Tool Test: 3+ Horsepower Plunge Routers

 

This always amazes me: How does a 15 Amp motor running of a "houselhold circuit" (assuming 120 V) deliver 3+ HP ?

Modern magic...

 

The rating of a router is peak horsepower, not mean or average horsepower. As one is routing, the router is generally taking much lower power than the rated peak power from the receptacle.

As one routes, the router might hit a tough spot, say a knot in the wood. The router struggles to keep going, drawing more power from the receptacle. Once through the tough spot, the router finds things easier. So, the power drops again. This peak in the power drawn by the router should be not more than the rated peak horsepower.

Okay, one asks why the circuit protector (fuse or circuit breaker) doesn't trip. Well, that has to do with the response of the protector. A 15 Amp protector will carry 15 Amps, or less, indefinitely. It may carry 30 Amp for say 10 seconds without tripping. 60 Amps for 2.5 seconds. And so forth. (An example curve showing this relation is at http://downloads.eatoncanada.ca/dow...ircuit Breaker Time-Current Curves For QUICKLAG Industrial Circuit Breakers.pdf)

Back to the question: 3 HP would be about 2241W or 18.7 Amps at 120V. If it takes one three or four seconds to get through the rough spot, then the 15-Amp protector is not likely to trip. If one keeps the router plowing through a rough spot for say two minutes, without letting up on the router, then the protector is likely to trip.

Ah ha! Not magic; just smoke and mirrors.

Cassandra

 

Why do American vendors always quote HP when European ones always quote wattage? Just curious.

Looking at the selection of routers it seems a few are a bit out-dated. The Makita 3612C was been replaced in the EU by the Makita RP2301FCX a while back whilst deWalt brought out a new top end workshop router (the DW626) five or more years back, although the DW625 is still in production (and now more than 25 years old).

 

It could be the funny voltage you have in the UK after all it's not a light bulb.

=========peak HP makes more sense to me than watts..====


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They say they push the routers until the stalled out. Yikes! Talk about pushing something to the breaking point - I can't imagine pushing a router that far to the limit.

 

It's really easy with Corian, believe me, the stuff eats routers for breakfast in production environments! We had a brand spanking new Hitachi M12V2 on a job last year which did all of 3 days on a big Corian job before it overheated and cooked the motor (did I tell you that bench joiners can be real animals?). The replacement did a bit better (2 weeks) but the company decided not to buy them for some reason. The deWalts we had tended to last a lot longer, as did the Freud FT2000s (although they had a certain tendency to shed parts)

The best router I came across (at least for solid surface) was the Festool OF2200. Pity the cost is in orbit, but they are built like a tank. Most of the guys I know doing solid surface have migrated to Festool eventually for just that reason. I've got the 150mm Rotex myself together with two of the smaller plunge routers so the next logical steps would be the OF2200 and a matching industrial vacuum cleaner in stylish green. That always assume the missus doesn't catch me spending so much money!

 

Just in time for Christmas!

It always seems to come down to blue vs. green, and then blue wins with the budget conscious... Although orange is also entering into the picture...

 

Most manufacturers quote *amps* as input and *power (HP, watts)* as output. A 18.7 Amp motor would have to have a 100% efficiency to deliver 3 HP. I doubt router motors are much more than 60% efficient (anyone has better figures?), so the peak current would be over 30 Amp.

However, thanks for the link to the graphs. If I interpret them correctly a 15 Amp rated breaker could carry 30 Amps for a whole minute (give or take - there are two curves).

That explains why I was able to weld on a 15Amp breaker

 

That explains why I was able to weld on a 15Amp breaker

I have welded many a screwdriver or set of pliers at 15A.

Even tried my own flesh on a number of occasions, did not work so well.

 

Hi DJ

If you are going to drop 200.oo bucks for a router I would suggest the Red top below, it comes with a lift built in (in all 3 basses , that way you have one for the router table and the others for hand jobs) and if you want a power lift just pop in a power nut driver from the top side and you have it done..

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Just as a foot note, I can think of anyone in their right mind would buy a router for 800.oo dollars. more money than brains I think..
But that is just my 2 cents after all it's just a motor that can spin a router bit..

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Even tried my own flesh on a number of occasions, did not work so well.

For flesh oxyacetylene is a better choice. Followed by superglue...