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View Full Version : Spindle lock mechanism for 2.2kW china spindle



Jonathan
12-08-2012, 02:24 PM
As in the title... pretty simple just using a servo to shove a spanner on to the spindle:

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(Finish is a bit pathetic due to forgetting to do up one of the X-ballnuts after cleaning it!)

My hope was I could set it to push the spanner in whilst the spindle is running at the lowest speed (4Hz / 240rpm), but there's too much friction when the spanner pushes against the spindle for it to engage. I'm sure after a bit of experimentation with the spanner shape, or even adding a nylon tip / a bearing on the end to reduce the friction it should be possible to get it to engage reliably. For the moment it's fine how it is since as soon as you start tightening the nut the spindle will rotate to the correct position and lock. The servo will apply about 35N so I'm in no danger of damaging the spindle bearings.


http://www.youtube.com/watch?v=D0I_JYOFevc&feature=youtube_gdata

One less spanner to loose :)

I'll tidy up the drawings and post them if anyone's interested.

Next step is to automate the collet nut spanner...

John S
12-08-2012, 03:35 PM
Where is the interlock to stop you starting the spindle with the lock in ?

You could have put a push button on a spring load seeing as you still have to undo the nut.
that way it's fail proof, and cheaper.

Jonathan
12-08-2012, 03:56 PM
This is just a proof of principle made from stuff I had lying around. I've considered putting some means to sense if the spindle lock is disengaged before starting since that's important when the rest of the tool change process is automated.

Just out of interest I tried starting the spindle with the lock engaged.. not a lot happened, the VFD just displays an error after a very short delay.

Edit: Actually since I'll replace the servo tested with a PIC and pushbutton anyway all I need to do is make the spanner only engage when the button is held down. That effectively achieves the same as the spring...

i2i
12-08-2012, 04:29 PM
a microswitch on the back of the spanner that inhibits the run command to the vfd would be good.

JAZZCNC
12-08-2012, 06:39 PM
One less spanner to loose :)

Boy you need to get out more.?? . . . Knock a fooooking nail in wall next to machine then hang the spanner on it.!! . . . Stop being lazy go out use the saved time to nail one of them pretty Uni birds.!!. . . :triumphant:

John S
12-08-2012, 09:50 PM
Boy you need to get out more.?? . . . Knock a fooooking nail in wall next to machine then hang the spanner on it.!! . . . Stop being lazy go out use the saved time to nail one of them pretty Uni birds.!!. . . :triumphant:

What ?? How can he?? You have just told him to use the nail to hang the spanner on ??????????????

craigrobbo
13-08-2012, 09:23 PM
One step closer to an auto tool changer!

Think you could build up a tool changer for our little machines??

Craig

John S
13-08-2012, 09:32 PM
One step closer to an auto tool changer!

Think you could build up a tool changer for our little machines??

Craig

No he's looking for another nail :love_heart:

wilfy
13-08-2012, 09:39 PM
No he's looking for another nail :love_heart:

or something to nail ;)