Removable fin design

I'm working on a large project that will have fins that will span just over 4 feet. I'm looking for pics of designs that have the fins able to be removed to make transportation and storage easier. The fins will be made from 1/2" Baltic Birch.

I have a few ideas in my head, but would rather not redesign the wheel if possible.

I will have another project right behind this one that will have even larger fins, so now is the time to try it.

Any help would be appreciated.

Thanks

Some discussion of this topic and build references in this thread: https://www.rocketryforum.com/showthread.php?61839-3-4-Scale-Nike-Smoke-Input-Opinions-Thread.

One of our club members has a large rocket with removable fins. The fin can is built with two CRs that are held apart with pairs of wood stringers. To prep, the fins are inserted in to the slots in the BT and bolts and nuts are used to bolt them between pairs of stringers. The motor hole is 125mm so at 5", there's room to reach up inside and bolt the fins to the stringers. There is no motor mount tube, the inside edges of the stringer act as the motor guides.

dixontj93060 said:

Some discussion of this topic and build references in this thread: https://www.rocketryforum.com/showthread.php?61839-3-4-Scale-Nike-Smoke-Input-Opinions-Thread.

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Thanks Tim. So far I like the method that Team Vatsaas used: https://www.vatsaas.org/rtv/construction/removable/fins.aspx

But we are still early in the development. This thread has already made a change to the original design.

Handeman said:

One of our club members has a large rocket with removable fins. The fin can is built with two CRs that are held apart with pairs of wood stringers. To prep, the fins are inserted in to the slots in the BT and bolts and nuts are used to bolt them between pairs of stringers. The motor hole is 125mm so at 5", there's room to reach up inside and bolt the fins to the stringers. There is no motor mount tube, the inside edges of the stringer act as the motor guides.

Click to expand...

Have any pictures by chance?

RandyM said:

Have any pictures by chance?

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Unfortunately no. It was interesting watching him slide the bolt through the stringers and fins. Had to get them lined up, which seemed to be the biggest issue. Once the bolt were in place, the washers and nuts went on, a few twists with the small wrenches and everything was solid. And everything done through the motor hole.

Hi Randy,

I do this on my projects. Although it's handy that the fins are removable for repair, replacement, storage, I find I usually don't disassemble. But I have a storage unit so that helps. Check out either my Iris or Terrier-Sandhawk build threads:

https://www.rocketryforum.com/showthread.php?15239-7-5-quot-Iris-Build

https://www.rocketryforum.com/showthread.php?58229-7-5-quot-6-quot-Terrier-Sandhawk

Both of those rockets have flown just past Mach 1, no issues.

I've seen other large rockets use just 1 vertical spar (I remember thinking it looked like a 2x4) to which the fins were bolted, simple but effective.

Good luck,

Jerry

RandyM said:

I'm working on a large project that will have fins that will span just over 4 feet. I'm looking for pics of designs that have the fins able to be removed to make transportation and storage easier. The fins will be made from 1/2" Baltic Birch.

I have a few ideas in my head, but would rather not redesign the wheel if possible.

I will have another project right behind this one that will have even larger fins, so now is the time to try it.

Any help would be appreciated.

Thanks

Click to expand...

RandyM said:

Thanks Tim. So far I like the method that Team Vatsaas used: https://www.vatsaas.org/rtv/construction/removable/fins.aspx

But we are still early in the development. This thread has already made a change to the original design.

Click to expand...

Randy thanks for that link! My 3/4 scale Nike Smoke design follows the principles in the Gila Monster as shown at the end of that article. Hadn't seen that before so it's nice to get confirmation that my design direction has merit.