The Launch Pad FLAIL - 2015 Build Thread

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morlock

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I received my TLP FLAIL kit late last fall and haven't done much with it... until I recently started dreaming of rockets again. Apparently, winter and snow will go away in ~2 months here, so I better be prepared to let fly some birds before the fields are sown.

Here is the original page for the FLAIL kit: https://www.the-launch-pad.com/#!blank/c1j13 and the kit image:

35d516_551b7acbda7d1ffa488d214132c9af2a.jpg_srz_p_960_330_75_22_0.50_1.20_0.00_jpg_srz


The body tube in my kit is smaller in diameter at one of the ends, so I will order new tubing for this build. While I am waiting for my new tube, I have started work on some other parts.

I have built the motor mount (I used a 95 mm long mount so I can use E motors) and the tail cone section:

01.jpg

I cut and folded the nosecone. I will need to glue it in place and paint it with thin CA.

02.jpg

I have cut, scored and folded the forward fins. I also cut the thin strips of wood that serve as the bases for these fins.

03.jpg

Next, I will assemble the forward fins and paint them, as well as the nosecone tip and tailcone, with thin CA.
 
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It's OK to not lengthen the BT and add a little Nose Weight.
I guess so, but I simmed the FLAIL in Open Rocket I am looking to around 80 grams of nose weight if I do not lengthen. Otherwise, it goes down to 60 grams. so I do have to add weight anyway and may as well leave the length unchanged as you say.

I am using a 100mm long motor mount to accomodate longer, thus heavier, motors. This is probably why I have to add that much weight.

Have you had cases where you needed that much nose weight?

Here is the .ork file:

View attachment tlp_flail.ork
 
I built my TLP Martel AS37 with a few modifications. It flies straight as a laser. I just weighed the Nose Cone and it comes in at 3.9oz.
I use that model as reference because it is one that I also see people lengthening the BT on.
If you want to be able to fly on BP motors than yeah, you probably want to keep the Nose Weight down. I built the Martel with the Idea that it would fly on E15 and above.
 
I am looking to fly it on D21, E15, and E30. The other D and E motors I can easily have access to seem underpowered, but some may work in low wind situations.

I wish there were more high thrust short burn time motors.
 
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Are you planning on flying it from a rod or a rail?
I guess that factors into it a little bit as well. My TLP Kits are all set up for my rail, so that I can be sure my velocity when they leave the launcher is high enough that they fly straight.
If you are interested in E20-4 motors, keep your eyes open on Amazon.com. I got some there for $13.13 for 2 with free shipping.
 
I don't plan switching to a rail until 2016. I'll have a house and a car by then, meaning more space and better transportation, which is not the case now. I will launch these from a 120 cm long 1/4 in rod. The rockets have approximately 85 cm of rod to accelerate. I am aiming at 13 m/s or more when they exit the rod.

I'm pretty sure all these SI units don't mean much to some of you, just as inches and feet per second are less meaningful to me :p
 
Those find look nasty to make - I will be wishing you well with this one and watching to see how it goes.
 
The forward fins are indeed more scary to do, but luckily I did some paper modeling during the Holidays, which helped me get a better grip of how to score the paper properly. Once you can score an fold well, the rest is much easier.

Here are the fins and glue ready to start the assembly:

05_four_fins_prior_to_gluing.jpg 04_getting_ready_to_glue_forward_fins.jpg

I used carpenter glue and the double gluing method, as shown below. Put a very small ribbon of glue on both parts, flatten it with a damp finger, let it dry for a minute ad then fold and glue. You do not want to flatten the fin to join the parts but rather run a finger nail along the edge so the two parts are joined but the join has an angle.

06_double_glue_on_forward_fins.jpg07_one_glued_forward_fin.jpg

I also added some yellow glue inside the tip of the nosecone extension to make it more sturdy. I added small (~1mm cubes) of Popsicle wood in the glue so it will not reduce too much. It is only the very tip that needs that treatment since around 70% of the length of the extension will be glued directly to the nosecone. I'm pretty pleased with the result so far.

08_reinforcing_nosecone_extension_tip.jpg

Next steps:

- Gluing the wood base of the forward fins with CA.
- Gluing the extension to the nosecone.
- Paining the forward fins and nosecone extension with thin CA.
- Cutting the rear fins from balsa and papering them.
- Placing my order to get the BT-80 tube for that project since the one included in the kit was damaged (smaller diameter at one of the two ends).
 
Looking good!

I painted finishing epoxy on all the interior surfaces of the foreword fins, this really toughened them up.

The exterior surfaces were soaked with thin CA and sanded smooth.

Sand paper was wrapped around the BT-80 and the curve of the body tube was sanded into the balsa. This will aid in getting a strong glue joint and keeping the fins where they belong after bouncing of the ground during a landing.
 
Looking good!

I painted finishing epoxy on all the interior surfaces of the foreword fins, this really toughened them up.

The exterior surfaces were soaked with thin CA and sanded smooth.

Sand paper was wrapped around the BT-80 and the curve of the body tube was sanded into the balsa. This will aid in getting a strong glue joint and keeping the fins where they belong after bouncing of the ground during a landing.
Thanks for the encouragement and tips. I wanted to paint the interiors of the fins too with some thin CA, at least put some along the interior edges. I also wanted to sand the balsa at the bottom of the fins to fit the tube, but I didn't think of putting the sanding paper directly on the BT-80 tube for a perfect fit. I'll do that!

How did you glue the thin balsa pieced into the base of the fins? The fit is pretty tight and maybe I should have put them in place at the same time I glued the fins themselves... I think I will use thin CA cause with carpenter glue I really fear it will bond before they are set in place properly. Maybe thin Epoxy would be best, but I work indoors in a not so well ventilated apartment with a baby, so I'll have to wait for summer (~2-3 months away) to really use Epoxy.
 
Thanks for the encouragement and tips. I wanted to paint the interiors of the fins too with some thin CA, at least put some along the interior edges. I also wanted to sand the balsa at the bottom of the fins to fit the tube, but I didn't think of putting the sanding paper directly on the BT-80 tube for a perfect fit. I'll do that!

How did you glue the thin balsa pieced into the base of the fins? The fit is pretty tight and maybe I should have put them in place at the same time I glued the fins themselves... I think I will use thin CA cause with carpenter glue I really fear it will bond before they are set in place properly. Maybe thin Epoxy would be best, but I work indoors in a not so well ventilated apartment with a baby, so I'll have to wait for summer (~2-3 months away) to really use Epoxy.

I used JB weld epoxy. It has great strength (holding power) and is workable for 1 hour + before it starts to get stiff.

I have found it has very little smell. In fact you have to put it right under you nose to smell it.

I use a tooth pick to apply it where I want it and a q-tip dampened with rubbing alcohol will clean off any slop before the JB Weld sets up permanently.
 
I used JB weld epoxy. It has great strength (holding power) and is workable for 1 hour + before it starts to get stiff.

I have found it has very little smell. In fact you have to put it right under you nose to smell it.

I use a tooth pick to apply it where I want it and a q-tip dampened with rubbing alcohol will clean off any slop before the JB Weld sets up permanently.
There seem to be a great many different epoxy products from JB Weld. Can you remember which specific one you used?
 
There seem to be a great many different epoxy products from JB Weld. Can you remember which specific one you used?

I purchased this at Lowes (a large home improvement store) but any other large home improvement store or Wal Mart will carry it.

Some rocketry vendors carry it or do a web search for it.

IMG_1515.jpg
 
I tried using Gorilla 5 minute epoxy to fillet the fins of a square rocket. I ended up with two very nice fillets and a bad headache... Since I live in an apartment with our 10 months old baby and cannot ventilate the place properly since it is freezing outside, I will try to leave epoxy and even CA out of the building process as much as possible.

This is why I tried another avenue for strengthening the nosecone extension. I doubled it with another layer of cardboard and some carpenter glue to join them. I expect the result to be pretty sturdy. If I account for the fact that I also hardened the tip from the inside by applying carpenter glue, and that most of the extension will be directly in contact with the nosecone (for which I will use CA), I have no fear about the strength of the result. I will also 'paint' the extension with some yellow glue.

I will think of a way of doing a similar job on the forward fins. That is, not to paint them with CA but maybe double them and paint them with yellow glue too. A few more grams won't be a problem anyways.
 
The nosecone extension dried surprisingly rigid with two layers of cardboard and yellow glue in between. I glued it to the nosecone with thin CA.

09_nosecone_extension_glued.jpg

Onto the forward fins now!
 
I started reinforcing the forward fins from inside with small balsa triangles glued with CA but run out of glue... I'll get some tomorrow to finish that part.

In the mean time, I cut the 24 cardboard triangles that I will use to reinforce these forward fins from the outside by gluing them with yellow glue.

I also cut and papered the rear fins:

10_cut_out_rear_fins.jpg11_papered_rear_fins.jpg

I used normal printer paper with stick glue. This technique is much faster than using yellow glue and the risk of having the fins bend is much reduced. I think the added rigidity is probably nearly as good as with yellow glue.
 
Here is a transparency shot of the reinforced forward fins.

14_forward_fin_transparency.jpg

They are still missing their second skin. I am waiting for the internal glue to dry and I will apply the 24 triangles and yellow glue to hopefully make the fins much stronger.

I then worked on the external cabling tubes. Basically sanded them and rounded the extremities as per the instructions:

12_cable_tubes_cut.jpg 13_cable_tubes_rounded.jpg
 
All right. Back to building the FLAIL.

I ditched the cardboard forward fins and replaced them with plywood versions I made out of ceiling fans :)

34a6c1aa66fd1b919eabddcd78b11012.jpg


0063a5d793f58db1d8b219d130919ea4.jpg


And I started gluing them:

38ede073ed6ea84902bd91711123b2b5.jpg
 
Here is the latest update. Epoxy fillets done. Launch guides glued. 50 grams added to nosecone.
8fb4f9f52ece125baaaf9551294c3be2.jpg
 
I just glued the two cable tunnels on the thing.

I'm hoping to finish it this week, put on a primer coat and launch the weekend after that!
d794dc5ead00d85cc8c660fb4ce0618e.jpg
 
All right. Back to building the FLAIL.

I ditched the cardboard forward fins and replaced them with plywood versions I made out of ceiling fans :)

34a6c1aa66fd1b919eabddcd78b11012.jpg


0063a5d793f58db1d8b219d130919ea4.jpg


And I started gluing them:

38ede073ed6ea84902bd91711123b2b5.jpg



Awesome.

You can get the shapes right enough, then just fill with some Bondo or JB Weld and fine tune them by sanding to perfection.

I ditched the paper fins on my TLP Gabriel kit too in favor of my own method.
 
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