How big is too big for a streamer?

After a two day (successful!) search for my Vagabond that drifted nearly 2000' on its 18" chute this past Saturday, I'm thinking about putting it up on a streamer when there is more than just a gentle wind, particularly if I decide to send it up on a F motor at some point.

It is a bit over built from the stock model, it has birch ply fins and centering rings, and a scratch-built baffle. With a spent Aerotech 24/40 it comes in at about 7 oz. Calculators say I'd need something about 50" in length, question is, will it come down without getting banged up too bad should it land on a firmer surface? Club field this time of year is generally fairly soft, but the ground gets a little more firm in the summer months.

I've launched my Vegabond with a much smaller streamer (probably 20") and it broke a fin landing on a hard stone surface. If you have a soft landing area I would say you should be fine.

I guess I should mention I upgraded the fins to 1/8" birch plywood and used TTW construction. I'm not much of a fan of surface mounted fins on larger rockets.

See what results you get from these. The main uncertainty comes from the estimation of Cd::

How to Calculate Streamer Size

https://www.sunward1.com/images-tarc/Streamer Calculations (Cooke) (Jun 09).pdf

Streamer Recovery Basics for TARC

https://www.sunward1.com/images-tarc/Streamer Recovery Tutorial (Jul 09).pdf

byoungblood said:

After a two day (successful!) search for my Vagabond that drifted nearly 2000' on its 18" chute this past Saturday, I'm thinking about putting it up on a streamer when there is more than just a gentle wind, particularly if I decide to send it up on a F motor at some point.

It is a bit over built from the stock model, it has birch ply fins and centering rings, and a scratch-built baffle. With a spent Aerotech 24/40 it comes in at about 7 oz. Calculators say I'd need something about 50" in length, question is, will it come down without getting banged up too bad should it land on a firmer surface? Club field this time of year is generally fairly soft, but the ground gets a little more firm in the summer months.

Click to expand...

Just so you are aware:
The only limiting factor on the streamer size you can use is the amount of rolled material that can be slide into the airframe.
I and many other NAR competition flyers requrlarly use streamers as large are 10" x 120" accordain folded 1 or 1.5mil silver Mylar. Believe it or not that size streamer fits will in a BT-50 size model.
My original Estes Goblin KIT model came with a 2" x 120" orange crape paper streamer to bring that fairly heavy BT-55 model down with a spent D12 motor casing.

48 or 50 inch long 4 or 6 inch wide streamer should bring your Vagabond down just fine.

One little trick I've found helpful on Long Sport Streamers is to fold the streamer in half, Then half it again, and a third or even 4th time before rolling tightly to fit into the model. This helps the stream open promptly after ejection.

A streamer may be useful to reduce the chance of the rocket getting caught in a tree or to make it easier to find in tall grass. But, if your goal is just o reduce the distance the rocket drifts, switching to a smaller parachute, or cutting a spill hole in the current parachute, may be an easier solution to your problem.

-- Roger