4.7x Upsacle Der BIG Red Max.

[Fuddrucker]

Hello all,

Well, after thinking about what kind of a BIG project I wanted to build for over two years, I finally chose to upscale the Estes Der Big Red Max. This was my very first rocket ever and has always been one of my top favorites.

I got the "Der Big Red Max Deluxe Model Rocketry Outfit" as a birthday present when I was about 14 or 15, (about 28 years ago). I have always wanted to build a large version of this kit but one thing always kept me from building it. Decals.

Well, along comes Stickershock and once I saw those decals, my mind was made up! Now I can blame Mark for making me spend all my $$$$ building this thing, lol.

Anyway, I started working on this back in April and actually took pictures along the way to post a build thread. As work progresses, I will update the thread.


Details.......

Launching at Rocstock 30, Nov. 12th, 2009. Lucerne Valley, CA.
If it survives, launching again at LDRS29, same location.

4.7x upsacle.
7.5" Diameter, 75mm, appx. 40lbs. on the pad.
PerfectFlight miniAlt/WD as primary system for drouge/main ejection with a HiAlt45K as a backup.
Aerotech K700 for first flight, estimated altitude of 2450'. I may do first flight on a Aerotech L1390G.

I don't know how many of the younger crowd here even knew there was a "BIG" Red Max, so just for them, here is a pic showing the ad from the 1981 catalog. The older crowd here (like me), should remember it.

...Fudd

 

[Fuddrucker]

Ok, on with the build......

I ordered up the tubes, couplers and nose cone from LOC Precision. I started off by peeling the glassline layer off the body tubes (actually I opened the box and went Mmmmmm raawwwcket paaarrrrts for about two years) and applying West systems epoxy to the tubes so it could soak in a bit.

First pics are a few shots of mixing epoxy that is a requirement of all mid and high power build threads.

...Fudd

 

[Fuddrucker]

Laying up the first layer of 6oz. glass. Trimming the edges so it lays easier and then smoothing out the lumps.

 

[Fuddrucker]

First layer smoothed out and curing. Once tacky, I trimmed off the edges of the first layer and applied a second layer of 6oz. glass. I first applied a layer of epoxy, then laid down the glass. Smoothed a bit, trimmed the edges, and began to smooth the rest out.

This is the third tube I did. As usual, I got so wrapped up in the build process, I forgot to have pics taken of me working on the first two tubes. You can see the other two in the background of some of the pics.

...Fudd

 

[stickershock23]

Nice Fudd.... Blame me... The decals price just went up!

LOL looking good so far. Enjoy sanding your tubes.. (I hate that part)

 

[Fuddrucker]

Nice Fudd.... Blame me... The decals price just went up!

LOL looking good so far. Enjoy sanding your tubes.. (I hate that part)

Hahahaha....gotta blame someone, it's never my fault. Even when I forget to arm my electronics, it's because someone distracted me. :roll:

OK, all joking aside now, on with the thread....

...Fudd

 

[Fuddrucker]

Moving along.....

Second layer all smoothed out and curing. After trimming the second layer edges I filled the weave. To fill the weave I use Kilz primer with a roller. Usually 2 coats do it. The stuff is very thick, fills and sands nicely.

Sanded tubes in three stages. First with 150, then 200, then finish with 250.
Smooth as a baby's behind and eventhough you can see the seem when un-painted, you can't feel it. Took about 30 minutes total to complete the sanding on each tube. I love orbital sanders.

 

[Fuddrucker]

On to the motor mount tube and fins....

I'm using a 75mm tube and I peel the glassline off of it as well. I have found that running a sharp x-acto knife along the seam the entire length of the tube to score the glassline paper works well to peel it. After scoring the tube all the way, just start to peel at one end, pull, pull, pull, and it usually comes off in one piece.

I Used 5/16" 7-ply birtch for the rings and bulkheads cut out with a scroll saw. As usual, I forgot to take pics while cutting the rings and bulkheads out so I "re-created it" by just placing the ring back in the cutout and took a pic. You get the idea.

After using a hole saw to cut out the center of the rings, I sand them using my drill press and a sanding drum to the right size. I then place them onto a scrap piece of 75mm tube and use the drum to sand all the pieces at the same time to get them all even for a snug fit inside the 7.5" dia. body tube.

 

[Fuddrucker]

Dry fitting onto the MMT (glassline still on in this shot), and taking a pic to show the size comparison of just the motor mount and the actual Estes kit.

After everything is sanded and test fit, I drilled the holes for the allthread.

Ran the allthread through the rings, spun the nuts 272,467 times, and attached the u-bolt for the shock cord. It looks all crooked in the pic, but that's because the rings are just dry fit to the tube at this point. Used blue loc-tite on the nuts so they won't come loose.

 

[Fuddrucker]

Making the fins and slotting the tubes.....

Hmmm,,,,guess what, I forgot to get pics of me cutting the fins D'oh!! That's to bad too because I almost killed myself. It was great, you shoulda been there. I used 1/2" Baltic Birtch. I started with a 5x5' piece and cut it on my table saw into four 2-1/2' x 2-1/2' squares. I was able to fit 2 fins in one piece and I thought I would use my band saw to cut the fins out. Nope, I was not able to follow the lines very well because the blade wanted to flex to much.

Ok, so I will use the table saw. I figured, hmmm all nice straight cuts, should be fine. I cut the first fin out perfectly!! Impressed with my awesome skilz, I moved on to the second one. Going along fine until the third cut along the fin. I was halfway through the cut and started to cut to far off the line. I tried to compensate, (I do it all the time, but sloooowly) but did it too fast this time and WHAM, it binded up on the blade and shot it back at me before I even know what happened.

Luckly, I was standing to the side a bit and it just nailed me in the gut. Lots of cushion there anyway, but I was shaking quite a bit for a while. After taking a break, I cut out the last two fins and am happy to report all went well.

Here are some shots of the completed motor mount, the fins dry fit between the rings, (one showing the Estes kit next to it for size comparison again) and the tube after making the cuts for the fin slots with a jigsaw.

After thinking about it for a while I deceided to add a second u-bolt. This way, I could add a second shock cord and the rocket should land more evenly on all three fins instead of at an angle and landing on just one, hopefully avoiding cracking or breaking a fin.

 

[Fuddrucker]

Attaching the fins....

Since the fins are so big and heavy I wanted to be sure they stayed on during landing. I drilled a hole thru the cenering rings top and bottom into the fins and ran 2" screws into the fins. (see first pic) I also epoxied some blocks onto the rings on both sides top and bottom to help keep the fins from breaking the bond to the MMT on landing.

Next I laid down some 6oz. glass on each side, then epoxied it all with West Systems for what will hopefully be a very strong bond.

 

[Fuddrucker]

Glassing the couplers....

I used two layers of 6oz. glass on the inside of the couplers. Overkill?, perhaps, but I like to build everything as strong as I can. I don't worry about the weight, I would rather have a good, strong, high performace rocket. Besides, I can always use a bigger motor.

Since this rocket is going to be pretty big, I thought it would be nice if I could break it down into smaller pieces to make transportation easier. To acomplish this I decieded to make the couplers removeable instead of gluing them in. Nothing new about this technique, I have seen it used by several others and I just thought it was a good idea. I have done this on a few other rockets and it has always worked out well.

First I made eight 1-1/2" x 1-1/2" blocks out of 5/16" birch. Drilled a hole, sanded the edges down a little, then inserted a T-nut. After drilling the holes in the body tubes and couplers, I epoxied the blocks to the inside of the couplers and used the screws in the attachment points to hold everything in place while the epoxy cured.

Now, I can just insert the couplers into the tubes and attch them to the tube with four screws. When I am ready to pack up the rocket, just unscrew, pull the tubes off and it is much easier to transport.

 

[Fuddrucker]

I did epoxy one coupler in. The bottom end of the aft coupler gets glued in because the second body tube will be attached using screws.

 

[Fuddrucker]

Ebay construction....

Cut out the bulkheads out of what,,,,correct, 5/16" birch. Using the drill press with a sanding drum, I set the drill press about 3/16" above the deck so I could sand away the sides of the bulkheads halfway down. This way, the bulkheads would slip inside the coupler halfway down creating a nice seal instead of just laying on top. You can get an idea of what I mean by looking at the bulkheads in the first pic. You can see how there is a lip on them where it would slip into the coupler halfway.

Next, I cut off a 2-1/2" section of body tube from one of the three tubes and centered it on a glassed coupler. Made a sled from 5/16" birch, and glued six 3/4" sections of 1/4" launch lug onto the sled. Ran two 12-1/2" lengths of 1/4" all thread through the lug sections.

On each bulkhead, I added two 1" PVC caps, U-bolts, and some terminal strips for connecting the electronics to the e-matches.

 

[Fuddrucker]

When I slotted the tubes, I saved the strips so I could use the to fill in the gaps that would be left at the tail of the rocket after gluing the fincan into the tube. Once cured, I cut the strips down to size and glued them to each end of the centering rings. Worked out great and I will just fill the seams with a little putty. I still need to trim the aft ends to make them even.

A few shots of the rocket all dry fit together with other rockets to show size comparison. I still need to mount the electronics, drill vent holes and mounting holes for switches and rail buttons, and make fin fillets, (my least favorite part of the build), and sand, sand, sand.

Will continue to update the thread once I complete more work.

...Fudd

 

[DAllen]

Ran the allthread through the rings, spun the nuts 272,467 times, and attached the u-bolt for the shock cord.

Nah...Don't do that. Grab your drill, chuck that all thread just like a bit. Put one hand on the nut and the other on the drill and squeeze that trigger until that nut is where you want it. I've done this a lot and is quite the time-saver.

Build is looking great so far.

-Dave

 

[Fuddrucker]

Sooooo,,,, Does anyone want to see the finished product?

...Fudd

 

[Pantherjon]

Ummm, yeah! Silly question!:roll:

 

[Fuddrucker]

Well, ok. You talked me into it. Here it is all painted up and with the decals applied from Stickershock. Thanks to Mark, the decals really make it look AWESOME!!

...Fudd

 

[Pantherjon]

Looks awesome!

 

[kelltym88]

Awesome job, Gary:clap::clap:

 

[blackjack2564]

Been waiting along time for those finished shots! Outstanding, what's the maiden flight gonna be? Still the K-700?

 

[Fuddrucker]

Nope, I am going with an L850 instead.

...Fudd

 

[Peartree]

Sir, *that* is stellar.

:clap::clap:

Here's to hoping it flies as well as it looks.

 

[Breeze1913]

Great job!!
Thank you for sharing the build thread.

How did the flight go??

 

[stickershock23]

Fudd will tell you the whole story, but I heard it went perfect. even stuck the landing!!

 

[Fuddrucker]

Ok, OK, I am a little slow at updating things this time of year but here is the launch update.

It flew, it landed, I recovered it, it's back home.

...Fudd

 

[Fuddrucker]

LOL, ok here is what really happened.....

After a long debate and to many nerves getting rattled around with some of the motors that were being suggested by the vendor at the launch, I decieded to stay on the conservative side and go with an L850 since the L1390g was not available to me at the time.

It had been pretty windy the entire day before and I was worried that the wind would kick up again on Sat. so I had it ready to launch by10am. Weather could not have been better. The wind had totally stopped for the launch and it was time to hit the button. Man, I was nervous. They counted down, 3, 2, 1, and I just stared at the motor praying that it would light and NOT CATO. I saw the flame, and BAM, it was going, going, and going.

It flew great!! Launch was nice and straight, went to 3020' (lower than the rocsim prediction of 4500') electronics all worked as planned, and even stuck the landing the way I had designed it to. PERFECT!! I could not have been happier, and I honestly could not thing of anything that I would have done differently. I was extremely pleased. Next time it is going up on a sparky of some sort at LDRS!

Thanks to everyone for all your great comments and to StickerShock23 for the decals that made it look so cool sitting on the pad

...Fudd

 

[Fuddrucker]

A few more shots.

...Fudd

 

[Fuddrucker]

And the last few of the landing...

...Fudd