Tuesday, May 31, 2011

Estes Saturn V Build Part 51 RCS Nozzle Drill

The instructions suggest using a scribe or sharp pencil to make a gluing hole for the R.C.S. nozzles.

A sharp pencil? Don't try it, you'll never get it through the body tube wall.
I started the hole with a small awl.

The hole diameter was widened by twirling a #11 blade in the hole.

The instructions say the hole should be 1/16" diameter. The gluing pin on the back of the R.C.S. nozzle piece is actually a little smaller than that.

The hole edges were cleaned up with a small diamond rat tail file.

As you are widening the hole, check for a good fit using the pin on the back of the nozzle piece.

Time spent on build: :30
Total time on build so far: 50:00

LAUNCH! Schoolyard May 31. 2011

I left the house at 7:30 a.m.
It seems as soon as it warms up, the winds start. The winds were already blowing.
I figured I'd start with nose-blow recovery and move up to parachute.

I couldn't get the STAR SNOOP to ignite. I know, MicroMaxx are temperamental.
I took it off the tripod launcher and set up the FlisKits HONEST JOHN.
It's reliable and a true flyer. I would guess it reached 125 feet. The streamer ejected early, and landed without damage.

I pulled the bad igniter in the Star Snoop and re-used the one that just launched the Honest John.
This time - Success! Good flight with nose blow recovery.

The Hot Rod Rockets BELL BOTTOM flew to an estimated 300 feet with an A3-4t engine. It's easy to see the red prism streamer on recovery.

This next model had me concerned - with good reason.

It's a new build from an OOP company called Stellar Dimensions.The square bodied XANADUNE.
I'd read of ejection failures on RocketReviews.com.
With an Estes A8-3, it spun on the way up, the fins are canted.
At ejection, only the nose cone blew, the tightly packed parachute didn't eject. In that narrow midsection there is little room for a parachute.

Take a look at the casing pulled after the flight.
Most of the ejection charge blew out the back, down the open corners of the square bodied engine mount.
I'll be doing a build thread on this blog after the Saturn V is finished.

And lastly, the Semroc ASTRON was launched using a Quest A6-4.
In the picture you can see one of the last Tiger Tail igniters I have. They take a little longer to ignite, but still work well.

I'm not a fan of the Quest Chinese A6-4 engines anymore.
This one veered off vertical like half of the others did.

They are loud during boost though!
A reefed parachute brought it down 100 yards away.

Monday, May 30, 2011

Rocketguy Videos on YouTube

Did you ever wonder how to open up a kit bag?
"Nose cones roll, be careful with that."

Grab a beer, and check out the video HERE
If rocketry ever needed a spokeperson, he's the man.
He said "package" eleven times, I counted. But wait, there's more!
This is only the first video in the series.

I'm sure he meant well, but the videos produced by the NAR are much better.
Check them out HERE

Estes Saturn V Build Part 50 RCS Nozzle Guide

I know, my build is a little out of sequence.
After you've built a dozen rockets, most builders veer away from the order of the instructions.

The R.C.S. nozzle marking guide is cut from the instruction sheet.
I wrapped it as directed and marked the tube at the arrow locations.
The first picture shows it lined up and marked per the instructions.

I did my usual check and rotated the guide 90 degrees up to the next mark on the right. It didn't line up! Good thing I didn't drill any holes yet.

I can assume these R.C.S. nozzles should be equally spaced 90 degrees around the tube. In order for the guide to be correct, the first arrow mark should be where the ends of the wrap meet and are taped. Disregard the arrow right to the left of the wrap ends and mark where the guide ends meet. The other three arrows should be correct.

NOTE: Go to the Centuri instructions HERE
Check page 47 for the Template Cutout Sheet. The RCS Nozzle Placement Guide is on the upper left side. All four of the nozzle locations are equally spaced around the guide. You could print this guide and use it instead or make your own. It will fit the service module tube.

I made my own marking guide by cutting a strip of paper to the correct height and folding it into quarters.

Using the guide I made, pencil marks were made for the drilling. Notice I made a "cross hair" to have a better center point.

Time spent on build: :30
Total time on build so far: 49:30

Sunday, May 29, 2011

Estes Saturn V Build Part 49 Masking Touchup

After removing all the tape, there was some expected rough edges. It didn't turn out badly, considering I used a generic masking tape.

Some touch up was done with a fine point Sharpie.
Around the nubs, I went back with some white paint sprayed into the can cap.
The Rustoleum Painter's Touch takes touch up very well. When brushed over it doesn't lift the base color. The 2x formula covers easily with a brush.

Touch ups are in progress here, still a little more work yet.

I found it interesting that the Estes box cover picture has the white nubs painted black! Their builder probably gave in to the tough mask. I don't blame him on this one.

TRIVIA: The paint pattern pictures in the Estes instructions are from their original kit - not the version you are building! The pictured Estes Saturn V had embossed card stock wraps instead of the Centuri vacuform pieces.

Time spent on build: 1:00
Total time on build so far: 49:00

New Goblin Kit From Semroc!

I always look forward to a new release from Semroc.
This time it's my all time favorite - THE GOBLIN
Check out the specs HERE
I'll usually download the instructions and check their altitude predictions.
The picture at the right is from the Semroc online catalog.

I've got quite a history with this design.
The following copy was lifted from the EMRR/Rocket Reviews Family Picture Contest a few years back:

After getting back into the hobby, I discovered cloning. These four family Goblins were not built from commercial kits.

My first attempt was an all time favorite - The Goblin. It was built stock, around the BT-55 airframe. All parts were ordered through Semroc. The plans were from Jim Z’s site and the decals from Excelsior. It has flown many times on B6-4s and C6-5s. Back in the 1970s I lost my original Goblin on a D13, I haven’t gotten the nerve to fly the clone on a D12.

My BIG Goblin is a 1.7 upscale. It was the first big model I’d built since the Enerjet days. The body tube is the Semroc heavy duty 225 tubing. Through the wall basswood fins, and that big BD-25588 nose cone. The engine mount is made for 24mm engines. Recovery includes a baffle and a 24" rip-stop nylon parachute. I know (now) there are available kitted upscales of the Goblin, but this one was upscaled and built from parts.

My Baby Goblin is a “carded” model from the Rocketry Blog website: http://rocketry.wordpress.com/ultimate-paper-rocket-guide/paper-rocket-partial-builds/ All parts were printed on 110 lb. Cardstock. The nose cone is balsa and a small streamer is used for recovery. It has flown using Quest Micro-Maxx engines.

Just added is my new fleet favorite, The “Franken Goblin”! This model was built and flown as “The New Member of the Family” for the 2009 EMRR Challenge. The economy dictated which parts were available, anything and everything already in my spare parts box. From existing and retired models, I pulled and cut-away enough parts to piece together the “monster”! The mainframe is 8 ½" of BT-60. A Goony? Well, sort of - but just a little “scarier.” I’d bought decal paper but hadn’t used it yet. This model cried out for a revised “Goblin” treatment. Overall, I was happy with my first attempt at decals. The green and black paint decor suits the Frankenstein theme. A stable, fun and reliable flyer, B6-4 engines are a great fit.

TRIVIA: If you want your Goblin to be true to the Wayne Kellner original design, flip the "3" fin decals on their backs. Or, 90 degrees clockwise.

Another new kit is the PSC INFINITY. Check it out HERE
It's a two-stage design to celebrate the Pittsburgh Space Command's 25th anniversary.
A sharp looking bird with an unusual 2 stage cluster. The booster recovers with a streamer.
Read the story behind the design on the down loadable instructions. It's interesting how they tied in the club colors.

Saturday, May 28, 2011

Estes Saturn V Build Part 48 Masking Reduction

This is a tough part of the mask.
Those raised nubs on the reduction wrap are rounded and not very high. Trying to get tape to adhere to the angled sides will take some extra consideration.

First, a thin band of Scotch tape was tried. No luck.
I ended up using a strip of standard masking tape cut to 1/8" wide.

TIP: Don't use masking tape right off the roll. Chances are, the sticky edge won't be clean or give you a sharp line.
A strip is torn off and set on the glass patio door. A new, clean edge is cut with a strait edge.

This 1/8" wide strip was wrapped around the four nubs on the reduction wrapper. Right now the tops are open, but to match the small curves, you need the flexibility of a thinner strip.

Clear Scotch tape was used on the straight lines going down the adapter. You can see where the clear tape was marked with a Sharpie first - off the model.
Masking tape strips were used going around the adapter.

NOTE! The masking lengths in the Estes instructions are wrong! On the reduction wrap the height should be 1 3/16", not 1 1/8".

I can only guess these are the masking area measurements from the older Estes kits. The instruction measurements don't fit the raised masking areas on the Centuri vacuform wraps.
Molded into the corrugation on the wraps are raised areas to make the masking a little easier. Lay your tape separation masks on the raised areas, not at the 1 1/8" suggested spacing.

Going around the reduction wrap can only be done with a flexible tape. The less wide the strip, the more it can follow the curve. 1/8" wide strips of masking tape worked well.

In the BMS Peter Alway Saturn V kit, you are give a pre-cut vinyl wrap for the reduction adapter. At first, I wasn't too hot on the idea of the vinyl wrap, but it turned out great! Certainly a lot easier than masking a straight line around a tapered adapter.

After shooting the black, the mask didn't look very pretty.
I used Rustoleum Painter's Touch 2X coverage. I'm used to it and get pretty good results.
I know it's gloss - for now. Decals lay down better on gloss paint.
Planning ahead, I might hit it with a dullcoat after decals are applied.

Time spent on build: 1:30
Total time on build so far: 48:00

Estes Saturn V Build Part 47 Third Stage Wrap

After spraying, here's what I was left with.
I pulled the tape before the paint had totally set up, maybe 15 minutes after spraying the black.
So far, so good.

There was glitches, a few small bits of black had got underneath the tape. Before the paint sets up, you can usually push the paint back with a knife tip.

Note I said "push" and not scrape.
If you scrape the paint, you run the risk of knocking off some of the white exposing the gray primer underneath. If you do scrape, scrape lightly - just enough to remove some of the black.

Time spent on build: 1:00
Total time on build so far: 46:30

Friday, May 27, 2011

Estes Saturn V Build Part 46 Masking

Oh boy - here comes the fun!
The first mask should be the easiest - the upper 2nd stage wrapper.
I'll be doing each masked section separately.

If I were to mask the entire rocket in one sitting, some of the taped areas might come loose after sitting too long.

This is a big hard project to mask! Take your time, plan ahead.

With all the complex surfaces involved, chances are that some areas will give you problems and require touchup.

This is the first piece of Scotch tape used in the mask.
First the tape was colored with a black marker so it could be seen against the white. A new, clean edge was cut with a straightedge on my patio glass door. I never use tape as it comes off the roll. A new edge is always cut.

The vacuform wrap seams were masked first.
There is no way to get a good painting seal by trying to press any long strip of tape into this recess. It'll take some smaller pieces to get a clean mask.

On the other side of this wrap you run into the flat wood tunnel.
There are three pieces of Scotch tape here. Two thin strips on the sides of the tunnel, one wider piece over the top.

Again, all three pieces were cut by laying the tape on glass, blackening the tape with a Sharpie pen then cutting clean edges with a straightedge.

Finally, a long piece is rolled around the tube centered on the flat raised line.

The long piece of tape (above) shows a thick line and a thin line below it. That thin line is just an black overlap from another piece I cut from it. Disregard the lower line.

Masking tape is layed on top of the scotch tape to extend the mask. Still more copy paper is taped to that. Whew!

Time spent on build: :45
Total time on build so far: 45:30

MX-774 Fix!

A while back, Bradycros on TRF referred me to some MX-774 scale plans.
Every picture I'd seen showed the small squares at the rear of the fins as black.
Of course they were black, every picture of the MX-774 is a black and white photograph!

As it turns out, the little squares are red.

I finally made the correction in time for the May TTRA launch.
Sure it's subtle, but it does make a difference!

Estes Saturn V Build Part 45 White Basecoat

I didn't take any pictures of the model sprayed with gray primer.

It always amazes me how many flaws show up when sprayed gray. Suffice to say, I had a bit of sanding to remove some glue spots and rough edges.
After the gray primer was sanded the overall white followed.

TRIVIA: I found it interesting, in the original Centuri instructions, they have you paint the entire rocket black first, mask and then paint it white!
They explained (at the time) that the white paint adhered better over the black as opposed to the black over white.

I can't see doing it this way. Can you imagine how much extra white paint (and added weight) it would take to cover over a black undercoat?

The above picture shows the lower half painted white. The roll of paper was taped to the inside of the body tube to keep paint out of the tube.

The upper end got the same paper roll block. I did ball up a small towel and pushed that into the top to keep the shock cords in the tube.
The corrugations on the upper 2nd stage wrapper are deeper than all the rest. You can see gray primer showing through after I thought I'd got a good coverage. I had to go back and shoot white again from the sides to cover all the deep gray.

Time spent on build: 1:30
Total time on build so far: 43:45

Thursday, May 26, 2011

Estes Saturn V Build Part 44 One Last Fix!

Take a look at the box cover picture. There is a pretty substantial gap at the rounded front of the fairing.

The fairing tip is raised from the height of the lowest wrap.

I thought about filling the gap with scrap plastic from the vacuform sheets. I took a simpler route.
It took two fillets of white glue to fill the gap.

I know, white glue won't stick to the vacuform plastic. but, it does stick to the body tube. That'll be plenty to hold the fill glue in place.

Next up - gray primer!
While the primer will add a little weight, it also helps the final coats stick better with all the complex masking coming up. It's amazing how many small flaws you can see when the primer is dry.

Time spent on build: :30
Total time on build so far: 43:45

Estes Saturn V Build Part 43 Launch Lugs

The lugs are glued to leftover tunnel wood standoffs.

A slight curve was sanded to match the body tube.

This shows the difference in the fits, unsanded on the left and contour sanded on the right.

I didn't glue the lugs centered on the seam line, but a little to the left. The 3/16" rod would run too close to the raised S-II motor beside the seam. Check yours with a launch rod and you'll see what I mean.

NOTE: Check Step 40 of the Centuri instructions HERE
It says to check the lug clearance using a 3/16" launch rod to make sure the rod doesn't hit any of the raised areas on the vacuform wraps. The illustration clearly shows the lugs glued to the side of the alignment line.

Time spent on build: 1:00
Total time on build so far: 42:45

Wednesday, May 25, 2011

Estes Saturn V Build Part 42 Shock Cord Mount

Nothing too special here, the classic Estes tri-fold mount.
I do set the shock cord at an angle so the finished mount isn't too thick. This way the rubber lays beside itself in the folds instead of two or three layers of rubber and paper.

I pre-scored the mount folds before gluing.
The end of the shock cord was cut at an angle to better fit into the fold.

Before gluing, roll a slight curve into the mount to better fit the inside of the body tube.

The curve should not be as extreme as shown in the picture. In a tube this large it's a subtle curve.

The instructions say to glue them on opposite sides, 2" from the top of the tube.

Time spent on build: :30
Total time on build so far: 41:45

LAUNCH! Schoolyard May 25, 2011

I was out at 7:45 a.m. to beat the heat and wind.

Here's my kitbash of the Estes Bullpup kit, turned into an MX-774.
It flew well with an Estes A8-3 with parachute recovery.
Estimated altitude was 250'.
To information on the conversion, go HERE

This little ASP Jayhawk gets great altitude for a MicroMaxx engine.
Stability - well, it did veer to a little North.
I would guess it got 150 feet up, it's only 3 1/2" tall.
Very fast off the pad, it's a hard one to keep an eye on. But, it was recovered.

I was recovering a model when I met Brandon. He was on his way to school and had questions about the rocket.
I invited him over and answered more questions. I gave him a card with a few rocketry web addresses.

Brandon took me up on the offer to launch the carded MINI BERTHA powered with an Estes A3-4t.

After hitting over 650', it drifted under a streamer and landed 200 yards from the launcher.
After five minutes of looking, I almost gave up. It never fails, about the time you are going to chalk up as a loss, you find it.

Also flown:
The Quest powered FLIC with an Estes A3-4t engine. I'd estimate the altitude at 600' with a slow turn during boost. Even though the rod was slightly angled for the wind, it still drifted 200 yards away.

Tuesday, May 24, 2011

Estes Saturn V Build Part 41 Parachutes

Here's a corner from the parachute sheet.

It's a copy of the older Centuri Saturn V kit parachutes.

While the sheet corner directions show a shroud line simply looped under a tape disk, the supplied disks have a center hole.

As I've explained before, lift the disk off the backing using your knife blade, not with your fingers.

Touching the self-adhesive disks will diminish the adhesion on the parachute.
Using a knife lets you get a more accurate placement on the printed circle.

I'm concerned because the disks aren't sticking very well to the thick parachute material. I'll wait a few days before tying on the shroud lines. Sometimes a self-adhesive will stick better after a few days and become more permanent.

Time spent on build: 1:45
Total time on build so far: 41:15

Estes Saturn V Build Part 40 Parachute Hook

You can see the original Centuri Saturn V plans HERE
It's a fascinating read. There are scans of the vacuform wraps as supplied in the Centuri kit, #KS-12.
The wraps and fin edges were die-cut. Check out the rough edges and the plastic lip surrounding the interstage wrap.

This scan also includes the original hand written instructions by Centuri designer Keith Niskern. It's a good insight into what goes into producing instructions.

The reason I bring this up -
On page 46 is a PDF of the service module wrap. I always thought the Centuri service module looked better than the silver painted Estes version.
If cut correctly out of trim Monokote, it should cover up the filled slit under the U shaped hook.

Here's how the hook turned out after filling and spraying.

Monday, May 23, 2011

Estes Saturn V Build Part 39 Parachute Hook

There is a short piece of brass wire in the kit.
This is bent into a hook to be attached to the 18" upper body parachute. The hook allows the upper section to hang at an angle, reducing the chance of damage to the tower in a hard landing.

While the instructions don't say so, the illustration is full size. I bent mine as best I could to match it, but it's slightly larger.

You are instructed to cut a 1/4" slit above the shroud.

NOTE: The instructions say "slit", but you should cut a thin slot as wide as the wire diameter. My slit was the width of my X-Acto blade and not wide enough for an easy insertion of the wire.

The "U" shape in the wire is pushed through the slit. In my case, this raised the edges of the cut line.

Time spent on build: :45
Total time on build so far: 39:30

Estes Saturn V Build Part 38 Nozzle Fix

Earlier I had glued the supply tube to the nozzle.

Looking at the picture you can see the top of the supply tube is lower than the gluing nub on the nozzle top.

If left like this, the nozzles wouldn't glue in straight to the bottom plate.

I'll have to lengthen the supply tube.

Using the rotary punch, a small "donut" was made from a double thickness of scrap vacuform plastic.

I wanted the ring to be about the same diameter as the top of the supply tube gluing nub.

Here's the donut ring glued on the top of the supply tube.
Another ring is shown on my fingertip.

When all is painted and glued in place it won't be noticeable.

Time spent on build: :30
Total time on build so far: 38:45