"Shimming" a C6-3 for Big Daddy instead of C11-3 & Big Daddy chute packing

We want to launch our Big Daddy for the first time today, and without any C11-3's for the first flight and no larger motors, I decided to use some black and masking tape to "shim" up a couple of C6-3's to try. I know that Estes makes 24mm to 18mm adapters, but I don't have ready access to any today. Aside from wasting tape, does anyone see any potential for damage to the rocket? By layering the tape I was able to create a better than factory fit inside the motor mount.

Has anyone else ever tried this rig, and if so, how was the performance? These two motors seem to have some similiarities in performance, with thrust time being the major difference. The thrust duration is 1.6 seconds in the C6-3 and .8 seconds in the C11-3. I will also be using the kit-supplied one inch spacer to go from the E motors down to the C11's and D's. Any opinions, good or bad?

Also, what is the preferred way to pack the chute in the Big Daddy? I have tried several folds/rolls, and even without wadding my packed parachute wants to push back on the nosecone. This 24" chute seems to be quite a bit thicker/heavier gauge than the smaller Estes chutes, which I like, but it is much less forgiving as well. Thanks in advance.

Stratos283

Probably not the best way to do this. I tried it with a Quest D5 into a 24mm motor mount and the heat that transferred through to the outside of the casing made the tape a gummy mess and may have contributed to the failure of the rocket. Of course, D5s are known for running hot, so it may just have been that motor, but I would still suggest that you use a motor adapter (the plastic adapters from Estes are really nice). You can make your own out of 2-1/2" of BT-20, a motor mount and three AR2050 rings. Cut the back one to make a gap for the motor hook and glue it flush with the back of the adapter. A second goes about midway down the tube (maybe an inch from the front) over the motor hook. The last one is flush with the back of the tube.

A third option is to knock the residue and nozzle out of a spent 24mm motor (C11 or D12), strip a layor or two of the paper from the inside of the motor until your 18mm motor fits inside and friction fit your motor inside. A bit heavier than an adapter, but it works.

A C6 more than likely won't have enough of an initial thrust spike to get a Big Daddy off of the pad safely. See this review. The C11 has an average thrust of 10.9N, while a C6 has a 4.7N average thrust (Thrustcurve.org)

Chris

Whoa!! There is a significant difference between a C6 and a C11. And, it's never good to use an engine that is not recommended for a kit. I would not use the C6 for this rocket. You might just have to wait...... I would think if you launch this at a club launch, they won't let you fly it either, with a C6.

kelltym88 said:

Whoa!! There is a significant difference between a C6 and a C11. And, it's never good to use an engine that is not recommended for a kit. I would not use the C6 for this rocket. You might just have to wait...... I would think if you launch this at a club launch, they won't let you fly it either, with a C6.

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Yeah, I wouldn't expect that a club launch would approve this, lol, but we pretty much are on our own in this area. However, I do think I'll wait. That's why I asked. This is my best job/finish ever on a rocket, and I'd hate for it to barely come off the pad and nose over and drive itself into the ground. I definitely can wait until I get to the hobby shop. Thanks folks.

Stratos283

Geeze, did I sound like Shred? OMG!! hahaha....(you know I love you, buddy) :wink:

I think with the short burn time it would work as far as a substitute for an adaptor. However using a spent 24mm to build your own adapter rings would be easy also.

As for the thrust problem. I agree that a C6 isn't going to do well unless you built that Big Daddy lighter than most.

One option might be to add some A10's around the motor mount if it sticks out.

kelltym88 said:

Geeze, did I sound like Shred? OMG!! hahaha....(you know I love you, buddy) :wink:

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You kinda did...funny

I did my first launch on a D12-3. With all of the epoxy and paint I put on it I didn't want to take a chance on a low deploy. It was a great flight to about 500ft and ejection just past apogee.

D12-3 for sure. I've seen D12-5's nose in on days with a breeze 8-10. I believe part of the problem is the super long/heavy shoulder on the nosecone. When this model turns downward at apogee it is difficult to blow the nose off. I cut the shoulder down on mine and added a plywood bulkhead disc and screw eye. Same model flown recently with the new E12. turned in a great flight.

I tried a C11 in my Big Daddy and it made a nice slow liftoff, but likely didn't get more than 150 feet up before it powered off. then it weathercocked into the wind and dropped like mad till the ejection about 25-30 feet off the ground. I won't do that again, and I would not try a C6.

I totaled my first Big Daddy trying to use a C6-3. Was not enough umph off the launch pad. Powered prang down the driveway.

UncleVanya said:

I think with the short burn time it would work as far as a substitute for an adaptor. However using a spent 24mm to build your own adapter rings would be easy also.

As for the thrust problem. I agree that a C6 isn't going to do well unless you built that Big Daddy lighter than most.

One option might be to add some A10's around the motor mount if it sticks out.

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I MOST DEFINITELY won't do it now!!!! That thing has a whole can of Krylon blue on it and another can of clear enamel! It's the lead sled of Big Daddy's!!!!!!

Stratos283