Estes Alpha Build Thread

[Woody's Workshop]

I have a couple 6" sticky back 220 grit sanding discs stuck to a piece of Melamine coated particle board for sanding. Take the body tube and twist it as you criss cross sand the body tube until it gets smooth. But DO NOT sand through the coating. (If you do sand through, sand after the first coat of glue to get rid of the knobs. Give that area(s) a thin coat of glue to seal it, then recoat the entire tube)

After sanding, I mark for fins and the launch lug. I use a different color for the launch lug so a mistake doesn't happen and you put a fin in the wrong place. (yeup, I've done that)

I have several sets of Estes Accessories so I use the fin marking guides to hold the BT while I coat it with TiteBond III. (I've tried all the TiteBond's, and the III sand's the easiest without gumming and clogging.)
I gave this tube one good heavy even coat and that was enough to sand smooth. Using the same criss cross while you twist sanding you get a nice round and even finish.

While the BT is drying up, I started on the Engine Mount. I followed the instructions and didn't test fit it. I thought since the Alpha has been around a long time, the instructions would be correct. However, to pull the engine hook back far enough to get the engine in and out, you stretch the BT. My choice was to slot the BT and glue the inside of the TB around the cut out. Since the Engine Mount had already been glued in place, I didn't have much choice. ALWAYS test fit!

Some sanding was necessary to make things fit proper. I added fillets on the sleeve and engine block before gluing the engine mount in place as well. When gluing the engine mount assembly in place, I applied an ample amount inside the BT and twisted it several times to make sure there was good coverage all around the centering sleeve. When it began to grab, I set the engine hook to line up with the launch lug line.

The kit DID NOT include a engine block. I chose to add one. It is too easy for the engine hook to slide up through the cut you make in the engine mount tube without one. (This has happened to me before, so I always add an engine block/thrust ring)

I use the tube marking gauge to make sure the engine hook goes in straight, and mark for the wide centering ring. (I'll be doing a scratch build using 2 centering rings with kevlar to correct the error with the way the engine hook stretches the BT, and to eliminate the folding rubber band shock cord mount.

 

[Woody's Workshop]

It was time to start on the fins. I lined them all up, used scrap pieces of balsa to protect the fins from the clamps. I like to set the clamps so I can sand at least 2 edges of the fins before I have to reposition the clamps. I then sanded all edges EXCEPT the root edge to 60 degrees.

When papering, I don't sand the "Fuzz" off the front and back sides of the fins. I take a piece of paper and make a fold in it so there is plenty of paper to cover both sides of the fin. The fold ALWAYS goes over the leading edge. Trim the paper around the fin leaving enough for play and additional trimming after gluing. Also, enough over the root edge if you plan on mounting the fins with tabs. (I did not use tabs on the fins on the Alpha, but I did on the Quest Courier, build thread coming soon)

Glue one side of the fin down to the paper by applying glue to the fin. You don't want puddles of glue, but you don't want dry spots either. I use several strokes to get good coverage and spread the glue evenly. Use a pencil or some smooth object to flatten the paper to the fin and on the taper of the leading edge.

Trim the other 2 fin edges so the paper will fold over to where the taper starts on the other side, and glue them down. Glue the second side down, press and smooth out the paper. Trim, glue and seal the 2 remaining edges to the opposite side where the taper begins. This gives you two paper layers over the area of the fin that takes the most beating on landings.

You can either leave extra paper over the root edge to protect it from excess glue, or trim it. I used old X-ACTO blades and stuck them in the root edge for something to hold on to and to clamp to. Apply 4 to 5 good coats of TiteBond III to the entire fin (except the root edge) letting it dry in between coats. I usually wait 48 to 72 hours (2 to 3 days) before I sand the fins.

 

[Woody's Workshop]

Starting the 2nd day of the Alpha build, the glue has had about 24 hours to dry. With on one good coat on it, it was dry enough to sand.
Using the criss cross and twisting it came out perfect.

There is a few things that needs to be discussed when sanding glue.
First of all, the grits. You can use 120 grit for initial smoothing, but you will want to go to 180 or 220 grit once 120 gets a smooth surface. I mostly use 180 and 220 grits.
Second, the amount of pressure you put on it is crucial. Too much pressure does several things.
It will heat the glue and it will become gummy and roll and peal up. It also dulls the sand paper faster, and it will gum up the grit.
Let the sandpaper do the cutting and don't try and go too fast and take too much off too quickly.
Sanding glue is a patient man's thing. (For you speed builders, you will get highly frustrated quickly)

And I moved onto the Quest Courier to start that build while the fins were taking a few days for the glue to dry up enough for sanding.

 

[Woody's Workshop]

It's time to sand the fins. Using the flat Melamine surface with the 2 - 6" sticky back 220 grit disc and a sanding block out of the same Melamine surface, I use a circular motion in clock wise and counter clock wise directions on one side of the fins. Remember the importance of light pressure and not to go too fast. If you feel that the glue is "Rolling Up" between the sandpaper and fin, STOP right away. Continuing to sand may dent the balsa. (Especially if the cause of the "Roll Up" is Too Much Pressure!)
There are 3 main reasons you will get "Roll Up" often. 1) Too much pressure 2) Sanding too fast 3) The glue isn't set up enough.
When you get both sides sanded smooth, you can move onto sanding the taper on the edges.

Once the fins are all sanded, it's time to set up the fin jig and test fit them.
I always apply an ample amount of glue to the fin so it can slide around without sticking in the wrong spot right away. I use a small damp paint brush to smooth out the ooze on both sides of the fin in kind of a mini fillet. This helps stabilize the fins when you get to putting fins in between 2 boards (or laying on 2 fins if there is 4 or more) when adding the fillets.

 

[Woody's Workshop]

I typically do fillets in 3 applications (ones that don't use paper tabs as this one does. More on that in the Quest Courier Build Thread, coming soon)
I use a paint brush and just form a bead at the junction of fin and BT. No paddling the glue yet.

Let it dry until the color changes all the way through. Typically, this takes anywhere between 6 and 12 hours depending upon the how much you put on at first.
I use a paint brush and and add another bead (without sanding) as the first bead has shrunk up quite a bit at the deepest part.

On the third coat it's usually the thinnest and most important for feathering into the BT and fin...and at the leading and trailing points where you could end up wasting a lot of time sanding, removing too much excess glue to get a good looking transition from fin to BT.
Lay down a bead of glue, and paddle it out so it feathers up the BT and fin. I use wooden paddle spoon that comes with ice cream cups.

I use the sanding board on them first to get rid of burs, and it helps to dip it in water before spreading glue.
This helps from too much glue sticking to the paddle, and it helps from pulling and moving glue around too much.
Then, repeat for the other 2 sides.

In the photo's you can see I use either 2x4's or 1x4's, or some other sizes with rubber bands around them to lightly pinch on one fin to hold the rocket level to add fillets.

I prep for the launch lug at this time while fillets are drying up. And when I get to the last side, which I make it a point of being where the launch lug goes, I also install the launch lug. Typically, I never glue a launch lug right onto the BT. When you add primer, paint and decals...Many times the launch rod will ride on the BT and "Hang Up" a little, depleting the performance of the rocket flight. It can also ruin the paint job and/or decals.
I use standard 120lb card stock.
(I have a whole bunch of the stuff I brought home from work about 12 years ago when they were going to throw it out after they got rid of their dot matrix printers)
I make a fold of about a 3/16 to 1/4 inch, glue it and clamp it for couple hours.
I then cut it to the width of the launch lug and taper the ends.
I glue the card stock riser on first, and then the launch lug.

 

[Woody's Workshop]

I do the fillets on the launch lug the same way I do the fillets on the fins.
I have all sorts of different pieces of wood, in all kinds of sizes and shapes from my scraps when I had my wood shop.
Those 3M gold stick-it sanding discs and 3-1/4" wide rolls really come in handy. (I'm glad I had some in my tool box when I quit doing auto body repair, but it's almost all gone)

Sanding fillets is really hard to explain, but in the simplest form...
You sand away from the fillet. Meaning from after where it starts on the BT, and sand across the fillet and onto the fin... In a criss cross patter, evenly sanding. And then reverse...from the fin side, to the BT side. (and the same with a launch lug)

Try NOT to send into the edge of fillet. You will have a greater chance to pull up the glue from the dryer glue on the BT or fin.
(By brushing on some water a few minutes before you add fillets to the fin (launch lug) and BT it will aid in softening up the older glue to let the fresher glue bite in better.)

I find that between 8 to 12 strokes in one direction, then go the opposite direction (in the criss cross pattern) is the fastest way to remover excess material. When the scratches disappear from the previous direction, it's faster to change direction and go across the scratches until they disappear, then switch again.
Remember, let the sand paper do the work. Use light pressure, and don't go too fast. If glue is "Rolling Up", then you are using too much pressure, going too fast or the glue hasn't set up enough.

In some cases, you may have not used enough glue. You can add more, but I have found out by trial and error that adding glue at this point is NOT the best method.
Using Tamiya White Putty dries faster and sands easier without pulling off the previous layer like glue likes to do.
You can use a paint brush and add water to the glue that has dried for quite awhile to soften it up to get a better bite, but the chances of glue pulling off is still high.

Once the nose cone is sanded, using the criss cross twisting method (and adding Tamiya White Putty, if needed) sanding is done. And the fillets are all sanded...
You are ready for primer.
(This build thread is dealing with a plastic nose cone. I will do a balsa nose cone and/or transition using glue in the near future. The Javelin and Super Flea will have balsa nose cones.)

Right now, I don't have any primer. So this build thread has gone as far as it can until I can afford to get some primer.
I'll be starting a scratch build of this same rocket using a different method to mount the Engine Mount and Shock Cord Mount while I wait...Along with getting the Quest Courier to this point so I can do that build thread. (And I'll be working on the Scrappy-55 build, and the pair of Mini's...Javelin and Super Flea as I took bottles back and had enough to order the 2 nose cones I needed.)

After Priming, wet sanding, painting and decal application...I'll coat the inside of the BT with glue when I install the shock cord mount and install snap swivels and parachute.

 

[Woody's Workshop]

I did a drawing last night, but I was tired and did it wrong...so I deleted it.
I did put the EM together last night, cut the fins & Kevlar and found the correct nose cone.
I cut 4 fins because I used scrap from my 3/32" box. Left over pieces from another build.
Back when I was trying to find the best way to use glue I would thin it 50/50 with water for the first coat to get it to soak in. These scrap pieces were from that era.

So I cut 4 as the balsa is somewhat warped. I paper and glue up all 4, weigh them all and use the 3 closest to matching weight.
As soon as I take the dog out, I'll be working on the RocSim to see how stable it is.

HINT: When papering and using glue, up the thickness of balsa by .0625 (1/16") to counter the added weight of the paper and glue. It isn't exact and nothing will be unless you weigh it and input the weight. But it's close enough to get a more accurate simulation and stability factor.

EDIT: With a C6-7 it has a margin of 1.36 stability using the added HINT above, 36" of 1/4" flat elastic for the kevlar, elastic and snap swivels and an Estes 12" plastic parachute with the launch lug the same as it is on the kit.
Looks like nothing needs to change, and the sim put it over 1000'.

 

[JStarStar]

Thumbs up on your decision to add an engine block/thrust ring to the motor mount assembly.

I have found that motor mounts using only the motor hook to secure the motor in place tend to start ripping loose after a handful of flights.

The motor-hook-only design transfers the entire thrust of the motor to the airframe through a tiny little piece of metal cutting through the paper motor tube. Use of an engine block prevents this problem.

So whenever I build a rocket with a motor hook, I put in an engine block as well.

 

[Woody's Workshop]

I've got the BT sanded down, coated with TiteBond III and sanded down.
Added the engine mount last night and will be putting on the papered & tabbed fins on today.
Back and Hips are giving me much grief today, so I probably won't get a whole lot done.
I go the 29th for another back procedure, so I'll be doing some suffering until then.
I'll be slowed down a bit on activities until then due to back and hip pain.
Can't sit on that hard stool or stand too long at any one time.
I'll add pics as soon as I get to town and pic up more batteries for the camera.