Making body tubes

[rockets]

As some of you know I own a rocket business.

Well, I'm in the planning stage of making some HPR kits, (Hopefully coming in late 2019)

I am looking at the possibility of making my own body tubes for 2.6", 3" and 4" kits.

I was wondering what's involved in making body tubes?

What materials do you need?

Do you need any special machines or tools?


Does anyone have any experience making their own body tubes here on TRF?


Thank you all!!




Thanks,

 

[tim cubbedge]

The easiest to make are fiberglass tubes. Tfish has some really good videos out there. I learned a lot from watching them. Basically you'll need some fiberglass cloth and some good laminating epoxy. A mandrel will help but motor cases work too. Many people make their own. Watch Tony's video, again & again!

 

[rharshberger]

Its going to come down to how much YOUR time is worth and quantity and quality. If its for you personally and its only a few, like Tim said fiberlass tubes are easiest. A FG airframe can take an hour +/- to make (plus cure time) with prep, doing the work and cleanup, requires chemicals, protective gear, and a largish area to work, and a mandrel. Paper tubes can be made but tend to be weaker and heavier than the ones sold for rocketry. Filament wound FG tubes require a specialized winding machine and mandrels. Unless needing a specialty (scale tube or something) paper tubes are easier bought. If its for business purposes then its probably better to buy in bulk.

 

[dhbarr]

What would make your HPR tubes different from all the other ones available?

If the answer is nothing, then consider spending your time on more interesting things.

If the answer is "I'll be cheaper" then please stop yourself right now before you ruin your enjoyment.

If the answer is "I have a new idea!" then great! Go for it! But realize you will probably spend a great deal of money trying to prove your concept.

I wish you the best of luck.

 

[dr wogz]

https://paramounttube.com/hobby-rocket-tubes/

People / companies specialize in all sorts of things. Once you make an investment in tooling for a particular "thing", you become specialized in that "thing" and people will then come to you to buy that "thing". And, in order to make the "thing" competitively , you need to reduce your costs to be competitive with other like minded people / companies. this means getting your materials cheaply, making them efficiently & accurately, and reducing labour.

Making tubes for your business will take time away for what you really want to do: design & sell rockets. Deviating from this will make you less competitive, and learning the new skill / technology will be a huge learning (and costly) endeavour. Stick to what you know..

Madcow, Binder, Estes, all have their tubes made by a tube maker for this very reason. They, like you, are in the business of putting kits together.

While it is noble of you to know how tubes are made, and maybe also make a few yourself, you are better off buying tubes from a known tube maker. This ensures quality, cost, and their expertise on the subject. (And, if there is a fault, you can blame them!) But do expect to meet their minimums (minimums to buy to get the pricing & for them to make their profit)..

 

[Bat-mite]

Since it might be easier to cut CRs than to make tubes, consider making CRs for existing tubes like paper towel rolls. Fill the spirals, give them a wrap of FG on the outside, cut CRs, and sell as a kit. Nose cone sizing would still be an issue.

 

[JimJarvis50]

I've made my own carbon fiber tubes for 10 years or so. I make my own because I can control the size/thickness, etc., which I often need to do, and because it's a hobby. I would never make tubes as a business, though - no way to be competitive. If you want to see how I do it, there are links, but I would not recommend doing it.

Jim

 

[rockets]

I have only looked into making body tubes for ARS for a couple of reasons.

1. I have gotten quotes from several companies, and they pretty much all require a $1,000 minimum order for wholesale pricing, and I can't do that.
2. Buying tubes can get costly because of shipping, so it gets expensive after a while.
3. I could make my own tubing without having to order special lengths, (I could do it myself) I could save a lot of $$$ on shipping, and I don't have to spend a lot of money to get tubing.
4. This would be a great learning experience for me.


If this isn't the best thing for me to do at this time, then I will have figure something else out.



Thanks,

 

[JimJarvis50]

The Longhorn Rocketry Association (University of Texas) has a lot of members that do their L1 & L2 certifications at our launches. I would just be guessing, but perhaps 2 or 3 dozen of them have done this over the past few years. They all make their own 4" fiberglass tubes. I don't know if they do this for the experience or to reduce costs, but it would seem this is on the order of what you want to do. You might ask them for some feedback.

Jim

 

[kuririn]

Andrew,
If you want to do this just to learn the process, here's a link showing how to construct paper tubes from Kraft paper:

https://www.instructables.com/id/Make-your-own-Kraft-Paper-Tubes/

Note that you will need some kind of form or mandrel to wrap the paper around, and it needs to be the exact od to match the id of the tube you are making. So you will either have to make one, or find a pipe with the exact dimensions you are looking for. The finish will be more like a paper towel tube rather than a commercial model rocket tube ( no glassine coating ). So I doubt if you will want to use them as body tubes in your kits.

May I suggest that you source your tubes from a vendor that can give you the best combination of up front cost plus shipping? I know of one vendor that gives free shipping on orders over $48 (Jonrocket). There may be others, check around, and ask for any bulk or vendor discounts. You can save money without having to spend a thousand dollars. I applaud your entrepreneurial spirit. Good luck.

 

[pondman]

I have only looked into making body tubes for ARS for a couple of reasons.

1. I have gotten quotes from several companies, and they pretty much all require a $1,000 minimum order for wholesale pricing, and I can't do that.
2. Buying tubes can get costly because of shipping, so it gets expensive after a while.
3. I could make my own tubing without having to order special lengths, (I could do it myself) I could save a lot of $$$ on shipping, and I don't have to spend a lot of money to get tubing.
4. This would be a great learning experience for me.


If this isn't the best thing for me to do at this time, then I will have figure something else out.



Thanks,

Bill Good makes his own tubes and fins, and has done several for me. Since he is "local" you may want to catch him at a launch.

 

[boatgeek]

I have only looked into making body tubes for ARS for a couple of reasons.

1. I have gotten quotes from several companies, and they pretty much all require a $1,000 minimum order for wholesale pricing, and I can't do that.
2. Buying tubes can get costly because of shipping, so it gets expensive after a while.
3. I could make my own tubing without having to order special lengths, (I could do it myself) I could save a lot of $$$ on shipping, and I don't have to spend a lot of money to get tubing.
4. This would be a great learning experience for me.

If this isn't the best thing for me to do at this time, then I will have figure something else out.

Thanks,

1. You'll probably spend a fair bit of money getting tube production up to speed, not to mention finishing the tubes.
2. You'll still need to ship raw materials, and fiberglass resins probably ship hazmat. If you have a local wholesale-price supplier, that may not matter.
3. If this is a business, make sure your long-term business model includes paying you for your time. If you make a profit of $5 per tube after materials and spend 2 hours making it, you're paying yourself $2.50/hour.
4. Absolutely true. It is super fun to build a tube. It is far less fun to finish a tube to commercial quality.

You might consider setting kit prices so that you make less money (or don't pay yourself for time) when you buy tubes at retail rates. When (hopefully) your business grows enough to support wholesale orders, you'll have a higher profit margin. Also, I'm an engineer, not a business major, so take my advice with a grain of salt.

 

[neil_w]

Suggestion: make some of your own tubes for the learning experience. Purchase commercial tubes for your kits.

 

[rockets]

Bill Good makes his own tubes and fins, and has done several for me. Since he is "local" you may want to catch him at a launch.

I would assume that he makes composite tubing, and not cardboard tubing, correct?



Thanks,

 

[pondman]

I would assume that he makes composite tubing, and not cardboard tubing, correct?



Thanks,

Correct; but he may have some thoughts around cardboard......

 

[Bluegrass Rocket]

Manufacturing kraft paper tubes is like any other industry starting from the beginning, it takes tons of money and man hours and knowledge. If you plan on selling a few kits, say 10-20, then you could learn to roll your own and call it experience. Like others have said here, it would take out any enjoyment and soon you wouldn’t have any fun.
The machine you need to make tubes you could import from a Chinese maker for probably under $150,000. Maybe. You would need a room or warehouse to put the machine in, 50 feet by 100 feet minimum. It takes special rolls of kraft paper in different thicknesses and special adhesives that you would have to source and purchase. Then the specialty sized mandrel that you roll the paper on, another few thousand plus. For each size. This kind of machinery is not plug and play, it would probably take several weeks to produce a tube with the quality you would desire. ALL of your time would be spent trying to make tubes. And after nearly $200,000 and hundreds of man hours you could have one $2.00 tube. Don’t even get me started on making plastic nose cones.
It’s not that you can’t make your own tubes, it’s just not worth your time. Unless you plan on making your living making tubing for others.

Do what every small rocket company does that makes kits with paper tubes, buy already made tubes. Find your best source and buy them. Not from the manufacturer, starting out, but from distributors. Plan on working up to the point that you can purchase from the factory. It’s like any new small business, have a plan and goals, work hard to accomplish them. Some things you will be able to make yourself, others you will have to have made. Anything is possible with time and determination. Best of luck. PM me if you have questions.

 

[prfesser]

I've made a whole lot of paper tubes, mostly spiral-wound. Body tubes, motor mount tubes, motor casings for skyrockets, casting/liner tube sets for research rocketry. Gummed non-reinforced paper tape is cheap and easy to work with. That being said...

In a word: don't. One paper tube is easy to make. Four or five, not too hard. 20 tubes is a chore and a half, especially in the sizes you're talking about. Since you're looking at standard sizes, you want to buy the tubes anyway. Imagine spending days making a bunch of tubes, then finding that they've shrunk a couple thousandths and the nose cone don't fit. Fiberglass and the like won't shrink, but the time investment is pretty stiff.

(BTW the finish on gummed tape that I've used is quite smooth. Not as good as glassine but much better than paper-towel tubes. And don't you sand off a lot of that glassine anyway?)

Best -- Terry

 

[GlenP]

I make LPR body tubes from cardstock convolute wound. This leaves a seam along one side of the body which is maybe not the most desirable, but hey, you gotta put the launch lug on there somewhere anyway. I use a glue stick on cardstock paper to wrap around spent engine casings or dowels with a little wax paper wrap so the glue does not stick, 13mm, 18mm, 24mm, or even smaller 3/8" or 1/4".

I wanted to see how large a body tube I could make from one single sheet of cardstock 8 1/2" x 11" and came up with a diameter of 8-1/2"/Pi or about 2.7" which is the Center Punch 24mm powered rocket below.

Dr. Zooch Saturn 1B kit includes a dowel and pre-printed 'wraps' so you can roll your own tanks.

I typically make downscales like this 13mm Groove Tube, all hand rolled tubes. The R2-D2 body is also a handmade body tube, about 2-7/8" dia, the entire model was a template printed on cardstock on an ink jet color printer, so no painting required, just semi-gloss clear coat over the whole thing.

Good luck with the HPR and composite stuff, but if you are interested in trying out cardstock for LPR you can have a lot of fun with that too. I agree that it is fun for small quantities or prototyping, but not sure if hand rolling scales up well to larger batches or mass production runs.