Routers


bigarm

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Long before the PC 7518 was available I had a PC speedtronic 5182 EHD 3+hp commercial duty router. I put many tough hours on it and replaced it with a 7518 when parts got hard to find. Finally found parts and have reserved it for the biggest bits I have. 

Yes you can make doors with a smaller router if you take multiple passes and you may probably shorten the life of the motor.  But if you want the router to last get something over 3 hp and take care of it. 

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7 hours ago, wdwerker said:

Long before the PC 7518 was available I had a PC speedtronic 5182 EHD 3+hp commercial duty router. I put many tough hours on it and replaced it with a 7518 when parts got hard to find. Finally found parts and have reserved it for the biggest bits I have. 

Yes you can make doors with a smaller router if you take multiple passes and you may probably shorten the life of the motor.  But if you want the router to last get something over 3 hp and take care of it. 

But that is a using a rather bunk measure of horse power. If the definition of horsepower is 746 watts you can only get 2.4 hp on a 15 amp 120 circuit.  So why not use the motor from one of those 7 hp shop vacs it is clearly more powerful right?  Except of course it really isn't.

 

Rather like those old craftsman tablesaws that claimed to be 3hp but really are more like 1.5 hp.  So what is the real hoursepower and is that the important metric or not?

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I say no to your last question. If they are printing inflated HP ratings, is the rating not inflated equally across the range? So someone says "look for the 3hp model" and someone always chirps in with how it is not a true 3. Somewhere it becomes like a 2x4, it is only 1.5x3.5 and we adjust. 3hp just becomes a label to help guide. 

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8 minutes ago, C Shaffer said:

I say no to your last question. If they are printing inflated HP ratings, is the rating not inflated equally across the range? So someone says "look for the 3hp model" and someone always chirps in with how it is not a true 3. Somewhere it becomes like a 2x4, it is only 1.5x3.5 and we adjust. 3hp just becomes a label to help guide. 

But what about the new Bosch MRC23 that isn't inflated?  It only claims to be 2.3hp and so wouldn't be viewed as a 3hp model despite being functionally equivalent at least in terms of power.  This only works if veryone is useing the same scale and in tablesaws they now seem to all be using the same scale so you no longer have claims about 3hp contractors saws that are totally different in terms of power from a 3hp cabinet saw.

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I really hate that tool makers rate the motors in amps these days. That tells me exactly NOTHING about the work the tool can accomplish, only how much juice I may pay for while using it.  KW ratings are no better, as kw is a unit of energy - in this case, how much electrical energy the tool will consume, presumably while producing maximum torque.

Horsepower actually tells me how much work ( force x distance) a tool can do in a given amount of time. With a known horsepower rating (assuming it is accurate), a bit diameter, and  the material shear strenght, it is possible to calculate how deep the tool can cut at a given feedrate without slowing the motor below the desired speed.

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8 minutes ago, wtnhighlander said:

I really hate that tool makers rate the motors in amps these days. That tells me exactly NOTHING about the work the tool can accomplish, only how much juice I may pay for while using it.  KW ratings are no better, as kw is a unit of energy - in this case, how much electrical energy the tool will consume, presumably while producing maximum torque.

Horsepower actually tells me how much work ( force x distance) a tool can do in a given amount of time. With a known horsepower rating (assuming it is accurate), a bit diameter, and  the material shear strenght, it is possible to calculate how deep the tool can cut at a given feedrate without slowing the motor below the desired speed.

They are all measures of energy.  Talking energy consumed vs energy output is a reasonable distinction but it is all energy.  Energy is force over distance so it works if it is volts times amps or torque times RPM's.

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20 minutes ago, ponderingturtle said:

They are all measures of energy.  Talking energy consumed vs energy output is a reasonable distinction but it is all energy.  Energy is force over distance so it works if it is volts times amps or torque times RPM's.

Horsepower ratings are "supposed" to be based on actual measured torque and speed. Simply listing a motor's current draw does not account for heat losses in the machine, which does no useful work.

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19 minutes ago, wtnhighlander said:

Horsepower ratings are "supposed" to be based on actual measured torque and speed. Simply listing a motor's current draw does not account for heat losses in the machine, which does no useful work.

And yet they have so many that clearly are lying. 3.25 HP is more than can be run on a 15 amp 110 circuit,  so either they need to win the noble prize for physics for free energy, or are lying.  At a guess they probably got away with Max Torque x Max RPM but that is of course BS in terms of real power.

 

It is was real they would so have invented a perpetual motion machine.

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Horsepower ratings are "supposed" to be based on actual measured torque and speed. Simply listing a motor's current draw does not account for heat losses in the machine, which does no useful work.

And yet they have so many that clearly are lying. 3.25 HP is more than can be run on a 15 amp 110 circuit,  so either they need to win the noble prize for physics for free energy, or are lying.

Hence the quotes around -supposed-. ?

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5 hours ago, ponderingturtle said:

And yet they have so many that clearly are lying. 3.25 HP is more than can be run on a 15 amp 110 circuit,  so either they need to win the noble prize for physics for free energy, or are lying.  At a guess they probably got away with Max Torque x Max RPM but that is of course BS in terms of real power.

 

It is was real they would so have invented a perpetual motion machine.

3.25 HP from 15 amps? Why not 4 HP? http://www.amazon.com/Bosch-GTS1031-10-Inch-Portable-Jobsite/dp/B004O7FX20

It's like PMPO Watts for speakers... BS

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Quoting PB, when talking about the Watt to HP formula a while ago:

On March 26, 2015 at 6:20 PM, dwacker said:

The way it was explained to me was those calculations work fine if your calculating the hp of a light bulb. Motors in general and especially cheap motors you need to look at power factor to calculate HP thus the difference between real power and apparent power. This is really why so many induction motors produced today don't really have stated HP.

 

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All I have to say is from my experience....... For my router table I have the tried and true Porta Cable 7518 mounted on the Wood Peckers lift..... It has been in my table for going on close to 10 years now and has not failed me yet... I have used it with 1/8 in straight bits up to the whopping 3 1/2 in. Panel bits with out issues at all...................

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