unipolar stepper motor

#1
Hi all,

recently i've managed to burnout a phase in one of these link$...
i'm already getting another three on tuseday next week,
for those who can't get the link working it's a 48 step unipolar stepper, rated for 12v and with enough curent can deliver upto 500g/cm worth of torque, depending on the datasheet you look at
i was running it at 14v for fairly long periods of time,

for laughs i want to rewind it maybe even give it a little more "mmmph" and or run it at a higher voltage to get more bang for my $$$

any hints,ideas,words of "no" it's too dangerous,debates of an off topic nature all appreciated,
-=(-_-)=-
 
#2
I don't know about rewinding a stepper, that would be very difficult.

I do know that to increase the torque at high speed you can increase the voltage because the transient current change is relatively slow.

If you want cheap/free steppers rip apart some printers. Inkjets are plentiful and they are full of motors. Most are rated to 24V and fairly torquey.
 
#3
From the couple that I have pulled apart they are straight forward round coils
on a top and bottom plastic former (a couple of hundred turns each).

You could probably get the wire form a Motor Rewinder bloke etc.
But the hardest part may be getting the thing apart without damaging it
so much that it won't go back together properely.

Spot Welding is the bane of all tinkerers, the only way to break a Spot Weld is
to drill one side of the weld out completely. You have to make custom made drills
bits that resemble an Endmill (almost flat).
Or rotate 1 of the 2 plates, which only works on a single weld.

Some others I have here use small plastic posts molded into the coil former
which protrude through the outer metal casing and are melted to form a plastic
rivet head when assembled. Once you drill out the plastic there is nothing left
to hold it together when re-assembled. You can use 2 larger plates and make
a sandwich to hold it, but it ain't pretty.

Only the larger motors and larger $$ usually have 4 simple blots :(
The mass produced motors are usually a throw away item when broke unfortunately.
 
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