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Graziano Sag 12 Joystick wiring and internals question and info request

upthebikes

Cast Iron
Joined
Aug 23, 2007
Location
Great Lakes USA
In my ongoing efforts to get this lathe running again, I pulled the transmission and motor assembly out. I tested the motor and it spins nice and quiet. Turning over the transmission by means of the outboard pulley, all gears mesh and rotate smoothly. When the motor is coupled to the trans, the output shaft turns smoothly and oil starts slinging a bit so I am fairly certain the problems I am having are not mechanical.

Could someone with a Sag 12 be so kind as to advise me on the joystick wiring? I am pulling wires to trace them to figure out what the problem here is.

I have a single speed motor, no brake configuration. When I pulled the joystick, I see light blue wires labeled 1-4 are connected to inputs 1-4 accordingly. Light blue wires 5 and 6 are soldered to contact switches on the inside of the joystick assembly. I see no label for "forward" or "F" on the joystick, but I do see an "R" (assuming for reverse). There are two wires connected into the R switch, a light blue (which is not numbered, let's call it 7) and a dark blue (which is not numbered let's call it 8.) Light blue 7 goes from the R terminal to the contact switch and is soldered to it. Dark blue 8 runs from the same R terminal, through the body and out past the wiring harness.

My question is, should both of these wires be connected to the same R terminal? And where is the position for the Forward clutch on this joystick, as there is no label?

Thank you all!

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I am not very good with electrics, so will just show you what my lathe has, others might be able to clarify. This is a single speed, no brake.

I am almost certain the forward and reverse switches are not in your photos, they are inside the end of the carriage. They can be seen in the parts book, 2x regular microswitches. When you lift the joystick upwards, a cam actuates the forward switch, drop the lever for reverse.

I have taken photos of my joystick switch, it is not quite the same as yours, i.e. there are no connections on the bottom face of the switch. A couple of the wire numbers have vanished, probably slipped down their wires out of sight.

The sketch shows the switch as if it has been unwrapped and laid flat.


sag 12 joystick 01.jpg sag 12 joystick 02.jpg sag 12 joystick 03.jpg sag 12 joystick 04.jpg
 
Thank you Bill and Peter. I see the microswitches for f and r under the housing, so 1-4 are the speed selectors. I'm still wondering what the "r" designation is for, since it is not reverse. Maybe "return" for return voltage?

I have referenced texasturnado's thread many times and it is an incredible resource.
 
I'd wonder if the electrical term for earth in Italian, is different to the "normal" usage...which I would think would need a T? :)

A 12 sold at auction down here last week for the better part of 6k.
 
UTB,

Have you got the wiring diagram for your lathe? Here is a page from my manual, it shows a single speed, no brake model, with "Siemens Type" electrics.

BTW, as Texas Turnado and others have found out, the wiring going into the transmission fails on these SAG 12 lathes. I checked mine recently and the insulation is crumbling and falling off the wires, just as it did on TT's lathe. I am not sure why that is, but I suspect it might be a common problem. I haven't got my lathe under power yet, but I am reluctant to run it without replacing the transmission/clutch wiring - :(


SAG 12 51 edit.jpg SAG 12 51 red.jpg SAG 12 52 red.jpg
 
Hi Peter - thank you for the schematic. I also have a Siemens type.

I took the transmission out and did a continuity test with a multimeter on all the clutch wires. A few of them were bad/brittle. The problem areas were not near the transmission, but near the black rectangular plastic wiring junction box that connects the transmission to the joystick wires.

I cut the wires back some and added new machine wire by means of push on cable clips. After doing so, I now have continuity on all the circuits 1-6 from the transmission. I am going to make a little rack to hold all the clips and bolt this rack to the outside of the transmission housing to keep it nice and neat. IMG_3210.jpg
 
Graziano SAG 12 restoration progress

GrazianoLathe.jpgGrazianoRestored.jpg
Mostly finished restoring my SAG 12. Photos are before and after. Let me know if I can help with troubleshooting electrics.
 
Your Sag 12 looks great. Is that a VFD mounted near the headstock? Are you using it in combination with the clutches?

Yes. VFD is set to 60 Hz output, and I am presently using the clutches, which all work well. However, I am considering removing the transmission and replacing the motor/trans assembly with a motor and the VFD. In that case, the motor/trans assembly will be for sale.
 








 
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