PC 7518 Speed Fluctuates

[julian abram]

I rarely run a large diameter bit on my PC 7518 but ran a large diameter panel cutter today. This was a Freud bit with backcutter, on the label it recommended 12,000 rpm so I adjusted the speed control to the nearest setting of 13,000 before starting. I noticed the router speed would speed up and slow down with no load. As I ran the panel it seemed like the speed stabilized and ran stead as the panel was being cut. Is this normal for the speed to fluctuate with out a load?

[Mike Heidrick]

Yes it is normal.

[pat warner]

Not normal. The speed control is on the way out.
Don't know why PC has had so much trouble with speed controllers. But they do. The 518's were terrible.
I have had a 6 7518's. And this last one, a year old, is good.
I would be suspicious of a control that fluctuates.
DW, Milwaukee, and Bosch are much more stable.

[Bruce Wrenn]

The capacitors are the most likely problem. Bad capacitors are common in
PC speed controls. Same goes for flat screen TV's. Fixed one today with a bad $0.59 cap.

[scott vroom]

I had the same issue and called PC...they told me it was normal.

[Mike Heidrick]

Same here when I called the.. I am not arguing with Pat though. :)

[julian abram]

Well, different opinions on this, I'm a router amateur but think I'm going to lean toward Pat's thought. My horse sense says this cannot be normal. Guess I will just keep running it until it dies.

[Nick Decker]

When I run mine at one of the lower speeds, it starts fast and throttles back to the lower speed. I just figured that was the way the controller adjusted it, so I wait a second or two until it stabilizes. After that it doesn't seem to go up or down.

[George Bokros]

Mine has worked like this for a long time. I can't remember if it ever worked any differently.

[Larry Edgerton]

The speed controls on mine act like they are on a time delay, and have since new. As a cut gets heavier it slows and then ramps up to meet the larger need. Have burnt one out, but three still suvive. I just wired around the one that burnt out. .

[Robert Stanton]

My PC 7518 speed controller died once under warranty and I got it fixed. It has failed again with very little use. I am wiring around it with an aftermarket speed control.

[Mark Bolton]

This may cause a stir but I have been using electronic tools since Metabo started releasing them in the late 80s early 90s. The speed control is not a speed control in the sense that most people think about it. It is not statically throttling voltage to the motor. It's an electronic speed control which sets a fixed amount of power based on the setting chosen and then applies more power as the controller sees the load increase. In the case of metabo this almost made them bail out of the US market because in the case of an angle grinder for instance, the tool will wind up to speed on 90 volts holding he remaining 30 in reaerve. As you bear down (load) the tool, it applies more and more power to maintain the desired RPM. US monkeys, not hearing the tool bog down, would think they were not grinding, so they would bear down harder and harder not looking at the work but rather thinking if the tool wasnt bogging they werent grinding.

The 7518 is the same way. It idles with a fixed power consumption based on the switch setting and as you apply load to the router it feeds more power to maintain RPM and not bog. Freewheeling the router can lead to the controller cycling/surging with a large cutter but the instant load is applied its smooth sailing

[Nick Decker]

US monkeys?

[Mark Bolton]

Yes, an individual who rather than visually, and tactiley (sp), gauges the quality and speed of production, instead relies on things like sound, time, the number of swipes or passes, over a part, to pass it through to the next station.

You can take issue with it all you want but at the time these individuals we're actually over grinding due to tool performance as opposed to grinding to the spec. Through observation.

[Nick Decker]

Not really taking issue, but I find it odd that people in the U.S. would, as a group, fall into this category. Sounds like a training problem, rather than a national one.

[Mark Bolton]

Don't I wish.

[Robert Stanton]

My PC 7518 speed control has failed twice and I can assure you the modulating speed observed when new is not the same as when it begins failing. The OP is describing the failure of his speed control. Soon it will only run at two speeds. On and off. The US monkeys and their angle grinders don't apply in this case.