Router speed control

[ljoe1969]

Hi.

I found this add on the web today.

http://www.woodcraft.com/family.aspx?familyid=3957

Does anyone know how to make one of these diy?

[gar]

050729-1045 EST USA

I have comment on the ad. The writer of the ad does not know the meaning of horsepower.

They are reasonably correct on torque, but at lower speeds there is less cooling because the internal fan is running slower, and generally maximum current has to be reduced for continuous duty or an external fan used.

Basically a motor is constant torque limited from a continuous duty basis for thermal reasons.

Horspower = constant * speed * torque. Thus, horsepower goes from zero at zero speed to maximum at maximum speed for a constant torque. Therefore, full horsepower is not available over the full speed range.

These comments relate to maximum steady state capability of a motor.

.

[erase42]

cant tell you how to make one, but you can get them on ebay for as little as 15 dollars. I tore one apart once and they are quite simple, there is a pot, a power transistor and only a couple other components.

[sol]

Yes they are quite simple, Harbor Freight has them on sale for $12 frequently so DIY does not seem worth the trouble by the time you include cord, box, switch, knob, receptacle, etc. The cheap ones have served me well; are used regularly on router vac and router.

[ljoe1969]

Thanks.