Chop saw

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Jorg50
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Chop saw

Post by Jorg50 »

I have a Makita chop saw 2000watts, my major problem is when there is the need to cut angle iron the straight section against the grinding disc cuts good but the flat section that is downward gets glazed and the more pressure you put the worst it gets and will never cut, water has been added, a stone has been put to the surface of the grinding disc no no success. The grinding disc is from Bronco and it is for stainless. Other gridding have been tried but with worst results. Has anyone had this experience and had a solution and would like to share.
Thanks in advance for any help.
ERIE S-1 BERKSHIRES
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Re: Chop saw

Post by ERIE S-1 BERKSHIRES »

Is your Arbor a 1in Arbor and do you know the exact RPMs output of the saw if so? I bought a carbide Diablo 10 in blade from Home Depot or Lowe's need to match RPM's. I cut through 2x4 tubing 3/16 wall in probably 10 seconds and the metal is not even hot but you can touch it
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Harold_V
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Re: Chop saw

Post by Harold_V »

Jorg50 wrote: Tue May 26, 2020 4:28 am The grinding disc is from Bronco and it is for stainless.
That may well be your problem. Stainless is (typically) ground with silicon carbide, which dulls almost instantly when cutting carbon steel, which I assume you are attempting to cut.

Try using a blade recommended for steel, which should be made of aluminum oxide. If they don't make mention of the abrasive type, select one that is NOT recommended for grinding rock or concrete (aluminum oxide is never recommended for grinding either of them).

You should expect that the cut will take longer and require greater pressure once the diameter of the wheel is engaged with a greater area. As the area increases, the blade floats easier, thus it cuts less.

H
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BadDog
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Re: Chop saw

Post by BadDog »

I put aside my chop saw a long time ago. Loud, messy, and just as you describe, the blades (cheap that I used) would sometimes glaze over and make cuts difficult with far more heat. Well over a decade ago I got a cheap 4x6 HF bandsaw, not much difference in price from a chap saw. Ever since I've been using my band saws for everything, and I couldn't tell you where my chop saw got off to. Seems like maybe I sold or gave it to someone. Either way, it's not been missed.

Just saw Harold's post. My disks were cheap disks, but meant for steel, and they sometimes did the same thing. Could be the cheap blades I used, but even if they worked perfect, I would rather use my bandsaw just from the noise and mess.
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Jorg50
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Re: Chop saw

Post by Jorg50 »

ERIE S-1 BERKSHIRES wrote: Tue May 26, 2020 6:29 am Is your Arbor a 1in Arbor and do you know the exact RPMs output of the saw if so? I bought a carbide Diablo 10 in blade from Home Depot or Lowe's need to match RPM's. I cut through 2x4 tubing 3/16 wall in probably 10 seconds and the metal is not even hot but you can touch it
The RPM is 3800. My problem is getting that carbide disc to match the RPM for my chop saw. I am from Europe and the difficulty is greater. My disc is Dronco from Germany and not Bronco. What is the RPM from your Chop Saw? How many carbide teeth does your blade has?
Jorg50
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Re: Chop saw

Post by Jorg50 »

Harold_V wrote: Tue May 26, 2020 3:53 pm
Jorg50 wrote: Tue May 26, 2020 4:28 am The grinding disc is from Bronco and it is for stainless.
That may well be your problem. Stainless is (typically) ground with silicon carbide, which dulls almost instantly when cutting carbon steel, which I assume you are attempting to cut.

Try using a blade recommended for steel, which should be made of aluminum oxide. If they don't make mention of the abrasive type, select one that is NOT recommended for grinding rock or concrete (aluminum oxide is never recommended for grinding either of them).

You should expect that the cut will take longer and require greater pressure once the diameter of the wheel is engaged with a greater area. As the area increases, the blade floats easier, thus it cuts less.

H
As always nice discrition. I used the stainless disc because it did cut better then the discc for stell. My abrasive disc's are Dronco from Germany even tho I am not certain if they are made with from aluminum oxide. The other issue with the stainless disc is that you should be careful with your down force because the disc is thin and the cut will not be straight even with the steel disc there is the possibility for the cut not to be straight. I will try to find a disc to cut steel that is made with aluminum oxide and give that a try.
Russ Hanscom
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Re: Chop saw

Post by Russ Hanscom »

Besides the blade, work orientation is also important. If you cut angle stock with the 90 degree edge up and the two tips down, then all of the cuts will be in a thinner orientation of the stock. If you are cutting flat bar, stand it on edge.
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BadDog
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Re: Chop saw

Post by BadDog »

That's smart orientation regardless of cutting device. Generally works well for anything other than square (or channel) where it's not easily mounted/clamped on a corner.
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liveaboard
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Re: Chop saw

Post by liveaboard »

Jorg50;
you ask about carbide teeth, but you said it was a grinding wheel.
Is that a carbide tooth 'drysaw' or the kind with a grinding disk?

Carbide tooth type saw is max rpm 2,000
grinding type would be around 3.500 as you describe.

These saws have really poor clamps; they work ok at 90 degrees but when you cut angles, the stock slips and jams the blade.
Jorg50
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Re: Chop saw

Post by Jorg50 »

Russ Hanscom wrote: Wed May 27, 2020 1:17 pm Besides the blade, work orientation is also important. If you cut angle stock with the 90 degree edge up and the two tips down, then all of the cuts will be in a thinner orientation of the stock. If you are cutting flat bar, stand it on edge.
That is right but some iron profiles you have to cut them flat like the U and I if they are wide enough that you can not them straight or 90 degrees.
Jorg50
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Re: Chop saw

Post by Jorg50 »

liveaboard wrote: Thu May 28, 2020 2:10 am Jorg50;
you ask about carbide teeth, but you said it was a grinding wheel.
Is that a carbide tooth 'drysaw' or the kind with a grinding disk?

Carbide tooth type saw is max rpm 2,000
grinding type would be around 3.500 as you describe.

These saws have really poor clamps; they work ok at 90 degrees but when you cut angles, the stock slips and jams the blade.
liveaboard, it is a grinding disc and the RPM is 3800. Yes you are right the clamps are not well made, l had to modify them now they better then before but that kind of Chop saw with a grinding disc never make a straight cut and when comes the to make angles it is even worst with the carbite teeth saw it is a little better because the disc does not distort.
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liveaboard
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Re: Chop saw

Post by liveaboard »

Check the motor brushes; if they're worn out the motor speed could be dropping. That would cause your problem.
If the speed is right, then it has to be the disk that's wrong.

I have a carbide tooth one for 20 years; it works ok but the blades are expensive, and wear out quick if heavy things or hard things are cut.
When I cut angles, I add a clamp or big vicegrip to hold the stock to the fence. That works well.
I spray cutting fluid at it when I cut anything even a little bit heavy, that really helps.
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