Proxxon conversion

[Jonathan]

I didn't mean to shout last post. It is just that I couldn't see how a motor unconnected with power could feel different when turned with wires connected/un con.

If you turn the motor there is a magnetic field being moved across the coils, so an emf is induced in those coils. If you connect the coils together wrong, they are likely to be short circuited or the current is in opposite directions. Either way a current then flows in the wires. As a current is flowing you have a force (F=BIL) on the wire, and hence the motor rotor. So it takes more torque to turn it.
Another way of thinking of it is in terms of energy. Imagine if you turn the motor faster and faster in this situation, it induces a current in the wires which gets greater as you turn it faster. That current must cause the wires to heat up, due to their resistance, but that energy (heat) has to come from somewhere (conservation of energy) so it gets harder to turn.

If I connect wires as per above from Jonathan, the motor does indeed get stiffer to turn by hand. Connecting Thus however-

Yellow / Black
Blue / Red
Brown / White
Green / Orange
and the motor feels much the same as unconnected. So what is going on here? Is there no standard.

What's going on is I got the wires wrong and you're right!
Thats why I mentioned the harder to turn thing, as a precaution. The datasheet is a bit ambiguous in my opinion as each phase is not marked, only the individual coils so it's 50:50. Most datasheets give you a diagram for each configuration.
This one for instance has a diagram for each of the configurations, and the coil starts are marked:

http://www.slidesandballscrews.com/p...H88-3008BF.pdf

Sorry for the mistake :cry:

[Phil Gravett]

No need to apologize, your tip about stiff motor was the clincher. I am grateful for any info. (even wrong info, 'cos it gets me thinking)
My original data sheet for the motors didn't even have the colours marked. I came across www.probotix.com data sheet for their motors that show the different configerations but could'nt be sure the colours were the same. When I applied the colours from the Zapp sheet that you sent me the link for, it all started to make sense.
So, now I think I connect Yell/Blk to A+
Blue/Red - A-
Brn / White B+
Green/ Orange B-
and if motor turns wrong way then swap A+ & A- around (or B+/B-) ?
Cheers Phil.

[Jonathan]

and if motor turns wrong way then swap A+ & A- around (or B+/B-) ?
Cheers Phil.

Yes that will have the desired effect.