Noob question on Chop Saws

[Doobreydoo]

Hi all,

I have been skulking around the forums for a little time now, learning what i can.  I am very much a junior blacksmith/bladesmith but am slowly starting to produce some blades and damascus.

Its been a heck of a learning curve, but I am getting there.

Anyway, the reason for the post, I have purchase a while a go a Evolution Evosaw355

Hoping to use it to cut steel plates for my projects.

I have used it to cut some steel, which has been ok and recently tried it on the damacus billet.  The billet was about an inch thick by 1.5" wide.  Simply put, it struggled to the point that it wouldn't go through the billet at the end! The blade it comes with is a 355mm mild steel tct blade (66 tetth).  

My rather noob question is this.  Is this the right blade for cutting damascus?  Should I (could I) change it for a cold chop saw type blade?  If so, which one?

BTW I annealed the damascus - heated it, let it cool slowly in the air, before chopping it !

What a I doing wrong!!!

 

Thanks all

Doobs!

[DuEulear]

Ok i will give this one a go. 

I have a carbide chop saw in my shop at home and i work for a steel processing plant we manufacture decarb free tool steel bar from HR plate. Most of the saws we use to rip cut bars from plate are cold saws. 

Hr tool steel plate is sold in anealed condition but we have run into hardend spots usually near a flame cut end that are only 1/2 inch thick. But destroy a 24” coldsaw blade almost immediatly.

there are diffrent speeds and feeds for evry type of toolsteel. 

And blade lubes misted when cutting it.

What alloys are you making damascus from? 

Check your blade you may have removed teeth.

if you need a new blade dont resume the same cut you will only kill it.

flip the billet and try from the other side

personally if i allready had trouble i would re anneal then try again or finish that cut with a hot cut on the anvil. 

Feed slow but steady on toolsteel tont push too hard the blade needs time to work

Air cooling a tool steel billet is usually a normalizing not a full anealing. I would suggest bringing to just below critical and a through soak then slow cooling in vermiculite wich will take a billit that size about 12-20 hrs careful it might still be toasty the next morning . 

Susan

 

 

[Irondragon Forge ClayWorks]

While you were "skulking" did you happen to read this? READ THIS FIRST

[Kozzy]

That style of saw is pushing it if you hit any hard spots.  On a similar note, anything that work hardens like the chrome bearing steels that sometimes show up in damascus will magically become like sawing through rock with the slightest hesitation.  Fine for dead soft low carbon steels.  You can push them into harder stuff a bit but they aren't designed for that.  Many brands also have too much flex in the mounts--they deflect as pressure is applied due to not being rigid enough which can cause severe problems like tooth breakage.  

Cheap blades DO NOT work in this kind of saw.  You can sort of fudge them into cutting but they are so inferior that you might as well buy blades at the junk store.  You need to throw some good money at a good blade to get reasonable results.  Typically triple chip grind, zero to slightly negative rake (more negative in softer material).

Personally I'd probably cut the more questionable stuff with an abrasive saw.  I hate the things due to the heat and mess but they are reliable, blades are fairly cheap, and you can often pick one up for a song and a dance used (try pawn shops).

[Kozzy]

Meant to say Nickel and not chrome in the above.   Was working with T314 specs earlier and had chrome on the brain.

[vern509]

Using a similar saw, like other have said the issue with the base flexing is real, it causes the blade and cut alignment to shift.  I can hear a shift in tone when it happens.  And mine seems to run best when kept cool, so lots of small bites.  (Not really adding anything new, just confirming the advice given above, especially about the abrasive cut off saw).

[Frosty]

You're pushing too hard Vern, it's the almost universal cause of saws flexing: bed, blade, clamp, etc. The only exception I'm aware of is a loose pivot on the saw and that's pretty obvious. You have to let the saw work at it's pace. NO household power saw will cut straight or for long if you force it. 

The industrial saws you see blast through large structural stock with a shower of sparks in a second or so are powered by 3+ HP, 3 phase motors and wouldn't flex if you pushed them with a pickup truck. What the average guy or shop can afford needs a light hand.

Frosty The Lucky.

[Kozzy]

But with a carbide blade, you have to take a reasonable bite...carbide likes a pretty big bite in metals or it will tend to dull surprisingly easily. It HATES small bites and effective rubbing rather than cutting.   Taking a reasonable bite of .003 or so per tooth is often enough load on the low end saws that they will flex.  In fact, they will sometimes (on the really cheap versions) flex enough under just their own weight that it can be a bit of an issue.  Often the pivot mounts are the weak point.

Yes, you can simply go slower but the cost for that is effective "rubbing" of the teeth to some extent so much lower blade life (and sometimes other problems like surface work hardening).

You make do with your budget and tools you have, of course--that's SOP.  But there are times when you can add  simple bracing to the tool...such as to the stamped base on a small saw like this to help reduce the flex issues.  The HP available is generally (but not always) enough to take the depth of cut that works if you can just chase down and eliminate most flex from the loads involved.

Note that the photo above implies it has a cast base so I speaking in theoreticals here...many people have to make do with HF level tools and those can often be improved with a little addition of time and touch-up.

Just as an example, with the O.Ps 66 tooth blade at 1500 RPM, even the lowest .0005" per tooth D.O.C., that saw to be running well for a carbide tooth blade should be moving through steel material at about 49.5" per minute.  .0005" D.O.C. is way too low for carbide in general.  It becomes clear why rigidity is important in this kind of saw.

[Frosty]

I don't believe I suggested just letting the blade ride against anything. That'd be like just holding your knife against a steak hoping bites fall off. If your saw can't use carbide blades DO   NOT   USE   CARBIDE   BLADES. Good GRIEF!  Do we need to tell folks a bicycle chain won't cut in a chain saw too?

The problem is RARELY the tool. In this case people are hogging the blade or using the wrong kind. Operator error in either case. I've been using vernier carbide circle saw blades to cut steel for decades and I buy the cheapest pawn shop circle saws I can find because the metal cuttings or dust when I use hot saw blades tends to eat circle saws. 

You can go slow but you can't just let them rub. You realize there is a difference between a slow feed and just letting a blade ride don't you?

You have to LISTEN TO YOUR TOOLS, they tell you what's happening and how, If you YOU PAY ATTENTION. Power saws especially talk to you, if you're warping the saw YOU are doing something wrong. 10 to 1 you're feeding it too hard. If you've ever pushed a circle saw too hard you know what I mean.

Frosty The Lucky.