ABOVE THE BLAST DEFLECTOR -
Stepen Fitton posted:
"This is after only 2 flights on D12s. Any ideas for building my 2nd Saturn V kit to keep the vacuform fin fairings from melting?
Vin Sauriol replied:
"How close was it to the blast plate?"
"1-2 more inches up next time. Anything I send is 4” from the plate."
G. Harry Stine would say: "When in doubt, follow the instructions."
These pictures are from the Estes instructions:
I know the excitement of launching your BIG rocket the first time, nobody carries the instructions to the launch site.
On the right is Mark Stephens Saturn V. Without a blast deflector, this shows what can happen using a J engine!
If you have ever watched a slow motion launch video, you'll see the engine blast bounce and reflect back up to the bottom of your rocket. Some of my rockets have charred fins.
The Saturn V is heavy and much slower off the launcher, a moment longer subjected to the heat flashback.
I made some card stock crescents that strengthen and could help prevent the melting of the thin plastic.
For Part One - CLICK HERE
For Part Two - CLICK HERE
I've gotten much better at getting rockets back looking the way they did before I put them on the pad. Raising them a little more than I used to is a big part of that.
ReplyDeleteOur club uses standoffs - usually either clothes pins or used motor casings. I guess a lot of clubs probably do the same. But they can be in pretty bad shape. I often bring a couple new clothes pins just in case.
Hi Daniel,
DeleteSometimes at club launches I'll notice a first timer not using a standoff, or raising the model over a foot up the launch rod.
Chris - would the shape of Odd'l blast deflector help with this?
ReplyDeleteI have to be honest and say I've never noticed that in the instructions. I haven't had this issue, even with high power rockets, but I will certainly pay attention now.
Hi Metal,
DeleteThe Odd'l Blast Deflector (or any angled deflector) would help. That Saturn V fairing plastic is thin, it wouldn't take much to melt it.
You'll see charred fins on minimum diameter models where the fins trail beyond the back of the body tube.
Glue a 2" launch lug to the inside of the BT101 (far enough up that it doesn't foul the display nozzle assy. Then, on the pad, you can slide a 10" dowel (or bamboo skewer etc) in it - instant pad leg! The dowel will slide out on launch and, if it doesn't, it won't foul the flight characteristics
ReplyDeleteHi Phill,
DeleteYep, that would work! Great idea. The Estes instructions show masking tape around the launch rod. It'd take a few wraps of tape to hold up this heavy rocket.