Boxford BUD carriage stop ?

[hunter27]

Hi all
I have just bought a Boxford BUD lathe that has a 3 phase motor converted to run off single phase through an inverter. On looking around it for first time properly today I noticed around the back of the head stock it has a junction box wired to 3 safety interlocks I think, one for the back gear, one for the change gear door and one to stop the carriage or tool hitting the chuck which has an adjustable rod fitted to the carriage.
None of these are connected up, probably from when it was converted to run on single phase.
I am not bothered about the other two but would like the carriage stop to work is it just a matter of interrupting the on wire from the 6 wire control box to the inverter so if it got too close it would turn the lathe off.
Thanks for any help
Pete

 

[Maker]

A sensor to stop you getting too close to the chuck will need adjusting every time you change the tool, adjust the toolpost, adjust the topslide or change chuck. It will be a huge pain in the **** and you'll inevitably eventually stop using it.

It's easy to work very near the chuck without hitting a jaw.

You'd be better off fitting a foot switch to shut it off in an emergency if you think it's getting too close or something else bad is happening. Your inverter may have DC braking that can stop the motor instantly and the foot switch could operate this rather than simply switch it off.

 

[hunter27]

I agree it might become a nuisance but I guess it was built like that originally and by winding the adjustment right back it will be inoperative anyway but I still think it would be a good idea to have it even if only for occasional use.
Pete

 

[Pete.]

A sensor to stop you getting too close to the chuck will need adjusting every time you change the tool, adjust the toolpost, adjust the topslide or change chuck. It will be a huge pain in the **** and you'll inevitably eventually stop using it.

It's easy to work very near the chuck without hitting a jaw.

You'd be better off fitting a foot switch to shut it off in an emergency if you think it's getting too close or something else bad is happening. Your inverter may have DC braking that can stop the motor instantly and the foot switch could operate this rather than simply switch it off.

You right but my lathe comes with a stop built into the fwd/rev lever and it takes moments to set. I don't use it for turning but it makes screwcutting an absolute breeze. An inverter fitted with a braking resistor could do the same.

 

[rikrobson]

I suspect this lathe may have come from a school hence the cut outs.
You'll be fighting with the cut out if you are working close to the chuck. The auto feeds are not there so you can skive of. You should be watching the machine at all times. Power feeds are for screw cutting and a smooth cut on a long run.

 

[hunter27]

I suspect this lathe may have come from a school hence the cut outs.
You'll be fighting with the cut out if you are working close to the chuck. The auto feeds are not there so you can skive of. You should be watching the machine at all times. Power feeds are for screw cutting and a smooth cut on a long run.

Thanks I have been checking the wiring today all the interlocks do work but are just not wired in, I am just in the process of wiring them back in but will have to check how fast it stops the chuck. It's surprising how many lathes the schools get through, every other one I saw said that they thought it originally came from a school
I don't intend leaving it running unattended but like the idea of a failsafe and it is easy to neutralise it by adjusting the carriage shut off rod.
Thanks for all replies.
Pete

 

[Shox Dr]

Slow down speed is a function of programming. You need to make sure it has the correct size braking resistor fitted.

 

[Wendelspanswick]

Thanks I have been checking the wiring today all the interlocks do work but are just not wired in, I am just in the process of wiring them back in but will have to check how fast it stops the chuck. It's surprising how many lathes the schools get through, every other one I saw said that they thought it originally came from a school
I don't intend leaving it running unattended but like the idea of a failsafe and it is easy to neutralise it by adjusting the carriage shut off rod.
Thanks for all replies.
Pete

Rather than the cut off switch interrupting the on switch it needs to trigger the off switch as once the motor is running the on switch has no function.

 

[oilyneil]

Dont forget the chuck is screwed on, i wouldn't reccomend having a very quick stop time incase the chuck loosened with anything heavy in it.
Have a look at the tech spec for the inverter as you may be able to programme/wire it for emergency stop as well as nomal run/stop, if so you could have a quick emergency stop , just remember to check it hasn't loosened after using it !
I run a 2 sec slow down on mine in normal use, seems fast enough stop without being hammered

 

[hunter27]

Well after testing all the safety circuit I went into the control panel that has the red/green combined on/off switch, a rotary speed selector and a reverse direction switch. I disconnected the feed wire to the on/off switch and the motor would not run so I wired the safety switches in series with this wire and the switch, now all the safety switches work. The lathe switches off and stops turning pretty quick if any of the switches are activated, if the switch is made again the motor does not restart itself until it is physically switched back on.
I guess this is how the manufacturers designed it to be originally before it was converted to single phase and inverter.
I have no info on the inverter apart from it being a IMO Jaguar CDS 150 from around mid 1990s vintage I think.
Thanks oilyneil I hadn't thought about the chuck coming loose, I will keep an eye on it.
Thanks
Pete

 

[RichardM]

Originally the micro switches cut the supply to the no-volt contactor and tripped that. I have mine working single phase with all the cutouts in use, It's noit hard to adjust the rear cut out - just an allen screw, but you would be better with a little bar welded on the end so you don't have to get the allen key out. Very useful for repeatability stop when turning, stick it on auto feed and let the switch cut it off when it reaches the desired position and I wouldn't be without mine for that reason.

 

[hunter27]

Hi RichardM
I have it wired up all up now, the thing that I don't understand is the microswitch on the back gear lever stops the lathe motor as soon as the allen screw locking it is unscrewed a couple of turns so how it the lathe going to work with the backgear selected ? there is no way to make the microswitch without the screw in it's original locked position.
Agree with allen key in the saddle lock will come up with a better idea for locking that
Pete