Exhaust deflector

[Sooner Boomer]

I was wandering through Ace yesterday. Couldn't find the paint I wanted. Bought all the smallest quick-links. Then spotted something that sparked an idea. My personal launch system is a music stand tripod with a keyless chuck on top. To protect the chuck, I usually use a clean, empty tin can with a hole through the bottom It's held up to the exhaust of an H motor. I think this has a bit more style. It's a 90 degree bend for a downspout, with a 6" piece of brass tubing epoxied on the outside. It will work with any rod 1/4" or smaller.

 

[Sandy H.]

Might be interesting to see if using that method vs. a flat plate effects altitude. We know a - forgetting the name, but the pop-off tube method with foam plug - increases altitude for sure.

Either way, for fun flying, if you like it and it works, then I'm onboard! Should look cool.

Sandy.

 

[Sooner Boomer]

Now I need to get a water deluge system working

 

[Steve Shannon]

Understand that by diverting the thrust you will be applying a horizontal force to your tripod. Be especially careful when flying something with a high thrust.
Also, most metal gutter pieces are galvanized. The fumes of zinc burning in an open flame should not be inhaled.

 

[teepot]

I used a piece of aluminum plate for a deflector. It was about a 1/16th thick. Exhaust burned right thru it on the first flight. I am worried it would do the same thing to the gutter material. But it looks cool. Try it and see what happens. Maybe get a small pond pump to spray water in it. I have a solar one for a water feature that is for the local wildlife. Drop the pump in a bucket of water and turn it on. They come with a variety of nozzles. The steam would look very realistic.

 

[rharshberger]

Understand that by diverting the thrust you will be applying a horizontal force to your tripod. Be especially careful when flying something with a high thrust.
Also, most metal gutter pieces are galvanized. The fumes of zinc burning in an open flame should not be inhaled.

Most (afaik all for the last 30+ years) residential guttering like that piece is aluminum, commercial guttering is usually electro-galvanized (zinc or other metal) steel which is then painted whatever color the gutter needs to be. I worked as a gutter installer for a year or so after getting out of the Army. Really cheap guttering is the plastic crap sold at the big box home improvement stores.

 

[FredA]

Steve is right - you're going to get a sideways push from the thrust.

When sitting on the pad at first ignition, the blast plate gets the same thrust as the motor.

 

[Troy3003]

Understand that by diverting the thrust you will be applying a horizontal force to your tripod. Be especially careful when flying something with a high thrust.
Also, most metal gutter pieces are galvanized. The fumes of zinc burning in an open flame should not be inhaled.

I would assume there wouldn't be anyone in the vicinity to breathe those fumes, lol.

 

[Bowman]

Given that we know that some composite propellant burns/consumes aluminum as part of the formula, we know it is hot enough.
I would expect burn-through to be very likely. Thereby depositing slag on your drill chuck.
It would probably look cool though, especially with the water deluge.

 

[Buzzard]

I have been using a gutter elbow on my competition tower launcher since the '70s. It is really useful here in North Texas when the grass is dried out. I have flown F class motors out of the tower. The attached picture is a D Egg Loft flight out of the tower. You can see the diverted exhaust to the lower left. I have never noted any movement of the tower due to the diverted exhaus. I should note that I do stake down the tripod to keep it steady in any wind.

 

[Sooner Boomer]

Our club flies as much from a rail as they do from a rod. Well, probably *more* from the rail right now as I'm about the only one flying hobby stuff. I was thinking about how to add one of these to the 1010 rail we use. There would be NO danger of tipping the rail over from re-directed thrust.

 

[Blast it Tom!]

I've done this all my life... I've posted it before, but here is my son launching on a pad he made some 30 years ago, at least... we "BAR'd" last year...


The thing is low enough to the ground and heavy enough that the side thrust of our little hobby rockets aren't an issue. But clearly in dry Texas grass you may want to have some water handy or clear an area of the ground for flammables.

And yes, I've often thought about a pad with a tower and water deluge! Anything to keep the kids interested!

Edited to add: the diagonal surface of the deflector is 3/4" plywood with a 1/8" steel cover plate.

 

[Sooner Boomer]

I've done this all my life... I've posted it before, but here is my son launching on a pad he made some 30 years ago, at least... we "BAR'd" last year...
View attachment 476898

The thing is low enough to the ground and heavy enough that the side thrust of our little hobby rockets aren't an issue. But clearly in dry Texas grass you may want to have some water handy or clear an area of the ground for flammables.

And yes, I've often thought about a pad with a tower and water deluge! Anything to keep the kids interested!

Edited to add: the diagonal surface of the deflector is 3/4" plywood with a 1/8" steel cover plate.

Looks like a great way to launch! Yours is purpose built, I'm modifying existing stuff. (and I'm not going to be terribly upset if it doesn't work).

 

[Blast it Tom!]

Looks like a great way to launch! Yours is purpose built, I'm modifying existing stuff. (and I'm not going to be terribly upset if it doesn't work).

Yes it is a great way for the little stuff. I thought yours was quite ingenuous... goes to show how we always have rockets on our minds! You see a random piece of hardware and it sparks a rocketry idea! And like you said, it's not like you sunk a ton of money into it if it doesn't work!

 

[Hobie1dog]

I always thought this would work really great and cheap.

 

[tsmith1315]

I always thought this would work really great and cheap.

 

[Sandy H.]

Buh-dum-chee

 

[Blast it Tom!]

It's not a real exhaust deflector, it's only cymballic!

 

[DigBaddy]

Ha! I just built a new pad with a 1/4" rod and used a cymbal from my son's old, cheap and therefore destroyed, drum set.

 

[Blast it Tom!]

@DigBaddy - see here...
https://media1.tenor.com/images/ba022f7ddefd8533a88a20474a8aa232/tenor.gif?itemid=5300322

 

[ep29030]

In farm country, a disc blade (new or worn) will never wear out. I've used 12-14" abrasive cutting wheels, old grinder wheels, and even 4" electrical box covers for blast deflectors.

 

[Steve Shannon]

When my kids were young and money was tight I had them build their own launch pads and controllers. We went to goodwill and bought stainlesss steel pan lids for 25¢. I drilled a hole in each to slide down over the launch rod.

 

[Blast it Tom!]

Cool, Steve. My son built that 2x4 based behemoth when he was about 14, one day while I was at work, from scrap stuff in the garage. I was flabbergasted when I got home. I'd only basically described the version I'd built when I was younger, and wasn't sure he was that interested in rocketry, and boom! There is a launch pad! We've upgraded it since getting fully into rocketry again, adding the steel plate and also adding a 3/4" piece of plywood on the bottom, as all he had at the time was underlay. We aslo added longer leveling adjusters just the other day to get us up out of the grass better and allow more adjustment. You could stand on this thing and jump up and down!

We tend to fly in as calm a conditions as possible, so are generally launching pretty close to vertical.

 

[MadRocketer]

Galvanized steel pipe elbow works great! Don’t mind my son’s cockeyed launch lug. It still flew great!

 

[lakeroadster]

I was wandering through Ace yesterday. Couldn't find the paint I wanted. Bought all the smallest quick-links. Then spotted something that sparked an idea. My personal launch system is a music stand tripod with a keyless chuck on top. To protect the chuck, I usually use a clean, empty tin can with a hole through the bottom It's held up to the exhaust of an H motor. I think this has a bit more style. It's a 90 degree bend for a downspout, with a 6" piece of brass tubing epoxied on the outside. It will work with any rod 1/4" or smaller.

View attachment 476287
View attachment 476288
View attachment 476289

Those gutter elbows are really thin. I'm thinking an H motor will punch a hole right through it. Report back, a video would be even better.

Also note that if the motor cato's via the rear nozzle, you'll be directing all those bit's horizontally.

 

[Sooner Boomer]

Those gutter elbows are really thin. I'm thinking an H motor will punch a hole right through it. Report back, a video would be even better.

There's a local launch on the 21st. I'll try it then. I don't know how big a motor can launch from my tripod. May only be a G.

Also note that if the motor cato's via the rear nozzle, you'll be directing all those bit's horizontally.

An extra special parting gift for the audience!

 

[Ronz Rocketz]

In farm country, a disc blade (new or worn) will never wear out. I've used 12-14" abrasive cutting wheels, old grinder wheels, and even 4" electrical box covers for blast deflectors.

I paid $6 for 10.

https://www.amazon.com/gp/product/B082R9PS95/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[mjennings]

Club I was with for a while used flower pots on the LPR pads. It would be heavy but there is likely some form of terra Cotta curve out there.

 

[Exactimator]

A little water deluge system could be something fun to play around with. Something like an upside down 2 liter bottle. Maybe a stopper you could pull with a string to start flow.

As for deflectors, I always preferred non-metallic. Seems more often than not the clips would touch the deflector and short. Ceramic tiles with a hole drilled in the center work well.

 

[ep29030]

I like to use 12" tiles, with a hole drilled in center for launch rod; however, we used some on the club's mid/high power pads and snapped several of them. I found a place on eBay that cuts round and square stainless, and I purchased some 1/8" x 10" SS plates. These will never wear out. Deflectors seem to clean better if they are coated with WD-40 before use. I'll have to try some spray Lithium grease to see if it works better.