3D printed 29mm fin can

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rockets

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I'm in search of a 29mm 3D printed fin can. I'm getting very frustrated with trying to put straight fins on my MD 29mm rocket, I just messed up my second one, and I'm wasting $$ :mad:
I'm looking for something like this:
3d_printed_fin_can.png
It needs to have 3 straight fins, that need to be as aerodynamic as possible. It also needs a coupler at the top, so I can fit the BT on top of the fin can.
Don't want to spend too much, probably nothing over $20 if possible.

PM me if you're interested.


Thanks,
 

ScrapDaddy

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I mean putting on fins straight is a pretty relevant skill that you'd likely wanna pick up at some point...

Here is a fin wrap alignment template maker: https://www.payloadbay.com/index.php?page=Tools&action=FINWRAPS

Here is one of those templates for one you would cut out of posterboard: https://www.payloadbay.com/index.php?page=Tools&action=FINWRAPS


As a bonus, here is a video of Tim Van Milligan showing you how you use those correctly to ensure straight fins: [YOUTUBE]kpHyIl8A3Ec[/YOUTUBE]
 

Bat-mite

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Yup. That's what I do. A piece of foam board from Hobby Lobby, a free PayloadBay.com template, and an X-Acto knife are all you need. I build every rocket that way, from Estes to my 55# Formula 200.
 

rockets

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Yeah, I have used fin guides, sometimes works, but not always. In fact, I have an Estes fin alignment guide. Will work sometimes, but not always.
I don't have very good eyes.

Thanks,
 

Bat-mite

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Yeah, I have used fin guides, sometimes works, but not always. In fact, I have an Estes fin alignment guide. Will work sometimes, but not always.
I don't have very good eyes.

Thanks,
We're not talking about the ones that sit on the ground under the rocket and depend on your eyes. We're talking about ones you cut out and slide over your fins. They can't "not work."

Like this, only you cut them out of foam board with a ruler. No wood tools needed.

 

rockets

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We're not talking about the ones that sit on the ground under the rocket and depend on your eyes. We're talking about ones you cut out and slide over your fins. They can't "not work."

Like this, only you cut them out of foam board with a ruler. No wood tools needed.

May look into that.
Thanks,
 

NateLowrie

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Andrew,

I agree with the others that it's an essential skill to have and master. Have you delved into your failures with the fin guide? Why didn't it work? What are some ways to mitigate that failure mechanism? Have you tried a guide like the posterboard guide or just the estes fine guide?

Not having "very good eyes" is a piss poor excuse. The whole point of jigs and fixtures is to take human error out of the process. If you have a good jig, you shouldn't need to judge anything with your eyes, just verify the fin is mounted correctly to the jig. Jim Jarvis uses the hardboard/foamboard guide with angle iron for some extreme performance builds. Start with the above questions and lets get to the root of your process problem first.

As for the original question, nothing commercially but a quick google search gives a number of models that can be use or adapted.
 

Cl(VII)

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What size motors are you looking to fly? That shoulder/coupler section is going to limit length.

You also need to consider other things with 3D printed materials. How fast will you go (influences fin thickness and material)? How hot will the motor get (Influences material used)?

3D printing sounds easy, but it isn't like regular printing. Print time will also directly translate to price, and $20 ain't gonna buy much print time. A fin can like you have drawn with appropriate (maybe) fin thickness, and long enough to accommodate a 29-40/120 case would probably take 4-6 hours on my printer. That is assuming it prints perfectly the first time, and doesn't need any tweaking to the design or print settings. Also, you are asking someone to design the part from your sketch. Chances are you won't get exactly what you envision without more detailed info.

As a side note. I believe it is typical to provide 1 cal between the rocket base and the fins on a MD rocket. I believe I ready this is to allow the turbulent airflow from the fins to smooth out before the base of the rocket. That may be the reason, but I find it protects the fins too. Due to the nature of the beast (high flights and small recovery spaces) you tend to land MD rockets a little faster than normal. 3D printed fins are not going to take a beating like fiberglass or CF would.

If someone is gonna take the commission more power to them, but you should probably resign yourself to figuring out the fin alignment issue.
 

rockets

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What size motors are you looking to fly? That shoulder/coupler section is going to limit length.

You also need to consider other things with 3D printed materials. How fast will you go (influences fin thickness and material)? How hot will the motor get (Influences material used)?

3D printing sounds easy, but it isn't like regular printing. Print time will also directly translate to price, and $20 ain't gonna buy much print time. A fin can like you have drawn with appropriate (maybe) fin thickness, and long enough to accommodate a 29-40/120 case would probably take 4-6 hours on my printer. That is assuming it prints perfectly the first time, and doesn't need any tweaking to the design or print settings. Also, you are asking someone to design the part from your sketch. Chances are you won't get exactly what you envision without more detailed info.

As a side note. I believe it is typical to provide 1 cal between the rocket base and the fins on a MD rocket. I believe I ready this is to allow the turbulent airflow from the fins to smooth out before the base of the rocket. That may be the reason, but I find it protects the fins too. Due to the nature of the beast (high flights and small recovery spaces) you tend to land MD rockets a little faster than normal. 3D printed fins are not going to take a beating like fiberglass or CF would.

If someone is gonna take the commission more power to them, but you should probably resign yourself to figuring out the fin alignment issue.
It's going to fly on an F10. The fins have to be really straight, because I'm going for the TRA record. This is my second attempt at a TRA altitude record.
. If I'm going to try the fins again, then I will have to order a long piece of BT from Apogee rockets. Sure, it's only $4, but that isn't including shipping. So now it's going to be more like $14.
And what if I mess up again & again, then that's another $14 down the drain. I have been so frustrated with wasting time & money, I figured this would be an easy way out.

Thanks,
 

dr wogz

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Andrew, build yourself one of these form a spent motor case or tube that fits into the motor mount. file two notches at the diameter, so a rod / toothpick held in place is centered. then just sight down & adjust your fins so they are perpendicular. Remember to also align your fin with te line you made. Align one side of eth fin on the line, don't try to center the fin on the line. Or, make two lines a fin width apart, and glue your fin in-between the two lines.

fin align 5.JPG

fin align 1.JPG

fin align 4.JPG

fin align 3.JPG

dx3_0668.JPG
 

Eric

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I am not sure I would feel satisfied holding a record with something that I just purchased. Designing, building, perfecting and flying my own product would mean way more to me. I think a small time and monetary loss in trying again would mean more to my achievement. I agree in perfecting you fin alignment jigs.

But, if someone was to print some fin cans that would hold my 29/40-120 hardware and fit right in a nice tube. I'm not saying I wouldn't buy one and enjoy flying it.
 

3stoogesrocketry

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It's going to fly on an F10. The fins have to be really straight, because I'm going for the TRA record. This is my second attempt at a TRA altitude record.
. If I'm going to try the fins again, then I will have to order a long piece of BT from Apogee rockets. Sure, it's only $4, but that isn't including shipping. So now it's going to be more like $14.
And what if I mess up again & again, then that's another $14 down the drain. I have been so frustrated with wasting time & money, I figured this would be an easy way out.

Thanks,
What will you be using for electronic deployment and retrieval . As I'm sure you already know , the F10 motor has a 8 second delay . It will still most likely be traveling up when it deploys . Also make sure your altimeter is on the approved list by Tripoli . How are you planing on launching this rocket ? Off a rod will be a bad desicion as lugs eat away at you top speed , they are draggy . What will you be using for shock cord and recovery gear ?

P.S. Your choice of materials for this build are very important.

Eric
 

rockets

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What will you be using for electronic deployment and retrieval . As I'm sure you already know , the F10 motor has a 8 second delay . It will still most likely be traveling up when it deploys . Also make sure your altimeter is on the approved list by Tripoli . How are you planing on launching this rocket ? Off a rod will be a bad desicion as lugs eat away at you top speed , they are draggy . What will you be using for shock cord and recovery gear ?

P.S. Your choice of materials for this build are very important.

Eric
Eletronics: PerfectFlite APRA altimeter, RDF transmitter tracker.
Launch Pad: 3 3ft tall PVC pipes, the rocket rests between the three PVC pipes.
Recovery: Kevlar shock cord, either streamer, or small parachute.
Thanks,
 

cavecentral

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It's going to fly on an F10. The fins have to be really straight, because I'm going for the TRA record. This is my second attempt at a TRA altitude record.
. If I'm going to try the fins again, then I will have to order a long piece of BT from Apogee rockets. Sure, it's only $4, but that isn't including shipping. So now it's going to be more like $14.
And what if I mess up again & again, then that's another $14 down the drain. I have been so frustrated with wasting time & money, I figured this would be an easy way out.

Thanks,
Are you familiar with www.balsamachining.com? I think they still have flat rate of $6 for shipping for tubes etc. Usually sell 34" lengths (not including motors). Their school rocket and 3" school rocket are great deals.
 

3stoogesrocketry

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Eletronics: PerfectFlite APRA altimeter, RDF transmitter tracker.
Launch Pad: 3 3ft tall PVC pipes, the rocket rests between the three PVC pipes.
Recovery: Kevlar shock cord, either streamer, or small parachute.
Thanks,
Ok , looks like your on the right track for electronics . I would use a much longer tower. At least 5 feet . The rocket will not be accelerating very hard and you don't want it to arc into the wind or downrange . Also PVC is flexible and could bend "throwing" the rocket out at a angle. You will need to have a secure top plate to keep the poles where they need to stay . I would use a streamer to get it back quick and not drift to far.

Eric

I tried for the H altitude three times . It is hard , best of luck.
 

vcp

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I'm in search of a 29mm 3D printed fin can. I'm getting very frustrated with trying to put straight fins on my MD 29mm rocket, I just messed up my second one, and I'm wasting $$ :mad:
I'm looking for something like this:
View attachment 325969
It needs to have 3 straight fins, that need to be as aerodynamic as possible. It also needs a coupler at the top, so I can fit the BT on top of the fin can.
Don't want to spend too much, probably nothing over $20 if possible.

PM me if you're interested.


Thanks,
If you're still in the market... I just ran across this fin can that I did two or three years ago; I'd forgotten it was 29mm. It is airfoiled and filleted. It's 4 fins, but if I can find the code it's easy to reprint with three. Bad news is that it's a tube thru the can style, so the OD is 32mm. I could possibly refactor it to a 29mm OD coupler style, again if I can find the original code, and if you're still interested. This is printed in ABS.

Gary
 

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rockets

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If you're still in the market... I just ran across this fin can that I did two or three years ago; I'd forgotten it was 29mm. It is airfoiled and filleted. It's 4 fins, but if I can find the code it's easy to reprint with three. Bad news is that it's a tube thru the can style, so the OD is 32mm. I could possibly refactor it to a 29mm OD coupler style, again if I can find the original code, and if you're still interested. This is printed in ABS.

Gary
I tried to glue the fins, again :eyeroll: and it didn't turn out as good as I was hoping for. So, yes I'm still looking for one.
I'll send ya a PM so we can talk about this more privately...


Thanks,
 

Locksmith

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You might want to look into seeing if their is a Maker Space or some times called hacker space in or near the city you live. Most of the ones I have been to would be more then happy to print it for you for no more then the cost of the filament especially those who are still learning to print, or better yet join and get access to not only multiple 3d printers but depending on how big of space it is are local one for example has 2 laser cutters, lathes, multiple extremely nice soldering stations, i think 5-6 3d printers all different. And being younger your yearly membership will probably be less then paying someone to print 1 thing.
Good Luck
J
 

jdbwizzard

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I would not recommend a 3d printed fin can for this motor. I have a done testing with my 3d printer. I have a full 13mm md rocket 3d printed. It does well as long as you give it time to cool before picking it up. That being said a long burn motor like the f10 is going to generate a lot of heat and 3d printed parts are not good for this amount of heat. Even when printed in abs or petg. I have tried motor mount and lets say the results didn't go so well. Just my experience though.
 

rockets

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I would not recommend a 3d printed fin can for this motor. I have a done testing with my 3d printer. I have a full 13mm md rocket 3d printed. It does well as long as you give it time to cool before picking it up. That being said a long burn motor like the f10 is going to generate a lot of heat and 3d printed parts are not good for this amount of heat. Even when printed in abs or petg. I have tried motor mount and lets say the results didn't go so well. Just my experience though.
Yeah, I see what you mean, I'm doing multiple tests before the real flight..
And hey, BTW, do you go to any TMO launches? (I saw your signature about you flying at WSR) :)

Thanks,
 
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