Control speed of chop saw?

[Trickasabrick]

Do any of you know if you could control the speed of an abrasive chop saw to bring it down into the range of a dry saw (1000 to 1300 rpm) with something like what you use to control a variable speed drill? The HF chop saw I've got has a motor with brushes, and from what I understand, that would be one prerequisite to cheaply control the speed. I'd love to be able to use the carbide metal cutting blades in it, and even tried the Bullet blade with no luck. It seems that if I could slow it down, maybe the blades would work in it. Maybe a switch like I have on my portable band saw where you can limit the travel with a threaded adjuster? Has anybody tried this?

Thanks,
Dave

[hankj]

The way speed is reduced on that type of motor is by reducing the voltage. Unfortunately, the tool's horsepower is reduced in propotion to the voltage. You might find that when you drop the voltage low enough to get the motor down to 1000 rpm, there won't be enough oomph left to cut butter!

Hank

[Zrexxer]

Harbor Freight has their router speed controller for universal motors on sale now for $9.99, try it and let us know.

[MAC702]

I'm with Hank. Lower RPM saws have gear-reduced motors, which increase the torque while lowering the speed. What you propose will lower both speed and torque. But, hey, give it a try!

[Roger]

Light dimmers work by reducing voltage. Motor speed controls work by pulsing current on and off, with lower speed setting off period is longer and corresponding full voltage on pulse is shorter. Same system is used electronic control of electric stove element.

[Some Creep]

You can get cheap 1/2 HP VFD's from ebay for less than $100. I don't know if this is how much you were thinking of spending, but it's an option. A VFD will control your speed without the huge loss in torque.

I'm not a big fan of the cheap drives because I'm not a fan of risking my seldom-seen money on possible bad manufacturers. I tend to get the name-brand stuff when it's available for cheap or get the knock-off stuff for WAY cheap (or free) when I come across it.........

[yorkiepap]

Hey Dave,
Your thoughts to reduce the rpm of an abrasive saw is defeating. Abrasive blade saws are designed to get the maximum efficiency from an abrasive blade because of the SFM(Surface Feet per Minute) the blade affords to cut effectively. Your best bet for a lot of metal cutting is to simply purchase a decent 14" dry cut saw such as a Porter Cable that is very reasonably priced and very reliable. I have one and use the Freud Diablo 14", 72T, C-7 grade ferrous blades and I average 600-800 cuts before re-sharpening is warranted. Just some "food for thought"......Denny

[Mr Meck]

Remotor for 460 and use a frequency controler. Our chop saw uses 460, no controller, and 16 in blades. Very effective on 1/4 x 2 angle. Count to three its done.

[MAC702]

Light dimmers work by reducing voltage. Motor speed controls work by pulsing current on and off, with lower speed setting off period is longer and corresponding full voltage on pulse is shorter. Same system is used electronic control of electric stove element.

Actually, you can get light dimmers and motor speed controllers that use both methods.

[Trickasabrick]

Well, I bought one of the cheap ($10) HF router controllers and tried it briefly last night. It does indeed reduce the voltage, and it also reduces the torque. On the full setting, it measured 110 volts, and on the variable setting it measured from 100 volts on high to about 90 volts on low. I tried it with my old Bullet blade that was still on the saw, and it still cut through a piece of 1/8 flat bar although a little slow. The interesting thing is that this blade had all but quit cutting at 3800 rpm, but seemed to at least still cut at probably 1500 rpm (medium speed on the controller). I don't think this will be a great solution, but it was worth a try to see what happened. I may use it on the new Bullet blade to see if I can get it to live a little longer, but eventually, I'll probably get one of the real dry saws. I'm a cheap SOB, so I had to try.

[Meach]

I just got back from Fabtech 2007 and found just what I (And you) are looking for. It is a metal cutting blade made for the high speed abrasive saws. I talked to the guy and said "Are you sure these blades will spin at the abrasive saw speeds?" His reply was this is exactly the reason his company made the blade. For those with abrasive saws who want a blade that lasts 25 times longer and cuts extremely fast. I saw him cut 1/4 x 2" steel rectangle stock like it was pine. I just got home so I when I unpack I will post the name of the Manufacturer and the contact information.

[Trickasabrick]

Sounds like what I've been looking for Meach. I'll be very interested to see how long it lasts. The Bullet Ind. blade was supposed to work like that, but in practice, the one I got only lasted about 5 good cuts. Do you have any idea how much the blades are going to sell for? Post your results when you try it out.

[Meach]

www.cuttech.com made in USA!!
Cermet tip, 5 times faster, last 25 times longer
1-800-722-0305 I believe the 14" was $175.00

If it lasts like they claim they are worth it. Sure cut fast! He said few do but they can be re-sharpened 4-5 times.

Made by Cut Technologies Metal L.L.C.

I'm gonna order one. I'll start a new post when it arrives and I try it out.

Meach.........

[hankj]

Thanks, pal!

Hank