Homemade Logo Rocket

[bradycros]

[QUOTE=sodmeister;96893]Geeze.....I missed this info.I was wondering how you made the NC pointy without the hat ,but did not want to ask for fear of hijacking this thread and going into another direction.
I`ll check the LOGO thread.

Very good build article you have going there.I don`t know how I missed it ,but sure am glad I found it !! You have some very good ideas and many of them pertain to Launch pad kits (one of my favorites)

And yet another use for JB weld....BRAVO !

Paul

Thanks, I enjoy building TLP kits to.

[bradycros]

The nose cones from TLP that I have worked have not been what I would call round. The seams from the molding process are flat. Hold the nose cone with the finger tips of one hand, about mid-cone and spin the nose cone with the other hand. You'll feel those flat spots. That doesn't work for me, I'm going to mess with it until I get round, or at least rounder (see post #65).

[dave carver]

Permatex makes a clay epoxy putty that might work better for this. The two parts for the epoxy are rolled together, you cut off what you need and knead it together until it's a solid color, a bluish white in this case, and form to your hearts content. It's set up hard after 45 minutes.

[bradycros]

I wasn't aware of that. That's a good thing to know. Thanks for sharing.

[bradycros]

I use these (Spatula Set, 4pc's) to help lay down the filler (Elmer's Carpenter's Wood Filler) into the seams of the nose cone and start forming the basic shape I want.

If you haven't already, sand the nose cone before using filler, this gives the filler (and later on, paint) a surface to grab on to. Any mold release left from the original molding process must be removed.

If you've ever glued nose weight into a nose cone, only to have it come loose later, (I'm going to assume you didn't use wood glue) it's because the mold release wasn't removed or wasn't removed good enough. Same thing will happen to materials apply'd to the outside of the nose cone.

To see the spatula set, (their the same size as dental tools) go to www.hobbylinc.com , select the hand tools box, then enter product number squ10705 into the search box. Their not a "gotta have" tool, but they do make them selfs handi.

It looks like there's a large amount of filler on the nose cone. There really isn't. It's only built up a very small amount, but feathered way out to cover the flat spots. Yeah, that much. Look at pictures two and three, read the numbers on the scales display. After being sanded to the desired shape, the filler has added 2 grams of weight, TWO GRAMS. That's BOTH sides.

Having a variety of sanding blocks at your disposal is a real plus. Use smaller "body tube" sanding blocks (see page 2, post #51 for a "how to") as your working up to the tip of the nose cone. Enlarge picture four to see the contents better.

You'd think by slathering a healthy layer of the filler on and then sanding it down to the wanted shape would work just fine. I use to think so too. Now I know we both would be wrong. Ask me how I know that.

It's much better to cover the area with a small amount of filler at a time. Sand that down, see where more is needed, apply... sand that down... see where more is needed, apply... sand that down... I thinking you can see the pattern developing here. Keep going until you achive the shape you want. A hand held blow dryer will decrease filler drying time enormously.

I soaked thin CA into the wood filler (I recommend you do this outside, whew..ee). This was done by dipping a Q-tip into the bottle of CA and using it like a paint brush. You could use a real paint brush, but you won't get very far before the bristles become rock like. Ask me how I know that. The Q-tip method works much better.

Why am I performing what seems to be a completly unnessasary task?

Because the wood filler has no strength of its own. If it were to be twisted, pushed or pulled it would fracture. Fractures cause crumbling, and crumbling leads to dust. The coat of CA soaked into the wood filler lends it strength and stops all that. The nose cone filler will not soak up a bunch of primer on its first application.

These reasons pretty much much push the coat of CA task into the nessasary zone for me. It works for me, if it doesn't work for you, skip it.

Lightly sand the CA coated filler smooth, 320 grit sand paper will work fine.

Remember that your at the start of the finishing process right now. Any flaw you can see now, your really going to see after primer is spray'd on. Repair all blemishes between coats of paint as you find them. Do this between every coat of paint and the final paint will be killer. If your thinking the paint will cover all them little flaws, you would be mistaken. It will magnifiy them. Paint, repair and sand...repeat...paint, repair and sand... repeat....

All this sounds like alot when your reading it (even more so when your writting it). But when your actully doing it, it's not alot.

[hcmbanjo]

This has been one of the best "new tips" threads I've seen in a long time.
Who says you can't teach an old dog new tricks.

The JB Weld is certainly a cheaper option than the Fix-It Epoxy. I'm also going to try the curved body tube sanding tool.

If it's not too much - could you explain how you did the fillets on the Executioner? I usually build rockets up to 2 feet in length and have used epoxy, wood filler and white glue for fillets. Your fillets look to be built up.

This thread could be copied to the Techniques Section of the forum. I don't think it's reaching everyone under the Logo Rocket title.

And people say I spend to much time in the building stages. Nice work!

[bradycros]

If it's not too much - could you explain how you did the fillets on the Executioner?

And people say I spend to much time in the building stages. Nice work!

I need to sand some bevels on the fins first, then fill them. Then install them. I can explain how to do the fillets as I'm doing them.

.

[bradycros]

I put bevels on the fins with the bevel making jig I made out of scrap material. The jig does just what it was made to do, and it does it very well. However the process is mind numbingly tedious. I need to think up and make a electrafiyed gizmo to do this.

Pic #1: Getting started by knocking the corners down.

Pic #2: One down, three to go.

Pic #3 & 4: Finished product.

[bradycros]

Guitar string or paper clip? I'm going to insert one or the other (along with epoxy) into the the tips to make them resistant to being cracked or busted off during the impact phase of recovery.

[bradycros]

Extended a line from the the arch in the following edge to the edge of the tip. I needed to see how much of the tip will need reinforcement at a minimum.

On the flat side of the fin I drew lines by measuring 1/8 inch in and 3/8 inch in from the edge of the tip and placed tic marks, moved down about an inch or so and repeated the measurments and again placed tic marks. The tic marks are connected, giving me a referance line for drilling straight.

On the 1/8 inch side of the fin I eyeballed where the referance marks should be for placement of the drill bit (X marks the spot).

The point of a nail was pushed into those marks so the tip of the drill will sit in the indentation and not wander around when the drilling is started.

[bradycros]

When the drill is starting to dig into the fin, visualy line up the drill bit with the referance line drawn on the fin to ensure it is going in squarely.

Asuming you have the root edge away from you like I do, lift the root edge towards you 90 degrees and check the drill is going in squarely at this position also.

I ran the drill in deep enough that I could no longer see the the twists in the drill bit and stop'd.

[bradycros]

You could use a ruler for this, but I used the drill bit. The results will be the same. Lined up the end of the twist in the drill with the following edge. Put a tic mark where the drill tip is on or next to the referance line. Drill a vent hole where the referance line and tic mark intersect. A hole is only needed on one side of the fin, no need to go all the way thru the fin. If this was done right the vent hole will have gone right into the guitar string hole.

This vent hole will allow the injected epoxy to fill the guitar string hole. Without the vent hole, air would be traped in the hole and you would not be able to fill the hole completly with epoxy. Maximum adhesion of the guitar string to the fin tip is the goal.

You can catch a peek of the guitar string in the vent hole. The guitar strings need a final triming. The end of the guitar string should be below the opening of the hole. Filler will hide all this later.

[bradycros]

Fins are beveled, tip reinforsement installed, filler applied, filler sanded,filler sealed with CA, and CA sanded. Fins are ready to install.

[atlcdp]

I built a turning rig, I can't call it a lathe, out of scrape 1" x 6" plank and a couple of 3/8" I.D. bearing. It works fine for Balsa, but not so good for anything heavier, like Bass wood.

It is simply a 2' long 1"x6" plank with two 6" long 1"x6" planks perpendicular to the base and parallell to each other. I used scape pieces of wood to make triangular braces for each joint.

I have used a drill and a dowel many times in the past. It works great for Balsa. I would really love to get a quality, tabletop wood lathe. They run around $250-$350 dollars, but I have other rocket stuff to spend that money on.

[bradycros]

I have used a drill and a dowel many times in the past. It works great for Balsa. I would really love to get a quality, tabletop wood lathe. They run around $250-$350 dollars, but I have other rocket stuff to spend that money on.

I agree, the drill and dowel method works well on small cones. It gets kind'a iffy when you try it on larger cones though. The cone for the Logo rocket was fairly easy, since it's just a straight line from the base of the cone to the tip.

[bradycros]

I've decided to add what I've heard others call "glue rivets" to the root edge of the fins.
I know they don't "rivet" anything at all.
I also know the surface area of the root edge will be increased by "X" percent.
More surface area = more area for adhesion. More adhesion area = more strength.
I'm all for that.
The holes are only 3-4 mm's deep and 10 mm's apart.

[bradycros]

The Fin Tool Guide (http://www.payloadbay.com/index.php?...tion=FINGUIDES) creats a template for positioning fins around a body tube. The template can be printed actual size. You can print the guide on heavy paper (or glue the printout to a sheet of foamboard) and cut out the hole for the body tube and the slits for the fins. This allows the guide to be used as a jig for holding the fins in place until the glue dries.
I got foamboard in the crafts section at Wal Mart.
You'll need to cut off a peice of the templet where the leading edge and body tube meet, allowing room for where the fillet will be.
If you've never tried this method, your going to like it.

[bradycros]

Are these the fillets you want to reproduce?

[hcmbanjo]

Oh Yes!
I really like the taper at the top of the leading edge/body tube joint.

I like the idea of strengthening the fin tips using the imbedded guitar string. I've got a few extra guitar strings hanging around.

I'm still here and enjoying the build thread. Thanks for showing me how it should really be done.

[bradycros]

As these fillets are going to be built up, a strong base will be needed. Small epoxy fillets will work for this.

Details for making fillets can be found on page one, posts #25 thru #28.

Pic 1: Epoxy is applied with a tooth pick.

Pic 2: Epoxy is smoothed out with the spoon from the spatula set. You can see the spoon was wiped off often.

Pic 3: Tooth pick is used to scrape of beads of epoxy made frome using the spoon. Again, you can see it was wiped off often.

Pic 4: Residue left from srapeing off epoxy is cleaned off with rubbing alcohol and Q-tips. Alot more then one Q-tip was used to do this.

Set aside until epoxy is cured.

[bradycros]

I purchased several differant diameter dowels from Lowes 3/16, 1/4, 5/16, 3/8, 1/2, 5/8, 7/8, 1 and 1 & 1/8 inches. I'll start off with the 5/16 inch dowel. I cut off 4 inch peices of the dowels because that length feels comfortable in my hand. I finished off the ends of the 4 inch peices so they'll be flat and smooth.

You could soak CA into the edge of the dowel to make it resistent to wear, then sand it smooth again. Load up the 5/16 inch dowel with some wood filler diluted down to the consistency you like to work with.

Spread out the filler, leaving extra at the leading edge/body tube joint and the following edge/body tube joint. You can't shape anything if there's nothing there to shape, we'll get into details about that soon.

Scrape the excess filler off from where it's not wanted on both the body tube and the fin. One of the spatulas from the Spatula Set works well for this. You could use a butter knife, the dull side of a X-acto blade or small peice of stiff card board. The results would be the same. The better you are at getting the excess off now, means the less you'll be sanding off later.

You could use a hand held blow dryer to dry out the filler faster. You can still scrape off any filler you might have missed after it's dry.

[bradycros]

Cradle the 5/16 dowel in a peice of 320 grit sand paper. I like to use the clog resistent type from 3m.

Pinch the sand paper together between your thumb and fore finger. Rotate the dowel back and forth in the main fillet, bevel fillet, leading edge fillet and trailing edge fillet. I like to have a sharply defined edge that draws attention to the different angles. I think rounding them off would detract from the look. If you scraped all the excess filler off this doesn't take long.

The desired taper effect will start to show its self as the diameter of the dowels used to make the fillets increases. Once it does start to show up, the sanding starts to get arts'y. You have to decide how large your going to make it and where it stops. You have to make the transition from body tube to taper to leading edge as smooth as your sanding and shaping skills will allow, on all sides. The top of the bevel on the leading edge was left flat so that transition would appear to be seamless. The point where the taper seems to grow out of the body tube needs to be straight across the curvature of the tube to be visually appealing, then repeat all those proportions for the other fins. Tell your self "this going to take awhile" and set your mind to the task. You will have sanding and shaping skills when your finished with the last fin. Then you'll probly go back to the first fin and start tweaking it to make it look as good as the last fin.

Do not sand any harder in any one place then is needed. If you do, you'll start to sand a trench into the body tube and the fin. To keep the trenching to a minimum, I start the dowel rotating while it's a little ways out on the body tube and at the same time roll the dowel into the fillet, then out of the fillet and on to the flat of the fin. Works fine the other way round too.

[bradycros]

I applied CA to the filler with a Q-tip. I've noticed the CA doesn't penetrate into the filler as deeply as you might think it would. I've observed this from sanding other parts. So, after sanding, I've decided to coat each layer with CA (composite filler?filler lamination?) to keep the filler stiff and in place, opposed to soaking the filler only once at the end of the filling and shaping process.

In the before and after kinda shot you can see the the taper above the leading edge is just starting to form. The following edge taper is starting to shape up nicely already. I've finished filling in all the fillets since the photo was taken.

For the fillets and tapers that don't look so hot (see pic's), go ahead and use your finger tip to rub some filler into the craters, it will be easy to feather out since the first layer of filler has been hardend. Sand, lightly apply some CA over the patches. Some light sanding is needed agian, then start all over by moving up to the 1/2 inch dowel and work your magic with it.

[bradycros]

Can you belive the differance between using a 5/16 inch dowel and a 1/2 inch dowel? Enlarge pictures one and two to see details.

Lay down another layer of filler with the 1/2 inch dowel. Scrape off excess again with tool of your choice. A damp Q-tip will remove the filler residue left after scrapeing. If you didn't use CA to seal the body tube after filling the spirals, I recommend you do not use a damp Q-tip on bare card board.

Cradle the 1/2 inch dowel in sand paper and knock down any high spots. Using your finger, apply filler to any low spots in the fillets, really start to build up and shape the tapers and feather them out.

Use a blow dryer to speed up the drying time of the tapers. Start shapeing tapers with the 1/2 inch dowel. Repeat filling and feathering low spots until your pleased with the results. When you are pleased, seal with CA again and sand smooth. Then move up to the 5/8 inch dowel.

The last dowel size I used on the Executioner was 5/8 inch, and it's a 2.6 inch body tube.

The Logo rocket is a 3 inch body tube. I'll decide if I want to go with larger fillets after I see how the 5/8 inch fillets look.

[bradycros]

I am wondering what other nose cones will do for the look of this rocket? Hmmm...

[hcmbanjo]

Bradycros,
Thanks for taking the time to show your fillet technique.
On smaller rockets epoxy is too much. I rarely fly mid power where epoxy might be needed. This looks like a good solution for my sport LPR builds. I didn't have much luck using Titebond Moulding and Trim Glue.

I'm looking forward to trying your methods soon.

[bradycros]

To get the tips to line up, I measured 190 mm down from the top of the body tube and placed a tic mark in four seperate places.

[bradycros]

Alined a paper wrap and connected the dots. Now I know where to make all the tapers blend in.

[bradycros]

Ready ror paint.

[bradycros]

I forgot to mention I went with the 7/8 inch dowel to build up and finish the root edge fillets. The 1 & 1/8 dowel was used on the leading and following tapers.

Before and after shots. Expand to see details.