Dual Saw -- anyone use one?

Dec 10, 2009 37 Replies

Really? Google "climb cut" RAS. The very first hit:

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Comment from contributor D: There is only one really safe way to cross cut on a RAS - by putting the stock against the fence and then pulling the yoke and blade towards you. This is, technically, a climb cut since you're feeding the blade to the stock in the same direction the blade is rotating. Yes, the blade can "climb" into the stock and the motor can jerk towards the operator. However, that's why you should pull the yoke through the stock with a bit of a "stiff arm" (so to speak), to minimize motor movement should this happen.

Who's ignerint now?

AND, btw, this explains but another lie on the dualsaw mis-infomercial: You CAN cut in either direction with a circular saw (backwards would be climb), you just gotta be careful, and use a "stiff arm". Not recommended, of course.

And, indeed, the dual saw DOES facilitate this bi-directional cutting, but it is an utterly trivial feature. They also strongly imply that *because* of the opposite blade rotation, the dual saw can plunge cut and a circular saw can't. Carpenters plunge cut every day with circular saws. Sheeit, you can plunge cut with a recip saw, if you know what yer doin.

Well, *I* can plunge cut with recip saw..... clearly YOU can't.....

Btw, I disagree mightily with Contributor D:

Climb cuttung, as he correctly describes, indeed requires a "stiff arm", and is thusly a very big pita for thick material. Otoh, Push cutting (conventional) imo is MUCH preferred on an RAS, and safer. And *easier*.

Conventional cut is, of course, how one uses a table saw or circular saw.

Otoh, machinists generally prefer milling in climb, altho material and tooling can vary the equation -- strangely, I've had much better finishes in some mateials using conventional finish cuts... but, gee, look who I'm talking to.....

Any questions?

Oh, btw, I need not have even googled or cited anything, as the "physics" that yer ignerint buddee RicodJour refers to is self-evident, and I could have argued this from geometry alone. Too much work, tho, and no doubt futile for you and yer dualsaw buddee, so I did the google for you.. I'm sure the folks on rec.woodworking can help you out further, if you are still in your chronic daze.

He's just trolling without knowing he's a troll. It happens. His blind spot is in believing that he has information instead of going to look for it. If he'd said that the Dual Saw looks like a piece of crap and asked for input he might have gotten something out of the thread, and I probably would have agreed with him and pointed out the disconcerting number of people who report burning the motor out in short order.

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Yeah, I saw that. Moot, tho. The dualsaw is still near-useless, even with a motor that doesn't burn out.

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Instead he extrapolates to a universal to form his opinion, makes outlandish and erroneous claims, ===================================================

Name one. If anything, I left a lot of s*it out, for brevity. So point out one error.

YOU just made one gigantic implicit error by tacitly agreeing with S***ty Two about the climb cut business. I guess you really don't know about climb cutting, and knee-jerk agreed with S***ty, without looking it up. But you did look up the below stuff, not even realizing that what you cite are totally different horses, the difference between a cannon and a firecracker -- even those both use gunpowder. And changes nothing in this debate.

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and deftly demonstrates that he doesn't know as much as he thinks he does.

There's really nothing new about the technology. I don't recall who said that they didn't see the counter rotating blade technology used in rescue operations, and that if they were, they couldn't be corded, but...

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for the ICE crowd.
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Someone who had seen the Dual Saw infomercial might have recalled that the 'inventor' was a Euro firefighter. The odds of him having seen something similar to the Dual Saw on the job were pretty good, and saying "patented technology" doesn't mean the whole tool is patented. Maybe the guy's contribution was to patent an affordable modification that allowed the expensive tool to be mass-produced for the consumer market.

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Heh, just like Tony Little, who say the Gazelle in a rehab unit for burn victims, and said, Hey, this is great for burn victims who are barely alive, it should be GREAT for healthy people, so they'll never ever EVER ever get fit.

Did you see the SIZE of those saws??? Holy s*it.....

Context, dude, context.

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In any event, the OP didn't bother to look, clearly doesn't understand basic vector physics, and spouts off about something he's never touched. The old saying "throwing the baby out with the bath water" seems to be the OP's standard operating procedure. ==========================================================

Vector physics? Was it you who stated that the counter-rotating blades result in zero angular momentum, ergo no gyroscopic effect? Hmmm, lessee..... wait a minute.... No, that was ME! Holy s*it.....

Hmmm, I guess, hmm, cuz the angular momentum vectors (normal to the plane of rotation) cancel out?? YESSSS, THAT MUST BE IT!!!!

Now, you and S***ty should go back to playing with your wooden blocks, and make sure you don't touch ANY power tools without adult supervision.

Don't forget to point out all my outlandish and erroneous claims.

Interesting. I've never heard of such a thing with a saw blade, and DAGS to see if there was such a beast as a circular saw climb cut - the search didn't turn up a single example in the first two pages of results. Can you post a link to a climb cutting machine or something you wrote about it?

In the machines you're talking about, the workpiece/sawblade is moving in the opposite direction to the normal direction of movement. With the Dual Saw type of saws, one of the counter rotating blades is always moving opposite the 'normal' direction of movement - and in fact that that is the primary reason the tool can get away without hold downs and feed mechanisms (equal and opposite canceling and all of that), and the reason that the tool shouldn't grab and kick, it seems to me that the tool isn't climb cutting, so much as just cutting. The adjectives canceled out. So is there really a climb cut in such a tool? ======================================================

Not only are you an idiot, you are a long-winded pedantic idiot. Goodgawd.....

Can you say " Ray-Dee-All Arm Saw ", boyzngerlz??

I'm loving this. You're the guy who said the people on rec.woodworking didn't know how to use a circular saw, and now you're demonstrating that you don't know that routers and mills are the tools that are capable of climb cuts. Running a circular saw backwards is not a climb cut. But keep digging - it's entertaining.

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Apparently you are digging a lot faster than I am. But, in defense of your sorry ignerint ass, I see you posted this before Ed H replied.

But it just goes to show you can't think for yourself. You STILL can't see that the concepts of climb vs conventional cutting apply to ANY tangentially-approached device. Wake up, dude. goodgawd.... So much for vector physics, eh?

Heh, we'll see how big of a person you are, by the size of the humble pie you wind up eating -- esp. when you won't be able to cite ANY of my "outlandish or erroneous claims" regarding that effing useless dual saw.

I knew you'd ask that. It was between 20 and 25 years ago; the story was about using wirecut EDM to shape sinterred diamond compacts on the cutters used in both metalworking (a minor use) and woodworking (the major use), particularly on commercial spindle-shapers and routers. The discussion about saw blades was peripheral to the subject, because EDM isn't used to shape the edges of those.

All I can recall is this: In production rip-sawing, the issue is how the cutter *exits* the cut, rather than how it enters. Apparently -- and this is from memory -- saw blades used in commercial ripping just barely extend through the top of the cut, so the re-entry isn't an issue. On the top side of the work, it's almost the same whether you consider it climb- or conventional-cutting. But it makes a big difference when the blade finally leaves the bottom of the cut. If it's cutting when it comes out of the workpiece, it's going to tear the edges of the cut, as any hobbyist woodworker knows from conventional work with a table saw. In the discussion, running the blade in the reverse direction of what most of us condider the "conventional" one, in which the blade exits the work "not cutting," was what they were calling "climb cutting," and apparently that's the preferred mode for production. It requires friction drive and hold-down rollers; the work is fed under power.

BTW, some commercial saws operate upside-down, with the blade(s) above the work, so you might have to reverse "up" and "down" from this discussion. That may just be for multi-blade ripping of lumber; I've never actually seen one of those saws.

I never got involved in studying production woodworking except for that single application, and it was because I covered tooling for a couple of metalworking magazines and I had a client who made special wire EDMs for that work, when I wasn't a staff editor.

Sorry I can't refer you to my article. That old stuff isn't archived online and I wrote over 350 articles about metalworking and tooling, so I don't remember where it ran.

A good question; I don't know about those saws. I hesitated to jump in here at all, except to point out that there is something that is, or was, called "climb cutting" in production sawing, and that it's similar to what we mean by the term in metalworking, with milling cutters.

I will now go back to my nap.

To what end? There's no argument that the majority of the stuff you find on infomercials is targeted at insomniacs that are awake in the middle of the night and buying something, anything!, lets them feel like they're doing something useful. But "debunking" an infomercial is an exercise in futility. Watching an infomercial is a waste of time, and MythBusting them would be an even bigger waste.

The angst-ridden one seems to believe that we should be living in a perfect world, and he can fix this one if only people will listen to him. That way lies madness.

Everything should be taken with a grain of salt. Getting upset about the inequity of a _commercial_ seems pretty low on the list of things to get upset about. At least for sane people.

R

"Existential Angst" wrote

You can count me in as a viewer of InfomercialBusters, just like MythBusters. Could be some interesting s*it.

Steve

Everything should be taken with a grain of salt. Getting upset about the inequity of a _commercial_ seems pretty low on the list of things to get upset about. At least for sane people. ==========

Two products that live up to the informercial hype, and more. G2 Swivel Sweeper and NuWave Oven. Both terrific products. Two products that are a complete waste of money. Steam Zapper and Perfect Pancake Maker.

Cheri

I guess Sham-Wows are in the middle?

They are actually good product, especially when you get them at half the price at Ocean State Job Lot. I'm sure a store near you has them too.

Can they really suck up Coke off the floor under a piece of carpet? Through the carpet, and leave the underside bone-dry, like in the commercial?

I have a coworker who has a couple of them, and when I asked him that, he just scowled at me and went back to his Bridgeport.

Thanks, Rich

Err... Actually the term was used way back in the days of horizontal milling machines where the term is actually descriptive as in "climb milling" the cutter actually does try to climb onto the work...

And as far a saw blades are concerned, while the term, per se, wasn't used the concept was certainly know in the days of the old circular saw mills, even the early steam powered mills.

Regards,

J.B.

Well, I hope you enjoyed paying 4x the normal price, as much as you enjoy the products. Billy Mays died in a mansion, donchaknow.

Speaking of 4x the price, think Dyson.... vs. regular ole Hoover -- oh, and lest RicodJour bind up his panties again, this is according to Consumer Reports -- fwiw. Ditto Oreck, whose customer svc and parts are but another scam. Ditto Bose.... etc. The common theme to all these over-priced middling-to-under-quality items: head-pounding marketing.

Not at all. You are of course well able to choose how you spend your time. Please feel free to start your infomercial MythBusting dweeb site. I'm sure watching programs in the wee hours of the morning that you know are selling to suckers, and then investigating, debunking the claims, and posting the results, will improve your life immeasurably.

R

To what end? There's no argument that the majority of the stuff you find on infomercials is targeted at insomniacs that are awake in the middle of the night and buying something, anything!, lets them feel like they're doing something useful. But "debunking" an infomercial is an exercise in futility. Watching an infomercial is a waste of time, and MythBusting them would be an even bigger waste.

The angst-ridden one seems to believe that we should be living in a perfect world, and he can fix this one if only people will listen to him. That way lies madness.

Everything should be taken with a grain of salt. Getting upset about the inequity of a _commercial_ seems pretty low on the list of things to get upset about. At least for sane people.

R

So, are you saying that before I have a thought or take any action in my life, I should run it by you first? Is that what you are saying, Sparky?

Steve

I'm sorry, but in order to think this, you must have RicodJour's WRITTEN permission. You have gone entirely out of bounds on this one. The consequences will be severe.

Steve

Not at all. You are of course well able to choose how you spend your time. Please feel free to start your infomercial MythBusting dweeb site. I'm sure watching programs in the wee hours of the morning that you know are selling to suckers, and then investigating, debunking the claims, and posting the results, will improve your life immeasurably.

R

No, I believe that the next action I take will improve my life just somewhat ...................

plink! bye.

Never tried that, but they do hold moisture well, are good for spills I've had and for drying the car. They do those jobs much better than a regular cloth rag or paper towel.

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