Defective rod on new launch pad

[Lord Rory Gin]

I used a 3ft brass rod for many years. Stainless rods are best because they keep rust away. After that comes brass, then standard metal rods. You can get rods at most hardware stores (Lowe’s, Menards, Tractor Supply). Welding shops also carry rods 3ft rods. Also, McMaster-Carr online carries them. I’d go to a local store first—shipping is ridiculous on things over 30 inches anymore.

After flight, use a Scotch Brite pad on them, soaked with a little WD-40 or Sewing Matching Oil. Scrub the rods, then remove junk with paper towel and put a little oil on the rod to prevent corrosion until the next use. I bought a piece of 1” PVC pipe at hardware store and made a launch rod storage container. Put a cap on each end. Make sure one cap is removable

Come to think of it; I haven't cleaned my rods in ages. Probably just once in 4 years.

However, "this one time... at launch camp", a rocket took off and took the launch rod with it - the rod was pretty loose in the wood base so it didn't present much resistance.

 

[Handeman]

At McMaster-Carr, a 36"L 1/8" Dia. 304 SST rod #89535K16 is $4.77. The 316 SST #89325K88 is $14.27, but almost nothing affects it, even motor exhaust won't affect it.

Our club uses the 304 that sit out in the field from October to April and the biggest issue we have is people that put masking tape on them to keep the rocket above the blast plate. The tape disintegrates but leaves enough residue to make other rockets stick to the rod.

 

[lr64]

Maybe your club should keep some kind of clip tethered to the plate that can be put on instead of tape. Or a bottle of Goo Gone.

 

[Handeman]

Maybe your club should keep some kind of clip tethered to the plate that can be put on instead of tape. Or a bottle of Goo Gone.

we keep cloth pins around and WD40, but when you get that many people, there's always a few.

 

[ep29030]

About 4 years ago I replaced most of my old rods with the 304 Stainless from Mc-Master Carr. I keep a set of 1/8, 3/16, 1/4 rods and a 1010 rail for 4-H club launches. I have a homebrew 4-pad launch setup that I’ve used for more than 10 years now with 4-H and scout groups. The other trade-up you can make is moving to better quality blast deflectors. I found some 304SS pieces of 18ga plate that became blast deflectors. Spray them with WD-40 before launching and they are easier to clean afterward. I suppose a thin layer of grease would work as well. I’ve never used disc blades but have thought about it—heavy, dome-shaped large pieces of steel that are reasonably priced at farm stores (Tractor Supply, Runnings, Rural King). Better yet, find a farmer ready to replace some discs and take the used ones.

 

[lr64]

we keep cloth pins around and WD40, but when you get that many people, there's always a few.

On some rocketry site recently, I saw a spiral thing that would grip the rod and hold the rocket up like a clothes pin, but would stay on the rod while adjusting. It might be less likely to wander off.

Snip. ... The other trade-up you can make is moving to better quality blast deflectors. I found some 304SS pieces of 18ga plate that became blast deflectors. Spray them with WD-40 before launching and they are easier to clean afterward. I suppose a thin layer of grease would work as well. I’ve never used disc blades but have thought about it—heavy, dome-shaped large pieces of steel that are reasonably priced at farm stores (Tractor Supply, Runnings, Rural King). Better yet, find a farmer ready to replace some discs and take the used ones.

I imagine the right kind of Pyrex or ceramic bowl, or flower pot, or tile with a hole drilled in the middle, might work here. I saw an inverted ceramic bowl thing on one vendor's site that was sold as a blast shield.

Maybe a sacrificial piece of wet cardboard to keep things clean?

 

[Azamiryou]

On some rocketry site recently, I saw a spiral thing that would grip the rod and hold the rocket up like a clothes pin, but would stay on the rod while adjusting. It might be less likely to wander off.

Sounds like the Odd'l Rockets "Raise" spring.

I absolutely love mine, it works like a charm — but it requires one simple instruction to use (pinch the spring for it to loosen so you can adjust it).

For a rod that's going to be used by a bunch of random people, that's one instruction too many. I easily imagine people just trying to yank it up and down the rod. It'd be bent out of shape in no time, and half the people would give up and use tape anyway.

 

[ep29030]

I imagine the right kind of Pyrex or ceramic bowl, or flower pot, or tile with a hole drilled in the middle, might work here. I saw an inverted ceramic bowl thing on one vendor's site that was sold as a blast shield.

Maybe a sacrificial piece of wet cardboard to keep things clean?

I've used 12" pieces of tile with center-drilled hole and they work fine for model rockets. Once you get to high power, the motors have enough force to break tiles--we tried some at club launches and broke a dozen tiles. For high power, steel deflectors (or Nomex blankets on the ground) are necessary.

 

[lr64]

Azimiryou:
That looks like what I saw.

Mark N.:
You could just use a thicker tile, or something glued to the back of the tile. Or two or three tiles glued together. There is also something called cement board, which might be a cheap way to go if you had to do a bunch. As I recall, one RC club made boxes of them to put over your lipos while using their charging station.