Well, I think you'll find your issue is primarily the rod you launched off of. I fly my Io off a 1/4" rod all the time and while sometimes a little rod whip occurs, it's not a big deal. The club 1/4" rods are pretty stiff - perhaps the type of steel involved is not quite so stiff. A rail is overkill for an Io, though I will admit I fly my Callisto (upsized Io) off a rail.

Warren Musselman

Been a while since I thought about rod material, isn't cold rolled steel the material of choice. Plenty of metal places stock it.
JS

I prefer tempered (AKA spring) steel. Stiff, and the reason I like it is that if it does bend, it springs back easily (it doesn't stay bent), so that overall, it maintains a straighter launch rod over time. If you used the rod that came with the pad, it is probably aluminum. Get a good spring steel rod and your problems should end.

Spring steel is expensive though, and cold rolled will also work. Basically, get a steel rod, and you'll probably be fine. I just prefer the tempered.

Ok great- thanks guys, thats the input I was looking for.

Oh yeah a rail is total overkill for the Io. I was just thinking for future use it would be nice to build up.

The research I did this weekend surprised me. Like I said, I'm a newb for the most part and the unistrut made me smile.
I have installed so much of that stuff (and have a bunch too).....

So steel it is. I'm going to get on that ASAP. The second launch was a little spooky. I should have seen right around 700' but instead got maybe 300' altitude with the rest of the burn pushing the Io horizontal.

Kind of reminded me of a cruise missile flying over land. 😯

Tim, when we get replacement rods for the club equipment we go to Colorado iron and metals off of Mulburry in FC. We allways get stainelss steel rods and have them cut to 8' lengths. I like the SS because it is stiff and easy to clean off the nasty horrible crud that sticks to the rods. The rods are cheap and clean.

Dale.

Thanks for the info Dale!

I have a whole launch pad/launcher situation to sort out. I built my controller years ago, but it is only 6 volt and this last launch I was using Copperheads (blah) so I had to modify things.

Used a 6v relay with the coil being tripped by the controller and the NO contacts passing the 12v from the lantern batts.

It was really ugly, and I had to hold the button so long it was just stupid, then the rod whip made the whole thing worse.

An 8' stainless whip is now in the immediate future! Thanks for the reply!

Tim,

Might try better batteries, preferably re-chargeables. For light weight and total compact-ness I've used 6v Li photo batteries that have yet to fail, but if I did more stuff on my own, I'd look long and hard at Li-Poly in the 9V range. I don't want to lug even a motorcycle battery and for energy density and low internal resistance, Li poly is hard to beat. Prices have dropping sharply as well--probably under 50 bucks for battery and charger with diligent shopping. Unless you're doing wire runs of over 100' or clusters, bet you'd be good to go even w/o relay. Course Ni-cad c cell based packs are good too.
JS

PS: Copperheads have their uses, but reliable ignition of rocket motors aint one of them 😆

Oh no worries- I knew the lantern batts would be a pain but it was what I had at the moment.
I'm actually a master electrician and I was just being lazy. Even worse is I am a licensed amateur radio operator and have probably 100 amps worth of 12+ volt power supplies laying around here.

The copperheads wont fire at 6 volts will they??

My main problem was the rod whip. The lantern batts just added an extra little bit of "reality".

Yeah the Copperheads suck. They actually worked ok though. I sanded both sides a little before I attached the clips and everything worked out ok.
The mid-high power stuff is so new and amazing to me.

Don't get me started on my adventure with PML expanding foam tonight 😆

ugh!

I have been converting all my rockets to 1/4" Rail Buttons.

Over kill on some but fantastic launches.

I built a portable rail from aluminum and use a plastic
christmas stand to support it. I anchor it to the ground with
tent stakes. All total weighs less than a pound. The rail
is 7' long and fits between the seats of my car, and the
stand in the trunk. The tree stand allows me to adjust
angle for the wind also.

Most of my rockets range from 10oz to 30oz.