Wayco's RW Mongoose 54 build

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Wayco

Desert Rat Rocketeer
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I have been trying to find time for this for about a month now, so for all of you that have been waiting with baited breath (yeah, right) here is my build thread for the carbon fiber Mongoose 54.
I have several minimum diameter rockets in my fleet, from an Apogee Aspire way back in my youth, to the biggest, which is an RW carbon fiber Mongoose 75. I started a build thread on the 75 a while back and lost interest in it, so this is the first build thread of a Rocketry Warehouse kit since then.
I previously built two Wildman Blackhawk 54's, and the methods I developed building them will be used in this build. Both of my Blackhawks have flown over 20,000 ft. and the Mongoose 75 recently broke my personal altitude record flying on an M840 to 28, 905 ft. All of my high altitude flights have been successfully recovered with one damaged Blackhawk when an ematch failed to deploy the drogue at 22,300 ft. It has been rebuilt and flown successfully since then with redundant altimeters to reduce the chance of a bad recovery.

I have been fielding a bunch of questions on a couple of other threads regarding this rocket, so you will probably see some pic's I posted on them here. Starting with what's in the kit:
013.jpg


It comes with two body tubes, the fincan is 40" long, and the payload tube is 20" long. The first pic. is of all the components laying on an 8 ft. table, so it's a good sized rocket. The body tube walls are .045" thick and the fins are .090" thick. The couplers are also made from CF, with the avbay 8" long and the nosecone coupler is 4.25" long. The kit also includes two short pieces of CF coupler and a bulkhead for internal motor retention:
011.jpg


The avbay has most of the parts included too. Hardware and sled, and two CF lids with the lip cut perfectly to seal your altimeters in:
010.jpg


The nosecone is made with filament wound fiberglass and a metal tip, and is well suited for my Eggfinder. The N/C matches up perfectly with the payload tube.
009.jpg


I'm starting this build with the internal retention. I purchased a 5/16" x 18 nut and glued it between a u-bolt onto the bulkhead. The u-bolt is 1.25" wide, and I'm adding a swivel to it to attach the drogue shock cord to. I used one of the short coupler pieces, glued to the bottom of the bulkplate:
028.jpg


My previous Blackhawks were sized to fit the longest CTI motor, but now that Sharon is starting into the mysterious world of research motors, I am sizing this rocket to fit the longest snap-ring case we have, the Kosden 2650, which is slightly longer than the CTI 6XL:
004_1.jpg


To do this, I lay the motor casing up against the fincan and place the retainer above it:
006_1.jpg


I'm adding a little space between to accommodate the LOKI 54/2800 casing, in the hopes that we will be getting that casing in the future. The bottom mark on the tube is 8.5 inches from the top of the fincan, just enough room for a small drogue and the shock cord. Remember when sizing, your avbay and charge cups take up a good bit of space, and you REALLY need oversized charge cups if you are flying over the 20k mark. More on this later. After marking where your retainer is going, slip the fin guide over the tube and mark three spots for your screws to hold it all in place:
007_1.jpg


Slide the retainer into the fincan to the measured top mark, and drill a hole through the tube and coupler. I'm using 6-32 flat head screws for this, so I'm drilling 9/64" holes. Place a screw through the hole and move onto the next. Drill another hole and put a screw through it. Drill the last hole and remove the retainer. To install pem nuts, you will have to enlarge the holes in the coupler/retainer to 7/32". Here is how I press the pem nut into the retainer:
009_1.jpg


By tightening the nut while holding the screw, it draws the pem nut up into the coupler.
After I have the pem nut seated, I add a dab of glue to it. You only need to have one of these little buggers come loose to understand why. Here is the finished retainer:
011_1.jpg


That's about all I have time for today, might start sticking fins next, or maybe build the redundant avbay. Let me know what you are interested in, and I will try to get to it. Meanwhile, post up any questions regarding what I have done so far.
Thanks for watching!

 
The two things I'm debating, thoughts appreciated.

1) How to bevel the fins.

2) To T2T or not.
 
Does the bulkhead for the internal motor retention recessed into the coupler a bit or does it sit flush on the end? Kurt

It sits flush, with a fillet inside, and a little epoxy sandwiched between them.

I am watching.

Are you going to bevel the fins?

Nope, but I will round the edges. There are a lot of special things that the guys trying for records do, but I just like to fly rockets.

The two things I'm debating, thoughts appreciated.

1) How to bevel the fins.

2) To T2T or not.

None of my minimum diameter rockets have tip to tip or any extra material besides fillets. I will be using Rocketpoxy, it has always worked for me.
 
Thanks for doing this thread, the detail and effort you put in is very much appreciated and will help me finally get some minimum diameter rockets off the build pile and into the air.

I really like your motor retention setup and plan to use it. The swivel is a nice touch I might also borrow if I can get past the idea that it might pull apart. What is the load rating?

I am also curious to learn how you are prepping surfaces for the fin attach.

Looking forward to seeing more. Thanks.
 
Great stuff Wayco. I might use your retention idea. How long is the retention coupler piece? This might be a bit early, but could you give specifics on what quick links that you use including the size, and where you get them from? I have noticed that different vendors have different strength ratings for quick links. I am also a bit worried that the quick links on my previous 54 mm MD rocket were on the small side. A lot of good stuff between your build, and Kurt and Chuck's builds.
 
Great stuff Wayco. I might use your retention idea. How long is the retention coupler piece? This might be a bit early, but could you give specifics on what quick links that you use including the size, and where you get them from? I have noticed that different vendors have different strength ratings for quick links. I am also a bit worried that the quick links on my previous 54 mm MD rocket were on the small side. A lot of good stuff between your build, and Kurt and Chuck's builds.

Ummmm, Give Chuck and Fred all the credit. Mine's still in the box. That way I can "pimp" the best out of both builds:wink::eyeroll::lol: Kurt :bangpan:
 
Ummmm, Give Chuck and Fred all the credit. Mine's still in the box. That way I can "pimp" the best out of both builds:wink::eyeroll::lol: Kurt :bangpan:

It's all good. Wayco put some good stuff in your thread. I really like learning from all of you experienced guys (and gals). I am also really amazed at how rocketry is progressing with all of the materials, thin walled tubing,nosecones, electronics, kits, AP, motor hardware, and all of the techniques.
 
Ummmm, Give Chuck and Fred all the credit. Mine's still in the box. That way I can "pimp" the best out of both builds:wink::eyeroll::lol: Kurt :bangpan:

Dang Kurt, I thought we got you squared away on that "Fred" stuff, you can call me Wayco or Wayne or "Hey You", but I really hate my first name. Don't make me sic Sharon on you. :no:

I'm sticking fins on today, in between setting up files for the boss. I might get some pictures and another post in later today though.
As far as hardware is concerned, I use a 100x formula as a rule of thumb. The swivel that is mounted to the U-bolt is rated at 1000 lbs. This Mongoose is gonna weigh in at about 3 lbs. If I have a problem during recovery that creates 100 g's of force, the rocket might weigh 300 lbs. Not even close, and I use a nylon streamer or a small 12" bucket drogue that probably won't let that happen. Most of my hardware is made from stainless steel, but not that particular swivel. Quick links are almost all SS, and I got a bunch of them from Wildman at Airfest. He had a great sale on them there. He also had a new size in between 1/8" and 3/16" that fit over his SS eyebolts. They might be 5/32" and they are marked 300#. That's good enough for me.
Hey, I'm a Rocketman, some of the science I don't understand....
 
Dang Kurt, I thought we got you squared away on that "Fred" stuff, you can call me Wayco or Wayne or "Hey You", but I really hate my first name. Don't make me sic Sharon on you. :no:

I'm sticking fins on today, in between setting up files for the boss. I might get some pictures and another post in later today though.
As far as hardware is concerned, I use a 100x formula as a rule of thumb. The swivel that is mounted to the U-bolt is rated at 1000 lbs. This Mongoose is gonna weigh in at about 3 lbs. If I have a problem during recovery that creates 100 g's of force, the rocket might weigh 300 lbs. Not even close, and I use a nylon streamer or a small 12" bucket drogue that probably won't let that happen. Most of my hardware is made from stainless steel, but not that particular swivel. Quick links are almost all SS, and I got a bunch of them from Wildman at Airfest. He had a great sale on them there. He also had a new size in between 1/8" and 3/16" that fit over his SS eyebolts. They might be 5/32" and they are marked 300#. That's good enough for me.
Hey, I'm a Rocketman, some of the science I don't understand....
Kurt :confused:
OOOPPPPPPsss, I'll post a sign on my monitor. I forgot...........:bangpan::surprised::y::shock:
 


They might be 5/32" and they are marked 300#. That's good enough for me.
Hey, I'm a Rocketman, some of the science I don't understand....

Thanks 5/32" from Wildman, will do. Aero Pack has a nice SS collection of swivels, eyebolts, u-bolts, quick links (not 5/32" though), and other assorted SS hardware if anyone is interested.
 
Ok, but for the sake of discussion what if a tower isn't available?

Use Bill's fly away guides from AMW. If you need to shim it, use a rubberband on the inside of the guide like mentioned by Jim Hendricksen. Man that sounds good to me.

Oh Wayne, you can call me Allen if you want. That's my "real" first name.

Kurt
 
Use Bill's fly away guides from AMW. If you need to shim it, use a rubberband on the inside of the guide like mentioned by Jim Hendricksen. Man that sounds good to me.

Oh Wayne, you can call me Allen if you want. That's my "real" first name.

Kurt

I see AMW sells the fly-aways for 54mm in both thin wall & thick wall FG. What is the 54mm CF for the Mongoose considered?
 
Use Bill's fly away guides from AMW. If you need to shim it, use a rubberband on the inside of the guide like mentioned by Jim Hendricksen. Man that sounds good to me.

Oh Wayne, you can call me Allen if you want. That's my "real" first name.

Kurt

:bangbang: AKS AKA Allen?

I see AMW sells the fly-aways for 54mm in both thin wall & thick wall FG. What is the 54mm CF for the Mongoose considered?

I have both the RW carbon fiber tubing and the black fiberglass thinwall tubing. Carbon fiber OD. is 2.245 and the thinwall is 2.241. Either guide will work if you use the rubber band like Crazy Jim suggests.
 
:


I have both the RW carbon fiber tubing and the black fiberglass thinwall tubing. Carbon fiber OD. is 2.245 and the thinwall is 2.241. Either guide will work if you use the rubber band like Crazy Jim suggests.

Wayco,

These are certainly interesting. Have you ever used them in any or your high performance Blackhawk 54 flights, or know of similar flights where people have used these fly aways? They certainly would simplify mounting of rail guides.
 
Charlie flew a 54 minimum on K-300 worked perfectly.
Several flights at Midwest power used them...they were a big hit.
I cannot honestly tell what motors were flown, but some I saw were definitely high thrust

Funny story....

one gentleman was struggling to set up his tower in preparation for flight. After a successful flight with guides put a big smile on his face.....he was seen later tossing his tower in the on site dumpster!
 
Wayco,

These are certainly interesting. Have you ever used them in any or your high performance Blackhawk 54 flights, or know of similar flights where people have used these fly aways? They certainly would simplify mounting of rail guides.

No, never used them, nor have I seen them being used. I picked up a set of each from AMW at Airfest last August, but have not fit them to any of my rockets. I have a nice tower that is easy to transport in my toy hauler trailer.
 
Charlie flew a 54 minimum on K-300 worked perfectly.
Several flights at Midwest power used them...they were a big hit.
I cannot honestly tell what motors were flown, but some I saw were definitely high thrust

Funny story....

one gentleman was struggling to set up his tower in preparation for flight. After a successful flight with guides put a big smile on his face.....he was seen later tossing his tower in the on site dumpster!

Thanks Jim. Good story. These are another cool rocketry innovation. Fly away guides would definitely fit in my car better than a tower. I did some searching on these guides after reading your post. Here is a link to high performance flights using the guides. Looks pretty good to me.

https://www.rocketryforum.com/showt...il-guides-54mm-3D-printed-available-now/page9

on Post #246. I guess I will have to get some of those ordered. Thanks for the tips.
 
Yesterday I stuck fins on the fincan with Rocketpoxy. First I marked off the 1 caliper from the aft of the tube to where the rear edge of the fins line up:
002%202.jpg

Silver sharpies work great on black tube. I also used the fin guide to mark the position of the fins and added a pencil line forward to mark where to sand. I don't use coarse sandpaper on carbon fiber or filament wound fiberglass. Instead I excite the molecules with 220 grit and wipe the dust off with acetone. This is done right before I apply the epoxy. Rocketpoxy needs to set up for about 20 minutes in a 75* room to make it stick to the root of the fin. I also cut little notches into the root of the fin with my dremel:
003%202.jpg


Be sure to check the clearance on the fin guides, mine needed some work before the fins would slide freely through the slots. This can be accomplished with a flat needle file, I get the diamond encrusted ones at Harbor freight for about $7 for the whole set:
https://www.harborfreight.com/needle-file-set-10-pc-69876.html
I also had to open up the hole for the tube a bit. You want to be able to fit them through with very little drag. I use a long narrow blade to apply the epoxy:
091.jpg


Start with the fin vertical while applying the epoxy, but hold it horizontally and let it sag a bit before you slide it into the guides, it helps to keep it from getting on the guide.
099.jpg


Insert the front end first, far enough to clear the rear guide,then seat it in between the forward and rear marks, then tape it down. You might want to practice this with the fin without glue on it to get the guide spacing right. You can always move them together after the fin is set.
009%202.jpg


Now leave it alone until the epoxy is hard. That takes about two hours with Rocketpoxy, and that's with my space heater warming the room up to about 85*. If you look closely at the bottom of the fin slot on the guides, you can see how I use a dremel sanding barrel to clearance the area where the epoxy squishes out of the joint. You want to check and make sure there is no epoxy along the slot and on the guide. No fun removing the guide that is epoxied to the rocket.
:facepalm:
After you have let the epoxy cure, rotate the tube to the next fin, mix up the next batch of epoxy, let it set up and slide the guides off and sand the next area. Sand the root of the fin and wipe it with acetone, repeat the process.
On the second set of fins, I had a little extra epoxy, so I marked and sanded the avbay coupler and the switch band used to mark my offset for the fins. I don't put the switch band in the middle, it's offset closer to the aft end, to make more room for the drogue and over-sized charge cups. Put a piece of tape at the top and apply epoxy to the coupler, then slide the switch band up to the tape, the excess epoxy can be removed with the tape and wipe any residue off with a q-tip and alcohol.
I should be able to do the fillets tomorrow, if not it will get them done this weekend. Stay tuned....

 
Charlie flew a 54 minimum on K-300 worked perfectly.
Several flights at Midwest power used them...they were a big hit.
I cannot honestly tell what motors were flown, but some I saw were definitely high thrust

Funny story....

one gentleman was struggling to set up his tower in preparation for flight. After a successful flight with guides put a big smile on his face.....he was seen later tossing his tower in the on site dumpster!

Was that you??????:shock: Kurt :rolleyes:
 
:bangbang: AKS AKA Allen?

Allen Kurt. Dad started a business in the basement around the time I was born. His first name is Albert. Parents had the foresight to think, "What if a customer calls and asks for Al? Who do we give the phone to?"
Well, business grew out of basement when I hit 2 years old so it really didn't matter. I hadn't learned how to dial yet. Middle name stuck. Allen or Al is not a bad or foogly name but my parents ended up using my middle
name. I didn't know how to spell Allen until the 5th grade when I looked on the birth certificate in the baby book. For fun, I asked my mother how it was spelled and she said, "A-L-A-N". I said, "Nope."
She said, "Whad'ya mean, I named you!" I held out the birth certificate and she gave out a, "Well I'll be!" A. Kurt Savegnago
 
Both of my Grandfathers and a great Grandfather were named Fred. I have two sisters and we all go by our middle names, Jayne, Wayne and Elayne. What were my parents thinking?
 
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