Router Speed Controller?

[Andrew]

http://www.busybeetools.com/products/router-speed-control-115v-15a....

Found this little item while looking for a replacement switch for my jointer. Does anyone know if this would work for other tools, especially belt sanders? I don't know enough about the finer points of electrical stuff to say. Would be pretty handy though, much easier for the small shop than custom wiring an existing tool or setting up stepped pulleys.

[Russell Vance]

HI Andrew,

The industrial ones work OK for brushed motors although when they slow down they seem to "step" and clunk and the original cheap one we had with our big green Hitachi router melted down quite quickly.   It appears that its not the current rating that you need to beware of with the cheap ones but the current draw on start-up and what sort of start circuit the motor you wish to control has.  That's all I know and we don't use them anymore as multi-speed tools are more common and cheaper these days.

Rusty.

[J R Emmett]

I agree with Rusty on using them for larger motors.  I do use one with my venerable Porter Cable router - particularly when using acrylic templates.   Most of these are based on a simple SCR (Silicon Controlled Rectifier) circuit that works pretty well with brushed motors - as long as you don't push the current rating AND (as Rusty states) there isn't a big current surge on startup.  Might work OK on a small bench top belt sander (1" belt, 4" disc) like the little Delta that I use to shape nut blanks.

BTW - They do have other uses:

• I also use it to control the temperature on the mini-crock pot I use for wax potting pickups
• I believe that there was another post about using it to control heater blanket temperatures

[Andrew]

So would it be safe to assume that this wouldnt be a permanent solution in most cases? Thanks for the pointers guys.

[J R Emmett]

Whether it's a permanent solution depends on the application.  I've been using mine for almost 15 years.  If (and when) my Porter-Cable router dies, I'll definitely purchase a variable speed model.

[Robbie Collins]

You could wire in a thermistor to create an inrush current limiter:

http://www.ametherm.com/inrush-current/surge-current-causes-and-pre...

[Andrew]

Most of that stuff seems over my head, but I think they pinned down the reason my jointer switch has failed. I may have to look into this a little further.

[Russell Vance]

Andrew,

Hi mate, jointers have a heavy cutter head and the high starter current will kill a flimsy start circuit quickly (the Powermatic start circuit went west quickly in our case)......if you can get a higher capacity switch it's money well spent.

Rusty.

[Andrew]

Yeah I was thinking something like that. I disassembled this one and cleaned it up nicely but that only lasted 6 months or so. Might be tricky to find a 'heavy duty' one that will fit without too much modification.

[Russell Vance]

Andrew,

At the risk of sounding like a heretic:  Google machinery start/safety  switches on ebay and type in "China" after "ebay".  A lot of this kind of switch hardware is now made there and it's cheap shipping.  If its a simple on/off machinery switch (single phase?)  Just buy the biggest rated switch you can afford (I'm partial to the big box types with the large red kill "mushroom" buttons for safety sake). 

The problem with the branded in-country stuff is it is priced for companies and purchasing department that will pay whatever they ask just to get their machines back on line.   A Start box for a Powermatic, from their spares department requires you to sell one of your children.

But and its a SERIOUS BUT - if you get a little lost in what you are doing with electricty - don't do it.  You never forget your first time becoming an "earth circuit" - some never remember.

Rusty.

[Andrew]

Well noted. One jointer boo boo was lots :).

[Howard Klepper]

Short answer is no.  Routers use universal motors, with speed control from a thyristor (a solid state on/off switch).  Almost all stationary shop machines use AC induction motors.  Speed control for these is more complex; it's done by varying the frequency and voltage of the AC.  These controls are mostly made for three-phase induction motors.

[Andrew]

Thanks for cutting to the short of it for me. Id hate to spend the cash for something that wouldnt work or might damage something. Im not hurting for a slow speed belt sander. Most things Id use one for I can probably do nearly as quickly with a few files.