Anyone flown an Estes Big Daddy on 38MM hardware?

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😳 120 G’s !!!!

The sim says 153g's on an H999 at current weight, with all the asterisks that I can put there. I expect with the changes required to run that motor, It will be a little heavier to hold ejection hardware unless I rebuild it, so I'd expect the upgraded one to be slower.

It took me about 10-12 months to move from a 29mm Big Daddy on big G's to a 38mm on a baby H, finally going to a full H. I expect it will take me at least that much time to go to the next level. I've got other rockets to fly, but this one is kind of cool, and it will probably stay at least a back burner project.

If I can get one to live on a full I or baby J with the Estes body tube and nose with wood fins and without external fiberglass, it would be pretty cool. I'll probably keep the stock paint jobs and decals on the future builds.

And, if I can only say I flew my Big Daddy on H's, that's OK.
 
The sim says 153g's on an H999 at current weight

I have noticed that with sims (more so RockSim), after 100Gs it starts to exaggerates. I have a small one that sims at 170G with the H669 and it only got too 99.3G. Next flight with that rocket on an H999 sims to 230Gs, but I don't think it will go above 150Gs. But with my Raven V4 maxing out at 105Gs I will not be able to get an accurate reading. All none Warp 9 flights with this rocket have been +/- 2 Gs from the sims.

One thing I noticed is that the burn time on my last H669 looked like 0.4 seconds, which could explain the lower Gs.
 
I have noticed that with sims (more so RockSim), after 100Gs it starts to exaggerates. I have a small one that sims at 170G with the H669 and it only got too 99.3G. Next flight with that rocket on an H999 sims to 230Gs, but I don't think it will go above 150Gs. But with my Raven V4 maxing out at 105Gs I will not be able to get an accurate reading. All none Warp 9 flights with this rocket have been +/- 2 Gs from the sims.

One thing I noticed is that the burn time on my last H669 looked like 0.4 seconds, which could explain the lower Gs.
I would imagine - after pulling 100G’s It’s all Academic...
 
I have noticed that with sims (more so RockSim), after 100Gs it starts to exaggerates. I have a small one that sims at 170G with the H669 and it only got too 99.3G. Next flight with that rocket on an H999 sims to 230Gs, but I don't think it will go above 150Gs. But with my Raven V4 maxing out at 105Gs I will not be able to get an accurate reading. All none Warp 9 flights with this rocket have been +/- 2 Gs from the sims.

One thing I noticed is that the burn time on my last H669 looked like 0.4 seconds, which could explain the lower Gs.

I agree. The sims I've looked at for mine seem aggressive. But, If you look at thrust to weight, it seems the sims might be conservative, though altitudes seem to disagree with this. Whenever I have the guts to put more electronics in the ride, I'll try to see which is closer to accurate. I expect 40-80G on an H-550 and around 110-140 on an H999. We'll see.

Big Daddys going big. BTW I used about six ounces of nose weight on Angry Daddy to balance it where a stock Daddy balances with a D12-3; just slightly in front of the leading edge of the fins at the root.



When I switch from a 38mm short H DMS to a full I, the nose weight will decrease, due to motor mass being in front of the CP. If the Angry Daddy was a 54mm, the weights will change, especially if the fin can is built light.

Cool video. Part of my inspiration to build the current 38mm. I'll build another.
 
Due to the 1/8" fiberglass fins I used, the Angry Daddy started out relatively tail-heavy. Using a two-grain 54mm motor, a decent percentage of motor weight is ahead of the target CG, so that helps some. Point being though, using the stock CG location will keep the rocket stable at least to around Mach 1.
 
Due to the 1/8" fiberglass fins I used, the Angry Daddy started out relatively tail-heavy. Using a two-grain 54mm motor, a decent percentage of motor weight is ahead of the target CG, so that helps some. Point being though, using the stock CG location will keep the rocket stable at least to around Mach 1.

What does the Angry Daddy weigh?
 
I've done three high power Big Daddy flights on two rockets.
H-283-Rocket1--small parachute and streamer
H-550-Rocket1--small parachute and streamer with tracker
H-238-Rocket2--Parachute with chute release with tracker

The second flight for Rocket2 will probably be an H-550 or an I-140, but it was built to fly a 54mm J-250. Weather/wind will decide when this may occur.

All of these flights were recovered. I'd suggest getting it back down quickly, streamer/small parachute if the rocket can handle it. I'd include a 2-4' corrugated mylar streamer in it either way. The flickering of the reflective material helps tracking a good bit.
 
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I have tried a lot of these personal alarms and this model has been the best:

https://www.amazon.com/gp/product/B07DMT8SLQ
They are smaller, cheaper and the loudest I have yet encountered. I very much recommend using ear plugs when you recover your rocket, these little guys can, and will, damage your hearing if you activate them in close proximity to people.
 
I finally have all the parts and am going to be starting my 38mm Big Daddy build. Here's the specs:

Rocket:
- Stock nose cone (modified)
- Stock airframe
- Launch Lab/Vander Burn 38mm plywood upgrade kit
- Aerotech 38mm retainer

Recovery:
- 10' 500lb kevlar shock cord
- 24" Estes nylon chute
- Top Flight 9" nomex blanket

Electronics:
- Jolly Logic Chute Release (500')
- Jolly Logic AltimeterThree

The first flight will be with an Aerotech G67R-9. Actually, all flights will be until I get my L1 certification! I'm going to remove the back of the nose cone and mount a bulkhead at the front of the shoulder with an eye bolt. This should a) fix the known ejection problems and b) give more space for the parachute. I've been modeling it in OpenRocket, and 2.5 oz in the tip of the nose cone gives me a stability of 0.861 cal with a CG of 12.287" and a CP of 14.869". It should be good to right around 2100' or so @ mach 0.5.

A couple of questions. First, are most of you guys running 1/4" lugs or 1010 buttons on your kit bashed Big Daddys? Second, with such a short airframe, how do you pack the chute (especially when running longer motors)? My 24" chute folded 3 times down to 3" long, has 1" of space between it and the 5" motor mount tube! Third, the Vander Burn upgrade kit comes with 3 centering rigs and an 8" motor mount tube. I'm assuming I should cut it down and only use two of the centering rings? Again, recovery packing is the issue here.
 
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First, are most of you guys running 1/4" lugs or 1010 buttons on your kit bashed Big Daddys? Second, with such a short airframe, how do you pack the chute (especially when running longer motors)? My 24" chute folded 3 times down to 3" long, has 1" of space between it and the 5" motor mount tube! Third, the Vander Burn upgrade kit comes with 3 centering rigs and an 8" motor mount tube. I'm assuming I should cut it down and only use two of the centering rings?

1/4" lugs.

Both my 38 and 54mm Big Daddy's have no bulkhead in the nose, just a kevlar tether on a glued in anchor with the nose weight. The parachute winds up largely in the nose.
I have two centering rings in all of mine, and the MMT is no longer than a 38mm H.
 
1/4" lugs.

Both my 38 and 54mm Big Daddy's have no bulkhead in the nose, just a kevlar tether on a glued in anchor with the nose weight. The parachute winds up largely in the nose.
I have two centering rings in all of mine, and the MMT is no longer than a 38mm H.

That's an idea! I could maybe even use a larger eye bolt as part of the ballast weight. That should leave plenty of room, as well as help bring the CG forward a bit. I just need to figure out the AltimeterThree mounting then, as I was going to mount it to the bulkhead.
 
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