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K'Tesh
06-30-2013, 12:19 PM
I've currently got a 1/8" and a 3/16" piano wire for my launch rods...

Is there anything I can do to them to reduce their drag on the rocket (other than sanding), or just don't worry about it?

Thanks
Jim
.

chrism
06-30-2013, 03:22 PM
You could use a metal polish on them to reduce friction.

jetlag
06-30-2013, 07:16 PM
Maybe get them powdercoated?

Allen

CPMcGraw
06-30-2013, 07:24 PM
I've currently got a 1/8" and a 3/16" piano wire for my launch rods...

Is there anything I can do to them to reduce their drag on the rocket (other than sanding), or just don't worry about it?

Thanks
Jim
.

Wipe it down after each session, and maybe oiled (or something with silicone) to act as a rust inhibitor in the down-time. It's the constant exposure to oxygen coupled with corrosives in the exhaust that wear down the surface of the rod.

Using a stainless steel rod would work, with less maintenance. You might even try a CF rod, if you can find one in the right length(s).

sandman
06-30-2013, 07:46 PM
These work great, never rust and self lubricating.

http://dragonplate.com/ecart/product.asp?pID=681&cID=40

Or just search "carbon rods".

Never sand a launch rod again.

luke strawwalker
06-30-2013, 09:38 PM
car wax works well so I've heard...

Later! OL JR :)

blackshire
06-30-2013, 10:05 PM
I second the use of stainless steel rods (mine has never rusted, and wiping it off with a moist paper towel keeps it slick and shiny). I haven't used carbon fiber rods, but I was going to suggest them as well--they don't rust either, they're light, and they can be quite stiff, which reduces rod whip and tip-off in windy conditions. (Aluminum launch rods whip less than steel rods of the same dimensions.)

Chas Russell
07-01-2013, 12:16 PM
I have some small Carbon Fiber rods that I have yet to try for LPR. Oh the other hand, years ago I received a 1/4" rod about 6 feet long from an associate. It was a reject from a project. Since that time I have taken it to several launches and NARAMs for use with higher power events, mostly Scale and Sport Scale flights. Since these were on composite motors, the base of the rod at the blast deflector eventually was delaminated due to heat and exhaust. So my CF rod is now closer to five feet in length.
Don't know if a well protected 1/8 or 3/16 rod with BP motors would last longer. Just wanted to mention that they will weaken after prolonged use. Still, they clean up well and are slick. Plus, they make a metallic clank when dropped on an end.

Chas

foamy
07-01-2013, 12:42 PM
snip... Since these were on composite motors, the base of the rod at the blast deflector eventually was delaminated due to heat and exhaust. So my CF rod is now closer to five feet in length.
Perhaps 2 or 3 inches(?) of over-size brass tubing slipped over the rod might cure that. Just a thought.

I tend to keep some fine steel wool in the box to polish the rods with. Cleans them up nicely and keeps rockets from sticking.

I like the dry lube idea that someone mentioned.

blackshire
07-01-2013, 12:57 PM
Perhaps 2 or 3 inches(?) of over-size brass tubing slipped over the rod might cure that. Just a thought.

I tend to keep some fine steel wool in the box to polish the rods with. Cleans them up nicely and keeps rockets from sticking.

I like the dry lube idea that someone mentioned.That sounds practical. Also, if someone produced carbon fiber (or maybe Kevlar fiber) launch rods, the resin that was used would affect its heat-resistance. For example, the Hysol high-temperature epoxy that was used to fabricate the non-metallic 3:1 ogive Tomahawk sounding rocket nose cones (the epoxy could also be used to glue cracked engine blocks) would yield very heat-resistant composite (carbon or Kevlar fiber) launch rods.

tmacklin
07-01-2013, 05:46 PM
This stuff http://www.hoppes.com/ should be in every range box. And it smells nice!

ghrocketman
07-02-2013, 09:10 AM
Go with stainless. I did back in about 1979 and still use the same 1/8 and 3/16 rods.
You will never regret it.
CF is nice IF you can protect it.

Mark II
07-11-2013, 02:19 AM
These work great, never rust and self lubricating.

http://dragonplate.com/ecart/product.asp?pID=681&cID=40

Or just search "carbon rods".

Never sand a launch rod again.Interesting. I wonder how the 0.050" x 24" rod would work as a MicroMaxx launch rod? It is difficult to keep steel wire rods of that diameter straight; they inevitably develop curves during routine handling. One 24" length would yield two MMX launch rods.

http://dragonplate.com/ecart/product.asp?pID=4510&cID=39

Mark II
07-11-2013, 02:29 AM
Simply keeping the rod clean and free of bends will eliminate just about all lug sticking problems. Adding some sort of lubricant won't do much more and it will discolor the rocket's paint job. Scotch-Brite or a metal Chore Boy plus some ammonia or citrus cleaner and a little bit of elbow grease will do the trick. No need to get any more complicated than that.

Mark II
07-11-2013, 02:47 AM
Stainless steel is easily the best material to use for launch rods. Aluminum rods are quite a bit less rigid than rods made of steel, and forget about brass. I should also mention that I have been doing fine during the past 8 years using launch rods made from zinc-plated steel.

Other options:

How about titanium?
http://www.onlinemetals.com/merchant.cfm?id=180&step=2&top_cat=1353

Or, for the ultimate whip-proof rod, tungsten :eek: :
http://www.torreyhillstech.com/wroddept.html

luke strawwalker
07-11-2013, 10:44 PM
Stainless steel is easily the best material to use for launch rods. Aluminum rods are quite a bit less rigid than rods made of steel, and forget about brass. I should also mention that I have been doing fine during the past 8 years using launch rods made from zinc-plated steel.

Other options:

How about titanium?
http://www.onlinemetals.com/merchant.cfm?id=180&step=2&top_cat=1353

Or, for the ultimate whip-proof rod, tungsten :eek: :
http://www.torreyhillstech.com/wroddept.html

I used 1/8 inch brazing rods for a LOT of years before I finally got some mild steel rods, got tired of fighting the rust, and replaced them with stainless steel...

Brass CAN work... Not the best solution, but they CAN work...

Later! OL JR :)

Mark II
07-11-2013, 11:06 PM
I used 1/8 inch brazing rods for a LOT of years before I finally got some mild steel rods, got tired of fighting the rust, and replaced them with stainless steel...

Brass CAN work... Not the best solution, but they CAN work...

Later! OL JR :)You must have found better ones than I have seen here. The shiny brass rods in the hardware stores in my area are like noodles. You can flex them quite easily by just grabbing one end and shaking. You can get a real mean whip action going without much effort.

I am serious about the plated steel. Haven't had any problems with them so far.

Mark II
07-11-2013, 11:18 PM
The titanium rod looks almost doable if you don't mind the initial outlay. I mean, unless it is stolen it will be the last launch rod that you'll ever have to buy. And when you are done with it and pass it on to your children, you'll be guaranteeing that they will never need to buy another launch rod either.

As for the tungsten, well...? I suppose it depends upon how much you are willing to pay to have the absolute coolest low power launch rod (the longest ones listed are 36") in the country. When they finally inherit it your great-great-grandkids will be able to go right out and launch off this rod, no problem.

Buy a few of those tungsten rods, fashion them into arrows, and use them for archery target shooting against three foot thick reinforced concrete blocks.

jetlag
07-12-2013, 04:32 AM
We use a lot of Tungsten in nuclear pharmacy for shielding due to its density. It is expensive. It is not tracked by the NSA the way depleted uranium is (which we also use).

Stainless steel will solve just about any problem a rocketeer might experience, though.

Allen