AI Tool Turret

[dave benson]

I'm at the point now, after cncing the mill and lathe, so at lthat I can have a look at the turret.
I haven't looked at it for what must close to two years and it had been through a fire and having the roof collapse in in it.
The only thing I knew before taking it apart was that the battery pack was ok as I could see
through the bluetooth dome that the bluetooth module was intact and if the batteries had caught fire
then there would not be anything left of the bluetooth module or anything else.
The fire had not breached into the interior but the radiant heat through the body walls was enough to melt the insulation on a few of the wires.
I pulled out the microprocessor and plugged it into pc and ran its medic routines and it is ok
including the on board memory. I've checked the main bearing and is ok too.
At this point I will need to clean all the surface rust and see if the sensors are ok and assemble it again.
edit to add another pic
Dave

[dave benson]

another pic

[dave benson]

I got a chance to dismantle the turret and have a closer look.
The micro-controller was ok, I had it connected to a serial monitor through the debug port
and connected it to mach3 successfully, it was sitting on a slab of UHMWPP which had melted
at one end.

I wondered how hot it had got inside so had a look at the melting points for   UHMWPP  130c
and led free solder around 217 c.

So, the temp was hot enough to melt the UHMWPP but not hot enough to melt the solder.
In any case it was a bit toasty in there.

I had no hopes for the Bluetooth module as the dome protective cover had melted and entombed the
module, Out of curiosity I powered it up and the light that indicates power (it flashes while waiting for a connection) lit up and
started blinking, It showed up as an Autoturret  in my pc's search for
Bluetooth devices so I ran Mach3 and connected to the module it still works!

I do have more BT modules so I'll use one of those but will try to dig this one out just to see if I can do it.

I wire brushed the plates making up the turret body and used an electrolysis bath for a couple of days and will let the paint dry another few days.

I tested the stepper driver modules after a through clean and there both ok.

I haven't had time to test the sensors yet, the homing sensor looks ok, but the servo pawl sensor
looks a bit shabby.

Tomorrow I'll go to my local electronics store and get some more Dupont jumper wires, and should be able to
assemble everything except for a new servo sensor which if its dead, I'll have to order some more.

Dave

[dave benson]

more pics

[dave benson]

I got a chance to do some more work on the turret.

The homing sensor tested ok, so I assembled the turret and cut the bluetooth sensor out
of its acrylic tomb and ran the calibration routines, once that was done I connected it to mach3
where it synchronised with mach3 and selected the current tool in mach3. 

So at this point to get it running, I had to replace the on\off switch, the bluetooth dome, wiring and the battery tray.

The last thing to do is get some neoprene for the gaskets, and as this is a new lathe I'll need to check the tool centre
height as the old lathe was in the 'old money' 9 x 20 and the new one is 10 x 22.

I did have to replace one stepper driver, not because it failed, one of the pins looked a bit bent and
through force of habit, I  bent it straight and it broke free from the board taking some of the traces with it.

I measured the battery voltages, and thought that they were all going to be bad, but some of them still had
some voltage see pic, I recharged the 3.84 volt cell and it charged up, don't know if it will perform under load though.

Dave

[dave benson]

Another small update.

After getting the turret back together and connecting to Mach3, I ran a long series of tests
to make sure that the turret firmware was the latest version, the latest version will go to the tool change
position (this depends on whether the tool is a right-hand tool or a left-hand tool) stop mach3
and pop up an alert that the tool requested is not in the tool turret and is not in the alias list.

This is for the semi auto mode, in manual mode its up to you to make sure the tools are in the turret.

In full auto mode the turret will also visually identify the tool, if it cannot find the tool it will park the turret, stop mach3 and wait.

Everything seemed fine, so I took the turret out and sat it on the lathe and fired up the computer
ran mach3 and the plugin, set the serial ports and connected to the turret, the turret connected
and what is supposed to happen is that the Mach3 connected window should say connected and you're ready to go, however
this didn't happen and it took 3 days of head scratching and manic activity to get it to work.

The image is of the turret sitting on the cross slide and the other is it actually working on the shop lathe computer.

At this point I have to swap the tools from the lathes tool post and measure center height difference and make a shim plate.

Dave

[dave benson]

As far as the turret goes, the last major machining item on the to do list has been done.
I had to machine a shim for the base plate, notionally you think that the plate thickness
would be (10-9)/2 = ½  inch  12.7 mm.
For me this value was 9.3 mm exactly, The measured value to get the tools on center height
with a 12 mm shank tool holder.

However, at the time when I made this particular turret, I had a disparate collection of tools that I had bought at estate sales
or local garage sales and some of them with imperial shanks.

So, I made a modification to the turret tool plate and rests so that I could use tools from 14 mm
to 8 mm (you can go smaller than this but I didn't have any tapered gibs made up for them).

So, to accommodate this range of tool shank sizes I had to machine the plate to 7.3 mm.
In the pic I've set up the tool height for a 12 mm shank tool 12 mm tools require a 2 mm shim
(exactly) to get the tool at center height.

I have removed for clarity the tool retention ring that secures the rear end of the tool shank against
the tool rest.

For a standard straight tool shank the tapered gibs go on top of the tool, they can also go on the bottom of the tool rest to adjust
the cutting angle of the tool. Some home made tools required this.

I made some test threads in aluminum mainly M12 x 1.75 to 6g, the nuts run on fine, but I don't have thread wires or a standard
to test the work against.

The root dia for the thread is 10.14 so I made it 10.2 as its easier to make chips than to put them back on I figured.
My intuition tells me that the thread fit is quite close, so I'll leave it for now and use it as
a test piece for picking up and existing thread (1) and (2) another 10 mm of threads.

Dave

[dave benson]

another pic