Antenna mounted on the nosecone

I don't know if this qualifies as electronic or high power rocketry... but here goes:

On the nosecones with the aluminum tip, the tip comes off revealing a hollow point. I was thinking for trackers such as the Eggfinder, how feasible would it be to turn the nosecone tip into a mounting point for an antenna? So it basically means the antenna screws onto the tip of the nosecone, probably improving reception.

I'm only wondering aerodynamically would it be a disaster? I think the aluminum tip is there because if the rocket ever gets to Mach 2, the tip wouldn't melt. I'm just thinking that I doubt the antenna could survive Mach 2...

You can put an antenna inside a nose cone with an aluminum tip, as long as you keep it a few inches away from the hardware. There's a "dead spot" at the end of a whip antenna, so the tip really has no effect on the signal. Most of the rockets with aluminum tips are at least 3" in diameter, so if you have a 5:1 nose cone it's like 15" long from tip to shoulder. Finding room for an Eggfinder shouldn't be a problem.

I have a Formula 75, it has a really long (about 14" or so without the tip) nosecone. Right now the problem I have is, first of all the motor mount tube is missing (I hope Rocketry Warehouse will fix it), and the other thing is I think the motor mount tube needs to be 24" long, otherwise it would be hard to put a J motor in it. It would also make hooking on the shock cord mount easier because I can only stick my hand partway into a 3" tube. Now the problem is the parachute won't fit with the MMT that long so I'm trying to figure out what to do about this...

You only need a MM in that kit around 12in. Glue a recovery Y-harness to the sides of MM, so that the end of the "Y" sticks out the tube a few inches. Problem solved.

You don't even really need a MM tube,I've seen plenty of designs with just CR"s or the fins center the motor.

Motor typically will stick out the front of MM in FG rockets.

Kinda hard like this... for one thing I'm using aeropack retainer which wouldn't really work without a MMT. I guess if worst comes to worst I'll just find a cheap paper MMT or something... they are not really critical structural component.

I'd go with the short standard mount with a y harness like Jim suggested. No need to change what works.

I built 2 Formula 75's; one mostly stock and other all I used was the tube for a booster.

The regular one: the motor mount is about 8-9" long.
I mounted an eye bolt on the forward most CR next, added a length of 1/8" Kevlar then, double it up.

You don't need a mm tube the same length of the air frame.


JD

I also used the NC that came with the Formula 75 to mount my TRS.
The tip is actually composite and not AL.
The antenna mounted outside of the bulkhead.

JD

I guess yours must be a different batch. The one I got is clearly black anodized aluminum, with a 1/4 - 20 thread inside the tip.

I always thought the reason for an aluminum tip on the FG nosecone wasn't to withstand Mach, it was to cut down on the FG tips breaking off when landing point first.

Like others have stated, you dont need the longer MMT & if you attach your shock cord to the NC tip, you have all that extra room for packing a chute.

timbucktoo said:

Like others have stated, you dont need the longer MMT & if you attach your shock cord to the NC tip, you have all that extra room for packing a chute.

Click to expand...

And this saves weight. I think it is time for a build that is minimalist without a motor mount tube and nose cone deployment.

Now the problem becomes, where does the Eggfinder go?

I would use RF falcon type trackers in a rocket like this.

cwbullet said:

I would use RF falcon type trackers in a rocket like this.

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Or even a Comm Spec tracker. Just tape to the shock cord.

Guess I could tape the eggfinder to the shock cord too

Actually it has more to do with the winding process.
You would have a hard time winding to a point.
It's easier for them to leave the tapered end open and either use an epoxy plug ( even more work) or just machine a piece from AL or you favorite metal of choice....


JD

Handeman said:

I always thought the reason for an aluminum tip on the FG nosecone wasn't to withstand Mach, it was to cut down on the FG tips breaking off when landing point first.

Click to expand...

JDcluster said:

Actually it has more to do with the winding process.
You would have a hard time winding to a point.
It's easier for them to leave the tapered end open and either use an epoxy plug ( even more work) or just machine a piece from AL or you favorite metal of choice....


JD

Click to expand...

Now that makes the most sense. Manufacturing processes make it cheaper and easier to use the aluminum tip! I didn't think it had anything to do with heat resistance at Mach speeds.

Thanks...