L3 Build Log - Wildman Interceptor A.A.D. 98

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fatherchaos

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My L3 attempt will be with a Wildman Interceptor AAD 98. I have one TAP member on tap (couldn't resist, thanks Kurt) and am on the lookout for a second. I have an Ultimate Darkstar kit on standby in the event I have to restart this process. Hopefully not. Also, I wanted to practice a few more building techniques before moving onto my 12', won't fit inside the house standing up, 98mm love rocket.

So here is my path forward.
The rocket has been modeled in solidworks for the majority of assembly parts so far. Additional parts to be modeled as I proceed. I will also prep an openrocket or rocksim file to match the solidworks model for simulation. Current estimated weight, with motor casing and no motor, is 13.5lbs. My expected pad weight is about 22.5lbs and return weight is about 19lbs. I estimate to hit about 12K ft on a Cesaroni M1830. Launch site is expected to be Lucerene Dry Lake (ROC), date to be determined as I near completion.

Main parachute range is from 9' (~19fps) to 11' (~16 fps). I have a 9' Rocketman ProXP on hand so if the return weight checks out I'll use that.
Drogue parachute is expected to be 3'. I have a Rocketman Mach II on hand and will likely go with that. I may pickup another Rocketman proXP to save on weight.
 
Last update: JUN-13-2017

Overview:
Length: 175.4 cm

Kit:
Wildman Interceptor A.A.D. 98, modified with a 24" motor mount tube to accomodate the aeropack tailcone.

Assembly Notes:
Head End Deployment
1/8" (x1) Pressure Relief port in upper portion of Booster and upper portion of Payload tube. Both below coupler/ebay
2-56 Nylon shear pins (x3) for nosecone retention
2-56 Nylon shear pins (x3) for booster-ebay retention
8-32 threaded Stainless Steel PEM nut & washer (x3) retention for ebay and payload tube.



Additional Parts:
Jb weld for Motor Retainer
West Systems epoxy
West Systems Colloidal Silica
Chopped carbon fiber
Aeropack 3.9in 75mm Tailcone retainer
Main Parachute: Rocketman ProXP 9'
Drogue Parachute: Rocketman ProXP 3'
3d Printed camera shroud (PLA filament)
Foxeer Legend 2 camera
Stainless Steel U-bolt 5/16-18, 1 3/4" internal spacing (x2), for ebay mounts.
Stainless Steel 1/4-20 threaded rod (x2) for ebay
25' 7/16" tubular Kevlar 3 point harness from onebadhawk for drogue attachment.
12.5' 7/16" tubular Kevlar 2 point harness from onebadhawk for main attachment. This is a 25' 2 point harness cut in half.

Altimeters:
Missileworks RRC3
Featherweight Raven 3

Component Weights (sanded and cleaned):
cr1 12.6g
cr2 11.9g
cr3 12.2g
cr4 12.4g
nc bulk 34.4g
ebay bulk 1 68.7g
ebay bulk 2 68.5g
fin 1 226.2g
fin 2 226.2g
fin3 226.1g
nc tip 67.4g
nc washer 4.7g
nc bolt nut 25.6g
nc 266.6g
nc coupler 184.5g
payload tube 397.3g
ebay coupler 253.1g
ebay vent band 31.4g
booster 815.5g
mmt 462g
aero pack retainer 41.4g
ap spacer 15.1g
ap tailcon 95.5g
*drogue ProXP 3' est 100g
main ProXP 9' 552.7g
*75mm 4G Case est 1440g (reference weight from another user, assembly not yet weighed)

* Estimated weights
Total Weight:5978.1g

Assembled Weights:
 
Wildman Interceptor AAD 98 parts supplied in kit:
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Solidworks Render:
interceptoraad98Capture.jpg
Initial component weights:
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Prefit after washing and light sanding:
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I've prepped the MMT surface and attached the 3.9inch 75mm Aeropack tailcone retainer using JB Weld. Attached using a smooth twisting motion and ample jb weld epoxy. Excess wiped up from outside and inside of the MMT. Cameo from my Ultimate Darkstar kit.
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My 98mm canvas phenolic kit went to 13k on an M-1101, so you are probably pretty close with altitude estimation.
 
Vent band and ebay tube was cleaned and prepped. I used jb weld for the vent band because I had left over epoxy from the nosecone fiberglass washer. Fin marks were transcribed from the booster section for spacing and alignment.

The nosecone fiberglass washer was set in jb weld based on the assumption this could be a high temp spot. The rest of the rocket will use west systems epoxy. I couldn't quite make the internal fillet I wanted due to my ham hook monkey fists... And I misplaced the dowel I intended to use.

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Yes. I wash the area with rubbing alcohol to remove mould release. Then sand with 150 grit. Wipe with rubbing alcohol to remove dust. Finally I apply the epoxy for the bond. This is a change to my previous techniques based on the stickied fiberglass bonding sanding thread.
 
The MMT was friction fitted back into the booster section with centering rings so I could check alignment and capture the fin slots onto the MMT. Since I had sanded the booster section base to be square with the aeropack tailcone lip, everything fit nearly perfectly.

However, as I was updating my solidworks model it dawned on me that the drogue chute cavity seemed rather small. The Mach II chute was rolled up and stuffed in the hole against the MMT (not into the MMT) with the 25' of kevlar 3 loop. Unfortunately, the beefy Mach II Drogue just won't fit so I've set it aside for now to use on the Ult. Darkstar. Moving forward I placed an order for a ProXP 3' drogue with rocketman. On the plus side, this will save almost a pound in weight. The Rocketman Mach II 3' weighed 426.1g. The Rocketman standard 3' I had on hand weighed 60.5g.
 
The MMT was friction fitted back into the booster section with centering rings so I could check alignment and capture the fin slots onto the MMT. Since I had sanded the booster section base to be square with the aeropack tailcone lip, everything fit nearly perfectly.

However, as I was updating my solidworks model it dawned on me that the drogue chute cavity seemed rather small. The Mach II chute was rolled up and stuffed in the hole against the MMT (not into the MMT) with the 25' of kevlar 3 loop. Unfortunately, the beefy Mach II Drogue just won't fit so I've set it aside for now to use on the Ult. Darkstar. Moving forward I placed an order for a ProXP 3' drogue with rocketman. On the plus side, this will save almost a pound in weight. The Rocketman Mach II 3' weighed 426.1g. The Rocketman standard 3' I had on hand weighed 60.5g.

I trashed the fincan on mine a little bit ago at mini Midwest Power, so I got the stuff to rebuild the fincan from Tim that night. Tim forgot and cut my booster at 43" instead of 33"... More room... For a 75/6400 case :dark: :dark:
I used a 12" or 18" Top Flight chute for my drogue. And a 40" Recon for the main.
 
Last edited:
So..... I just found out that McMaster Carr offers Solidworks 3d models for most of their parts. What a time saver! At least I taught myself how to model the fasteners before I found out about this. Let the downloading begin.
 
Nice to see another AAD 98 with a tailcone!

I watched your L2 video. Can't wait to see mine go up on an M!

And I just want to plant this seed for you: You have a fully assembled, built by you, L3 certifiable rocket :cool:
 
However, as I was updating my solidworks model it dawned on me that the drogue chute cavity seemed rather small. The Mach II chute was rolled up and stuffed in the hole against the MMT (not into the MMT) with the 25' of kevlar 3 loop. Unfortunately, the beefy Mach II Drogue just won't fit so I've set it aside for now to use on the Ult. Darkstar. Moving forward I placed an order for a ProXP 3' drogue with rocketman. On the plus side, this will save almost a pound in weight. The Rocketman Mach II 3' weighed 426.1g. The Rocketman standard 3' I had on hand weighed 60.5g.

Check the fit of your 9' Rocketman main, too. They pack a bit large and are a tight fit in a 4" tube. I had one that barely fit into a 4" Widman Drago, and it took a whole lot of shoving to get it in.
 
Check the fit of your 9' Rocketman main, too. They pack a bit large and are a tight fit in a 4" tube. I had one that barely fit into a 4" Widman Drago, and it took a whole lot of shoving to get it in.

Did an L3 just imply that "shoving" recovery gear into the airframe of a potentially heavy, high power vehicle is acceptable practice?

Lest we forget that when you advertise your advanced credentials, the things you say are not taken lightly by those less experienced.
 
I don't mean to call into question your methods, but with the retainer already attached to the motor mount how do you intend to do internal fillets? I always leave the retainer to be one of the last things I put on the rocket such that I can leave the rear centering ring out giving access to allow for internal fillets. I would think this would actually be a good candidate for foaming the fin can as well.

This is a very cool rocket, I look forward to seeing it all come together.
 
I don't mean to call into question your methods, but with the retainer already attached to the motor mount how do you intend to do internal fillets? I always leave the retainer to be one of the last things I put on the rocket such that I can leave the rear centering ring out giving access to allow for internal fillets. I would think this would actually be a good candidate for foaming the fin can as well.

This is a very cool rocket, I look forward to seeing it all come together.

Drill holes in airframe, mix epoxy and amendment, put epoxy into syringe, and inject into airframe holes. Internal fillets just need to be there so do not need to be pretty. It works really well.
 
Drill holes in airframe, mix epoxy and amendment, put epoxy into syringe, and inject into airframe holes. Internal fillets just need to be there so do not need to be pretty. It works really well.
I went over to wild man and was looking at the instructions for the dark star. I see how it's done and I agree, looks like a good method. What kind of syringe do you use and what is a good source.

i have been using Rocketpoxy to this point but not sure how well that would flow from a syringe.

I've been thinking about trying some different epoxy, I know there are lots of threads on that topic so I'll go read them and see where I land ��
 
I use basic 10ml syringes like you get for medications.

I have never used Rocketpoxy. I use Aeropoxy laminating resin with either chopped carbon or Kevlar pulp mixed in. I suspect Aeropoxy is thinner.
 
Just to confirm what most have already guessed, I am going the injected fillet route. I'll drill two holes for each fin slot per side (total of 8 holes per fin). These fins use two slots in the booster so it is almost like assembling a split fin design. The reason the retainer was attached to the MMT is part of my plan to assemble the rocket with the tailcone. This is my first aeropack tailcone so it gave me room to grow my methods... and a lot of holding parts wondering "how do I proceed..."

My current process for the tailcone retainer is to use it as a guide while assembling the mmt & booster to ensure a snug fit with the tailcone lip. I considered assembling like I would normally then sanding down the extended mmt till everything fit. That may have still been the better approach and I'll attempt that method on my next tailcone build. For now, the MMT + tailcone is used as a guide to fit snugly to the booster, score the MMT with the fin slots, fit the fins with all the CRs slid on, then tack the top CR in place. After I tack the top CR I'll withdraw the MMT and use that as a reference point to fit the fins again and tack the remaining CRs. This should result in a MMT that has properly spaced CRs so that when I reinsert it all the fins will fit, the tailcone will align with the booster, and the internal fillets won't leak everywhere.

Almost forgot to mention that I'll install the Y harness on the MMT during this process also. I have to keep reminding myself that so I don't end up with a well fitting booster section and no way to attach the kevlar cord.
 
Considering the size and weight of this rocket you need a much smaller drogue. 18" - no more than that. You can get something pretty basic for this. Check this
https://aeroconsystems.com/cart/all-parachutes/18-inch-hexagonal-parachute/

I checked my 3' parachute and it fit with ample room in the drogue cavity. I believe the 18" would give me a higher descent rate than I would prefer. I'm keeping an eye on the weight as I go and will make final adjustments to the parachute sizes in case the chutes I have are not sufficient.
 
Check the fit of your 9' Rocketman main, too. They pack a bit large and are a tight fit in a 4" tube. I had one that barely fit into a 4" Widman Drago, and it took a whole lot of shoving to get it in.

This did give me a bit of a fright when you mentioned it. Luckily, my 9' main (possibly soon to be 11' if the this thing doesn't go on a diet...) fit with a little creativity. Essentially I make a parachute "toquito" instead of the standard thick burrito roll. Since I'm doing head end deployment I was able to slide about 1/3 to half of the chute into the nosecone. Then I slide the remaining parachute and nosecone coupler into the payload tube. This worked pretty well and gave me just enough room for shock cord and charges against the bulk head. There is still pleanty of room in the nosecone also if I need to push anything further in. I'll just need to make sure I have a nice smooth fillet between the nosecone and coupler so that nothing snags when it gets pulled out.
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And since I always remember something after my initial post, I will be wrapping this up in a chute protector/nomex blanket.

Poketrainer walker thingy for scale.
 
Have you looked at the deployment bags that rocketman makes? Might be a good option for you on your main.
 
Have you looked at the deployment bags that rocketman makes? Might be a good option for you on your main.

I did consider this but I have not used them before. I'd probably need to mess around with one in the field to see if I prefer it over just wrapping it in a nomex blanket. Thanks for reminding me, I'll see if anyone at ROC will let me get touchy with it next time I'm out there. I intended to go to ROCstock today, but the evil W picked up and sent most people home before I could start my 3 hour drive.
 
Considering the size and weight of this rocket you need a much smaller drogue. 18" - no more than that. You can get something pretty basic for this. Check this
https://aeroconsystems.com/cart/all-parachutes/18-inch-hexagonal-parachute/

Yep, that's what I use...

I checked my 3' parachute and it fit with ample room in the drogue cavity. I believe the 18" would give me a higher descent rate than I would prefer. I'm keeping an eye on the weight as I go and will make final adjustments to the parachute sizes in case the chutes I have are not sufficient.

My finished and painted Interceptor weighed 12.2 lbs w/o motor. A 9' main will make this come down really slow. I put the AV bay in the middle and a Wildman 50" Recon fit fine in the payload bay and came down nice. But I'm landing on dirt. Obviously you must be landing on something harder... Or, just want a gentle ride down... Or have a much bigger motor case... :wink:
Anyways, I'm watching!
 
I checked my 3' parachute and it fit with ample room in the drogue cavity. I believe the 18" would give me a higher descent rate than I would prefer. I'm keeping an eye on the weight as I go and will make final adjustments to the parachute sizes in case the chutes I have are not sufficient.

I did my L3 with an Extreme Wildman. It was 16.4 pounds sans motor. With an AT 75-5120 on board it descended at about 85'/sec using the 18" drogue mentioned above. You do not want to go much slower on the drogue.
 
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