Semroc Maple Seed Build

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Skp

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As soon as I saw this kit at eRockets, I had to get it.
Maple Seed bag.jpg
There is very little information regarding the kit except that Carl was working on it in 2012.
The instructions indicate that some tweaking was required before it could be put into production, which was done by Eric Specht. As you can see from the parts picture, the KISS approach was not high on the priority list.
Maple Seed Parts.jpg
I have read and re-read the instructions a couple of times and there seems to be a missing step or lack of clarity regarding what are called the turbulators pictured below.
Maple Seed Turbulators.jpg
Three of them are square and three are curved at the end. The only ones shown or mentioned during the assembly instructions are the square ended ones. I believe they end up stacked together on 1 side of the leaf and the other side is flat. I have emailed Randy for clarification and will report back what he says.

I don't really know the best way to finish the maple seeds to protect from moisture and dirt without layering on paint. At this point, I am planning on not filling the wood and airbrushing a light coat of Createx acrylic paint.
 
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As soon as I saw this kit at eRockets, I had to get it.
View attachment 313705
There is very little information regarding the kit except that Carl was working on it in 2012.
The instructions indicate that some tweaking was required before it could be put into production, which was done by Eric Specht. As you can see from the parts picture, the KISS approach was not high on the priority list.
View attachment 313706
I have read and re-read the instructions a couple of times and there seems to be a missing step or lack of clarity regarding what are called the turbulators pictured below.
View attachment 313707
Three of them are square and three are curved at the end. The only ones shown or mentioned during the assembly instructions are the square ended ones. I believe they end up stacked together on 1 side of the leaf and the other side is flat. I have emailed Randy for clarification and will report back what he says.

I don't really know the best way to finish the maple seeds to protect from moisture and dirt without layering on paint. At this point, I am planning on not filling the wood and airbrushing a light coat of Createx acrylic paint.

I can ask Eric for clarification Tuesday night.
 
Looks like an interesting modification to the decades old Maple Seed 2-piece Helicopter recovery rocket. There are a number of other Maple seed type models out there this one looks like it is a bit bigger then most. The original Maple Seed was an 13mm motor rocket.
Centuri and Later Estes re-issued which i've DownScaled to a 2.6x Micro Flutter-By, Estes later Maple Seed rcovery rocket was the Tornado which I've also downscaled to T3 size.
All these type helicopter recovery models have a tendency to loose the upper part containing a single fin rotor so Bright Colors are all but required. I've had very good luck recovering all the parts of my 3 different Maple Seed Recovery rockets on MMX-II and A3-4T's in the 13mm original Maple Seed. They are all Really fun Fun, FUN to fly.

Will be looking forward to seeing how the Semroc Verison builds and flys.

655a_Maple Seed 13mm_11-14-06.jpg

338-sm_Micro Tornado (T3)_10-02-07.jpg

327a-sm_Micro Flutter-By 2.6x downscale_03-18-07.jpg
 
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Thank you Zeus-cat. I have not yet gotten a response from Randy, but he may be hunting down Eric as well.
 
Looks like an interesting modification to the decades old Maple Seed 2-piece Helicopter recovery rocket. There are a number of other Maple seed type models out there this one looks like it is a bit bigger then most. The original Maple Seed was an 13mm motor rocket.
Centuri and Later Estes re-issued which i've DownScaled to a 2.6x Micro Flutter-By, Estes later Maple Seed rcovery rocket was the Tornado which I've also downscaled to T3 size.
All these type helicopter recovery models have a tendency to loose the upper part containing a single fin rotor so Bright Colors are all but required. I've had very good luck recovering all the parts of my 3 different Maple Seed Recovery rockets on MMX-II and A3-4T's in the 13mm original Maple Seed. They are all Really fun Fun, FUN to fly.

Will be looking forward to seeing how the Semroc Verison builds and flys.

I had Odd'l Rockets Cyclone, and on the maiden flight the maple leaf part was lost. It worked amazingly well.
 
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The first step in the instructions say to follow instructions
Steps 2&3 are for the nose cone.
MS Nose cone parts.jpg
The balsa of the nose cone is very light weight. I have added the hardwood dowel to the parts to reduce the possibility of a pull out. I also decided to recess the washers into the cone so that I could build a glue cap over them.
MS nose cone fit.jpgMS nose cone glue.jpg
I am waiting for the initial glue to dry, and will then add a layer of glue over everything to lock it in.
 
Steps 4-8 cover the motor mount and are fairly standard. The only 2 deviations that I made were to add a small strip of paper just below where the hook penetrates the motor tube and to omit the attachment of the Kevlar shock cord to the engine hook.
MS Motor mount parts.jpg
I feel the strip of paper reduces the chances that the hook will tear the motor tube in the event of an energetic ejection charge.
I omitted the Kevlar shock cord due to having a few cords fail recently. I do have other plans that will be covered later.
MS motor mount assembled.jpg
The aft centering ring is 1in. from the end of the tube as per the instructions. That is farther forward than i tend to like, but it will work.
 
I know. Nose cones and motor mounts? How BORING. What about all those cool looking pieces?
MS Tube Hook Mount Parts.jpg
The 1st ones we get to make up the plates that are glued to the airframe and hook the fins.
In step 10 the instructions have you mark the tube for plate placement and the launch lug.
In step 11: they instruct to simply glue the hooks into the base plates and step 12: glue to the airframe hooks facing forward.
They are basswood and fit together perfectly. I did sand them very lightly to get most of the scorched wood off for better bonding.
MS burnt wood sanded..jpg
After gluing them together, I wiped ALL of the excess glue that appeared at the joint. Any glue blobs would likely impact fit later on.
MS Plates Assembled.jpg
I also wrapped a body tube with 100grit sand paper to curve the underside of the plate for better alignment and glue joint.
MS Sanding Mounting Plate.jpg
I am using the Estes tube cutting tool to make sure all the plates match location on the airframe, and am placing them to the right of the alignment line to aid in placing them vertically.
MS glued base plate.jpg

I have not yet heard back from Randy regarding clarification regarding the "Turbulators"
 
Where'd you get that 90* ruler? I like that. It kind of reminds me of an old Draftsmans scale.
 
Where'd you get that 90* ruler? I like that. It kind of reminds me of an old Draftsmans scale.

It is a 6-Inch Incra Precision Bend Rule and I got it off Amazon. It needs a .5 leaded mechanical pencil, which is not overly common.
 
I talked to Eric last night. He found that he omitted the launch lug attachment instructions.

The best way to determine the placement of the launch lug is to completely prep the rocket for flight, including the motor. Find the center of gravity for the rocket and center the launch lug on the CG.
 
I talked to Eric last night. He found that he omitted the launch lug attachment instructions.

The best way to determine the placement of the launch lug is to completely prep the rocket for flight, including the motor. Find the center of gravity for the rocket and center the launch lug on the CG.

Hello Zeus-cat,
I am glad you got to talk with Eric. I hope he sounded enthusiastic about how the Maple Seeds recover. The launch lug placement is covered in the instructions under step 30. I found the detail for placing the lug to be interesting. I plan to follow them, just in case it does make a difference in performance.
It really is the turbulators that are unclear. I do think that there is only way that makes sense, so lacking clarification I will assemble 1 fully and do some drop tests to see how it performs.
 
Randy responded to me confirming that the 2nd turbulator attaches stacked on top of the 1st turbulator. So on with the build.
MS Seed 1st step.jpg Step 13: Attach the pod head to the wing(used wood glue)
MS seed 2nd step.jpg Step 14: Attach the turbulator to the wing using thin CA(clips saved my skin)
MS seed 3rd step.jpg Step 15: Putting clay into the pod recess
MS back side step 1.jpg Step 16: Flip the wing over and repeat step 13 & 15(no turbulator for the back side. I did not get a picture with clay for the back side.)
MS seed hook.jpg Step 17: Glue the seed hook onto the pod.
MS Plate Placement.jpg Steps 18-21: The procedure to get the basswood plates positioned correctly and glued with thin CA (without getting it stuck to the rocket)
MS 2nd Turbulator.jpg (This should be step 22 of the instructions but was omitted) Step 22: Attach the turbulator with the curved end over the 1st turbulator snug against the basswood plate.

MS finished fins.jpg
Really pretty easy.
 
Ah, I wasn't paying close attention initially and didn't realize how this works. So the three maple seeds disconnect from the rocket and descend independently, while the airframe comes down by parachute?

That's a lot of pieces to track coming down. Also this means it is nothing like a larger version of the Oddl Cyclone, which was my first assumption.

The assembly looks pretty cool, another kit that is a testament to the wonders of laser cutting.
 
Talked to Randy this morning (my time), and he told me that updated instructions should be done by tomorrow.

I was also thinking that each of the fins should have your name and phone number written on them just in case one gets lost, then found.
 
Ah, I wasn't paying close attention initially and didn't realize how this works. So the three maple seeds disconnect from the rocket and descend independently, while the airframe comes down by parachute?

That's a lot of pieces to track coming down.


I have 3 kids and plan to paint each seed a different color and have each kid recover their favorite color.
 
I was also thinking that each of the fins should have your name and phone number written on them just in case one gets lost, then found.

That is a really good idea, thank you.
 
I have 3 kids and plan to paint each seed a different color and have each kid recover their favorite color.

What a great idea!

For tracking in the sky purposes, you may find it easier to distinguish them with different stripe patterns or something (since they'll be spinning). In any case, sounds like a super-fun launch activity for your family. :) I look forward to launch reports and/or video.
 
What a great idea!

For tracking in the sky purposes, you may find it easier to distinguish them with different stripe patterns or something (since they'll be spinning). In any case, sounds like a super-fun launch activity for your family. :) I look forward to launch reports and/or video.

I'd suggest a strip or two of Trim Monokote for them... I noticed that the strips that I had on my L1 build flashed nicely as the rocket came down spinning while under chute.
 
The next step is to glue in the motor mount, but I am skipping that step at the moment and moving on to balancing the seed fins.
MS CG Tool.jpg
Handy dandy guide to mark the center of gravity required.

MS CG Mark.jpg
Marked with permanent marker(I do actually want the mark to bleed through the paint)

MS Balanced.jpg
It is possible to follow the instructions and really get them to balance!

I did toss each of them a few times, and all of them were able to fall like a maple seed, but not every time. I figure mostly due to limitations on how high I could toss them.
I am not crazy about how easily the clay is able to detach from the fins, so I got some weights from Hobby Lobby for pinewood derby cars that you cut to size and have sticky tape. I will paint the fins and then re-balance them.
 
There has not been much progress on this, due to only needing to Paint, glue in the Motor Mount and shock cord, and Launch Lug. The launch lug placement has given me pause and made my mindsim kick into action. The instructions for step 30: Insert an unused D12-3. Take your balanced Maples Seeds and hang them on their hooks. Using a piece of cardstock or a ruler, balance your Maple Seed rocket and make a mark on the launch lug line at the balance point. Remove the seeds from the hooks. Mark the center of the launch lug with the mark you made on the launch lug line and glue it into place.
I imagine if I follow those instructions that the rocket will perform just fine. That being said, my mindsim says that is not best practice.

I have been lead to believe that the best place to put a launch lug is across the center of pressure. While the rocket is stationary on the pad, the cross wind is the strongest and most destabilizing force on the rocket and acts on the center of pressure. Once the motor ignites wind force goes from a sideways destabilizing force to a stabilizing force (which is acting on the center of pressure)in direct opposition to the thrust force(which pushes through the center of gravity).

With the fins on, anywhere on the airframe that I hold this rocket, it wants to turn into the wind. So I can safely say the the center of pressure is behind the airframe of the rocket. I therefore cannot put a launch lug across the center of pressure, but would it not be best to put it aft-ward as much as possible. Even if that means that it is behind the center of gravity.

Or would it be better to put it across the center of gravity because the center of pressure will be moved out from directly underneath the center of gravity no matter where the launch lug is placed causing an unstoppable twisting of the rocket on the rod. Therefore having the middle of the long launch lug at the center of gravity would mitigate the inevitable binding forces of the twist?

Am I thinking too much?
 
What about cutting the LL in two, putting one where recommended, and putting the second at the aft-most point on the BT just to put your mind at ease. :wink:
 
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