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mperegrinefalcon

mperegrinefalcon

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Hello people, I am starting a new scratch build, and shes a big one. I'm building an 8" diameter Black Fly. I have some Sanotube that I am using as the body tube and some plywood for the fins and centering rings. This rocket is going to be pretty much completely scratch built. I'm trying to make this entire rocket cost less then the M1075 I plan to fly it on. I am hoping to fly this at NARAM 60 and get my L3 cert there, so if you are planning to be there you might get to see it. I've checked with SCORE, and they have up to 20 feet of 1515 rail for their M launch pad. Now for some simulations:


Screenshot (26).jpg

(I don't know how to make this bigger)

The Sanotube is more like 8 5/8" in diameter. When I bought them they were in nested pairs, so I had to spend a little time finding ones that were the same size.


It stays well within the flight requirements of the Pueblo launch site, and off of the 20 foot rail it is plenty fast enough to be stable (~23 m/s).

My plan with this is tube have single head end deployment at apogee. I'm planning either a Cert-3 XL or Fruity Chutes Iris Ultra 72". I will be fiber glassing the body tube and fins with one layer of 6oz fiberglass, and reinforcing all the joins in the motor mount and bulkheads with fiberglass.
 
Kool, another BF build to watch come together!

And it's a biggie..... :headbang:

mperegrinefalcon said:
View attachment 343793

(I don't know how to make this bigger)
Click to expand...

Not to worry, it's a clickable thumbnail. Once clicked, it will display a popup with full size image. It's better to do it this way as it saves on bandwidth/load times for those that are so hindered.
 
I'm sure you know this already, and I don't mean to be an ass, but your sim file shows a very unstable rocket.
 
If you can get this together and drive it out there, I hope to see it!

Looking to get my L2 there as well.
 
Bat-mite said:
I'm sure you know this already, and I don't mean to be an ass, but your sim file shows a very unstable rocket.
Click to expand...

Yeah, I know that. I don't have any of the weights of the actual components yet, so that is just Open Rockets prediction of the weight and CG. Once I get the final CG and weight I can always add nose weight.
 
Nytrunner said:
If you can get this together and drive it out there, I hope to see it!

Looking to get my L2 there as well.
Click to expand...

Awesome!!! The actual body with tailcone isn't particularly big. It only has a length of 65.75", and the total span is 24.125", so I don't expect to have too much difficulty fitting it into my car. I will have plenty on time this summer to build as my work limits it's employees to 30 hours a week, so the only issue might be the money to pay for the motor, of course being just out of high school I don't have any bills so shouldn't be an issue. Also the launch site is only an hour drive away from me, so that makes it not too bad.
 
So I have done a little bit of building, not much though because I need to get a few more materials.

I have two lengths of Sanotube, and I am leaving one of them at the stock 48" length that it comes in. The other tube got cut into a 14" length and a 12" length. I split the part that was 12" down the center, and test fitted it inside the leftover tube and cut off the overlap. This is going to be used as a coupler.

20180428_214737.jpg20180428_214727.jpg

After sanding and cleaning the two pieces where they would be bonded, I mixed up a bunch of Rocketpoxy and slathered it everywhere on half of the coupler, and a line just inside the 14" long piece of Sanotube.

20180428_221925.jpg20180428_221952.jpg20180428_222006.jpg

I used some super glue to tack it in place and applied more epoxy to the outside of the exposed part of the coupler and another line just inside the body tube. I then simply slid it into the main body tube and wiped off the excess.

20180428_224947.jpg


I did this part last night, but it was late so I forgot to take a picture of the wiped down tube. I also have the fins cut out, but I need to sand them all to the same size and bevel the edges.

That's all the building I have for now,
Catch you peeps later.
 
mpitfield said:
I am sure you knows this but just in case, make sure you document everything for your TAPs. BTW have you spoken to your TAPs about your plans?
Click to expand...

I have contacted the L3CC for my club, but they haven't really gotten back to me about these plans. I figure that it shouldn't matter if I start building a little bit just yet. I am documenting this build here on the forum so that I have it documented for when I do hear back from them.
 
mperegrinefalcon said:
I have contacted the L3CC for my club, but they haven't really gotten back to me about these plans. I figure that it shouldn't matter if I start building a little bit just yet. I am documenting this build here on the forum so that I have it documented for when I do hear back from them.
Click to expand...

Mine was the same but as long as you document it, it should fine.
 
mperegrinefalcon said:
I'm going to attempt to make my own, but if that doesn't work, then I will just order the nosecone and tailcone from Python Rocketry.
Click to expand...

If you want help with the nose I can walk you through the process of scratch building to spec. I'm currently scratch building my 3", and will be using the same method for my 4" next year that hopefully will be my L3.
 
Barkley said:
If you want help with the nose I can walk you through the process of scratch building to spec. I'm currently scratch building my 3", and will be using the same method for my 4" next year that hopefully will be my L3.
Click to expand...

I will need all the tips I can get for that part of this build. What are some good articles I can read about it so I can do some research? I was planning to make a foam core with a drill and a jig for sanding the foam to shape, and then wrap that in the 3 layers of 6oz fiberglass. I would then use acetone to melt away the foam from the inside of the completed cone. My question with this is do I need to wait for the layers to cure in between or do I do all three layers at once?
 
mperegrinefalcon said:
I will need all the tips I can get for that part of this build. What are some good articles I can read about it so I can do some research? I was planning to make a foam core with a drill and a jig for sanding the foam to shape, and then wrap that in the 3 layers of 6oz fiberglass. I would then use acetone to melt away the foam from the inside of the completed cone. My question with this is do I need to wait for the layers to cure in between or do I do all three layers at once?
Click to expand...

Here's how I'm turning the NC for my 3" MD rocket. I made a plug in the shape I needed (in this case out of wood), then you make a parting board and glass that to make your mold. Pop the plug out, they lay up the finished part in the two part mold. Your nose will be so big that you'll have no issues glassing the inside for reinforcement. BTW, I'd recommend at least doubling your ply with the 6oz, if not more. You'll need weight in the nose anyway, so beef that sucker up. And yes, wax out your mold well (10 coats), then drop your cloth, wet it out, then drop the next while it's still wet - laminate all ply at once.

attachment.php


Here's the build thread if you're interested. The nose work starts at the end of page 2.

https://www.rocketryforum.com/showt...racus-Build-Thread/page2&highlight=BA+Baracus
 
Barkley said:
Here's how I'm turning the NC for my 3" MD rocket. I made a plug in the shape I needed (in this case out of wood), then you make a parting board and glass that to make your mold. Pop the plug out, they lay up the finished part in the two part mold. Your nose will be so big that you'll have no issues glassing the inside for reinforcement. BTW, I'd recommend at least doubling your ply with the 6oz, if not more. You'll need weight in the nose anyway, so beef that sucker up. And yes, wax out your mold well (10 coats), then drop your cloth, wet it out, then drop the next while it's still wet - laminate all ply at once.

attachment.php


Here's the build thread if you're interested. The nose work starts at the end of page 2.

https://www.rocketryforum.com/showt...racus-Build-Thread/page2&highlight=BA+Baracus
Click to expand...

Wow, that looks really nice! that CF is so sexy when its polished. I don't have any advanced tools like a lathe or vac bagging equipment. I was going to make a disposable core out of foam turned on a jig to hold a drill with a central rod going through the foam, and use that to shape my nosecone. Once I got that to where I was happy with it I would layup the fiberglass directly on the foam to creat the nosecone. I would do about 3 layers of 6oz fiberglass around the whole part and let that cure. I would then trim the excess off the rear an melt the foam core out from the center using acetone leaving me with a very thin nosecone that I can then reinforce from the inside. I don't know if this will work or not as I have no experience making my own composite parts. I think I will try making a 29mm nosecone with this method to see how/if it works.

Edit: The wax you use, is that just parafin wax or something different? Where is a good place to buy the FG cloth? I have only found it on amazon, but its not rolled.
 
mperegrinefalcon said:
Wow, that looks really nice! that CF is so sexy when its polished. I don't have any advanced tools like a lathe or vac bagging equipment. I was going to make a disposable core out of foam turned on a jig to hold a drill with a central rod going through the foam, and use that to shape my nosecone. Once I got that to where I was happy with it I would layup the fiberglass directly on the foam to creat the nosecone. I would do about 3 layers of 6oz fiberglass around the whole part and let that cure. I would then trim the excess off the rear an melt the foam core out from the center using acetone leaving me with a very thin nosecone that I can then reinforce from the inside. I don't know if this will work or not as I have no experience making my own composite parts. I think I will try making a 29mm nosecone with this method to see how/if it works.

Edit: The wax you use, is that just parafin wax or something different? Where is a good place to buy the FG cloth? I have only found it on amazon, but its not rolled.
Click to expand...

Re really nice, thanks! Re vac bag/lathe, don't worry about that - they're nice to haves, not must haves. If you're turning foam on a jig, run with what you have - but I still recommend making your plug then glassing molds around it. Re production method, there's no question that it's more work, but it gets you a better finished part because your OD hits your spec. If you make a perfect blank of your part then make the mold for it, you have the perfect OD for your rocket, and you build up your thickness on the inside. With your chosen method it's far harder to lay up on the inside of a cone once it's made.

Having said the above, there are many ways to skin a cat, and if a method works for you, go for it. The one caveat to that is you should really get your L3 TAPs on side before you go much further in the build. You don't want to get all the way to a finished product before your critical design review - if a TAP says something needs reinforcement or a rebuild, you're back to square one. And I'm not an L3, but ... I'd expect that 3 ply of 6 oz wouldn't be approved by your TAP. I'd also expect your TAP to want multiple wraps of your sonotube BT.

Re sourcing glass and resin, I live in Toronto now, so I get my kit from https://compositescanada.com/. When I lived in Texas I bought from https://www.fibreglast.com/. No affiliation with either, but if either Fibreglast or CC want to compensate me retroactively, I'm open to donations.

I also use the Meguiar's mold release wax shown below for parts. While paraffin might work, mold release wax is designed for purpose. Note, for making tubes I use Frekote mold release spray.

Also - forget the modeling clay. My lesson learned from this latest build is 'just use bondo'. Modelling clay doesn't stick to a fully waxed part, where Bondo does but loosely enough that you can easily pop it off when required.

attachment.php


One last tip - extra epoxy is weight with no additional stiffness. Wet out your first ply, then place the second ply so that it sucks up the excess epoxy from the layer below. Only wet out where it's needed, then drop the next ply. You save lots of weight that way.
 
Okay, thank you for the tips. I will try doing it the correct way with a proper plug made out of foam then glassed to make the cone, although thinking about it just a cone out of foam that has been glassed is probably strong enough to be a NC. I will try it out with a small model and see how/if they work. I will be getting 20 yards of 6oz E glass, but I will practice some with the 2oz that I have and some hardware store epoxy. I just need to save up the money for the glass and west systems epoxy.
 
Barkley said:
Re really nice, thanks! Re vac bag/lathe, don't worry about that - they're nice to haves, not must haves. If you're turning foam on a jig, run with what you have - but I still recommend making your plug then glassing molds around it. Re production method, there's no question that it's more work, but it gets you a better finished part because your OD hits your spec. If you make a perfect blank of your part then make the mold for it, you have the perfect OD for your rocket, and you build up your thickness on the inside. With your chosen method it's far harder to lay up on the inside of a cone once it's made.

Having said the above, there are many ways to skin a cat, and if a method works for you, go for it. The one caveat to that is you should really get your L3 TAPs on side before you go much further in the build. You don't want to get all the way to a finished product before your critical design review - if a TAP says something needs reinforcement or a rebuild, you're back to square one. And I'm not an L3, but ... I'd expect that 3 ply of 6 oz wouldn't be approved by your TAP. I'd also expect your TAP to want multiple wraps of your sonotube BT.

Re sourcing glass and resin, I live in Toronto now, so I get my kit from https://compositescanada.com/. When I lived in Texas I bought from https://www.fibreglast.com/. No affiliation with either, but if either Fibreglast or CC want to compensate me retroactively, I'm open to donations.

I also use the Meguiar's mold release wax shown below for parts. While paraffin might work, mold release wax is designed for purpose. Note, for making tubes I use Frekote mold release spray.

Also - forget the modeling clay. My lesson learned from this latest build is 'just use bondo'. Modelling clay doesn't stick to a fully waxed part, where Bondo does but loosely enough that you can easily pop it off when required.

attachment.php


One last tip - extra epoxy is weight with no additional stiffness. Wet out your first ply, then place the second ply so that it sucks up the excess epoxy from the layer below. Only wet out where it's needed, then drop the next ply. You save lots of weight that way.
Click to expand...

Why do you think a TAP or L3CC wouldn’t approve of three layers of 6 oz. glass?
 
Steve Shannon said:
Why do you think a TAP or L3CC wouldn’t approve of three layers of 6 oz. glass?
Click to expand...

Not sure of the TAPs opinion, but I've been making 4" nose cones with a 2 part mold and I prefer 5 layers of 6 oz, 3 is just too thin IMHO. For a cone that big, I would start at 8 - 10 and add more later if needed.
 
Handeman said:
Not sure of the TAPs opinion, but I've been making 4" nose cones with a 2 part mold and I prefer 5 layers of 6 oz, 3 is just too thin IMHO. For a cone that big, I would start at 8 - 10 and add more later if needed.
Click to expand...

This.

If he was going for an ultra high performance build and going for a record I could see taking the risk, but to underbuild then add nose weight - there's no benefit. Why risk your cert unnecessarily?
 
Barkley said:
This.

If he was going for an ultra high performance build and going for a record I could see taking the risk, but to underbuild then add nose weight - there's no benefit. Why risk your cert unnecessarily?
Click to expand...
Ya I'm going to build up the cone to the thickness of typical fiberglass tube, so probably about 8 layers. I will need a fair ammount of nose weight, so i will probably add more layers to add nose weight and extra stength instead of just lead
 
timbucktoo said:
Mine was the same but as long as you document it, it should fine.
Click to expand...

You are incorrect. The NAR L3 Certification procedure clearly requires a prospective L3 applicant to submit detailed plans to an L3CC member prior to the start of any construction. The intent of this requirement is specifically explained, to allow the project to be reviewed for structural inadequacies or design flaws. If a project that has design flaws is constructed without review, the degree of documentation is irrelevant. The project is still flawed, and likely to fail.

The L3CC exists to help fliers be (1) SAFE and (2)SUCCESSFUL in their L3 certification.

If the OP is who I think it is, I was contacted. And I responded by directing him to follow NAR's procedure.
 

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