Gallery, Projects and General > Project Logs
Mill Power feed
Bernd:
If they are permanent magnet motors you'll create a current trying to turn the shaft. Might not be good for your electronics. Could cause voltage spikes. Plus the faster you try to turn the motor the more resistance.
For an experiment take a DC permanent magnet motor and tie the two leads together. You'll feel the resistance of trying to generate a current.
Bernd
Darren:
That's the back EMF I was talking about before.
I decided that it wouldn't be a problem in this situation for two reasons.
a: These types of motors stop dead when the power is switched off.
b: By using a center off switch we have disconnected them from the power supply completely when the switch is off.
Point to note about permanent magnet motors, they make very in-efficient generators, you really have to spin em fast to be of any use.
Better to use a field coil type motor I believe. 3 phase types can be very good.
Divided he ad:
Well.... This should be interesting to some of you?
Since it was a bank holiday today I decided to have a go in the shop.... Not good weather and a day for free :)
So we left it needing a bit of a lever for the engage/disengage.... Well here's what I've been upto...
Bore a short adapter for holding a flanged bearing.
Make a rear part to the bearing housing then cut a slot in it and cross drill, tap one half M5 and drill 5mm clearance through the oter half.
(plasticcy aluminium!!)
Cross drill then shape and size (to 12mm) a mild steel bar
Cut the 8mm slot in the bar (made over length since I was making this up as I went along!)
Narrow the bar for the slot on the bearing holder to fit.
Make the mounting for the lever..
Mount the lever pivot mounting
Cut and turn down the driveshaft to take the bearing (tapped M4 into the centre to hold the bearing on, not shown)
A quick and rough assembly of all parts... (Handle not cut to length and the allen bolts are to be replaced with purpose made 5mm bars threaded only where needed)
Finally a couple of short vid's. Using the CB power supply donated by Darren (not yet modified) just to check it all works....
Got to swap the split link round... it's too deep on one side and occasionally catches the post! (the other side is the same depth as the rest of the chain)
Hope that shows this will work :thumbup:
Ralph :borg:
Brass_Machine:
Yup! I believe that shows it will work most definitely. Very good.
Eric
Divided he ad:
Thank you Eric :thumbup:
Just the electric trickery to figure out now..... I'm going back through the post to see what Darren wrote :coffee:
Ralph.
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