Metal cutting - oxyfuel cutting, plasma cutting, machining, grinding, and other preparatory work.
MCMIG85
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    Mon Nov 01, 2021 10:55 am

New to metal working. I was recently cutting some 1/8" thick 1.5" square tube mild steel with my used Black & Decker Model 3935 14” chop saw (3800 RPM) with 1" arbor. I noticed that as I was cutting, the blade seemed to be deflecting to the right. It was deflecting so much that it was actually cutting the edge of the kerf guide (shown by red arrows in picture).
It seems to cut very well with no deflection when I first use it. Then as I make more cuts it sometimes seems like it's not cutting at all. I'll be standing for a long time cutting and it seems like the blade is barely cutting even though I'm seeing sparks. I'm not sure what I'm doing wrong. Am I pushing down too hard on the handle? Are you supposed to just let the weight of the saw do the cutting? And why is the blade deflecting so much. Note: I was doing both straight and mitred cuts.
The blade I'm using is a Makita 14" x 1/8" x 1" arbor (model no. A-01351) max 3900 RPM. Any help would be appreciated!
blade deflecting.jpg
blade deflecting.jpg (2.35 MiB) Viewed 21560 times
cj737
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    Thu Sep 29, 2016 8:59 am

I would ditch that type of blade and purchase an appropriate steel cutting blade (36-48 tooth). Those friction discs are too thick to make accurate cuts, deflect (as you discovered) under downward pressure, and basically take an age to get the job done.

If you do opt for a steel cutting blade, use plenty of cutting fluid (NOT WD-40, cutting fluid) to prolong the life of the blade.
tweake
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    Mon Dec 18, 2017 4:53 am
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    New Zealand

not sure if thats due to the thickness of the material.
i would check the bushes in the hinge. it may be worn and its moving due to tension from the spring etc.
i don't use one, to many sparks, but family have a workshop and it gets used constantly without issues.
i use a bandsaw, much better for accurate cuts and no sparks, but a lot slower.
tweak it until it breaks
77cruiser
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    Tue Jan 31, 2017 10:27 am
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    Frostbite Falls, MN

I picked up one of these, much nicer cut. Bought on on sale locally, but they have nicer ones too.
https://store.evolutionpowertools.com/c ... ts/r355cps
https://store.evolutionpowertools.com/c ... -chop-saws
cwby
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    Wed Nov 13, 2019 7:07 pm

If you plan on using a steel cut off blade, make sure the saw RPM is within blade rating. Most steel saws like the Evolution run at lower RPM than abrasive saws.
metalmagpie
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    Mon Jul 15, 2024 12:58 pm

Ever notice that abrasive chop saw blades come in different thicknesses? Why do you suppose that is? I had all kinds of trouble with blades deflecting until I realized it was on those kind of cuts I was supposed to be using thick blades that won't deflect as easily. For me it was angled cuts where the blade would wander.

metalmagpie
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