By Bas Dickson Leach

2013-08-31

Manufacturer:Estes
Diameter:1.6400 inches
Length:16.2500 inches
Skill Level:1
Style:Sport

This is a stock BT60 Der Red Max kit modified to take a 29mm MMT. 

The other changes from stock all come from the requirements of mid/high power engines on the Estes kit.

Initial planned changes - Through the wall fins, Pro Series II motor retainer. Also looking at streamer recovery and possibly radio tracking as it sims out to several thousand feet... Not planning to reinforce the fins externally yet. I will see how much flex there is after the internal fillets are done as I want to keep the weight down ( due to streamer recovery).

 


   

2013-09-04

Cut some fin slots and mounted the fins to the fin can, cut the slots to allow the fin can to be slid into the body tube. Looking at the spaces inside I have decided to do some nose cone adaptations based around my big daddy conversion, involving cutting off the shoulder and mounting an attachment point in the tip of the nosecose. 

The fins have been tacked semi seriously in place with yellow glue and once they are dry epoxy internal fillets will be put in. Either that or some gorilla glue.

 


   

2013-09-04

Nosecone attachment point has been created out of some epoxy and a small steel curtain hook.

First I cut the nosecone shoulder off and then scratched the inside of the tip of the nosecone. I tied the stock elastic to the curtain hook, not worried about heat damage as the elastic will be attached to the nosecone and then a flameproof streamer will wad up and protect it. The other end will be flameproof as it attaches to the motormount/bodytube.

The curtain hook is then lowered into the nosecone and epoxy poured over it. The curtain hook is in a double J shape, the elastic is tied to the top and the bottom of the J is under the epoxy. This should give a strong attachment. I have used a similar set up in a modified Big Daddy with only one failure (which was a knotting issue) in almost a dozen flights.

Nosecone in Der Shred Max build


   

2013-09-08

Primer Coat and sanding

Managed a couple of days doing bits and pieces. Ended up doing internal foam Gorilla glue to the motor mount/fin can assembly. This was followed by external expoy fillets. This should give enough strength to the fins and rigidity to avoid flutter destruction.

Kevlar from an upper centering ring to a D ring, Flameproof streamer all installed and attached. Then managed to get the first coat of primer on and sanded smooth. Second coat will wait for the heavy rain currently beating down outside to finish. 

Decided on Rail buttons given the size motors this will be flying also as lugs if needed will be easy and quick to attach at the flying field, and also I can't wait to see how ridiculous this looks on the HPR rails...

 Also tried something I've not done before but wished I had on a couple of my other balsa finned rockets and took some extra epoxy and gave a coating to the fin edges along all sides. This should hopefully protect a little against dings from the nosecone and landings. 

 

 


   

2013-09-12

Apologies for no photos. Life got a bit hectic and I've had to pack the rocket away for a bit. Paint is done but might give nosecone another try. Decals are on and I think they are ok. I tried to "Shred" the lower decals a bit, and while it looked ok on the paper it isn't really noticeable on the rocket.

Also when all packed came in at 126 grams, but the COG was a little far back for the F/G motors I was thinking of using so some lead shot and epoxy has been added to the nose to bring that forward.

Pics and flight posts once it has been done!