Cost-effective blast deflector for HPR?

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prfesser

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Wondering what people have been using for blast deflectors for K/L/M impulse pads? I've heard of people using grinding disks, how's that working out? Stainless steel is expensive.
 

Woody's Workshop

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How about those Red Clay Pots?
They have a hole right in the center of the bottom of them.
Bigger one's should be able to slide down a 10 or 15 rail.
If you need to contain the sparks, put it on upright.
Or put it on upside down.
I think I seen a photo some time back with small one's being used on Low Power Saw Horse Pads.
 

hobie1dog

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1945 Buick Roadmaster Hubcap 🤪 Big, extremely tough, thick metal will last years.
 

K'Tesh

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I've read about table saw blades being used
 

Bowman

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How about Hardi Backer Board. The cement-based version tile backer for ceramic.
You need to make sure it is large enough that the blast doesn't get under it and send it flying but it should handle the temp.
I've used a small piece under welding and cutting torches and it seems to fare quite well temperature-wise.
My intent would be under the pad, not mounted on the rod/rail.
 

KennB

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I agree with @dhbarr as I believe he's referring to a harrow disk.
While typing this @Funkworks chimed in.
I'd suggest checking with some local farmers for used disks; you may be able to pick them up for free.
 

dhbarr

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Plow discs should be larger and thicker, but harrow discs would work fine as well, or a discer seeder. Used farmy type discy things :)
 

Funkworks

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I chimed in because I came very close to ordering one. I bailed because personally, I wouldn’t use it often enough to justify the S&H I was quoted.
 

Thundercloud

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I have one piece of 12 x 12 x .075 stainless that I purchased to make a blast deflector, but never did. I can put it up on Yard Sale if that interests anyone.
 

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Richard Dierking

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Like Steve said, concrete pavers on the ground. Blast deflectors attached to pads are a bad thing. I know that blast deflectors are required in many codes, but I know that some people remove blast deflectors attached to pads before they launch their rocket because they noticed that the rocket launches better without the blast deflector. Particularly blast deflectors that are angled and not a "V" design.
If you don't want to haul around a concrete paver, just leave it at the launch site. Chances are no one is going to take it. Sometimes, simple is better.
 

caveduck

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Like Steve said, concrete pavers on the ground. Blast deflectors attached to pads are a bad thing. I know that blast deflectors are required in many codes, but I know that some people remove blast deflectors attached to pads before they launch their rocket because they noticed that the rocket launches better without the blast deflector. Particularly blast deflectors that are angled and not a "V" design.
If you don't want to haul around a concrete paver, just leave it at the launch site. Chances are no one is going to take it. Sometimes, simple is better.
Yes, this is important! A motor with 100+lb of initial thrust puts a lot of force on a deflector attached to a pad...if you watch enough launch videos you can see the pads bending and jumping when the deflectors are attached to the structure. You do not want this force transmitted to move the launch rail or you can get a lot of whip, especially with spider type pads that are very springy. In the desert they can be on the ground...some tilt is helpful to prevent roasting the back end of the rockets.
 

prfesser

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Thanks to all of you for your help; some great ideas! I think I'll pick up a few pavers at Lowe's.

Best -- Terry
 

Handeman

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We just let our away cell dig a hole in the ground. It splashes some mud when there is water in the hole, but the next rain washes it all away. The hole gets plowed away at the end of season before the corn goes in.
 

boatgeek

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I saw a thing of beauty when I was launching last Saturday--a heavy duty cookie sheet with one end on the ground and the other leaning against the launch rail. You could probably pick up the cookie sheet for a few bucks at a thrift store. Doesn't matter if it's got a little snickerdoodle burned on--the AP will take care of that right quick!
 

Ez2cDave

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Go for the ULTIMATE in Heat Resistance . . . TUNGSTEN ( melts at 6200 F. ).

Dave F.
 

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I might have to try a paver also. Great idea.
 

GlueckAuf

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For my home built, Jawstand-based launcher, I used a cheap ceramic tile to deflect the blast away from the launcher. It's flame-proof, inexpensive to replace, and won't allow the ignitor alligator clips to short out if they come in contact with the plate. Using JB Weld, i epoxied an aluminum bracket to the tile that in turn mounts on the 10-10 rail with 2 button screws and weld nuts.

1617254364516.jpeg


Good skies,
GlueckAuf
 

AHansom

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It's no harrow/plow disc, but I noticed an orphaned 14" hi-hat top in the shop today. Got a couple of cracks, and no matching bottom!

View attachment 452679

I wonder what it'll sound like...
Put a hundred or so loose poprivets around that think and turn it into a sizzle cymbal. Only to be used with sparky motors!!!
 
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