet and not against the motor.

The 5 V is for the optical switches internal to the turret. These are used to identify the turret position using a grey scale encoder.

[Bert]

Hi Steve many thanks for info

I take it that the reason for the motor being 24v is that it will index faster round to next tool and more importantly wont burn it's self out when reversing into the holding position against ratchet ( could too many amps on the 12v do harm)

The wires I am looking at are as follow

red goes to +5v is for the optical internal switches ( any Idea how it works)
yellow goes to gnd

blue goes to pin 15 on bob ? what does it do
white goes to pin 13 on bob ? what does it do
mauve goes to pin 12 on bob ? what does it do

black goes to motor +24v for indexing and - for reversing
brown goes to motor - for indexing and +12v for reversing and holding

I have a circuit board that has been altered ( badly ) its a pc1623f a relay looks to have been added and maybe some prosesors removed the relay looks like it will reverse motor wires but the control coil for relay is 12v( what is the switching signal volt likely to be I think it's 5v ) but my bob only has 5v going to it, and it's very basic no relays ect

At one end of the board it has three orange terminals that only two are used one is for the relay coil trigger and the other is the coil - return it also uses this for the - return for the motor

any help would be good
many thanks
bert

[Denford Admin]

I think a photo of what you have would help.
Did you ever see this post:
viewtopic.php?f=43&t=1464&p=4918
Those pdf'd uploaded by bradders show the blue,white and mauve being the greyscale turret position inputs

Try to PM one of those guys - they must have got it working on Mach

[Steve]

The question about too many amps is not relevant. The amps are limited by Ohms law A = V / R

The resistance of the motor will limit the current. Reducing the voltage to half in the reverse direction reduces the current by half and therfore reduces the heat generated.

The A rating on a PSU only indicates the maximum that can be supplied.

[Steve]

Schematics for turret.

[Bert]

Hi Steve many thanks for drawings

Do you know what is meant by grey scale code not binary
On sheet 8 just above date box
bert

[Denford Admin]

A grey code is a pattern which only changes one input bit between each number in a sequence.
http://www.interfacebus.com/Glossary-of ... rcuit.html
http://mathworld.wolfram.com/GrayCode.html

[Bert]

Mind bogoling
There must be loads of folks who have got theres working
Has anyone got a plug and play solution
bert

[Steve]

The origional way was the plug and play solution..

You request a position. Index forward until the grey scale reports that position. Then you reverse the motor at half voltage and ensure the grey scale is still reporting the correct position.

[Denford Admin]

I doubt there are enough people wanting to do this to make it worth anyones while creating a plug and play solution, by which I take it you mean a plug-in for Mach?
You'll have a great sense of achievement once you get it working

[cncbasher]

if my memory serves their is information on the Mach3 forum on how to do this , but it should not be too difficult