rocket appropriate for D12-7?

The Rocketry Forum

Help Support The Rocketry Forum:

BABAR

Builds Rockets for NASA
TRF Lifetime Supporter
TRF Supporter
Joined
Aug 27, 2011
Messages
9,270
Reaction score
3,955
I flew an Estes Magician on a D12-5 (video below), so I imagine it would work great with a D12-7 as well.
Great flight, but scared the heck out of me after deployment, was sure it was gonna land in the road and scare some driver half to death!

did that rocket thermal close to the ground? Seemed like it was descending steadily and then the last 100 feet took forever.
 

bjphoenix

Well-Known Member
Joined
May 4, 2011
Messages
807
Reaction score
73
It is a challenge. I assume that keeping it in sight means under 500ft and drift no more than 1000ft with a D12-7. Here's my guess: a rocket that weighs about 200g and a 10mph wind with the rod canted slightly into the wind or using a 4' streamer. For the first motor, don't bother painting it until you successfully recover the rocket. Write your phone number on the tube in pencil.
I built a HiFlier XL but from some sims I ran it would probably be just fine with a D1-5. The HiFlier XL is 1.6" diameter. A 1.3" diameter would probably be closer to appropriate for the D12-7 but that much harder to see at apogee so I stuck with 1.6" diameter. I believe I had the D12-7 for my old Estes Python although again I think that one would probably also be OK with D12-5.
 

SharkWhisperer

Well-Known Member
Joined
Jan 27, 2021
Messages
503
Reaction score
333
I flew an Estes Magician on a D12-5 (video below), so I imagine it would work great with a D12-7 as well.
Magicians are fun. That's one I haven't fed to the trees yet in my small local field!

You were about perfectly horizontal at apogee when your ejection fired. An additional 2 seconds of freefall would have that bird traveling about 44 mph (64 fps) downwards. Might consider reinforcing that BT55 opening a bit (if you already haven't) and consider extending that shock cord a little longer from the 1-BT length it appears to be (from the nose cone hanging at the end), to reduce stresses on the BT lip. But 44 mph probably wouldn't zipper your bird with that elastic cord anyways...

A productive way to make use of your D12-7 inventory! And the extra 2s descent before popping might drop it closer to home and alleviate some worry about highway landings :=}
 

SharkWhisperer

Well-Known Member
Joined
Jan 27, 2021
Messages
503
Reaction score
333
I built a HiFlier XL but from some sims I ran it would probably be just fine with a D1-5. The HiFlier XL is 1.6" diameter. A 1.3" diameter would probably be closer to appropriate for the D12-7 but that much harder to see at apogee so I stuck with 1.6" diameter. I believe I had the D12-7 for my old Estes Python although again I think that one would probably also be OK with D12-5.
I've got an unbuilt Hi-Flyer XL and a pile of D12-7s, so will be interesting to read your flight report!
 

rklapp

NAR# 109557
TRF Supporter
Joined
May 8, 2020
Messages
2,336
Reaction score
1,793
Location
Oahu, Hawaii
I've got an unbuilt Hi-Flyer XL and a pile of D12-7s, so will be interesting to read your flight report!
I'm curious how you ended up with a pile of D12-7? My LHS has a box of D12-7. I asked why he has so many but still not sure.
 

SharkWhisperer

Well-Known Member
Joined
Jan 27, 2021
Messages
503
Reaction score
333
I'm curious how you ended up with a pile of D12-7? My LHS has a box of D12-7. I asked why he has so many but still not sure.
I make a lot of bulk purchases of (usually) older motors from Ebay and local private parties on Craigslist etc. 140 arrived a few weeks ago. I've flown many BP motors that are 30 years old, with only a few failures--never an ejection failure yet (though I've had a few with new BP motors), but a couple of low-thrust burns from likely mis-stored motors. Most are newer motors. If a package of Estes BP motors has gone south, most of the time this can be flagged by the accompanying igniters in previously unopened packages, because those tend to degrade first (if high humidity storage; doesn't indicate temp cycling...). I make a lot of my own igniters anyways, so that is not really an issue, but I'll fly those motors in less valuable rockets before trying them in favorites. With rare exception, have had very few issues.

When D motors can be acquired for a buck or two each, they tend to accumulate. Picked up a box of 60 mixed A-D's along with a pile of igniters and wadding last year locally for $30.

I don't fly that many higher-altitude or larger multi-stage rockets in the warmer months when my closest field is rather small, but they see use in the winter months when my environs are wide open. Hence the "pile" of D12-7s awaiting use.
 
Last edited:

icyclops

Well-Known Member
Joined
Aug 16, 2013
Messages
350
Reaction score
163
Great flight, but scared the heck out of me after deployment, was sure it was gonna land in the road and scare some driver half to death!

did that rocket thermal close to the ground? Seemed like it was descending steadily and then the last 100 feet took forever.
I had the same feeling…very questionable flight area so close to that road….
 

bjphoenix

Well-Known Member
Joined
May 4, 2011
Messages
807
Reaction score
73
I'm curious how you ended up with a pile of D12-7? My LHS has a box of D12-7. I asked why he has so many but still not sure.
I think the black powder D is the best bang for the buck, although I'm usually launching something like a Big Daddy on D12-3. If you're brave and have a big field, turns out there are a lot of interesting rockets that will fly high on D12-7. I was trying to walk the line between flying on D12-7 and staying low enough to have better chances of getting it back. I only had a 3-pack of D12-7, I think because I used to have an Estes Python. If the HiFlier survives those 3 then I'll just have to buy some more.
 

rklapp

NAR# 109557
TRF Supporter
Joined
May 8, 2020
Messages
2,336
Reaction score
1,793
Location
Oahu, Hawaii
I think the black powder D is the best bang for the buck, although I'm usually launching something like a Big Daddy on D12-3. If you're brave and have a big field, turns out there are a lot of interesting rockets that will fly high on D12-7. I was trying to walk the line between flying on D12-7 and staying low enough to have better chances of getting it back. I only had a 3-pack of D12-7, I think because I used to have an Estes Python. If the HiFlier survives those 3 then I'll just have to buy some more.
My Hiflier XL and Mercury Redstone are my two lucky rockets. Many close calls…

 

smstachwick

LPR/MPR sport flier with an eye to HPR and scale
TRF Supporter
Joined
Jul 30, 2021
Messages
197
Reaction score
136
Location
San Diego, CA

bjphoenix

Well-Known Member
Joined
May 4, 2011
Messages
807
Reaction score
73
I've got an unbuilt Hi-Flyer XL and a pile of D12-7s, so will be interesting to read your flight report!
We had a great launch today.* The HiFlyer on a D12-7 flew straight up curved over at apogee and came down just a little bit before ejection. It was high but was visible the entire flight. A slightly smaller rocket on a C6-5 was harder to see at apogee. The first flight the HiFlyer landed about 30' from the pad. The second flight it went straight up then angled a good amount off of vertical. I had to walk 1/4 mile to get that one. Launching off of a 3' rod but with blast protector and standoffs there was less rod length available. I recommend a 4' rod if you have it available.

*we had awesome launch conditions today, even if it was hot. Starting this morning it was about 85 degrees, bright and clear, and NO wind. Our host farmer had recently mowed and baled the grass on the field so our field was almost like my front yard. By the end of the launch it was about 93 degrees. This combination of conditions will be very rare.
 

SharkWhisperer

Well-Known Member
Joined
Jan 27, 2021
Messages
503
Reaction score
333
We had a great launch today.* The HiFlyer on a D12-7 flew straight up curved over at apogee and came down just a little bit before ejection. It was high but was visible the entire flight. A slightly smaller rocket on a C6-5 was harder to see at apogee. The first flight the HiFlyer landed about 30' from the pad. The second flight it went straight up then angled a good amount off of vertical. I had to walk 1/4 mile to get that one. Launching off of a 3' rod but with blast protector and standoffs there was less rod length available. I recommend a 4' rod if you have it available.

*we had awesome launch conditions today, even if it was hot. Starting this morning it was about 85 degrees, bright and clear, and NO wind. Our host farmer had recently mowed and baled the grass on the field so our field was almost like my front yard. By the end of the launch it was about 93 degrees. This combination of conditions will be very rare.
Niiiiice. Really encouraging! I can't wait to try mine out now!!! Post a video if you have one! Glad you enjoyed excellent weather for uncomplicated flights! I'm jealous!
 

bad_idea

Well-Known Member
TRF Supporter
Joined
Mar 19, 2021
Messages
56
Reaction score
34
Location
North Texas
We had a great launch today.* The HiFlyer on a D12-7 flew straight up curved over at apogee and came down just a little bit before ejection. It was high but was visible the entire flight. A slightly smaller rocket on a C6-5 was harder to see at apogee. The first flight the HiFlyer landed about 30' from the pad. The second flight it went straight up then angled a good amount off of vertical. I had to walk 1/4 mile to get that one. Launching off of a 3' rod but with blast protector and standoffs there was less rod length available. I recommend a 4' rod if you have it available.

*we had awesome launch conditions today, even if it was hot. Starting this morning it was about 85 degrees, bright and clear, and NO wind. Our host farmer had recently mowed and baled the grass on the field so our field was almost like my front yard. By the end of the launch it was about 93 degrees. This combination of conditions will be very rare.
Hey, those flights and field conditions sound familiar! I was the guy parked two cars south of you whose own D12-7 flight ended up decorating the only tree on the field, because evidently my rocket luck is snakebit. :D

This thread caught my eye when you refreshed it last week, but I didn't make the connection this morning when you showed me both the rocket and the pack of motors that brought it into being. :) Those were great flights, and you couldn't have had a better landing for the first one. Lovely build of the rocket too!
 
Top