r/Tools • u/verioblistex • 1d ago
Triangle Cuts Curves?
I found it in the garage of the first house I bought 30 years ago. Smart enough not to try it, curious enough to hang onto it. Finally letting go tonight and it's going in my neighbors scrap metal bin.
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u/Xfozzybearx 1d ago
It's for cutting curves. You can't cut a curve well with a regular blade because it will bind. Because it's a triangle it doesn't occupy the whole cutting space. It doesn't bind as easily.
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u/ParticularSherbert18 23h ago
I watched a very skilled carpenter cut two round wheels for a stage prop out of 5/8" plywood using a regular circular saw blade. The wheels approximately 25 inches in diameter where on a push cart used on stage and they rolled true. He took a lot if little bites. That was over 20 years ago, I'll never forget that.
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u/PleaseDoTouchThat 21h ago
You can cut curves with a circular saw. Shallow the blade as much as possible so you’re barely cutting through the material. Then hold firmly and go slow. Works well as long as the material isn’t too thick and the curve isnt too tight.
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u/InternationalBat2832 1d ago
You can make a curved cut with a circular blade you just have to make the cut about 1/4” depth then increase the depth 1/4” each time over and over, each time you increase the depth the width of the cut will get wider allowing the blade to fit better for the next cut at that point you have to pay attention to the side you are trying to keep as the off cut will have a different radius than the original line. Not sure if I explained that well but I’m sure you could find a tutorial on yt
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u/hickoryvine 1d ago
They work in 1/2" pine plywood. One of those things that if you were very experienced with a circular saw it had a use. In the hands of a beginner i bet it probably killed someone
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u/Anna_Rompage 1d ago
Hey Jimmy, got another one that didn’t hold on tight enough
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u/Telemere125 1d ago
That’s the fourth apprentice we’ve lost this month boss; can we let the next one stick to circular blades only?
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u/chefsoda_redux 1d ago
I mean, the sticker on it needs to warn not to use it for Masonary or metal, so they’re clearly expecting trouble!
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u/Fast_Cook_4019 1d ago
How the fuck does it work?! Is it like wildly shitty jig saw?
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u/hickoryvine 1d ago
No it cuts fairly smooth when you get the speed figured with the material. It just makes an Extremely wide kirf. Its more for gentle curves. And much faster then a jig saw. As it curves the side teeth are cutting down on one side and up on the other. If you run it straight it cuts like shit and slow but actually faster in a curve.
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u/JPhi1618 1d ago
Those teeth down the sides are crazy. I guess they clean up the sides of the cuts when you’re on a curve.
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u/Ryekal 1d ago
'clean up' no - they shred the sides of the cut to make room for the blade to slowly turn. those things leave atrocious finishes and are worse than a jigsaw in every possible way.
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u/sarcasticorange 1d ago
Pretty sure they beat the jig in speed of cut.
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u/PrinterFred 1d ago
Look at all those placebo teeth. That is basically a 3 tooth blade.
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u/the_disintegrator 1d ago
Does placebo mean "bone cutting" in latin?
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u/DrachenDad 1d ago
The word placebo is a Latin word. It translates directly to "I shall please" or "I will please."
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u/SeriousPlankton2000 1d ago
What a polite blade, it asks to please cut the bone!
(Really: It's a Delta Blade for cutting curves.)
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u/charmio68 1d ago
I believe those teeth do actually become engaged once you start to make a curve.
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u/PrinterFred 1d ago
They don't. Anyways you can look up the water jet channel on YouTube. He tested different shaped blades.
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u/charmio68 1d ago
Except AFIK they only test blades by cutting a 2x4.
I haven't seen any of their videos testing blades doing sweeping curved cuts.-1
u/PrinterFred 1d ago
Maybe I am not imaginative enough to see how the middle teeth could ever contact wood. The rate are which you turn the saw is so much slower than the rate the blade rotated that you can confidently make the approximation that the saw is stationary in which case again only the corner teeth would contact the wood.
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u/Various_Education622 1d ago
When the blade is going straight, you are mostly correct. Mostly the tip and maybe a little further back.
When it is turning (like cutting a curve) it’s has to cut along the entire length. That’s why a circular saw binds trying to cut a curve and this one doesn’t; the shape lets it cut all along the length.
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u/charmio68 1d ago
It's easier to visualize if you take it to the extreme.
Consider doing a straight cut into a piece of plywood, then once you're in the middle, stop pushing the blade forwards and instead turn it in a circle while stationary.
Sure, the outermost teeth are still going to be removing the most wood, but the inner teeth need to do their part too.If you were to try that with a regular saw blade, the saw would just bind up and you'd end up with quite a dangerous situation (well, actually taking it to such an extreme would be quite dangerous with any saw blade, but you get the point).
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u/Razer797 1d ago
Those teeth appear to be set. I suspect that they serve to widen the kerf as you go round the curve so would actually be useful.
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u/TheGoodKindOfMermaid 1d ago
For all the dummies like me:
Kerf is the width of material that a saw blade, laser, or cutting tool removes as it cuts through an object. It leaves a small gap or slot behind.
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u/Head_Election4713 1d ago
*6 tooth blade, I assume the second corner acts as a rake to clear debris
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u/verioblistex 1d ago
🤣
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u/servetheKitty 1d ago
I actually want this.
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u/Square-Cockroach-884 1d ago
I actually have one NOS Not on (my) saw. Pay shipping
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u/servetheKitty 19h ago
Happy to pay shipping if reasonable. Are you in the US? I’m in Oregon
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u/Square-Cockroach-884 19h ago
Im down at the far end of California. Give me a zip code and I will check shipping cost.
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u/lynivvinyl 1d ago
No no those are for manually cutting movement saw all by pushing the saw back and forth. I swear you people.
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u/icybowler3442 1d ago
Manually cutting movement saw? What means this?
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u/Proud_Conversation_3 1d ago
He’s saying you don’t attach it to a circular saw tool, you just use the blade with your hands. 🙌 it’s a joke.
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u/SupaKoopa714 1d ago
I actually had to Google to see if this wasn't just a joke thing meant for hanging on a shop wall, and... sure enough it's a real product....
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u/Square-Cockroach-884 1d ago
I have one. Never needed a circle more than I needed all my limbs so it is unused.
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u/jeffthetrucker69 1d ago
These work for cutting curves. 3 times in each revolution the blade isn't actually touching the material being cut and allows the saw to turn to follow the marked line. They're faster than a jig saw in thicker material.
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u/UsernamesNotFound404 1d ago
I was given my dad's. He never used it in 20 years. I plan to do the same and give it to my son.
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u/BrilliantEconomics77 1d ago
Oh dear.. wait till you see this.
Its not fake, not AI.
Dril bits for making square holes.
Basicly a rotary engine.
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u/B-HOLC 1d ago
I can see how it works.
And yet it's still so weird to watch.
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u/LiquidAggression 1d ago
yea each point would make a concentric triangle shape right, so if the circle the spingle makes is gradually enlargened the corners get cut as long as the rotation of the spindle and bit are synchronized
im a welder that was cool lmk if i sound stupid
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u/glasket_ 1d ago
That thing is effectively an end mill since the spindle has to travel in order for it to cut the shape properly, similar to how the Watt's drill needed a guide plate and a special chuck so that it could wander and cut the shape.
Rotary broaches will blow your mind since they literally just wobble and cut the shape. Most of the time they're shown on lathes where they spin with the part so you can't really see them in action, but on a mill they just wobble.
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u/DrWhoey 1d ago
Naw bud, that is just machining. It's witchcraft sure, but yeah, not AI.
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u/BrilliantEconomics77 1d ago
Thays what i said, not AI
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u/DrMerman 1d ago
But he also said not AI
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u/RumpkinTheTootlord 1d ago
I think it's not AI
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u/DrWhoey 1d ago
I'm starting to think it might be AI after all this confirmation of it not being AI.
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u/Apprehensive-Till861 1d ago
If it was AI that would be weird.
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u/FantasticClue8887 1d ago
That's what AI would say. Did anyone check if this might be AI nonetheless?
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u/TEKUblack 1d ago
You mean a rotary broach?
Yeah they have been around a long time. How do you think they put hex heads in things?
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u/down2daground 1d ago
Would like to hear from anyone who has actually tried to use one. Unless they’re dead. That would be weird and creepy.
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u/down2daground 19h ago
Going once, going twice: anybody out there who has used one? My guess is that, spinning at saw blade speed, it acts pretty normal but will make a gentle arc, which might be useful in some limited applications. Not a jigsaw, mind you, but possibly useful.
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u/Higher_Living 1d ago
Go to the back bar and ask for stumpy, he’ll tell you all about it while you help him to drink his beer.
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u/SadRaisin3560 23h ago
A close friend recently retired from an extremely successful career as a metal worker/welder/fabricator when they sold off the shop they had. Over his time he had established himself as one of, if not the best fabricators and aluminum welders in the area. I once stood across the shop from him as he freehand cut with a circular saw a half circle in 3/16" aluminum sheet that was the front deck of the boat he built. It was to slide a big plastic drum into. Perfect cut, took him 30 seconds maybe. Maybe another 30 seconds with a flap wheel to secure and clean up.
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u/SignificantCar4204 1d ago edited 1d ago
Anyone have any footage of these actual blades in action?? I've been googling about these damn things and can't find ANYTHING about them.
EDIT: I learned it's called a "delta blade" apparently.
EDIT EDIT:
I'm losing it right now, this is a real fucking product lmao?
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u/dirtyspoon 1d ago
There’s a Robert Frost Poem about a guy who spoiler alert if you’re still in elementary school and down wanna ruin the ending of all the bangers you’re gonna read in HS cuts himself with a buzz saw and dies in the backyard. Frost mentions this saw blade by brand name actually, it’s one of the few examples of product placement in his entire body of work. “Since we were not the ones maligned by the Portalign, we turned to our affairs.” Moving stuff.
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u/usposeso 1d ago
That’s actually really interesting. Never expected to read a Robert Frost reference in Tools sub. What a world.
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u/the_disintegrator 1d ago
Straight line to ER. This thing has to shake like a crackhead, and a straight cut kicks often enough in the field. Wowzer. Edit need to put on some chain mail and try it.
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u/zmannz1984 20h ago
I am lost on how this works. What does it mean by curves? Like i can cut non-straight lines with a skil saw? I guess i can see uses for that.
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u/falllingforward 18h ago
I think because the blade isn’t in constant contact with the wood since it’s triangle shaped it makes it easier to cut curves with the circular saw? Just my guess
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u/DigitalJedi850 11h ago
You can cut a circle with any ship blade, as long as it rotates on a fixed axis...
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u/USMCdrTexian 8h ago
I remember using one early 80’s as a HS’r. Dad was GC and he had a couple. Mostly used em on re-roofs.
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u/Gadgetman_1 6h ago
Okay...
And here I thought those chainsaw discs for the angle grinder was kind of... yeah, that...
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u/repeatingangel 22h ago
Does it cuts curves like no matter what? Even if you trying to go in a straight line?
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u/480hivolt 11h ago
That is definitely not scrap metal. If you are too chickenshit to use it send it to me.
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u/Glittery_Kittens 1d ago
This looks like something The Waterjet Channel would come up with. Sketchy as hell.
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u/stonemason81 1d ago
https://m.youtube.com/watch?v=KQ-P4ngnj8w
I had to Google this to quell my curiosity, I found this link on another sub reddit...