# Router Speed Control



## mr500 (Mar 27, 2012)

Hello all...I have a craftsman router that is not var speed. Only has 0-25000. I want to use the speed controller I found over at harbor freight. Anyone have any luck with those? 

Looking at making my first raised panel doors. The cutter only needs to run at 12000. Any help for a newbie will be most appreciated


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## mr500 (Mar 27, 2012)

???


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## BigJimAK (Mar 13, 2009)

Mike,

I have not worked with that specific speed controller but it appears the HF speed controller is similar to one I own from MLCS. Speed controllers are designed specifically for universal brush-type motors as used in routers. They work well with basic (non-electronic controlled) routers.

Routers with electronic circuitry for slow-start, variable speed or electronic braking may have issues with them however. Some people who are handy with electronics and electrical devices have gone in and bypassed the electronics in the router to use the speed controls but that is obviously done at your own risk, both for your safety and the risk of damage to the router.

Since your Craftsman does not have speed control and is unlikely to have electronic braking, I would focus on whether or not it has a soft-start. If it doesn't have a soft-start you will feel a very noticable torque in the router (trying to rotate) when you turn it on. Soft-start is added to some routers to accelerate the router speed slowly (speeding up over a second or two) rather than turning on like a light switch.

I hope this helps.

Jim


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## Dmeadows (Jun 28, 2011)

If your router does not have speed control, it does not have soft start either. both features are provided by the same electronics. The HF unit should work very well with your router, Mike.


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## KenBee (Jan 1, 2011)

mr500 said:


> Hello all...I have a craftsman router that is not var speed. Only has 0-25000. I want to use the speed controller I found over at harbor freight. Anyone have any luck with those?
> 
> Looking at making my first raised panel doors. The cutter only needs to run at 12000. Any help for a newbie will be most appreciated


I use the HF speed controller with my PC 892 table router and it works just fine. Even if it only lasts a year and has to be replaced I have still saved money.


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## mr500 (Mar 27, 2012)

Great Thanks so much. I have 2. The one I want to use does not have soft start. The other one does. Again great info thanks a BUNCH!!!!!


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## wbh1963 (Oct 11, 2011)

I have been using the HF speed controller for a few months and it works great with my older routers.


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## rwl7532 (Sep 8, 2011)

Question: why can't a simple dimmer control be wired up as a speed control for a router with neither variable speed or soft start?


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## wbh1963 (Oct 11, 2011)

rwl7532 said:


> Question: why can't a simple dimmer control be wired up as a speed control for a router with neither variable speed or soft start?



In North America most line power is 60 cycles per second (60hz). A huge portion of the rest of the planet uses a 50hz system. The RPM of 'dumb motors' can be affected by reducing or increasing the frequency or voltage delivered to the motor.

I'm not entirely sure what the affects of lowering the voltage to decrease the speed would be. As I understand it, the speed control devices manufactured for the 'router' application function by removing some of the AC pulses from the time period.

I suspect that decreasing the frequency instead of the voltage minimizes the proportional loss of torque (from the horsepower potential of the motor).

Would any of the 'real' motor geniuses on the board like to jump into this foray and let us know how far off (or possibly on!) target my best guesses are?


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## Dmeadows (Jun 28, 2011)

rwl7532 said:


> Question: why can't a simple dimmer control be wired up as a speed control for a router with neither variable speed or soft start?


Insufficient current rating.. they are usually only for a couple of hundred watts of lighting or less. If you can find a 15 amp one, it might work.. never tried it!


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## rwl7532 (Sep 8, 2011)

I see dimmers offered at Home Depot rated at 1000 watts. But with prices that are approaching $20, one may as well do the HF model. I haven't checked out E-bay.


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## bobj3 (Jan 17, 2006)

Hi 

I have tried it and the dimmers don't work they burn out in short order or to say right off the bat  I have used the HF ones for over 6 years and no problems at all you can get the 15amp or the 20 amp models from MLCS , stick with the device that works...sometimes you need to step up to the pump to play..

====


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## BigJimAK (Mar 13, 2009)

bobj3 said:


> ...sometimes you need to step up to the plump to play..


Don't let your Bride hear you saying that, BJ! :fie::fie::fie::haha::haha::haha:

Jim


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## wbh1963 (Oct 11, 2011)

rwl7532 said:


> I see dimmers offered at Home Depot rated at 1000 watts. But with prices that are approaching $20, one may as well do the HF model. I haven't checked out E-bay.



1000W only pencils out to about 8 amps, most routers would smoke it quick.


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## ggom20 (Feb 1, 2012)

Hello!

I've been formed as an electronics tech, and I can tell that it has to be designed for motor use.

The ones for dimmers are not.

Some made for motors will stand the power, but with poor results:
When need for some power, the motor will slow down.

Some made for motors will "try"to understand motor's speed and need for power and 
giving a bit more when needed.
-Those are the best ones to use separate from the motor.

The ones inside the machine can take advantage of using a motion captor
witch tell them what is the actual real speed of rotation.
Those are the best ones!

They are inside: Bosh, Festool, Metabo, Makita,and others witch I'm not aware, being far away from american market for tools.

Most of cheap routers don't have it even if they have "Speed control".
They just work as if they where outside the machine.

Been in the speed control problem as electronic specialist, we had to go for
motion caption, It's working a lot better.

About External Speed controlers I would not go to cheap because it's a difficult problem for the external circuitry to guess motor needs.

Two basical designs:

giving the motor a part of an alternance of alternative current.
Most of cheap design.

Giving the motor full waves, but not all the waves, far better.
not frequently used, but a lot better.

The third design,that you will see in future for your tools is to use some tri-phas motors and then change the speed by changing the number of cycles by second.

It already is made for CNC's. 
And for a tiny battery operated drill made by Festool.



About 50 HZ or 60Hz it does not change much things.
Things made for 50Hz should work on 60Hz , except turntables.
Regards.
Gérard


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## Dmeadows (Jun 28, 2011)

ggom20 said:


> Hello!
> 
> I've been formed as an electronics tech, and I can tell that it has to be designed for motor use.
> 
> ...


After all that, if your goal is to not spin a 3 1/2 inch panel raising bit at 25000 RPM... the $20.00 HF unit will work quite nicely!


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## malb (Sep 15, 2008)

wbh1963 said:


> In North America most line power is 60 cycles per second (60hz). A huge portion of the rest of the planet uses a 50hz system. The RPM of 'dumb motors' can be affected by reducing or increasing the frequency or voltage delivered to the motor.
> 
> I'm not entirely sure what the affects of lowering the voltage to decrease the speed would be. As I understand it, the speed control devices manufactured for the 'router' application function by removing some of the AC pulses from the time period.
> 
> ...


This is basically correct for Induction motors, the brushless units that typically operate larger table saws, drill presses, and other heavy duty mains machinery. These are fixed (low) speed motors (max 3000 RPM for 50 c/s mains or 3600 RPM for 60c/s mains) and the speed is related to the mains frequency with a small reduction in RPM as the motor is loaded.

Router motors are universal motors, which means that they have brushes built into the motor, and the speed is voltage dependant rather than frequency dependant. A basic universal motor should be capable of running from an appropriate voltage DC or AC supply, with a frequency up to about 100c/s. At higher frequencies the magnetic losses in the winding cores can become higher and limit the performance of the motor.

A dimmer style speed contoller which reduces the effective input voltage works with universal motors, but does not normally include any feedback to maintain motor RPM, so the router speed may vary as you load the motor by taking a heavier cut. A lot of the routers with built in speed control now sense the motor RPM and adjust to voltage to maintain speed.

For the original poster, you do not mention the model of your Craftsman router, or it's capabilities. If it is a fixed speed unit, and you want to slow it to half speed to turn a large panel raising bit, be aware that you are also reducing the airflow from the inbuilt cooling fan and significantly increasing the current draw of the unit, both things that can lead to overheating. Take light cuts and check the motor temperature after a few passes to ensure that you are not overheating the motor.


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## paduke (Mar 28, 2010)

Dmeadows said:


> If your router does not have speed control, it does not have soft start either. both features are provided by the same electronics. The HF unit should work very well with your router, Mike.


Duane
I have a craftsman with slow start and no variable speed


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## Dmeadows (Jun 28, 2011)

paduke said:


> Duane
> I have a craftsman with slow start and no variable speed


OK Bill, guess that's the exception that proves the rule! I would not recommend external speed control on it in that case. It may damage the soft start module.


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## Dmeadows (Jun 28, 2011)

malb said:


> For the original poster, you do not mention the model of your Craftsman router, or it's capabilities. If it is a fixed speed unit, and you want to slow it to half speed to turn a large panel raising bit, be aware that you are also reducing the airflow from the inbuilt cooling fan and significantly increasing the current draw of the unit, both things that can lead to overheating. Take light cuts and check the motor temperature after a few passes to ensure that you are not overheating the motor.


Actual measurements to not support this. At full speed no load my router pulls 9 amps. At lowest speed it pulls just under 5 amps. So yes there is less air flow, but also less heat! Also several members have done this for years with no adverse effect.


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