LocostUSA.com

This may have been mentioned before, but my quick search didnt reveal anything.

I wont/cant get into details, but as part of my career, im responsible for getting "new process" in to large scale manufacturing. This method of fastening has been around for a few decades now, but now it is really starting to hit the main stream. They have been using this method on bicycles for a while now i think.

The process is called Friction Drilling, Flow Drill being the leading brand name of the bits. Its a method of using a highly heat resistant, semi blunt "bit" that litterallly turns and melts its way though tube and forms a near perfect condition for for a fastener (no tapping required). Studies have shown that this type of fastening is just as strong as a pop nut, pop rivit, and much easier/cheaper than duez fasteners. Also works great for mouting objects directly to a tube, ie not the need for an additional bracket.

Here is more indepth read of the process and a nice little video.
http://www.buildlog.net/blog/2012/08/th ... -drilling/

And dont be discouraged by the "required CNC/high performance drill system..." I have very sucesfully done this at home, in my harbor freight drill press, and a craftsman 3/8" cordless drill...

NICE!!!!

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this story shall the good man teach his son,
and chrispin chrispian shall ne'er go by,
from this day to the end of the world.
but we in it shall be remembered.

Interesting. How does this method compare, strength-wise, to a nutsert?

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Peace, Ron

I'd expect its strength to be similar to a same-sized traditional rivet that's installed red-hot. As it cools it contracts and clamps the surfaces together stronger than just about any fastener.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
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sorry, that is what i ment by "pop nut"... with out the details, our independent tests show that the friction drills are about 30% stronger than the pop nut in a straight perpendicular tensil pull (both having threads pull out before hole failure), same stength in shear condition (bolt fail before threads) but it is about 120% stronger in a torque check... (the pop nut will spin in its hole before ruining threads, the friction drill will make the bolt twist off)

about the only thing that it couldnt beat in a blind fastener condition, was against a weld nut (a nut welded to the back side of the base) the weldnut obviously better, but its not practical for putting weld nuts inside of a tube, at least any distance from the end of said tube

the main benefit over a pop nut is that in a vibration condition (almost anything mobile), the friction hole will not loosen, it cant... its one piece.. with the pop nut being a seperate part, over time, the pop nut can loosen against the base... unless you feel like retorquing the fasteners all the time to pinch them more and "snugging" them up again.

What kind of RPMs are required for drilling steel? Can the drills be purchased in small quantities by the home user? Any idea about costs?

It does look interesting. It looks like your plunge speed has to be timed very well to compress the molten metal correctly.

Thanks for posting this.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

kiwi dave knows all about failing rivnuts.

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this story shall the good man teach his son,
and chrispin chrispian shall ne'er go by,
from this day to the end of the world.
but we in it shall be remembered.

So do I, I had to remove production ones that had failed in the B pillar of Volvo trucks, not fun as you can't get in behind them.


DMB, is this something you are directly involved with as i need this process for limitd production coming up soon.

On the flow drill website they have a parameters tab, lists all the info about RPM and plunge speed, per size.

http://www.flowdrill.com/machines

Just do a quick google search "friction drill" and there are several manufacturers. Flow Drill being the pioneer for the tool, their prices are a bit inflated... there are other manufactuers making them, and making them cheaper.

And for acquiring them.. we get ours through a private tool supplier. And pay about 40 bucks a piece for them (each bit). I do have an insider at Grainger, and they said that they would be stocking them soon. As it becomes more viable im sure more suppliers will pick them up. Im honestly surprised Mc Master doesnt already have them.

Their requirements are ment for "idea" conditions, most guys dont have access to a CNC machine... remember this is suggested and "good enough" as i said... ive done this process in my Harbor Freight Drill
http://www.harborfreight.com/heavy-duty ... 38142.html

It is something that i found, sourced, and got into full scale production. Feel free to PM me with any specific questions.

And IMHO pop nuts, riv nuts w/e they're called... are junk

I saw this at either a trade show or Oshkosh about 15 years ago and had forgotten about it. It is an excellent way to directly attach to a tube like on a Locost frame. Anyplace you could drill for a riv-nut you could use this. You do need to recognize that the nut is only about a grade 5 at best since it is melted, flowed and air cooled mild steel, so not for installing suspension, but for a lot of applications it is a really cool process.

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Planning a Duratec powered, Miata suspended 442

wow, that is slick!

It says lubrication is required, but why won't it just burn up and contaminate the metal?

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Noah

It seems that this process could change the heat treatment characteristics in the area of the new threaded hole.

1.5 hp for a 1/4" hole!?

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"My junk is organized. At least is was when I put it wherever it is." -olrowdy
Completed building GSXR1000 CMC7, "Locouki"
Website: http://projekt.com/locouki/

Not a defining statement. That it might be grade 5 is merely a part of an engineering equation.

A M10 grade 5 nut is stronger than an M8 grade 8 for example then considerations such as where and what forces will be applied apply.




Sure and so does welding, but we are generally dealing with mild steel tube in this forum so generally no noticeable effect overall.

I don't understand your statement about "no tapping required". It seems the drill leaves a very nice, smooth walled hole.

Bill