DC injection braking for metal turning lathe 1

[Tredders]

Hi All
I am a model engineer in Brisbane, Australia, and am treating myself to a new lathe.

I would like to install a DC injection braking system on the motor so the spindle will stop when the carriage gets to a certain point, eg when cutting a thread up to a shoulder.

The lathe motor is a single phase 2HP induction motor, running a 160 mm or 200 mm chuck.

I anticipate having a knockout bar moving under the carriage with the carriage until it pokes a button switch at the left end of the lathe bed to activate the DC brake.

I can assemble electronic parts safely so that the appliance will work.

Any direction or advice appreciated.
Thank you for your time & thoughts.

 

[waross]

Having a rod push a button is a bad idea. You can expect a lot of crushed buttons.
Better to use a lever and spring to hold the button down and let you rod move the lever away from the button arranged so that the rod can over travel past the lever without doing damage.
A cam passing a limit switch will work well also.
You may be disappointed with the stopping time of DC injection.
It may be more effective and easier to build to used an electric clutch/brake on the motor shaft.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Tredders]

Thanks Waross
I’m thinking I might stick with mechanical knockouts for the half nut and power feed levers and let the lathe spindle stop under it’s own inerta.
Regards
Tredders