Anyone flown an Estes Big Daddy on 38MM hardware?

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Donnager

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Last time at the range, I flew a Big daddy on a G-76 with a 29MM mount. It went well, so I built another one, and changed the following from stock:
CA hardened entire tube above Centering rings
3/8 plywood centering rings
Replaced Fins with Plywood
LOC 38MM MMT w/ aeropack retainer
Nose cone modified
The body tube is still stock
Heavy rocketpoxy fillets external, epoxy internal
Nose weight as required


At the last launch, a couple people (OK, I was one) thought it would be cool to see a Big Daddy on an H-550. I have run sims with this motor and it looks like it could break Mach (1.15-1.3) at around 17-18 oz, and go in the neighborhood of 3000 ft, depending on finish and final weight. I have high confidence in the strength of the fin can. The body is stout, but not LOC tube stout. Motor Mount should be fine. I am most concerned about fin flutter due to large fins, and airframe buckling under the 90G+ acceleration.

Has anyone flown one of these on a motor with this much hit, or with this much speed, or close to it? A baby "I" would probably not go as fast, but altitude could be higher, depending on my choices. I will probably run a big G or baby H first to be sure recovery works smoothly with the large motor.

I'll have plenty of help spotting it and will be running a couple of mylar streamers with a small parachute. Recovery descent will be fairly fast. I'm not worried about breaking it, and have blue tube and heavy nose cone for the next try if needed.
 
Paging Jim Jarvis! He has done several iterations on the Big Daddy. I think he said he made one that flies on J motors - 54mm.

I have this pic he sent saved for some reason.

IMG_4900.JPG
 
Our club just had a Big Daddy Stress Test contest event and they were flown on everything from D's to J's (with varying degrees of mods). An H550 has a very good chance of destroying the balsa fins due to flutter as you have mentioned.
Actually after reading your post a little better the plywood fins in combination with the rings would probably survive, put a coupler inside the body for the nose cone to sit on and it will probably last quite a few flights.
 
amirpc said:
Paging Jim Jarvis! He has done several iterations on the Big Daddy. I think he said he made one that flies on J motors - 54mm.

I have this pic he sent saved for some reason.

View attachment 395528
Click to expand...
Yep, those are mine. The one on the right flies on 2 grain 54 motors up to about 10K and the one on the left is 29mm. Both have the original balsa fins, air frame and nose cone. Unfortunately, the 29 mm one got lost in the trees a few years ago. My wife got me a replacement, but unfortunately, it crashed over the weekend. Last night, I got home from work, and there was another Big Daddy kit on the work bench.

Jim
 
rharshberger said:
Our club just had a Big Daddy Stress Test contest event and they were flown on everything from D's to J's (with varying degrees of mods). An H550 has a very good chance of destroying the balsa fins due to flutter as you have mentioned.
Actually after reading your post a little better the plywood fins in combination with the rings would probably survive, put a coupler inside the body for the nose cone to sit on and it will probably last quite a few flights.
Click to expand...

I can add that, maybe not a regular coupler but a custom hand cut one would work.

Thanks.
 
JimJarvis50 said:
Yep, those are mine. The one on the right flies on 2 grain 54 motors up to about 10K and the one on the left is 29mm. Both have the original balsa fins, air frame and nose cone. Unfortunately, the 29 mm one got lost in the trees a few years ago. My wife got me a replacement, but unfortunately, it crashed over the weekend. Last night, I got home from work, and there was another Big Daddy kit on the work bench.

Jim
Click to expand...

Original parts but encased in carbon fiber
 
JimJarvis50 said:
Yep, those are mine. The one on the right flies on 2 grain 54 motors up to about 10K and the one on the left is 29mm. Both have the original balsa fins, air frame and nose cone. Unfortunately, the 29 mm one got lost in the trees a few years ago. My wife got me a replacement, but unfortunately, it crashed over the weekend. Last night, I got home from work, and there was another Big Daddy kit on the work bench.

Jim
Click to expand...

She's a keeper
 
Here's an Estes kit with glassed tube and epoxy soaked balsa fins on one CTI 38mm I297 Skid. Flew it a few times on I800Vmax motors until I had a nozzle blow out.
XWkws5n.jpg

I800 Vmax nozzle blow out results.
2llIf5v.jpg

Latest build for 38mm motors - max three grain
DK4gdaJ.jpg

Almost ready build for 54mm four grain - maiden flight should be a K2045 Vmax.
7QrteBe.jpg
 
Threemorewishes said:
Here's an Estes kit with glassed tube and epoxy soaked balsa fins on one CTI 38mm I297 Skid. Flew it a few times on I800Vmax motors until I had a nozzle blow out.
XWkws5n.jpg

I800 Vmax nozzle blow out results.
2llIf5v.jpg

Latest build for 38mm motors - max three grain
DK4gdaJ.jpg

Almost ready build for 54mm four grain - maiden flight should be a K2045 Vmax.
7QrteBe.jpg
Click to expand...

Wow! What kind of altitude did you get on an I297? What do you expect for the K?
 
The I297 was around 5,000 feet. The K is about 10,000 feet. This is all from simulations as I had no electronics on board the I flights and the K has not flown yet.
 
Threemorewishes said:
The I297 was around 5,000 feet. The K is about 10,000 feet. This is all from simulations as I had no electronics on board the I flights and the K has not flown yet.
Click to expand...
I'd love to fly my Big Daddy on Vmax motors (I still have some), but mine doesn't have electronic recovery, which is required now for Vmax motors.

Jim
 
JimJarvis50 said:
I'd love to fly my Big Daddy on Vmax motors (I still have some), but mine doesn't have electronic recovery, which is required now for Vmax motors.
Jim
Click to expand...

The Tripoli rule change for Vmax and the need for recovery electronics has been addressed for the K flight with a micro timer powered by a Lipo. It fits in the 8mm deep space under a hatch between the fins and centering rings. The issue slowing the flight is the sonic beacon board, piezo and battery. The limited space between the motor tube and the inside face of the body tube are making the layout a real challenge. I may end up with a hatch cover that is proud of the body tube. It's not the end of the world but not optimal. I find these smaller air frames need a sonic beacon for recovery as they disappear in even the shortest vegetation. My fingers are crossed for a 2020 flight.
 
Threemorewishes said:
The Tripoli rule change for Vmax and the need for recovery electronics has been addressed for the K flight with a micro timer powered by a Lipo. It fits in the 8mm deep space under a hatch between the fins and centering rings. The issue slowing the flight is the sonic beacon board, piezo and battery. The limited space between the motor tube and the inside face of the body tube are making the layout a real challenge. I may end up with a hatch cover that is proud of the body tube. It's not the end of the world but not optimal. I find these smaller air frames need a sonic beacon for recovery as they disappear in even the shortest vegetation. My fingers are crossed for a 2020 flight.
Click to expand...
I think I might try to make a nose cone bay and use an altimeter and chute release. Hadn't thought about the space by the motor tube. Hmm.

Jim
 
This is cool thread! I’ve lightly thought of doing a estes conversion to an original estes one. I instead just got the amw fiberglass one that’s slightly bigger and did actually fly it on a k2045 vmax. It was a cool flight. My wife did the comparison videos of the estes one and the bigger amw version. It was fun project to do.
 

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Donnager said:
Last time at the range, I flew a Big daddy on a G-76 with a 29MM mount. It went well, so I built another one, and changed the following from stock:
CA hardened entire tube above Centering rings
3/8 plywood centering rings
Replaced Fins with Plywood
LOC 38MM MMT w/ aeropack retainer
Nose cone modified
The body tube is still stock
Heavy rocketpoxy fillets external, epoxy internal
Nose weight as required


At the last launch, a couple people (OK, I was one) thought it would be cool to see a Big Daddy on an H-550. I have run sims with this motor and it looks like it could break Mach (1.15-1.3) at around 17-18 oz, and go in the neighborhood of 3000 ft, depending on finish and final weight. I have high confidence in the strength of the fin can. The body is stout, but not LOC tube stout. Motor Mount should be fine. I am most concerned about fin flutter due to large fins, and airframe buckling under the 90G+ acceleration.

Has anyone flown one of these on a motor with this much hit, or with this much speed, or close to it? A baby "I" would probably not go as fast, but altitude could be higher, depending on my choices. I will probably run a big G or baby H first to be sure recovery works smoothly with the large motor.

I'll have plenty of help spotting it and will be running a couple of mylar streamers with a small parachute. Recovery descent will be fairly fast. I'm not worried about breaking it, and have blue tube and heavy nose cone for the next try if needed.
Click to expand...
You wouldn’t know the nose weight needed for 38 mm conversation?
 
Philip Tiberius D. said:
You wouldn’t know the nose weight needed for 38 mm conversation?
Click to expand...

Sorry for taking so long to respond.

My nose cone weighs about 11.5 oz, add the bulkhead and eye and you are around 12.

I don't know that this is the appropriate weight for your rockets nose. It took that much to get the balance point where I wanted it with an H-550 and the rear hardware I had selected. This is probably something to check on your particular rocket. If you get carried away on weight in the back, or you build light, this can be different.

Off the cuff, though, I'd say you should expect no less than 8 oz of lead, plus epoxy, glue, bulkheads, paint, etc.. if you expect to use a full weight DMS H. If you build heavy (thick fillets, etc...), this could increase. I believe my 38MM has an 8oz lead sinker threaded on tig wire in two directions through the nose, and the whole mess is buried in epoxy.

And.... It did fly on an H-550:). It was the only rocket I've flown on one where the motor was still on 300' up. It was scooting along pretty good.
 
Thanks @Donnager and yes @mo2872 building one now using the @Vanderburn upgrade (bass wood fins, 38mm wood center rings, Kevlar ejection retainer... T-88 epoxy all the way around, various calculations come up with 5.5 - 8.5 Oz of nose weight based on weights.
 
I recently had plans on modding my Estes big daddy kit for a 54mm motor mount and all the necessary mods to keep the airframe intact. Once my workshop is usable again I’d love to be able to get working on that.

Also thought about building a complete custom fiberglass and carbon fiber big daddy using (mostly) stock dimensions but excluding the motor mount entirely to take 75mm CTI 2-grain motors. I think the total length ends up around an inch or two longer than the original. Ordered the parts earlier this week and I hope to be flying it next September at black rock.
 
Tobor said:
Great thread!

I was wondering if you guys are aware of the 2005 Apogee article "The Simulation of Short Wide Rockets" (Issue #154)? In a nutshell, it proves that rockets like the Estes Big Daddy need less nose weight then RockSim or Openrocket suggest.
Click to expand...

I need to look at my numbers, but I am pretty sure I only had about 0.8ish cal stability with a simulated H550 (empty case with weight inside to simulate the actual weight) with my build. I didn't know the weight distribution in an actual motor, and assumed my "dumping dirt in an old motor to approximate weight of a loaded motor being a good weight simulator" wasn't as accurate as I'd like, so I tended to lean on the nose-heavy side.

I flew this one on an H-283 and it went great. I did have a little pucker doing the H-550--not that I was that worried the rocket would break (fin flutter)--I was a little concerned the balance would be off a little, and I might get a really fast skywriter. Went an ounce or so past what I thought I'd need, and flew it. One or two ounces on a rocket like this doesn't make much difference (to me), regarding altitude. I'm not one that loves to add nose weight to compensate for bad design until I'm happy......

I'm not a big fan of high powered sky writers, especially when they can reach the sound barrier within a second. A large motor on a bad combination can be a bad deal.

I am looking at some future flights:
1) H-999 in the same rocket (120G's, easy).
2) I-280/I-500 in a rocket built differently, but it will still be a Big Daddy (well past transonic)
3) J-425ish in the rocket from #2 above (LOL)
But I'll have to have some shop time to think it out and get interested.

So, two flights on an Estes Big Daddy that would certify for level 1. I'm Ok with that.

On to level 2? I may have to tuck my tail before I get too far. Stuff breaks.
 
Donnager said:
I need to look at my numbers, but I am pretty sure I only had about 0.8ish cal stability with a simulated H550 (empty case with weight inside to simulate the actual weight) with my build. I didn't know the weight distribution in an actual motor, and assumed my "dumping dirt in an old motor to approximate weight of a loaded motor being a good weight simulator" wasn't as accurate as I'd like, so I tended to lean on the nose-heavy side.

I flew this one on an H-283 and it went great. I did have a little pucker doing the H-550--not that I was that worried the rocket would break (fin flutter)--I was a little concerned the balance would be off a little, and I might get a really fast skywriter. Went an ounce or so past what I thought I'd need, and flew it. One or two ounces on a rocket like this doesn't make much difference (to me), regarding altitude. I'm not one that loves to add nose weight to compensate for bad design until I'm happy......

I'm not a big fan of high powered sky writers, especially when they can reach the sound barrier within a second. A large motor on a bad combination can be a bad deal.

I am looking at some future flights:
1) H-999 in the same rocket (120G's, easy).
2) I-280/I-500 in a rocket built differently, but it will still be a Big Daddy (well past transonic)
3) J-425ish in the rocket from #2 above (LOL)
But I'll have to have some shop time to think it out and get interested.

So, two flights on an Estes Big Daddy that would certify for level 1. I'm Ok with that.

On to level 2? I may have to tuck my tail before I get too far. Stuff breaks.
Click to expand...
😳 120 G’s !!!!
 

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