As in the title... pretty simple just using a servo to shove a spanner on to the spindle:
(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.
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...
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.John S -
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...
Last edited by Jonathan; 12-08-2012 at 02:04 PM.
a microswitch on the back of the spanner that inhibits the run command to the vfd would be good.
One step closer to an auto tool changer!
Think you could build up a tool changer for our little machines??
By spindeldoctor in forum Manufacturer NewsReplies: 0Last Post: 13-11-2013, 06:50 PM
By HankMcSpank in forum Routers, Spindles & ControllersReplies: 43Last Post: 29-08-2013, 09:19 PM
By 8iggles in forum Routers, Spindles & ControllersReplies: 18Last Post: 09-02-2011, 09:15 PM
By Robin Hewitt in forum Milling Machines, Builds & ConversionsReplies: 5Last Post: 30-08-2008, 07:15 AM