Any electrician's out there.advice needed !

[Martyboy70]

I'm building a type of centrifuge for my father in law and I'm using an old Audi A4 widow winder motor to power it. What I need to do is make the motor speed variable, any ideas what kit I need.....I.e a variable resistor ? What size would I need to cope with the power......amps etc ?
The reason for the variable speed is so the centrifuge can start slow as its got a bit of a lump to get up to speed and if it starts under full load it will probably burn the motor out.
Any help/advice appreciated 

[gobbleplease]

I'm not sure what a centrifuge is ? But if you are starting something that is going to be hard to get going with a dc motor at a lower voltage your torque will be greatly reduced so again it might not be enough to get it going.
Just a though.

[damoegan]

Just something like a 10k potentiometer should do the trick..

[Martyboy70]

What I'm gonna build is like 2 metal discs which sandwich a circular mould with a hole in the centre. The complete set up spins on its central axis then hot lead is poured in the centre, the centrifugal force makes the lead go to the edge of the mould which forms what ever the mould is while expelling any air.a bit like a wheel spinning and the wheel centre being where you pour the lead.
The discs probably weigh about 8-10kilos

[Martyboy70]

What I'm gonna build is like 2 metal discs which sandwich a circular mould with a hole in the centre. The complete set up spins on its central axis then hot lead is poured in the centre, the centrifugal force makes the lead go to the edge of the mould which forms what ever the mould is while expelling any air.a bit like a wheel spinning and the wheel centre being where you pour the lead.
The discs probably weigh about 8-10kilos

Not being a sparky what does 10k mean ?
Is it 10k ohms,watts,amps ????

[damoegan]

Resistance (Ohms) 

[john87]

I would imagine that using a variable resistor would limit the current at low rpm, therefore if the centrifuge requires more torque than the motor can produce at lower speeds than you may not achieve the desired effect? I am in no way in electrician though so feel free to disregard this opinion