Mega Der Big Red Max build

[Zyzzyva1000]

I am a sucker, and when Estes made the nose cone and body tube available again recently, I picked them up. Got the 1/4" plywood 38 mm upgrade kit from rocketry works and decided that this upgraded kit could use some fiberglass. So, 1 layer of a 4" fiberglass sleeve from Soller Composites, and we are making some progress. I have used ZPoxy finishing resin with good success for my laminating resin, and had some on hand so I went with that. The heat shrink tubing really helps make it look nice. Used a 1.5 inch dowl with some masking tape and the 3 centering rings to act as a mandrel and keep the tube from collapsing.




Have the forward and middle centering rings in place. Made a short tether out of some 1000 lb kevlar, will attach whatever spare cord I have laying around to it later. Not sure this is quite what CWBullet does, but I tied perfection loop knots and then put some heat shink over the tails to (hopefully) resist any loosening. While probably unneeded, I like leaving the aft centering ring off so I can do some internal fillets and then fill the void with 2 part expanding foam before placing the final centering ring. first of a pair of 3D printed fin alignment guides currently printing for the next step.

Here is the mockup

 

[Hobie1dog]

Thanks for the pictures, keep them coming.

 

[Zyzzyva1000]

Once the fin guides are done, will add the fins with some slow cure epoxy, then internal and external fillets, and then a single layer of fiberglass tip to tip layup. While waiting on that, I cut the end off the nosecone to add an ebay/tracker platform. A loc 3.9 stiff coupler (with 2 layers peeled off the outside) fits perfectly. Have a bulkhead for each end. Will probably just put one of my egg timer apogees inside. Last photo is a 3D printed sled I whipped up in fusion 360 for my eggfinder mini. I could put in inside the ebay. but I like having it sit 'on top' so I can easily move it to another rocket. Just need to add the heat press inserts for the screws. This will also move a bit more weight forward. Since the entire thing removes (will be held in place with plastic rivets), I can easily add however much nose weight is needed once I am done. Also in that last picture is the motor retainer. Printed from carbon fiber ASA.

 

[Zyzzyva1000]

Fins are on, internal and external fillets done, little expanding foam added for good measure (I have it so why not use it), and final centering ring added. Also finished the ebay - totally overkill for what I need, but it adds some needed nose weight and gives me room for future changes. Now just need to cut or print a sled and wire in the egg timer apogee that's been sitting around waiting for a new lease on life. Coming this week - starting the tip to tip fiberglass of the fins (going to need to use butcher paper to make the templates, and had to order more fiberglass - this is a lot of surface area to cover.

 

[Zyzzyva1000]

OK, so got a good amount of progress done this week. Got the tip to tip layup on the fins done (using 4 oz fiberglass I found on amazon that has worked well for several builds and is relatively cheap). I usually just make a template from paper and then trace onto the fiberglass (had to use butcher paper this time since the area is so large). Since I am painting this, I don't care that the sharpie transfers. I just lay the cloth down, paint on the epoxy resin and then put wax paper over the top and smooth it out with a straight edge. Gets it reasonably smooth and uniform.



Did a bunch of sanding and then I do primer in several steps. I use Bondo 907 for any big glaring areas that need to be filled, then sand and do the first layer of primer (I have used multiple filler primers, my favorite is definitely rustoleum 2 in 1 filler and primer-sandable - available at my local Walmart). After the first heavy coat, all the imperfections I couldn't see are revealed, so then I usually do some Elmer's carpenters wood filler to fill the small cosmetic pits, etc. Then more sanding and another coat of primer. In the past I would just keep on with the primer, but I find that filling the voids (while someone time consuming) leads to less need for primer (less weight and cheaper). Obviously I am sanding down between coats, but some little voids always persist. Did one final layer of primer and ready for topcoat tomorrow. And I will leave you with a picture of my cat attempting to help (doesn't matter the size of the box, he will try to get in it)

 

[Zyzzyva1000]

Used lacquer automotive paint, so painting was quick and easy. Spent a considerable amount of time on prep so was pretty much just able to spray and be done. Even manage to get the awesome stickershock decals on. Will give it until the end of the week, and then there's a can of 2K clear coat waiting to make this bullet proof. Then just need to add some rail buttons and finish the e-bay with a sled and charge well. Looks like the maiden flight will be at LDRS. Now just debating if I should add some nose weight, its about at the limit of whether base drag has a signifiant effect (10:1 length: diameter), so I will probably put some shot in and hold it with some 2 part foam and epoxy.

 

[Adam3836]

Used lacquer automotive paint, so painting was quick and easy. Spent a considerable amount of time on prep so was pretty much just able to spray and be done. Even manage to get the awesome stickershock decals on. Will give it until the end of the week, and then there's a can of 2K clear coat waiting to make this bullet proof. Then just need to add some rail buttons and finish the e-bay with a sled and charge well. Looks like the maiden flight will be at LDRS. Now just debating if I should add some nose weight, its about at the limit of whether base drag has a signifiant effect (10:1 length: diameter), so I will probably put some shot in and hold it with some 2 part foam and epoxy.
View attachment 587185

Nice work
Looks beautiful

 

[Zyzzyva1000]

And final update, printed a sled and finished the electronics bay. Had a quark sitting around, so that's the altimeter. Just to make it easier I added a mini wifi switch so I don't have to take the nose cone apart at the pad. Eggfinder mini installed up top for easier access (don't have to open the ebay to move it to another rocket), and it moves a little weight forward. Now just need to decide on a bit of nose weight. May also cut the motor retainer off and just install z clips, I mis calculated and ended accidentally moving the motor back a full inch. Would rather not move my CG rearward if I can help it.

 

[86mustang408w]

I just got mine yesterday from the Summer of 2013! 40" tall and 4" dia., that babies getting a 38mm mount....Good work man!!