Reviving the thread. I just put a new 5 hp motor on The Pressciousss, so I now have a 3 hp, 3450 rpm motor to mount on the chop saw. Still need to get pulleys & belts figured out, so that leads me to this question: 

We had previously discussed using a 1.5 hp motor at 1750 rpm using a pulley ratio of 1:1. If I use the new motor with that same ratio, that's double the speed and double the horsepower. Okay, so far so good. However, if I change the pulley ratio from the motor to the spindle to 1:2, that would effectively be the same as putting a 6 hp/1750 rpm motor on with a 1:1 ratio, right? Is that a good idea, or should I stick with 1:1?

I would go with which ever rpm was original.. I'm a big fan of more power vs rpm but it really depends on what you are looking to do.. 

The listings I’ve found online for the same model give its spindle speed as 3450 RPM and the motor as 3 hp. Looks like I got lucky.

Well, then you are all set..  i wasn't sure which blade you were after..   A cold cut saw blade runs pretty slow but with higher torque,  A carbide dipped blade runs at a slower RPM with medium torque and abrasive saws run fastest.. 

I have a carbide 14", 8" and 6 7/8" the last 2 are electric and battery like skill saws and are great for general work but the carbide is more expensive than abrasive..  The price on blades are much less now with a supply coming in from china, but for high carbon and knife work the abrasive saw is the best. 

In the end I was persuaded by arftist’s observation that I would probably need a more rigid body to safely use a carbide-tipped blade, plus they’re pretty expensive. 

They sure are more expensive.   For certain uses they are amazing.  

The cheapest overall cut off action is still a bandsaw with controlled down feed and with the right blade can cut normalized tool steels with little worry.  

The MaxSteel 14" carbide is handy but expensive to run..

The 6 7/8" battery Milwaukee is my go to for those quick jobs and at 8.00 to 12.00 per blade can be reasonable depending on the materials.  I've cut 1.25" sq with it, still faster than a hacksaw.   

 

The 8" electric Milwaukee I pull out for the larger more accurate run jobs.  The blades now are in the 8-12.00 range just like the smaller blades.  

In use one has to find the proper feed rate and minimize blade shock if the carbide is to last.

 

The abrasives cutoff saws are the only way to go with high carbon and low alloy flat steels because the machine and blades dont care if its hardened or not.   

So really each saw has a place in my shop because of the general purpose aspect.

 

If I did knives only abrasive saw would be it.

With the new diamond cutoff blades coming out these will be a game changer.

I do find myself using these more and more for roughing out work.

So, I've ordered a 3" double 3V pulley (with the appropriate bushing for a 5/8" bore) for the motor, and I'll be leaving the existing pulley on the spindle. That's a little less expensive than putting new single pulleys on both motor and spindle, and I get to keep the double belt arrangement and use the belts that came with the saw. Just need to mount all that up, wire in a switch (I'll probably use the switch and cable that this motor was using on The Pressciousss, since I had to upgrade the cable for use with the new 5hp), put in a blade, and give it a whirl.

You mean disk?  Abrasive disk?  Or is it a true cold cut saw? 

Yes, abrasive disk. 

Mounted the motor in its approximate final position and added an old lead sash weight as a counterbalance. 

Still figuring out where to run the wiring and mount the switch. There’s a pair of mounting holes at the front of the swing arm that I think is where the main switch used to be. There’s also a work light (with its own switch) that came with the saw that I need to figure out how to wire in as well. 

So, put the switches for the work light and the motor in a box at the front of the arm:

Running the main cord under the arm and out of the way. 

Belt tensioned, belt guard mounted, and we are good to go!

I tested it on a jackhammer bit, which was slow going (although it later blew through a piece of 1” pipe like Obi-Wan Kenobi’s lightsaber through Ponda Baba’s arm) but produced an impressive shower of sparks. 

I’m very happy with this. I was able to use a number of parts (motor, switch, box) I’d bought for other projects and reuse some others (power cord, plug, washers, bolts, nuts, etc) from the original setup of The Pressciousss, putting the total cost around $225. For an industrial chop saw, that’s not bad at all. 

Ooooh sparkly! Another shop ship launch at Johns! Congratulations.

 Frosty The Lucky.

JHCC, these will always cut faster on the flat.. So anytime you are cutting something always stand it narrow side up.  Nice work.

Solid bar  sections  like square and round are pretty slow compared to other methods, but where this will shine is on files, flat springs,  knife blades, etc, etc. Also anything that is hardened. 

Also today, they have thin kerf blades which will cut much better than the thick blades but will get used up faster. 

Its all a balancing act when it comes to cutting. 

One thing I really like about the cutoff bandsaw is the auto feed and auto shut off feature.   These features can be applied to this saw too, so on larger sections you can turn it on. put a weigth on the handle with a shutoff switch to engage when the cut is done.   

These are loud dirty saws but have a place in any shop.   
 

12 hours ago, jlpservicesinc said:

So anytime you are cutting something always stand it narrow side up.

The vise only opens to about 1-3/4", so it looks like I'd be standing up anything wider than that anyway. The clearance under the blade is about 4", which is probably bigger than I'm going to need.

12 hours ago, jlpservicesinc said:

Nice work.

Thanks!

the surface feet per minute depends on the the size of your wheel, 1750 rpm is probably ideal for a saw running a 12 inch wheel if you're doing wet cuts, when cutting dry you want a much higher SFPM 

heres the formula:

0.262 x D x RPM = SFPM
SFPM / 0.262 x D = RPM

With a 14" wheel running at 3,450 rpm, that gives me about 12,645 sfpm. Not bad at all for abrasive cutting.

Boy will the pieces fly a long way if a wheel breaks! 

It'll be a heck of a tool John, good job from scrounging to using. 

 Frosty The Lucky.

That’s why it’s a good thing that the blade is completely covered!

Yeah, I LIKE that about it.

 Frosty The Lucky.

Just spotted a box of 14" discs (Hilti model 436729) on the website of the industrial surplus place where I got the saw in the first place. These are normally about $230 for a box of ten, but I nabbed these (an opened box with 9 discs left) for $29.99. Score!

The problem in finding such deals is you can fill your shop to unusability!  I hope you have a set of sturdy shelves you can pile such stuff on and still be able to see/access it.

There's still space in the tool cabinet behind the treadle hammer. 

I think....

Do you have to hang from a harness attached to a skyhook to access it?

On 5/22/2020 at 10:39 AM, jlpservicesinc said:

Well, then you are all set..  i wasn't sure which blade you were after..   A cold cut saw blade runs pretty slow but with higher torque,  A carbide dipped blade runs at a slower RPM with medium torque and abrasive saws run fastest.. 

All this talk about thousands of rpm confuses me. Aren't we talking about cold saw? I have a 14" cold saw and it has a 2.5 hp motor turning the blade at 40 rpm

Am I missing something? 

No, we're not talking about a cold saw anymore. I decided to go with the original setup with an abrasive blade, since a cold saw would need a much more rigid frame to the saw.