fiberglass nosecone on phenolic body tube?

Off Grid Gecko

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Giving up on any kind of answer to my question straight from madcow. I sent them an email over a week ago and there has been no response.

TLDR: Will a 4" fiberglass nose cone fit well on a 4" madcow cardboard/phenolic body tube?

Background:

Building a DX-3 kit from MadCow Rocketry, the nosecone came a little oddly shaped. Point not centered, out of round, etc. With heat and pressure I was able to form it most of the way, but there's still an unnerving gap between where the nose cone joins the tube, exposing the end of the tube fully for around 1/4 to 1/3 of the circumference.

I've decided that I'm not going to fly it like that.

Dillema:

I don't want to trust another madcow nose cone. I know they are supposed to be the bees knees and all this, but I'm having trouble knowing at the moment who to trust with a plastic nose cone that will fit the tube well. Apogee has a 4" plastic cone for about $22 which is more than reasonable and I plan on getting some chutes from them anyway with my next order.

The more I think about it though, I tend to have the feeling (correct me if I'm wrong) that a fiberglass nose cone would be built to more exacting standards considering the price, and less prone to these silly kinds of deformations that plastic can be subjected to. They also tend to be hollow base out of the box and if it comes with a piece of coupler, I could use the cone in the future for experimental payloads, perhaps even move the NC from one rocket to another and let them share, as this is not the last 4" rocket I ever plan to build.

Has anyone had any experience mixing FG/Phenolic/Plastic in their kits? What has been your experience on fitment? Are the dimensions pretty much true across the board. I mean, the tubes seem to be mostly standardized, so I would hope that this would be an issue that wouldn't come up, but I haven't worked with fiberglass rockets at all so there's no way for me to know for sure without dropping close to $100 on a NC just to try.

Any help appreciated.

Afterthoughts:

I yanked the nose this morning to see about the possibility of cutting it, then heating and stuffing a coupler tube inside to "force it" to shape, but I'm uncertain of this strategy as well, and it seems like at the very least it will be a frustrating experience and more likely I'll end up destroying my nosecone and a handful of coupler tubes only to end up with an unsightly seam near the NC base that will never go away.
 

Steve Shannon

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There’s no reason not to use a fiberglass nosecone with a cardboard or phenolic body tube. PML sold a lot of kits that were that combination and people would then laminate the body tubes with fiberglass cloth. Just make sure the sizing is correct. Sometimes you end up with a slight lip when the body tube has a greater OD than the nosecone shoulder. I’ve known people who built that up to match. I never did.
 

Titan II

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Yes, the FG ones fit cardboard tubes. I have also had several MC plastic cones that have all been a perfect fit.
 
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Off Grid Gecko

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There’s no reason not to use a fiberglass nosecone with a cardboard or phenolic body tube. PML sold a lot of kits that were that combination and people would then laminate the body tubes with fiberglass cloth. Just make sure the sizing is correct. Sometimes you end up with a slight lip when the body tube has a greater OD than the nosecone shoulder. I’ve known people who built that up to match. I never did.
Funny enough the problem I'm trying to solve right now. haha. with a plastic nose cone. It lines up evenly on one side for like 2in and the rest of the nose is WAY too small. Not a slight lip but over 2mm in some places exposing the payload tube to incoming air if I fly it like this.

Thanks for the input. Part of my issue is figuring out the dimensions of some of these nosecones that don't seem to be listed. I'll check MadCow's FB cones again and see if I can find the spec sheet and then toss my micrometer on the body tube.
 

tsmith1315

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You'll find almost all mfrs list their tube dimensions. I expect their nose cones to fit flush with their tubes.
The only question is CW, where they offer std and thin wall tubes. Find one you like and call to verify?
 

Off Grid Gecko

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Madcow got ahold of me today. Sounds like they are going to send another cone. I sent back to ensure my tube dimensions are correct (that the tube didn't swell rather than the NC shrinking or something like that) just to be sure. Funny enough, I have a nosecone in my checkout cart rn at another place and didn't pull the trigger on the order last night.
I guess they've been backed up or something, they didn't say, but they did finally get back to me. Thought it was worth an update.
 

Off Grid Gecko

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New Nosecone arrived this morning at the post office. MUCH better fitter. Even a little tight in the tube. There's a small lip on the outside still showing but 100x better than the one that came with the kit. Time to drill a hole, add some weight, and start the testing. The rest of my recovery equipment will hopefully be arriving this week. Matches are done. All that's left is to start the testing! :)

For now I'll prolly leave the NC naked but I'll paint it later on, hopefully after I get my L2 :D
 

jqavins

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And the lesson is to always give the vendor the first chance to make things right. Most of them will, every time. You've got some other good reasons to consider going with a fiberglass nose cone (the open base and payloads thing you mentioned) and if you do you'll have the replacement MadCow cone in your parts inventory. And in the rare instance that a vendor doesn't make things right, you lose nothing by trying.
 

Off Grid Gecko

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For sure they did handle it, just had to wait a bit for the initial response. Since they didn't want the other one back I chopped the shoulder off and found that the plastic is VERY biased to one side. Thinking about thinning that side and then heat it up and force a coupler tube in there... just not sure how I"m going to do it yet, haha. Worth a try though since I can't use it for much else the way it is.

Pretty sure my next High - power rocket will be fiberglass. Maybe not for a heavy L3 build I'll use sonotube and make a NC for it, but definitely when I decide to make and l2-l3 capable machine that looks good, will prolly go fiberglass.
 

waltr

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For sure they did handle it, just had to wait a bit for the initial response. Since they didn't want the other one back I chopped the shoulder off and found that the plastic is VERY biased to one side. Thinking about thinning that side and then heat it up and force a coupler tube in there... just not sure how I"m going to do it yet, haha. Worth a try though since I can't use it for much else the way it is.
At least you have a 'free' nose cone to learn how to do a bay in. Even if the attempt fails.
 

Off Grid Gecko

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At least you have a 'free' nose cone to learn how to do a bay in. Even if the attempt fails.
The real trick will be learning how to even out the inside surface. But yeah, pretty much the way I'm looking at it.. I'm not sure what I'm going to build after this one, and hopefully after getting my L2 cert,, but I'd imagine there will be at least one more 4" rocket in the fleet before it's all over with.
 
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