Estes Big Daddy - 29mm Mod

[Tobor]

Since it will be some time before I receive my Black Saturday WM DarkStar Jr. (not complaining mind you) or open my Secret Santa gift (Shipping box is too big and too light to be anything other then a kit) I've decided to work on my build pile. I figured the Big Daddy would be an easy build, then I remembered there is an issue with it lawn darting. So I dug through the forums and verified the problem.

Based on all the above I've decided to setup my Big Daddy (BD) to accept my AT 29/40-120. I started with K'Tesh's OpenRocket file of the BD, deleted the pieces not required and made changes to some of the component materials. Then I started modding and adding stuff.

And the result is...





OpenRocket File (Link)

Motors:
E23-5: 500+ Ft.
F52-8: 1300+ Ft.
G76-8: 2000+ Ft.

With this setup I'll have to paper the fins with cardstock, so that will be a fun new thing for me.

Anyhoot, what do you guys think?

Edit: Oh and I realize that on F & G motors I'll have to use something like Jolly Logic's Chute Release along with a small drogue if it will fit...
Edit #2: Btw, the bulkhead labeled "Ejection Plate" will not be glued but float. This will allow the laundry to get "pulled" out of the NC.

 

[rharshberger]

I dont bother with drogues on rockets as small as Estes LPR birds usually, but a 6" or so chute, or maybe even a large streamer would be goood for visibility.

 

[BDB]

I did a 29 mm mod on my daughter's big daddy. I papered the fins, and I used BB's and epoxy to add weight to the nosecone. I don't remember off the top of my head how much weight, but it was substantial.

Here is a pic of a flight on a F23 and a pic of my nosecone mod. JLCR is perfect for this thing. Good luck with the build!

 

[Tobor]

Thanks guys. And man DBD, that pic of your BD on that motor looks sweet!

 

[K'Tesh]

I started with K'Tesh's OpenRocket file of the BD, deleted the pieces not required and made changes to some of the component materials.

Glad to hear that I was able to help with this! Looking forward to seeing more of your build/flights!

Pointy Side Up!
Jim

 

[Tobor]

Today I ordered parts for this puppy, so I should be ready for assembly late next week. And for the paint scheme, I think I will stick with the concept I used in OpenRocket. It's fairly simple so it won't be a headache to make happen.

I will also be working on my Secret Santa Momba kit side by side with Big Daddy.

Edit: Forgot to mention that 3 of the fins were broken when I opened this kit. Probably due to me storing the package in the same box with 3 other kits. So this makes up my mind about papering the fins.

 

[Tobor]

Parts arrived today for this build and my Momba, plus a few extra pieces.




Started working on MMT assembly and fleshing out the NC fwd. bulkhead setup. Need to run to the "Home Despot" for some overpriced hardware..... (Actually not always true).

 

[Tobor]

Note on fins:
Somewhere in Estes' manufacturing process they goofed. Fin slots and fin tabs are a half inch off of each other. Me thinks it's the fin tabs. With filler pieces in place, fin tabs are now centered on root edge. Installing fins without adding fillers exposes the first .5" of fin root to the pressure impulse of ejection charge.

Fly-away fins anyone...?

 

[Tobor]

Okay, so last night I finished basic construction. Fin fillets are next but can't decide weither to use Epoxy Putty or wait for my Aeropoxy to arrive on Monday. Ordered it from GLR. If I use the latter, I'll be adding microballoon filler to the mix.

 

[jqavins]

There's something about the BD that just begs for a 29mm upgrade. I had two kits in my build box, so I built one straight and upgraded the other to take a Ceseroni 29 mm 3 grain. In the three grain there's a baby H, and I used it for my L1 cert. flight.

As for papering the fins, These were going to be my first papered, and I screwed them up badly. Since I needed to make new fins from scratch, I used basswood and didn't need paper.

It did need plenty of nose weight.

 

[Tobor]

There's something about the BD that just begs for a 29mm upgrade. I had two kits in my build box, so I built one straight and upgraded the other to take a Ceseroni 29 mm 3 grain. In the three grain there's a baby H, and I used it for my L1 cert. flight.

As for papering the fins, These were going to be my first papered, and I screwed them up badly. Since I needed to make new fins from scratch, I used basswood and didn't need paper.

It did need plenty of nose weight.

Yeah, I feel 'ya on the papering thing. I've been building/tinkering things since the 4th grade and I've never been the neatest hobbyist. Long fingers tend to spread glues everywhere no matter how hard I try not to. That is what I expected with my first attempt at papering fins. But, to my surprise, the fins turned out every well. I did screw up the side of one fin a tad when I pulled too hard on the trailing edge (T.E) of the paper. The last ~0.25 inch ripped off mostly parallel to the T.E. but I didn't panic. I just trimmed off the ragged edge, added a bit more Titebond to re-wet the surface and laid in new paper. The next morning I lightly sanded the patch seam and then applied some Elmer's Wood Filler over it. Later that evening I sanded the filler smooth. Sandable primer will take care of any imperfections.

Something that did get messy was gluing the fins to the airframe. I didn't want to use my West System GFlex epoxy for the task and my GLR order of Aeropoxy won't arrive until next Monday, so I used JB Weld. :surprised:

Note that I intentionally did not paper the fin tabs as I wished to avoid having to widen the fin slots on the airframe. So before actually attaching fins I used the JBW to coat both sides of each tab. My "technique" was to apply JBW to the surface of one tab, rub it in with a gloved finger, used the heat gun/wand of my soldering station (@170°) to warm everything up and then used my finger to squeegee off the excess JBW. Rinse and repeat...

On the first fin slot I attempted to lay down some JBW on the MMT but the slot was too narrow even for the craft picks (Kind of like a flat toothpick for arts & crafts) I was using. Instead I just gobbed JBW on each CR where the front/rear edges of the fin tabs touch and then applied copious amounts of JBW to the bottom edge of each fin, one at a time, then inserted the fin, allowing the slot to scrape off the remaining excess epoxy off the sides of the tabs. After all fins were installed, I again used my heat gun to warm up each mini fillet that formed and smoothed it out with the larger radius end of a craft pick. After all that was finished, I used my Estes Fin Jig to line everything up and let it sit until the following evening.

 

[Tobor]

Well today I finally had the chance to fly this bird at Mini MWP. 1st and only flight was on AT E23-8T (Drilled for 6S delay). Flight was flawless. I was really surprised how well the chute deployed from the modded NC. Also like the fact that no chute protector is needed with this arrangement.

I will be using the same concept on my 3" BalckFly.

And I just realized I never posted a pic of my BD, aka "Big Red". I'll get around to that later tonight.

 

[crossfire]

Well today I finally had the chance to fly this bird at Mini MWP. 1st and only flight was on AT E23-8T (Drilled for 6S delay). Flight was flawless. I was really surprised how well the chute deployed from the modded NC. Also like the fact that no chute protector is needed with this arrangement.

I will be using the same concept on my 3" BalckFly.

And I just realized I never posted a pic of my BD, aka "Big Red". I'll get around to that later tonight.

Tobor
You were at MMWP I didn't see you there. We talked a while at the last Bong launch. This Sat. is TWA Bong launch
Gary

 

[AfterBurners]

Yeah, I feel 'ya on the papering thing. I've been building/tinkering things since the 4th grade and I've never been the neatest hobbyist. Long fingers tend to spread glues everywhere no matter how hard I try not to. That is what I expected with my first attempt at papering fins. But, to my surprise, the fins turned out every well. I did screw up the side of one fin a tad when I pulled too hard on the trailing edge (T.E) of the paper. The last ~0.25 inch ripped off mostly parallel to the T.E. but I didn't panic. I just trimmed off the ragged edge, added a bit more Titebond to re-wet the surface and laid in new paper. The next morning I lightly sanded the patch seam and then applied some Elmer's Wood Filler over it. Later that evening I sanded the filler smooth. Sandable primer will take care of any imperfections.

Something that did get messy was gluing the fins to the airframe. I didn't want to use my West System GFlex epoxy for the task and my GLR order of Aeropoxy won't arrive until next Monday, so I used JB Weld. :surprised:

Note that I intentionally did not paper the fin tabs as I wished to avoid having to widen the fin slots on the airframe. So before actually attaching fins I used the JBW to coat both sides of each tab. My "technique" was to apply JBW to the surface of one tab, rub it in with a gloved finger, used the heat gun/wand of my soldering station (@170°) to warm everything up and then used my finger to squeegee off the excess JBW. Rinse and repeat...

On the first fin slot I attempted to lay down some JBW on the MMT but the slot was too narrow even for the craft picks (Kind of like a flat toothpick for arts & crafts) I was using. Instead I just gobbed JBW on each CR where the front/rear edges of the fin tabs touch and then applied copious amounts of JBW to the bottom edge of each fin, one at a time, then inserted the fin, allowing the slot to scrape off the remaining excess epoxy off the sides of the tabs. After all fins were installed, I again used my heat gun to warm up each mini fillet that formed and smoothed it out with the larger radius end of a craft pick. After all that was finished, I used my Estes Fin Jig to line everything up and let it sit until the following evening.

View attachment 337095

When I paper the fins I use 3M spray adhesive. Spray the paper and lay over the balsa wood fin and press and smooth out the surface with your fingers, Come back and trim the edges. Now get some cheap thin CA just the least expensive you can find and coat both sides of the surface. Do this over a plastic zip lock bag (gallon size) if you have one? The CA won't stick to it. You could also use the plastic to coat the CA into the surface of the fin. Anyway after you have done both sides stand the fin(s) up and allow to air dry. Come back and sand with 220 and then 320. Fins will be smooth and hard.

 

[Tobor]

Tobor
You were at MMWP I didn't see you there. We talked a while at the last Bong launch. This Sat. is TWA Bong launch
Gary

Yes, I remember our conversation. I might make it to Bong this coming Saturday. Just depends how burned out I am from work. We have a BIG shipment coming in from India this week that will take the better part of two days to unload and another two days to properly stock.

Anyhoot, if I attend Bong, I'll be flying my Momba on some G76s.

When I paper the fins I use 3M spray adhesive. Spray the paper and lay over the balsa wood fin and press and smooth out the surface with your fingers, Come back and trim the edges. Now get some cheap thin CA just the least expensive you can find and coat both sides of the surface. Do this over a plastic zip lock bag (gallon size) if you have one? The CA won't stick to it. You could also use the plastic to coat the CA into the surface of the fin. Anyway after you have done both sides stand the fin(s) up and allow to air dry. Come back and sand with 220 and then 320. Fins will be smooth and hard.

Thanks for the tips. I already have a can of 3M 77 spray, so I'll give it a try on my Estes V2 build.

 

[K'Tesh]

Thanks for the tips. I already have a can of 3M 77 spray, so I'll give it a try on my Estes V2 build.

I would suggest that you try it out on some scrap balsa first.

 

[Tobor]

And finally, a picture of "Big Red" finished!

 

[jqavins]

Flight report is next, I presume? Also, two more questions and one more request:

How long a motor will that MMT hold?
What are you doing for motor retention?
Post a picture of the aft end, please? I'm just curious.​

If these have been asked before, my apologies.

Finally, I was re-reading to see if I'd already asked these, and saw again your post about the fin tabs being short. I had the same issue and, although it's water under the bridge now, I used a different and simpler solution: ignore it. The root edge lies directly over the gap, leaving only hairlines open on either side, which are sealed up when fillets are applied.

I didn't even need to have that problem, since I made my own basswood fins, but I had copied the original dimensions (except the tab depth of course) so had the same 1/2" gap.

 

[Tobor]

Flight report is next, I presume? Also, two more questions and one more request:

How long a motor will that MMT hold?
What are you doing for motor retention?
Post a picture of the aft end, please? I'm just curious.​

If these have been asked before, my apologies.

Finally, I was re-reading to see if I'd already asked these, and saw again your post about the fin tabs being short. I had the same issue and, although it's water under the bridge now, I used a different and simpler solution: ignore it. The root edge lies directly over the gap, leaving only hairlines open on either side, which are sealed up when fillets are applied.

I didn't even need to have that problem, since I made my own basswood fins, but I had copied the original dimensions (except the tab depth of course) so had the same 1/2" gap.

*Currently I only own one 29mm motor casing, an AT 29/40-120. I cut my MMT to 4.75 inches, which is just long enough for the 29/40-120 and the 0.25 inches needed at the back end for the motor retainer.

*The retainer I used is the Aero Pack RA29L.

And as requested...




As for a flight report? Okay...

Loaded "Big Red" with an AT E23-8T with 2 seconds drilled out of the delay.

Altitude: OR sim: 519 ft, Actual: Unknown but looked to be about 500ft.

Rocket slowed to nearly a dead stop at apogee then ejection charge fired. Laundry deployed picture perfect and rocket landed maybe 50 paces from pad.

 

[jqavins]

As for a flight report? Okay...

Loaded "Big Red" with an AT E23-8T with 2 seconds drilled out of the delay.

Altitude: OR sim: 519 ft, Actual: Unknown but looked to be about 500ft.

Rocket slowed to nearly a dead stop at apogee then ejection charge fired. Laundry deployed picture perfect and rocket landed maybe 50 paces from pad.

:clap::clap::handshake:

 

[jd2cylman]

This reminds me. I started one of these to use the AT E16's in. I gotta finish it one of these days...

 

[Tobor]

:clap::clap::handshake:

lol... Thanks.

This reminds me. I started one of these to use the AT E16's in. I gotta finish it one of these days...

Me thinks it's time to get jump'n!

 

[FlyBy01]

Would a 29/180 fit in one of these? H motor?

 

[Tobor]

Would a 29/180 fit in one of these? H motor?

Yes it would, but just barely. My 29/40-120 is 4.874" long, sans the Aft Closure. The 29/180 is 7.253" long, again sans the Aft Closure.

Links to Dimensional Drawings 29/180 - 29/40-120

 

[jqavins]

*Currently I only own one 29mm motor casing, an AT 29/40-120. I cut my MMT to 4.75 inches, which is just long enough for the 29/40-120 and the 0.25 inches needed at the back end for the motor retainer.

Would a 29/180 fit in one of these? H motor?

Yes it would, but just barely. My 29/40-120 is 4.874" long, sans the Aft Closure. The 29/180 is 7.253" long, again sans the Aft Closure.

Links to Dimensional Drawings 29/180 - 29/40-120

Now I'm confused. You said that, at 4.75", the tube was "just long enough" for your 29/40-120 case, but then say it will "just barely" take a 29/180 at 7.235". What's the deal?

Anyway, the H motor is exactly why I asked. You've got a flight proven build, so if it can take an H motor in a 29/180 case (or a Ceseroni 29mm 3 grain case which is 7.35" + 0.25" closure) then it'll make for a nice L1 flight. My 29mm Big Daddy is how I did mine (on a Ceseroni H90 if memory serves). Just make sure, if you've got 2.5" of motor sticking out the back that you've got enough nose weight to balance it.

 

[BDB]

If you cut the back off the nosecone and attach the harness to the tip of the interior of the cone, you should have plenty of length for a 7.25" motor. It will just protrude into the interior of the nosecone. The trick will be packing the recovery gear.

 

[jqavins]

That's what I did. I added a baffle to the top of the extended motor tube, using a liberally perforated bulkhead at the top with a piece of chore boy behind it. Worked fine.

One caveat: the plastic of the nose cone started cracking as I cut it. I left a lip of about 3/8" give or take then filleted the internal corner with JBW to reinforce it. That improved the rigidity as we as the strength. I wasn't so sure that JBW would adhere, but it did.

 

[Tobor]

Now I'm confused. You said that, at 4.75", the tube was "just long enough" for your 29/40-120 case, but then say it will "just barely" take a 29/180 at 7.235". What's the deal?

Anyway, the H motor is exactly why I asked. You've got a flight proven build, so if it can take an H motor in a 29/180 case (or a Ceseroni 29mm 3 grain case which is 7.35" + 0.25" closure) then it'll make for a nice L1 flight. My 29mm Big Daddy is how I did mine (on a Ceseroni H90 if memory serves). Just make sure, if you've got 2.5" of motor sticking out the back that you've got enough nose weight to balance it.

My answer was in regards to usable airframe length. As my mod of the Big Daddy required the purchase of a 29mm MMT, I cut it just long enough for the 29/40-120. Building this rocket for use with a 29/180 would require using a longer MMT. In any event, a 29/180 would fit inside the airframe, but just barely.

Sorry I was not clear.

 

[jd2cylman]

Now I'm confused. You said that, at 4.75", the tube was "just long enough" for your 29/40-120 case, but then say it will "just barely" take a 29/180 at 7.235". What's the deal?

Anyway, the H motor is exactly why I asked. You've got a flight proven build, so if it can take an H motor in a 29/180 case (or a Ceseroni 29mm 3 grain case which is 7.35" + 0.25" closure) then it'll make for a nice L1 flight. My 29mm Big Daddy is how I did mine (on a Ceseroni H90 if memory serves). Just make sure, if you've got 2.5" of motor sticking out the back that you've got enough nose weight to balance it.

My answer was in regards to usable airframe length. As my mod of the Big Daddy required the purchase of a 29mm MMT, I cut it just long enough for the 29/40-120. Building this rocket for use with a 29/180 would require using a longer MMT. In any event, a 29/180 would fit inside the airframe, but just barely.

Sorry I was not clear.

Actually, the motor tube only needs to be long enough to hold your fin tabs. You could stuff a 29/360 in there if the nose cone was long enough... Heck, a 2" chunk of motor tube would be long enough... All it has to do is hold the motor in the center of the rocket. :wink:

 

[rharshberger]

Actually, the motor tube only needs to be long enough to hold your fin tabs. You could stuff a 29/360 in there if the nose cone was long enough... Heck, a 2" chunk of motor tube would be long enough... All it has to do is hold the motor in the center of the rocket. :wink:

+1, full lenght MMTs are not needed really, but for some reason we seem to think they are.