Over head flxible grinder help

[tommy dunlop]

Don't work still runs backwards

 

[tommy dunlop]

It's starting to do me head in lol

 

[Seadog]

That doesn't make any sense at all. If you reverse the brushes it must change direction.

 

[tommy dunlop]

I thought it would do that by changing brown and blue at the plug, I've even reversed the magnet in the middle still goes backwards

 

[tommy dunlop]

Can I buy rotory burrs that cut in reverse lol

 

[Seadog]

No, no, no! It's AC - Alternating Current. The polarity at the plug changes 50 times a second (actually it's 100, but that doesn't matter here). It's the magnetic field polarities between the rotor and field coil that determines the direction of rotation.

 

[tommy dunlop]

What I can't work out is why it runs backwards in the first place what is the reason for it it reverse

 

[tommy dunlop]

So how does the lathe run forwards and backwards on a switch,it does have like a cylinder capitor on the back of the motor

 

[tommy dunlop]

Electrickory lol

 

[Seadog]

Your lathe is using a standard induction motor which will only run on AC. The direction of rotation is determined by a "magnetic kick" given by, usually, a start winding, which is then switched out of circuit. By reversing this winding, which is what the switch does, it kicks the rotor in the opposite direction. Once rotation is established it keeps going in the same direction until powered off.

As already mentioned, the motor you have is a Universal Motor. This will run from either AC or DC. The commutator, the segmented collar that the brushes run on, provides the reversal of the magnetic field to keep the motor spinning.

 

[tommy dunlop]

As a great man once said every days a school day

 

[tommy dunlop]

Ac/dc

 

[tommy dunlop]

Wonder what the L,R is left right?

 

[tommy dunlop]

L.R

 

[Seadog]

Lyme Regis?

 

[tommy dunlop]

 

[eddie49]

I've even reversed the magnet in the middle still goes backwards

Could you please explain this "magnet" thingy?

 

[tommy dunlop]

The magnet thing is the bit in the middle that gets fixed is it called a field winding, I pulled it out of the casing and reversed it and she still runs backwards

 

[tommy dunlop]

I wonder what Fred would say

 

[tommy dunlop]

Would it make any differance if I bought one of the d,c converters with speed controller and forward and reverse switching