motor swap?

[Van Huskey]

The part that bothers me is that you would contemplate cannibalizing a venerable cast iron DeWalt 7790 12" RAS to try to better a BORG Ridgid TS. That is grounds for confinement in an institution for observation, in some states!

~Chip~

Agreed, IF you really want to do a motor change sell the Delta and use the money for a motor, likely have some left over.

Get a high quality thin kerf rip blade and thin kerf crosscur blade and chances are it will be enough HP for 99% of situations.

Freud (Industrail not the BORG stuff), Forrest, Infinity and Tenryu are excellent blades to start with.

[Eric Wheeler]

Hi Aaron, thanks for the nameplate info from the DeWalt radial arm saw.

Based upon the 8 amp current at 240 volts it's about a 1 1/2 HP motor, which sounds like what you already have in your tablesaw.

regards, Rod.

I'm getting 2.7 HP with the 120 and the 240...how are you getting 1.5?

1 HP = 746 Watts
Watts = Volts x Amps
Watts / 746 = HP
(Volts x Amps) / 746 = HP
(120 x 17) / 746 = 2.7xxxx
(240 x 8.5) / 746 = 2.7xxxx

BTW, just cuz a motor lists an HP doesn't mean that's what it truely is, like mentioned it is marketing hype, they use the surge (startup power) current of the motor to do the calculation that I did. So for the split second that the motor is drawing many more amps (your lights usually dim) than rated, they use that number instead of the running current to calculate. Kinda like lawn and garden tractors, the last time I was looking into them they had 27 HP out, wouldn't surprise me if they had 30 HP by now, but take that 27 HP and put it up against an old 16 HP tractor and see which one is more capable.

[John Lanciani]

[QUOTE=Eric Wheeler;1509848]I'm getting 2.7 HP with the 120 and the 240...how are you getting 1.5?

1 HP = 746 Watts
Watts = Volts x Amps
Watts / 746 = HP
(Volts x Amps) / 746 = HP
(120 x 17) / 746 = 2.7xxxx
(240 x 8.5) / 746 = 2.7xxxx



Not quite. For an induction motor the formula for HP is volts x amps x power factor x efficiency / 746. For a consumer grade single phase motor, .80 is a safe bet for both power factor and efficiency at full load. Using the correct formula that motor is +/- 1.75 hp.

[Erik Christensen]

what chip said - but maybe a bit less harsh

your RAS is a much more desirable/capable/productive/functional tool IMHO than your table saw - so my strong recommendation is get your Dewalt tuned, aligned and setup vs stealing parts off it

this is kinda of like a guy who asks you about how to pull the motor from his Ferrari to put in his Yugo so it will go faster.... all you want to ask is.... WHY?????

[Jeff Bratt]

I'm getting 2.7 HP with the 120 and the 240...how are you getting 1.5?

You calculations assumption a motor with 100% efficiency converting electrical input power (watts) to mechanical output power (horsepower) - such a motor does not exist. Here are details on how motor HP is measured...
http://home.roadrunner.com/~jeffnann...rsepower2.html

[Eric Wheeler]

[QUOTE=John Lanciani;1510015]

I'm getting 2.7 HP with the 120 and the 240...how are you getting 1.5?

1 HP = 746 Watts
Watts = Volts x Amps
Watts / 746 = HP
(Volts x Amps) / 746 = HP
(120 x 17) / 746 = 2.7xxxx
(240 x 8.5) / 746 = 2.7xxxx



Not quite. For an induction motor the formula for HP is volts x amps x power factor x efficiency / 746. For a consumer grade single phase motor, .80 is a safe bet for both power factor and efficiency at full load. Using the correct formula that motor is +/- 1.75 hp.

Ahh, I vaguely remember now. It's been quite some time since my electrical theory class, and for the general purposes of the examples in the class we disregarded the power factor and efficiency, but now I recall that the prof mentioning those constants and said if we take his motors class we'll get more into it, I took communications instead so all I remembered was the formula we used that disregarded the constants.