7.5" LOC MegaMagg nose weight question

[Donnager]

I've got one of these under construction, and it will need a good bit of nose weight.

Anyone have a rough idea how much lead was required to be good for a 54mm/1706 case? I can't tell yet because I will be adding some electronics and a sled to the fin can, so the tail weight is mostly undetermined at this time (and I'm dragging butt on connecting the electronics). It looks like the nose weight will be a little more than the motor weight, depending on how it is installed.

I have plenty of lead pucks and shot laying around, but this one is going to need a lot.

 

[DMehalko]

Every build will be different of course and there is no set weight that is applicable for like-kits. Best advice will be to build the rocket in rocksim or openrock, inputting real world weights to get a safe CG.

Now that said, short fat rockets dont need the '1-cal' of stability, my Warlock which is similar, flies arrow-straight at 0.43cals

 

[David Schwantz]

that's right, every build is different. But do not rely on sims alone. They can give a good starting point. Weigh and balance if RTF form, paint, chutes, motor all in place. Only this will give you the exact amount of weight needed.

 

[Rocketjunkie]

There is a lot of base drag. You shouldn't need more than the weight of the altimeter bay.

 

[rharshberger]

There is a lot of base drag. You shouldn't need more than the weight of the altimeter bay.

Correct, and the Minie Magg (all versions benefit from the Base Drag Hack for OR and RocSim) aka the massless cone, to get a closer to correct amount if noseweight is needed.

 

[Donnager]

Thanks, all.

I'm not building it with a traditional altimeter bay. I'm installing the altimeter in the removable motor mount as redundant single-deploy. Charges will be fixed to the front of the insert, and I wasn't sure If I was going to recess them or not, and what types of canisters (if any) I'd use. It won't be dual deploy, just a low'n'slow and will have a chute release if I decide to get it a little higher. Electronics will be primary deployment and the motor will be backup.

I've gotten farther now and have a pretty good idea on what it's going to be. I wound up casting a small amount in the nose that will be permanent and I'll use the RNWS to adjust later. I've switched over to the electronics, now.