Molded Fiberglass Nosecones

[berlinetta]

I received a Rocketry Warehouse Hellfire kit for Christmas. I was trying to get the bulkhead into the nosecone tonight for a dry fit, but was unable to do so. Even after quite a bit of sanding, there was little progress. I was wondering two things. One, what would be easier, sanding the bulkhead down or sanding the nosecone interior with a dremel tool to open things up. The second thing is how far up the nosecone should the bulkhead go? Thank you in advance.

 

[cwbullet]

i recommend sanding the bulkhead so you do not weaken the nose cone. i would not use a power sander unless you test frequently. I took me 2-3 hours one day to get one to fit.

 

[berlinetta]

Thank you. I appreciate that.

Also, after reading your sig, I want to thank you for what you go for our country. Please stay safe and come home soon.

 

[sandman]

Wood is so much easier and easier on yourself (no fiberglass fibers to breath in!) to sand than fiberglass.

Plus if you screw it up you can always make another bulkhead.

Kind of hard to make another fiberglass nose cone.

 

[mkadams001]

i recommend sanding the bulkhead so you do not weaken the nose cone. i would not use a power sander unless you test frequently. I took me 2-3 hours one day to get one to fit.

For that length of time you should have used a power sander.

 

[cwbullet]

I am always leery of using a power sander. If you mess up, you have to buy another bulkhead. I often will replace the fiberglass with wood - it is easier to sand.

 

[jsargevt]

I took the bulkhead and just secured it to a bent wire eye with a nut on either side of the bulkhead to hold it still. I then chucked the threaded part into my drill. I then taped some sandpaper down to the table, spun the bulkhead with the drill at a reasonable speed and then lightly touched it to the paper. I could test the fit into the nose cone while it was chucked in the drill. Just make very little moves and test frequently.

The inside of the molded fiberglass cones isn't exactly round sometimes (at least it wasn't on my Madcow Goblin) but this worked very well to get a nice fit - especially since I was looking to put it deeper into the cone. Your mileage may vary, but it saved me a lot of sanding time.

 

[cwbullet]

Most of these nose cones are from Performance rocketry: Round is a relative term.

 

[sodmeister]

For my 6" FG nosecone ,I just made my own using 3/8" Baltic Birch ,and sanded to shape with my random orbit sander ,because as chuck said ,round is a relative term.Also ,the RO sander is not too aggresive using 180 grit and when it`s close enough ,epoxy takes care of the rest as well ,you can make a short coupler ring to sit in front of the bulkhead to further take up the forces of ejection.

I would not sand the NC inside shoulder.

I still use a dust mask and vacuum attached to my sander for sanding wood and a good respirator for sanding FG ! I also run an ambient whole shop dust collector when sanding.

Paul T

 

[berlinetta]

I don't have a power sander. The closest I have is my dremal tool. I will have to test frequently. I want to get the bulkhead in as far as I can.

 

[Handeman]

The last time I glued a bulkhead into a nose cone was a 4" nosecone. I use a bulkhead just big enough to hold a small u-bolt. It was about 2" diameter. I glued it in the nose cone as far forward as it would fit. I figured the further forward the weight the better. I just did a quick taper on the edges to get a close match to the nosecone and then use epoxy with some milled glass for strenthening. It's worked great so far.

 

[berlinetta]

It might be something to think about. I need as much room as possible for the main chute.