Blast deflector
 

Anyone know where I can purchase a new blast deflector plate? I had a slight accident out on the field a short while ago;while attempting to launch my Amazing Point the rocket failed to lift off the pad,caught fire,burned up and got so hot it melted the metal tube that slides over the launch rod that is attached to the blast deflector. I can't seem to find any listed on the websites.

The point has a flat bottom and you got "Bernoulli Lock".

http://www.rocketryforumarchive.com...ead.php?t=12544

The Estes deflectors have a plastic center standoff, not metal. you can replace it at a good hardware store for a few bucks by assembling a pipe nipple with a threaded end that passes through the central hole. Use a big wacher and a nut that mates with the threaded portion.

http://fittingsandadapters.com/maleconnector1.html


Or buy a new heavy duty deflector from NARTS and place a dead motor on it for a standoff.

https://blastzone.com/nar/narts/sto...=81620092133327

I like the pipe nipple idea.

In the old days, the blast deflectors used a roll pin. You can get those at the same good hardware stores, FWIW.

That said, my deflector doesn't have anything but the hole - no roll pins or otherwise, and it works fine. The key is that the rocket be positioned on the pad such that the exhaust will not shoot down thru the hole in the deflector and cook anything underneath - it's an alignment thing.

Doug

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Blast Deflector
 

The NAR Technical Services (NARTS) sells a heavy duty blast deflector with a roll pin to center it on a standard rod. Go to www.nar.org to access NARTS. Non-NAR members may purchase items, but there is a service charge. I do have one of the deflectors and it is 1/8 inch thick.
Did the ol' Point static test myself with an original Centuri kit way back when it was new. I usually put my clones or SEMROC versions at least 8 inch up using a closepin. I also twist wire extensions on the Estes igniters to make them easier to hookup. The Quest G2Q2 also helps with their long leads.


Chas

I normally launched the Point by wrapping some masking tape about six to eight inches on the rod from the deflector,per the instructions,and placing the rocket there. I also got some wire from work that I used as extensions for the igniter. Today I simply forgot to bring a roll of tape with me to the launch site,and tried to launch it as it sat on the defector. Didn't move,then went up in flames. Lesson learned. After I build my replacement,I may go with the G2Q2.

Interesting. Never heard that term before,but that's exactly what happened. Think I'll run down to the hardware store tomorrow and try the pipe nipple idea. My plate is still good,though a little warped from so many launchings.

Yeah, those plastic inserts for the Porta Pad II blast deflector deteriorate rather quickly anyway and need to be replaced eventually. Another source for a blast deflector is the back cover of an electrical outlet box. You can get those for for about 75¢ to $1.70 in the electrical department of your local hardware store. Get the biggest one that you can find, which will often be 4-11/16" x 4-11/16". A good way to mount it is to slip a spent motor (or something similar) over your rod and then slip the back cover plate down by inserting the launch rod through the mounting hole that is in one corner. Supported underneath by the spent motor, the panel will sit off-center and tipped at an angle, which is exactly the idea. It is off-center because the rocket (and motor) is off-center when it is placed on the launch rod, and now most of the deflector is underneath the rocket. In this configuration, the exhaust jet that hits it is deflected laterally away from the rod and the bottom of the rocket rather than being reflected directly back up at it. These galvanized steel back covers are quite durable; mine has been in service for 5 years now and it shows neither corrosion nor rust.

Great idea!
 

What a great idea! Too bad you can't patent it.
Neccesity is the mother of invention! :D

You might also want to check this out:

http://www.rocketreviews.com/oddl-r...an-stevens.html

Greg

or...
 

fill the bottom of 2 liter bottle with cement ( be sure to put a straw in the middle ) , they are funny looking , but the humps deflect fantastic