Challenge: Can You Beat This Scary Turbine PumpkinCutter Halloween Project ? Answered

. ROFLMAO!!! "Whoops." Good vid, the whoops only makes it better.

Haha yea, that Whoops was pretty funny. Nice videos mrfixits!

Hey, a big thanks to both NachoMahma and Brennn10 for your input. I do have a heck of a lot of fun doing these videos. They are not rehearsed and I don't do re-takes to fix glitches. It captures more of the wildness and mystery that way. (Even I don't know, what the ending is going to be!)

Also. I have repositioned the shut-off valve further away from the business end.

See recent pics for improvements.

This version looks slightly safer ! ;-)

yeah, I don't run away quite as fast...

That's why I ran! This is not yet a safe machine!

Yeah, I once saw a video of a few young fellows (engineers) blowing air from a compressor into an old bearing race, and wound it's spinning speed up until the race gave way and the bearings flew out. At the speed they were going, it would have nearly been like being shot had anyone been hit by them...As it was, 2 bearings are still (missing).

So, if the CD Turbine came apart at 15,000 rpm for example, yes it would be like being shot... by an old BB gun. According to the chart supplied by NachoMahma above, at 15,000 rpm, the speed of the 5" discs would be about 90 m/s (or 270 feet/second) or exactly the muzzle velocity of a very weak pump-action BB gun (not a good ol' Daisy with 450 fps).

This seems to have become my most oft quoted seasonal quote this year: "you'll put your eye out kid." LOL

Yes, I was going to use this line in my last post...it probably came from the common misuse of airguns in the old days. Anybody know?

From a movie...

Ooops, the movie is "A Christmas Story" and yes, it was about a B-B gun

Oh yes I remember something about that...A Daisy BB gun, I think. The roots of the phrase was in prehistoric times, originally uttered for the first time when a kid picked up a sharp stick. haha

Yep, Daisy Model 1938 Red Ryder... Back then, maximum nozzle velocity was 350 fps with a good lever-action pump. The new reproduction ones are only 280 fps (too many eyes poked out??) That would be roughly equivalent to 90 m/s, and when we consult the chart supplied by NachoMahma, above, we see for a 5 inch CD disc would be 14,000 rpm. I will post a new video where I take the CD Turbine up to 14,500 rpm, but without magnets between CD's.

The B-B gun was a "Red Ryder" :-)

. But it won't be BBs flying at you, it will be shards of plastic (hard to find on X-rays) or, in this case, a circular saw blade.

Absolutely... this is real world scary, not a phony-balony costume party. I plan to do the pumpkin cuttin' ceremony from around a corner with a long stick...

If you were to give each of the saw's teeth a slight upward twist, you could be looking at a 15krpm helicopter ricocheting around the place.

> evil grin <

Another thought - rather than cut the pumpkin, mount it on a toothless disc and run it up to full speed - imagine the scene when centripetal forces get the better of the pumpkin... =D

Thanks...both excellent suggestions! I've considered the first...don't want to go there except I will make something that revs up and flies. As for the second, hahaha, I will try it later and post the results!!

Hey Nach, thanks for this chart...it is EXACTLY what I was looking for! Obviously the rpms must be kept down for both safe experimentation or for any any reasonable use. I would not advise anyone to actually use the Skilsaw attachment...