Estes Mega Mosquito Build Thread

This will be my second Mega Mosquito that I've built. The first one ended up in the top of a tall rocket eating tree. When I got the second kit I remembered a few things that made this one particularly fun for me to build so I thought I'd take pictures and make a thread.



A couple of the things that make this one a little different for me than the other LPR kits I've built are the through the wall fins and the multiple layered fins that need to be glued up before preparing. I've also decided to paper these fins instead of filling the grain, due to the multiple layers.

I LOVED flying the first one of these that I had, so I'm very excited about having another one in my collection.

The multiple layer fins are huge. Each one has a middle section which has the thru the wall tab as well as some cut outs (I'm sure to save weight) and two outer layers, so the kit comes with NINE sheets of balsa.



There is a pre-slotted body tube and a big honkin nose cone, as well as the usual parts for making a motor mount, a launch lug, decal sheet, instructions etc. Estes also included the parts required for the original smaller Mosquito.

The first step is to build the motor mount. The through the wall fins will glue to this tube so I sanded off the glassine in order to give the glue a better grip (I'm not 100% sure if that is true, but I've read it a lot on here so there must be something to it). I also sanded the inner and outer edges of the centering rings to remove the little burrs left behind from the laser cutting. I needed them smooth so they'd slide easy in the body tube and on the motor tube.



One of the centering rings had a notch cut out so that the motor clip could be pulled away from the motor tube, but the other ring did not. This ring is supposed to slide over the clip too, but without a notch it would bend the ring, deform the tube, and generally not be that big of a deal. But I cut a little notch in it anyway. I also cut a notch on the underside of the motor block ring so the motor clip can recess. This way the top of the motor will touch the ring instead of only touching the clip.



Here is a picture of the motor block ring glued in place over the clip.



Next I'll add a ring of glue around the inside of the BT on top of the ring to add a little more strength.

I love the Mega-Mo,really need to fix mine. have you thought about making it a cluster?

The tabs on the fins that go thru the wall have a little step in them which is intended to make room for the big ring that goes around the motor tube. Clip retainer ring? Not sure what it's called.



Here's a picture of the fin held up to the motor tube.



The centering ring on the upper end of the tube is positioned using a fin in place all around the tube. Once I got it level and it seemed to be in place no matter where I put the fin, I put glue around the top and later the bottom of the CR at the tube.



The instructions call for the lower ring to be glued onto the motor tube now, using the fin to position it too. I've read on here about leaving the lower ring off until you can add glue to the inside where the fins touch the tube, so I'll do that this build. The last time I built one of these I glued both CRs in place and then later slid the fin in place with glue all over the edge of the tab as instructed. It flew fine and I'm pretty sure the fins were strong enough so I'd say doing it this way probably isn't necessary. But it isn't hurting anything either.

chadrog said:

I love the Mega-Mo,really need to fix mine. have you thought about making it a cluster?

Click to expand...

No, I'm sticking with the single engine on this one. I haven't ventured into multiple engine rockets yet.

I put some glue on the inside of the BT using a long piece of balsa I cut off the edge of the fin scrap and then slid the motor mount in place.



To make sure the motor tube was going to be at the correct angle I used the bottom CR on the motor tube, even though it wasn't glued. It could be removed after the glue on the upper ring had dried.



I put a lot of glue on the top and bottom of the upper CR, but since I didn't want the BT to pucker in as the glue dried, I used the long piece of balsa to remove most of it. It left a bit of a fillet in the corners and when it dried the BT was fine.



Here is the motor tube after the glue dried. It's in place, centered properly, and I now have access to the inside where the fin tabs will go.

As a side note, the little cutouts from the inner fins will make some nice fins for a couple of small scratch builds.

Before putting the fins on I wanted to fill the spirals, because it's a lot easier to do without the fins on. This tube actually had two spirals that needed to be dealt with. One was fairly deep and needed to be filled, the other was fairly shallow and I decided just to use primer.

The first step was to use my hobby knife to pat in a watered down mix of Carpenter's Wood Fill all the way around.



I sanded that down smooth so it was ready for primer.



Then I took the tube into my unfinished basement and shot primer directly down both spirals from just a few inches away. This really built up a lot of primer on the spirals and filled in the shallow spiral all the way. I've done this before on deeper spirals and it pretty much filled in those too. I think doing it twice, sanding in between the two, would probably fill most spirals without using CWF.



After the primer dried I sanded it smooth.



And then covered the entire tube with primer.



This will get sanded and primered at least one more time after the fins are put on, and by that time I'm sure it will be super smooth and look great painted.

H_Rocket said:

As a side note, the little cutouts from the inner fins will make some nice fins for a couple of small scratch builds.

Click to expand...

I remembered reading that before, and also read that only one of the three cut outs could really be used because of the direction of the grain.

So I looked at them and I think all 3 could be used if you turned them the right way. Every cut out had at least one side that was parallel to the grain.

But not really being a scratch builder I set my cut outs onto the trash pile and they were thrown out. I had enough scrap pieces of balsa from other builds so I didn't really want to keep them for repairs or scrap or whatever.

Thanks for pointing that out, I had planned on mentioning it when I got to the step where I removed those from the rest of the fins but might have forgotten. I never mind when people speak up and reply to my threads with anything... it shows me that at least one other person is reading them.

Here are the 6 fins for the outer layers of the 3 fins. They're laser cut and easy to remove using a hobby knife.



Usually when I remove a fin I go ahead and sand the edges to remove any burrs or burn marks, but in this case I know I'll be doing a lot of sanding after I glue them together, so I didn't sand yet. I just stacked them up and moved on to the inner fin layer.



These 3 fins have the cut outs to remove weight, and the thru the wall tab. Each of these get sandwiched in between two of the fins above.

Before gluing the fin sandwiches together I wanted to test fit them to see if they fit the same way as the first kit I built. I lined up the root edges as they would be when attached to the BT.



Then I looked at the other end.



You can see that these fins are not at all the same and will need some attention after they're glued together. At first I was very surprised when I saw this, thinking that with the laser cutting process they surely would be able to get them to fit correctly, but I'm wondering if they're this far off on purpose to force you to sand them down which makes for a better final product?

To glue them together I started with the middle section and put plenty of glue all over the surface, being careful not to glue the thru the wall tab.



Then I placed an outer section on top, lining up the root edges and letting the rest of the fin line up wherever it ended up. The important part is to make sure the root edges stay lined up as the glue sets up. I turned it over and did the same on the other side, and then put it under a stack of books while I did the next one.



My wife doesn't mind that I build on the kitchen table and pretty much keep half of it covered up all the time. I'm very lucky that way. She also has this stack of rather heavy cookbooks near the table that I have used on a lot of builds. These have turned out to be a really good tool for this. Cookbooks are covered with an almost wax like finish so they can be wiped off easily, and it keeps glue from sticking to them too.

In the picture above I have one fin sandwich on the table, a book on top of it, the other two fins on that, and the rest of the stack of books on that. This was plenty of weight, and after drying overnight the fins were inspected. They were all flat, the glue was dry and holding tight, and the edges of the fins were wildly out of alignment.

After the fins dried the root edges were still aligned properly. Here are all 3 fins held together with the tabs aligned and the root edges lined up.



But the other end, as well as the leading and trailing edge, were very rough looking. I needed to sand these down so they'd be smooth.

In my garage I have a workbench where I grabbed four clamps and a palm sander to improve these fins. I lined up the tabs the best I could, which left the root edges mostly lined up too, and then put the clamps all around. These held the fins so they wouldn't slide and would keep them all aligned.



I started on the leading edge. In the picture above you can see where I moved the clamps to expose it for sanding. In this picture you can see what it looks like after a few minutes of sanding.



After a few more minutes the leading edges are all sanded, flush, aligned, and looking good.



After a few minutes on the rounded end you can see how the middle layers of the fins are smaller than the outer layers. The burned edges of the middle layers aren't touched yet but the outer layers have been sanded.



After about 15 minutes total the fins are all smooth and they look great.



Using a palm sander for this makes it easy to do. It doesn't take away material too fast so as long as you keep the sander moving there's not much danger of making a mistake. If I had a belt or drum sander fixed in place I would have used that instead, but the palm sander was easy enough.

The fins weren't completely finished with sanding yet. They didn't fit in the slots. But instead of sanding the tabs thinner I used an Emery board to sand the slots wider.



I also used it to sand the root edge of the fins at the tabs to get the best fit. I numbered the fins and on the inside of the BT numbered the slots.

Here I am test fitting a fin to the rocket. You can see how I'll have access to add glue to the tab wherever it touches the motor tube and the inside of the BT.



Before gluing the fins in place I want to paper them.

Looking good, 'shtang. I'll be watching to see what tweaks/techniques you implement before going whole hog on mine.
I used the mini-mosquito that came with it in my Quato project.

Before I can paper the fins I realized I still needed to round over the fins. I'd left them square without thinking about it when I sanded them to the same size.

Here they are before rounding them over.


And after.



I only rounded up to within less than an inch of the root edge. This isn't for any reason other than for looks. I think it would look better to have the squared edge right on the body tube and the rest of the fin rounded. That is, if the papering of the fin turns out well with that shape. We'll see.

I don't have much experience papering fins. I've only done it once, on the previous Mega Mosquito, and I've already forgotten what worked and what didn't. I went back and read a lot of threads on here about how to do it and there are several ways that seem to work differently for different people. So I decided to do a few tests.

Test A - Wipe the glue onto the paper first and then put the fin onto the paper. I tried a few ways of spreading the glue and they all turned out the same. Bad. Here's one way I tried. I put glue on the edge of a plastic card and then wiped it along a piece of paper to quickly spread the glue.



I spread it quickly and tried to get it as even as I could, while also trying to get very little glue on the paper.



I tried it several times and whenever I'd get the glue on it almost immediately would wrinkle the paper.



If I put a fin on this paper it would look horrible.

Wiping the glue on the paper doesn't seem to work for me. Maybe I'm doing it wrong.

The next thing I tried was to wipe glue directly onto some balsa and then apply the paper. I used the card again to squeegee the glue lightly and evenly.



Then I put the paper onto the balsa and burnished it down.



After a few minutes... wrinkles.



This way wasn't looking too well either. Maybe I'm doing it wrong.

Only successes I've ever had with papering fins were when I used full-sheet label paper (self-adhesive) on both sides.

Aside from the ease of application, since the adhesive doesn't seem to be water-based, I've never had a problem with warped balsa, unlike some of my earlier attempts using white glue.

G.D.

The third test was to just spread the glue with my finger. When I was using the card I remembered that this was probably how I did it before. So I just put some glue on the balsa, and may have put on too much this test.



Then I spread it all over the balsa with my finger, getting it as thin as possible.



I placed some paper onto the balsa and used a sharpie to rub the paper onto the balsa all over. I wanted to make sure I avoided bubbles and got good contact all over.



This seemed to work the best. After I was done the paper was very smooth with very few wrinkles or bubbles.



And after about 20 minutes when the glue was totally dried the paper was very smooth.

Success! This is the way I'll paper the fins.

gdiscenza said:

Only successes I've ever had with papering fins were when I used full-sheet label paper (self-adhesive) on both sides.

Aside from the ease of application, since the adhesive doesn't seem to be water-based, I've never had a problem with warped balsa, unlike some of my earlier attempts using white glue.

G.D.

Click to expand...

I'd like to try using self adhesive paper someday too. I can definitely see how it would have some advantages over using glue!! My only concern would be that the adhesive paper wouldn't bond as well as glue would, and eventually would come loose and fall off. I think I remember someone posting on here that one of their rockets got really hot in the summer sun and the adhesive paper came off. Have you had any issues with the paper coming loose?

I have not had any problems with the paper coming loose, though 1/6 of the rockets I've papered was rapidly returned to pieces parts due to serious cluster failure. The fins survived, the airframe did not. My own fault for not using Q2G2 igniters instead of Estes.....

Anyway, the others have had their flights, and they sit on their pegs waiting to be brought to future launches, without any signs of adhesive failure.

G.D.

My Big Bertha (The Beat Stick!) Has almost 20 flights and the label paper has proved to be quite durable. I label paper most of my rocket's fins and I have had no problems.

I don't remember papering the fins being a problem like this. Maybe next time I'll switch to the sticker paper instead.

To paper my fins I first took a piece of paper and rolled it over the rounded front of the fin and worked with it to make sure it was pre-rounded. This was to try and avoid creasing the paper after the glue was already holding one side.



Then I applied the glue to one side of the balsa, wiped most of it off with my finger so very little glue remained. I pressed it to the paper and then used a sharpie to burnish the paper down, remove the bubbles, and get the paper rounded over the edges a bit. Then I put glue on the other side of the fin and repeated the steps until I had a paper and balsa taco.



I let it dry overnight and this morning I checked and there are quite a few small bumps all over the fin. I may have had this last time, I don't remember.



They're not all that large, and I'm sure a couple of coats of primer with sanding after each will give me a very smooth surface to work with.

But next time, I'm definitely trying sticker paper instead of glue.

I've used a covering iron to get small wrinkles out of paper. A regular iron on a non steam setting should work. The heat reactivates the glue and the preassure can get the wrinkle out. Your mileage may vary

Mushtang said:

I don't remember papering the fins being a problem like this. Maybe next time I'll switch to the sticker paper instead.

To paper my fins I first took a piece of paper and rolled it over the rounded front of the fin and worked with it to make sure it was pre-rounded. This was to try and avoid creasing the paper after the glue was already holding one side.

View attachment 115699

Then I applied the glue to one side of the balsa, wiped most of it off with my finger so very little glue remained. I pressed it to the paper and then used a sharpie to burnish the paper down, remove the bubbles, and get the paper rounded over the edges a bit. Then I put glue on the other side of the fin and repeated the steps until I had a paper and balsa taco.

View attachment 115700

I let it dry overnight and this morning I checked and there are quite a few small bumps all over the fin. I may have had this last time, I don't remember.

View attachment 115701

They're not all that large, and I'm sure a couple of coats of primer with sanding after each will give me a very smooth surface to work with.

But next time, I'm definitely trying sticker paper instead of glue.

Click to expand...

I put a fresh blade in the knife and cut the paper close to the edge of the fin along the root edge, leading edge, and rounded end. I left the paper that was wrapped around the leading edge.



The edges of the paper on the rounded end and trailing edge were not completely glued down. I guess the glue didn't get spread that far? Whatever the reason I felt like I wanted to make sure there was no place along the edge that the paper wasn't attached because it could look bad after being primed and painted. So I put a line of glue along the paper edge and let it soak for a minute, and then wiped 99% of it off with my finger.



A half hour later the edges of the paper were completely tacked down. Even a few places that looked like paper was sticking up felt smooth.



I'm pretty sure after a couple coats of primer and paint these fins will look good.

I like to feather the edge of the paper into the wood. rub a little glue into the feathered area, a little sanding and good to go.

To get the fins glued into place I used the double glue method. But first I needed to sand off the primer around the slots, so I would get glue to cardboard.



After that I applied glue to the root edge and tab edge of a fin, put it in place, removed it, and did the same for the other fins. After they nearly dried I put on more glue and pushed the fins in place. Using this method lets the fin stick in place quickly.



Here is a fin tab pressing glue onto the motor tube.



When replaced again later, the fin stays in place easily. I added a fillet to the outside of the BT at the fin, and then put another fin in place.



After all 3 fins were in place I let all the glue dry, and then added another fillet to the outside.