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