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[FloridaDave]

I have a 30" saw.  No motor.  Do I go with a 3 hp or 5 hp?  Price is not that much different.  16 amp or 22 amp.  220V is available.
Also is 1750 rpm best.  Looks like 1750 is also a good blade speed.
Had a 2 hp capacitor start 220V  Baldor that burned out after a few hours cutting?  Saw came with a ancient/huge 1.5 hp bad motor.  The 2 hp was a gift from a friend.
My knowledge of motors and rock saws is slim.  Am/was cutting petrified wood.  Blade looks fine - made some nice smooth cuts.
Yep, the saw is huge,  just bought a nice Covengton 18 general use.  Just want the "biggest saw in town" to share with my fellow rock hounds.  Figure a 6 pack of cheap beer will be a fair cutting price.

[Felicia]

Looked one up. Minnesota lapidary supply carries a 36" saw. It uses a 2hp overload protected motor, 6 speed, 115 vac, the ad says. The auto feed machine is also 13,000+ $. Anyway, at 115 vac a 2 hp motor pulls 29.5 amps; 230 vac, 9.3 amps, according to the chart. Larger use a much higher amperage. The amps you use will depend on what your wiring is rated for. What does it say on your breaker box for the line you will be using. Don't know why your motor burned out. Anyway I just wanted to let you know what I found out about a saw in that size range.

[FloridaDave]

The motor that burned up,  was running at peak amps.  Rated 18 (220) was running at 16/17 amp. (gauged)  A buddy said this probably caused the failure,  should be running at 12 amps.  Another buddy who claims to know motors said that when i changed the pulley from a light AL to a heavier steel,  that extra weight over taxed the motor that was already running near max.  I do not think that little extra weight was an issue,  but he (the expert) is adament.   The proper expert whom I just met said it was probably just running at max amps and as the saw engaged the amps slowly went up.
SO - what I need is a high amp motor.  Prefer too big over maybe too small.
motors are complicated to me - need advice that I can take to a parts counter and buy a motor with.  Or maybe on Ebay where there are many motors,  do want to avoid cheap china crap.
All I know about electric motors I know from messing with this machine,  ain't lapidary great.

[Felicia]

A matching motor controller, perhaps, to keep it running less than peak amps.

[hummingbirdstones]

i would give Tim at Cigar Box Rock in Bend, OR a call and ask him for advice.  They refurbish old lapidary equipment and have the knowledge to help you out with a saw that big. 

https://cigarboxrock.com/find-us/

[Slabbercabber]

Is there a chance you might have replaced an 1800 rpm motor with a 3600 rpm and used the same pulleys?

[Felicia]

Don't need a high amp motor, if you have one and engage it, it's amps will climb. More and more amps. This could be endless. Control the motor. Go on line at least, look up circuits. We don't want you to hurt yourself, or set things on fire. A few electrical parts and a reasonable sized motor will also be the cheapest way to go. Just FYI, many motors are electrically reversible, cw or ccw depends on how it is hooked up, so you can do what is most convenient.

[FloridaDave]

Spoke to Cigar Box Rock - they suggest a 2 HP 1750 Baldor (USA, NOt china)
Lots of good advice to crunch.  The burned motor was a 3500 with  4" to 14" pullys,  estimated blade speed of 1900
Cigar Box says slower blade speeds are best for large saws.
Controller?  What is that?  This may be the problem.  I had straight wired the motor to 220,  large dryer type plug - plug it in and let it run,  no controller or on off switch.  To turn off just unplug.  A controller or even a switch will take a bunch more homework.  Need info on what type or even model controller to buy.
I have a buddy who can probably help wire up a controller,  just need to get the part - will then figure out how to wire.
Thanks for all the imput - we are going to get the big saw running.

[Felicia]

I can't tell the part, really, but I'll try and do a bit of looking to see where you can get the info

[peruano]

You are messing with 220V. I'd make sure my buddy was an electrician or had lots of experience with electricity.

[Rustycat]

Spoke to Cigar Box Rock - they suggest a 2 HP 1750 Baldor (USA, NOt china)
Lots of good advice to crunch.  The burned motor was a 3500 with  4" to 14" pullys,  estimated blade speed of 1900
Cigar Box says slower blade speeds are best for large saws.
Controller?  What is that?  This may be the problem.  I had straight wired the motor to 220,  large dryer type plug - plug it in and let it run,  no controller or on off switch.  To turn off just unplug.  A controller or even a switch will take a bunch more homework.  Need info on what type or even model controller to buy.
I have a buddy who can probably help wire up a controller,  just need to get the part - will then figure out how to wire.
Thanks for all the imput - we are going to get the big saw running.

I don't know if you have considered how fast the cutting edge of your 30" is moving at 1900 RPMs, (15,000 SFM),  but it might have something to do with the stress being placed on it. 
  The reason is why a larger blade can cut through material faster than a smaller blade is a diameter; its outside edge is traveling much faster. Therefore, it is presenting more teeth to the material in a minute than the smaller blade. This is actually the important figure for determining whether a blade is appropriate for a particular type of material. To describe this, we need a more appropriate measurement. The number of feet that the blade rotates in a minute is called “Surface Feet per Minute” or abbreviated as SFM.
You can calculate the SFM for any circular saw blade fairly easily, with the following formula:
SFM = (diameter ÷ 12) x Π x RPM
Let me go over that with you. You start by taking your blade diameter in inches and dividing it by 12, to put it into fractions of a foot. Then you multiply that by Pi, which is 3.14. That number is then multiplied by the RPM of your saw. The answer to that tells you how many SFM (surface feet per minute) your blade is cutting.

[Felicia]

An electronic starters can also have current sensors and will limit the current, or find a current limiter.  That should do and won't break the bank. I don't know if you'd need or want a speed control to vary the speed, that's a different thing, depends on what you want. Recommended rpm from americandiamondtools.com is 1,200 rpm; never exceed 2,040 rpm. That's for the blade.  Your pulley setup will probably modify the blade speed from the motor speed, I don't know what you have. You'll have to do the math unless the weathersaw came with that data.

[kilowatt]

This switch should work for your saw, fits in outdoor box found in any hardware store, easy connection. Wire from plug connects to one end, wire to motor connects to other end. Use proper connectors in threaded holes in box for wire you have. Different switches will work, must be rated 220 volts or more and be rated for motor use

POWERTEC 71008 110/220V Single Phase On/Off Switch

[Stonemon]

Welcome to the forum kilowatt!

[Slabbercabber]

A two hp motor will not need a current limiter.  It is big enough that it will not be overloaded.  As long as it has a heat operated breaker on the motor shell, that is good enough.  Blade rpm is the motor rpm times the motor pulley diameter divided by the blade pulley diameter.  SFPM is RPM x diameter in feet x 3.14.  There are many charts available for SFPM related to the type of material being cut.  The one modification I would make is to put a limit switch attached to the carriage to shut the unit down when the cut is finished.  Waiting for the belts to start slipping is just looking for trouble. and sooner or later you will not be there to stop it.