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1/8 inch launch rods

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Bowhunter

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The best rod that i found to use is stainless steel tig welding rods they are alittle longer that the two piece kit rods but you have to cut the flat end off of them they dont rust and there strong
 

flying_silverad

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Originally posted by Bowhunter
The best rod that i found to use is stainless steel tig welding rods they are alittle longer that the two piece kit rods but you have to cut the flat end off of them they dont rust and there strong
How long do they come?
 

teflonrocketry1

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McMaster-Carr at: http://www.mcmaster.com
sells part number 7972A283 Gas and TIG Welding Rod, 316L Stainless Steel, 1/8" Dia, Approx 8 Rods/lb, $9.22 per 1lb package

Is that the specification of the welding rods you are using? I have some samples of 1/8 stainless steel rods that were rather soft and easily bent which is why I don't use them.

Bruce S. Levison, NAR #69055
 

Stones

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I TIG weld with all sizes of stainless rod (cres 321) and I concur with Bruce, it's a very "soft" rod.
 

Micromeister

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Precisely the reason, I only use type 316 or 316L stainless rods. with a yeild strength of 35-85 ksi and a Brinell hardness of 160-235 they are more then sufficent for model rockets up to 2 lbs. even the thin 1/8" rods are rather difficult to bend unless badly abused. Anything heavier then 2 lbs should be on a 3/16" or 1/4" rod anyway, same alloy is fine.
For cheap, rust free, easy fantastic and paper towel clean-up Stainless is your best choice. unless you want to spend a lot more money for titanium;) Carbon-Fiber rod is also available in 1/8" but has it's own set of draw-backs, including weakening over time, fibre sheading & ware. OK if your the only user..I wouldn't want them around a bunch of kids.
 

teflonrocketry1

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I use carbon steel music wire or drill rod for luanch rods. I usually get a 3 foot long section for around $1.00 at the local hardware store. I polish the rods up with fine steel wool and spray them down with penetrating oil after each use. I store them in a PVC pipe with an all thread that is soaked with household oil. I have been using this set of launch rods for over 10 years!

Bruce S. Levison, NAR #69055
 

Ryan S.

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Originally posted by Micromister
Carbon-Fiber rod is also available in 1/8" but has it's own set of draw-backs, including weakening over time, fibre sheading & ware. OK if your the only user..I wouldn't want them around a bunch of kids.

O man, the splinters hurt soo much
 

powderburner

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We have all kinds of parts getting laid up and cooked out in the factory, using a wide variety of graphite fiber composites. They trim the edges of the cooked parts to arrive at the final configuration, and drill out all the fastener holes. You should see the ventilation systems to contain the graphite fibers.

Remember the days when everyone thought it was OK to use asbestos all over the place?
 

Micromeister

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Bruce:
Like you, I used 36" drill rod for years. Music wire just bends to easily. I really got tried of the hassle sanding off the rust at each launch even with them stored in 1" PVC capped tubes rolled in oil soaked burlap. What a nasty, oily way to start and end a fun day of flying.
I said to myself..Self there has got to be a better way than this! And the word is Stainless steel. Not just any old Stainless but 316 or 316L stainless. Yes, it's more expensive, that $1.00 36" drill rod became a $6.00 stainless rod but the ease of fantastic and paper towel cleanup and just a tiny squirt of WD-40 make them well worth the little bit of extra money. Not to mention NEVER having to sandoff the rust again. We don't allow sandpaper on the field at all, Only emery boards until we change over all the micro clips to stainless also, than only scctchbrite pads will be allowed. Like I mentioned in the previous post the only thing better than this would be to triple the cost (about 18.00) to buy 1/8" x 36" Titanium rods;) Either stainless or titanium should be the last rod you'll very have to buy.
At the end of the flying day look mostly clean hands.

PS:
While on the subject of Stainless steel pad equipment add Stainless steel blast deflectors to the list, they also make a wonderful addition to your launchers. 16gage. 6" x 6" will handle just about anything MR or LRM. Teflon and Stainless Steel: two very important Model rocket support materials.
 

Stones

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Rgr that Micro, on the stainless blast deflectors. Although, I have one on the multi-pad that has quite a buildup of AP. Anyone know what cuts though this stuff?
 

teflonrocketry1

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Did you say stainless steel blast deflectors? I find that metal blast defectors reflect more exhaust back onto the rocket than they seem to deflect away. So I made deflectors out of cement (floor leveler) cast in the fluted bottom of a 3 liter plastic soda bottle. See page 8 of the Jan/Feb 1999 issue of NIRA's Leading Edge at:

http://www.nira-rocketry.org/LeadingEdge/JanFeb99.pdf

The cement absorbs and deflects the blast and there is less toasting at the aft end of the rocket. The raised parts are great for keeping ignitor clips separated.

I gave one these ablative blast deflectors to someone from WOOSH (that I cast back in 1998) when I went to an ECOF; it apparently is still good 5 years later, see page 6 of: http://www.wooshrocketry.org/WOOSHPop/wp8_2.pdf

I still have and use all the other ones I cast back then! They clean up easily with an old tooth brush and water.

Bruce S. Levison, NAR #69055
 

Micromeister

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Stones: Most will come off with fantastic, Some of the burn will not but becomes part of the deflector without the soot residue. the Deflector won't be as pretty as is was but still just as tough.
 

Micromeister

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Originally posted by teflonrocketry1
Did you say stainless steel blast deflectors? I find that metal blast defectors reflect more exhaust back onto the rocket than they seem to deflect away.

Humm! haven't seen that problem, unless you sit the model motor directly on the deflector... Not recommended for any type deflector, My 16 gage stainless deflectors have been in use since I reworks the system in 1983, all are still as good as the day they were made, all 17 are boxed with the launcher heads in a small handled tool box with the cloths pin standoff making it almost impossible to forget part of the system. Very handy,and easy to transport.
If you have an individual launcher the deflector can be formed into any angular configuration you like. You can even get away with thinner material on an angled deflector, here's a pic of the 22 gage stainless deflector I use on the pivot head of my solars powered launcher. This piece is another 20 year old much used deflector. I've NEVER seen a bit of "toasting" on the aft end of any model, competition to Large BP clusters to G or H AP motors. The 17pad satellite system were talking about has been used at every ECRM since 1989, loads of club and open events, with hundreds of flyers from at least 6 states I'm aware of.
Bruce it must be the distance between the motor and deflector that causing your model burning problem. Seems like 2 clothes pins distance (very precise scientific measurment:) works just fine for everything up to I impulse motors. I/we don't normally fly anything that big so I can't say if it makes any difference on bigger HRP stuff. Clean up is pretty much the same...Fantastic and paper towels, If a lot of AP motors are used you can add a wire brush to knock off the crud buildup.

I know this is way off subject of this thread, but one more thought about deflectors. No matter what the deflector material the purpose is to deflect the hot exhaust and burning propellant particles away from the ground, preventing grass fires, if you angle the deflector downward under the motor nozzle to protect the model, at some point the deflector should also come back to horizontal or even slightly add a little UP angle to accomplish the intended purpose of the deflector Fire Prevention.
 

teflonrocketry1

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Micromister,

That stainless steel deflector looks pretty cool! I like the fact you can move it around to accomodate different size launch rods.

I usually try to keep my rockets as close to the deflector as possible to provide a maximum launch guide length. I have been running simulations with RockSim, exploring minimum launch guide lengths. Sometimes 24 inches is not enough, which is what could happen with a large blast deflector and few clothes pins worth of separtion on a longer model rocket.

The worst toasting I usually see is from an Estes style launcher with a flat horizontal metal blast plate. I have also occaisonally seen an angled metal deflectors catch the exhaust gas just right and reflect it back onto part of the model and scorch it; that's how the fin can on my Astrocam got melted. Metal blast deflectors also conduct electricity and can short ingnitor clips; clip-wips seem especially prone to this in my hands.

The cement doesn't conduct electricity or heat, it also provides a nice weight to stabilize the launcher base. That is why I prefer cement or ceramic blast deflectors.

Bruce S. Levison, NAR #69055
 

wwattles

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I've shifted to mostly 4' rods for most of my larger rockets, especially the ones that are going to be going up slowly. 2 rods at Home Depot were well worth the investment!

WW
 

Tools R Us

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We use dirt ablative blast deflectors... :) Makes a big mess sometimes!
 

teflonrocketry1

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Tools R Us,

Excellent tube finned model! What is it, and what is it flying on?

When I was much younger the dirt worked fine for me too. Even used an un- bent coat hanger for a launch rod, all I did was push it into the ground.

Bruce S. Levison, NAR #69055
 

wwattles

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Better watch out... that dirt may accidentally contain some DHMO, and then you'd be in trouble!

WW
 

Tools R Us

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Excellent tube finned model! What is it, and what is it flying on?
It is our 10 inch sono tube rocket for testing our new 5 inch motors. That was the first flight of our 5 inch 3 grain motor, it consumed the 19 LB KNO3/SB fuel load in 5 seconds, pushing the 75 LB pig to 4876'! Some build photos;

http://www.trailertrashaerospace.com/Big_10inch.htm

Better watch out... that dirt may accidentally contain some DHMO, and then you'd be in trouble!
It rained most of the week, so we may in trouble!

We will have loads of pictures on the site as soon as I write the text for the 4-3 launch report. Here is a picture of the mess, the cinder blocks were put on the launcher legs for stability.
 

teflonrocketry1

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Originally posted by wwattles
Better watch out... that dirt may accidentally contain some DHMO, and then you'd be in trouble!

WW
Don't you mean H2O4?

Bruce S. Levison, NAR #69055
 
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