NARAM 53 Live!

NARAM will be live again at:
http://www.naramlive.com/naramlive-2011/
Once again Chris Taylor will be covering the NARAM.

I've attended three NARAMs back in 1975, 76 and 77.
For those who can't be there in person, NARAM Live is the next best thing.

I always looked forward to the Scale viewing. This year's Scale competition is Scale Altitude.
A favorite is the Manufacturer's Forum where all the vendors unveil new products. This forum takes place on Saturday night.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/31    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 22 Fin Fix and Decals

After the filler was sanded just the side with the dent was hit with gray primer.










Then the obligatory white undercoat. Red followed and the two fins were re-glued again.


Looking ahead at the decals:
I didn't realize it, but the rear decals don't have a clear background, but are black printed on a white backing. I would rather of had white lettering on clear, but I can see why Semroc did this.

When cutting out this decal, cut inside the black sides. Otherwise, you'll have a white border around the black box. You want to have the black decal to "meld" into the painted black rectangle.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/31    | توسط: فیروز قوچ داشی    |    | نظرات()

TIP: 13mm A10-3t vs. 18mm A8-3

Jason (Blackshire on YORF) came up with a great two-part 13mm engine mount adapter.

This adapter breaks in the middle. The engine slides in, nozzle down, in the lower half against a lower engine block. The upper half slides over the exposed top of the engine. In the upper top half of the adapter there is a longer engine block. Both halves of the adapter are taped together. The adapter and 13mm engine are slid into a standard 18mm engine mount.
I've used mine on occasion to fit a 13mm engine in an 18mm mount for the schoolyard launches.

Blackshire's conclusions are simple and valid:
Three 18mm A8-3 engines for $7.99 OR
Four 13mm A10-3t engines for $7.99

The thrust curves on these different diameter engines are pretty close.
The A10 has a higher initial peak and burns slightly longer.
The A8 has a lower initial peak, slightly higher sustain and shorter burn time.
The A10 thrust curve is HERE
The A8 thrust curve is HERE
I wasn't using the 13mm adapter as often as I should have. I figured the extra weight of the adapter with the engine installed would weigh far more than an 18mm A8-3 would. Boy, I was wrong!

An A10-3t engine in the 13mm adapter weighed .42 oz.
The A8-3 engine (alone) weighed .56 oz!

I guess I'll make a few more adapters and save some money while I'm at it.

Note: Jason sent me a message at YORF and added a few new pieces to the 13mm adapter history:

Hello Chris,
Thank you! I had never compared the weights of the two. Tim Van Milligan is partly responsible for the design. My original design called for peeling off the outer layers of the centering rings so that the adapter would fit inside a yellow engine spacer tube (to give the adapter the same shape as an 18 mm engine, mainly for its aerodynamics). Tim simplified (and no doubt lightened) it to create the variant that appeared in the "Peak of Flight" newsletter.
-- Jason

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/30    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 21 Oops!

This is what can happen when you take pictures for a blog by yourself. I dropped it!

The IRIS fell hard and broke off two fins. The fin on the left has a pretty good ding in the trailing edge.
Sure, it's all repairable.



I used CWF (without thinning it with water) right out of the tub.
For filling a corner ding like this, the CWF dries much harder and sticks better when used full strength.
A razor blade was used to apply and "trowel" off the filler.
The filler was left wider than the fin thickness so it could be sanded to the flat surfaces of the fin.





After the filler dried, it was sanded down and level with the rest of the fin surfaces.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/30    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 20 Fin Mask and Gluing

All four fins have been sprayed red. The root edge on the left still has the thin masking tape strip in place.
On the right, the tape has been removed.

I used a sanding block over the root edge to remove the paint "step" and to take off most of the red down to the bare wood.





A thin strip of Monokote Trim was removed for the root edge gluing.







Using the "double glue" method, the fins were glued in place.
I'm going back and adding some thin CA glue with a toothpick tip. The glue will be set at the rear of the root edge and under the fin tabs with the hope it will run underneath and reinforce the joint.



NOTE: Gluing the fins on after painting doesn't make for the strongest bond! Gluing bare balsa to a bare tube and fillets before painting is much stronger. But, taking into consideration the color separations on the body tube and the fin tabs getting in the way, this seemed to be the way to go.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/29    | توسط: فیروز قوچ داشی    |    | نظرات()

Estes A8-3 Burn Through

After the July 18 launch, I was removing the Estes A8-3 engine from my Squatty Body. Here's what the casing looked like.
To the right (nozzle) side you can see lots of charring and what looks like a hole.



I made a long cut down the length of the casing and unrolled the paper.
It's clearly a burn through.

I've seen this happen in monocopters with Quest Chinese made engines.
This is very unusual on an Estes engine.




Here's the inside of the engine mount showing the burn through hole. It didn't go through the outside body tube so it'll be okay for more flying.

NOTE: Never cut into a live, unused engine!
This expended (used) engine posed no danger when opened up for post-flight analysis.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/29    | توسط: فیروز قوچ داشی    |    | نظرات()

О человеке, умевшем любить

В этот день, 20 июля 1304 г., родился Франческо Петрарка (1304-1374), величайший поэт итальянского Возрождения. Что приходит на ум при упоминании этого имени? Конечно, сонеты! Между тем, в свое время он прославился благодаря дидактическим поэмам "Триумф Любви" и "Триумф Целомудрия", своду биографий выдающихся людей античности "О славных мужах" и другим трудам. В 1341 по решению римского сената он был увенчан лаврами поэта-лауреата.

Но все эти замечательные дела и сочинения остались достоянием прошлого. Сегодня мы знаем Петрарку как создателя образцовой любовной лирики, который обладал редчайшим талантом любить. В 1327, в Страстную Пятницу, в авиньонской церкви он встретил и полюбил девушку по имени Лаура – больше о ней ничего не известно. Именно она вдохновила Петрарку на лучшие его творения, именно ей посвящены его сонеты. Среди поэтов и писателей, испытавших влияние "Канцоньере" Петрарки – Джеффри Чосер, Томас Уайетт, Эдмунд Спенсер, Вашингтон Ирвинг и многие другие авторы разных национальностей и эпох.

Как вы думаете, Шекспир создал бы свои сонеты без Петрарки? Что для вас сонет? А любимые есть?

منبع:
http://irina-alicelovers.blogspot.com

نوشته شده در تاریخ 1390/04/29    | توسط: فیروز قوچ داشی    |    | نظرات()

LAUNCH! Schoolyard July 18, 2011

7:30 a.m., Soccer field - no wind!

Perfect conditions for the Odd'l Rockets CYCLONE with a 1/2A3-2t engine.

Straight boost to 375' with a little whistle heard from the air passing by the porthole. Clean separation at ejection. The upper single blade spins very fast as it almost hovers, both sections landed close to the launcher.





The FlisKits HONEST JOHN flew flawlessly to 125' with a MicroMaxx engine.

It was followed up by the 13mm Odd'l Rockets UP! CUP with a A10-3t engine. Clean flights from both birds.






My original prototype of the Odd'l Rockets SQUATTY BODY was launched with an Estes A8-3 engine. After dozens of flights, this one is showing a few scars.




Normally I wouldn't launch a B6-4 on the soccer field, but it's a perfect match in the Semroc CENTURION. Altitude was around 325'.
With one of the two 12" parachutes removed it still lands easy enough on the low cut grass.

This was one of those launch days when everything worked as planned.
All were recovered with no dings or repairs needed.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/28    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 19 Rear Color and Lugs

I used some aluminum Monokote trim material for the silver area behind the rear band. I used aluminum because the silver Monokote looked a little too metallic and shiny.

The lower launch lug was wrapped with the same trim material. I didn't wrap it all the way around, but left a narrow open strip of exposed lug for gluing.

A small rectangle was cut away for the lug to sit in. the lug was glued in place with wood glue.

The upper lug was painted white and glued to a masked rectangle on the upper body. Both lugs were lines up using a 18" length of launch rod.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/28    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 18 Color Separations

The tube is marked halfway between the upper and lower bands, around 7 1/2" from the top.

I wrapped card stock around the tube for an edge to cut against.
Use a sharp knife and cut carefully. The paint will chip off if cut to quickly.

Use a sanding block with 400 grit sandpaper to clean and square up the edge. The coupler is already inserted for support of the edge when sanding.

Remember the coupler from Parts 6 and 7?
Join the two cut halves together.

Turn the upper tube 90 degrees - Voila!



If you took the extra time to make sure the tube was masked evenly, you should have a clean separation with the corners matching up. Nobody will notice the cut tube, the sharp color breaks will hide the line.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/27    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 17 Color Separations

It's hard to see in this picture, but Scotch tape was used over the white area separation lines.
Masking tape covered the area between the thinner Scotch tape lines.





Here, the Scotch tape is removed. The mask line is looking clean so far.





With all the tape removed, here's where the tube stands now, four long bands. Two white and two in black.

Note, the fin root edge and launch lug gluing lines were masked for better adhesion on the body tube.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/27    | توسط: فیروز قوچ داشی    |    | نظرات()

Nykokt saft och bakandet

Svartvinbärskaka med glass.

Jag måste nog skaffa mig ett liv och inte bara baka och pyssla på här hemma :-). 

Sonen var till Stugun förra veckan och hittade saftessenser. Jag har inte hittat dom här i stan och nu när han hittade dom så fick han köpa med hem en drös.

Nykokt hallonsaft och kaka i långpanna.

I lördags var jag lite social med främmande av en granne. Vi satt ute och surrade och drack lite vin. Annars är det lugna fridfulla dagar här. Sönerna har slutat sina sommarjobb och har resten av lovet kvar med att bara göra det dom själva vill.

Kram

Strömma 

منبع:
http://lojrom-vittvin.blogspot.com

نوشته شده در تاریخ 1390/04/27    | توسط: فیروز قوچ داشی    |    | نظرات()

What! No Blog Posts Yesterday?

Sorry, I wasn't able to do any posts on July 16.
So far I've been able to keep up the blog when away doing shows.

I was in Elsah, Illinois doing a BIG show. Well, big for me anyway.
Sure, I had my laptop. But, on the isolated college campus the available WiFi signal was spotty at best.

But great company and the show venue certainly made up for limited computer access.
My thanks to the Principia College Summer program for knowing how to treat guest entertainers.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/26    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 16 Color Separations

You can see how the wrap strip overlapped itself and left a ridge.
It'll take some careful sanding and a little filling to make it less noticeable.

Now, on to the black / white body paint pattern.

This was first explained in post #6.
Instead of a difficult mask, I wanted to try something a little different.
The main body will be painted white, black, white, black all the way down it's length.
At the midway point, the tube will be cut in half.
Using the coupler made earlier, the upper and lower halves are joined.
The upper section will be turned 90 degrees.

If the masking was correct, you should have the desired paint pattern with very sharp color separations.
If this doesn't make sense yet, hang in there. It should be clear soon.

The body tube is divided into four EVEN sections. I used a four fin marking guide and extended the lines all the way up the body.
The guide was rotated 90 degrees and checked. The checked again and again!

To paint the color separations this way, the 1/4 divisions must be correct.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/26    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 15 Fin Tabs

After spraying the fins a white undercoat, I noticed the laser cut sides of the fin tabs weren't accepting the paint. They still looked brown.

I hit the sides with a light coating of white glue. After the glue dried, it was lightly sanded.

White paint was sprayed into the spray can cap and brushed onto the sides of the fin tabs. Again, a little sanding and another coat. This gave me an even coverage of white.

I still had some dips in the fin tab seam.

I applied a little wood filler and sanded.

The fins were lightly sprayed and sanded again.

The reflected light in the picture shows the sanded area around the tab.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/26    | توسط: فیروز قوچ داشی    |    | نظرات()

Посвящается вечно юной Алисе Лиддел

Это стихотворение мне подарила Женя Добренко, выпускница этого года, замечательная девочка, обладающая даром читать. И осмысливать прочитанное, как вы можете убедиться:

 

Алиса навсегда останется Алисой.
Лелея в памяти отрывки ярких снов,
Из Зазеркалья взглядом юным, чистым,
Смеясь, она мечтает вновь и вновь.

Алиса – светлый, вечный ангел детства,
Легенда, что живет у нас в сердцах,
И верит в то, что все вокруг чудесно,
 Достигнуть можно звезд на небесах.

 Душа твоя не старится, Алиса,
Едва ли ты когда-то подрастешь.
Люби свой мир и в сердце чистом
Ты сказку каждому в подарок принесешь. 

منبع:
http://irina-alicelovers.blogspot.com

نوشته شده در تاریخ 1390/04/26    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 14 Fin Tab Gluing

Looking very close, there are some extended corners on the square tabs.
Each tab was stood on end and the small extended corners cut square.

The laser burned sides were sanded and cleaned up a bit with 400 grit on a block.

A small glue line was set into the recesses with a sharpened dowel.

Not much glue was used, I didn't was glue to ooze out to the sides.

The tabs were set in place checking both sides to be sure they were even.

After checking the fit on the body tube, the tabs were just a little too thick. This raised the root edge above the body tube slightly.

This required a little sanding of the tabs down to and even with the root edge

The fin on the left shows the thick tabs. The fin on the right is the tabs sanded flush with the root edge.

EDIT: I was sent some great IRIS scale information from Massrokit, a TRF member.
From the closeup pictures of the real IRIS, the root edges of the fins don't make contact with the mainframe body. The only attachement points are the fin tabs and rear band.
So with the Semroc supplied fin tabs being a little high, they could actually "raise" the fins away from the body tube. For me, this wouldn't give a strong enough root edge joint. Still, an interesting twist.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/24    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 13 Engine Mount Gluing

The launch lug location had already been marked and masked on the tube. The engine hook will line up with the launch lug.

The engine mount in now glued in place.

Some instructions will have you place a bead of glue inside the tube, 1" from the end.
Because these centering rings are thin, I tried to place my glue ring closer to the place where the upper ring would eventually sit. This was farther inside than 1".
I used a rounded dowel to roll a bead of glue in the tube.

In the above picture, my sanding block was used to evenly push the mount into place. The flat side of the block insured the end of the mount tube was even with the main body tube.
The engine hook extends beyond the tube end, the block was set a little to the side of it when pushing the mount in place.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/24    | توسط: فیروز قوچ داشی    |    | نظرات()

Cleaning Up - TIP!

I've used the Mr. Clean Magic Erasers with good results on the walls of my house.
It never occurred to me to use them on light colored rockets.

These Scotch Brite erasers less expensive than the Mr. Clean brand.


After all that handling, the lower white area (with the flags) on my Saturn V was getting smudged and a little discolored. I'd painted the model with gloss white. You could imagine how dirty it would have been if it were painted with a flat finish!

Under a running faucet I wet one of the Scotch Brite erasers then wrung out most of the water.

It cleaned up very well and could save a touch up down the road. You can see the dirt it removed on the pad.

NOTE: I'm not going to make any compatibility guarantee with these erasers and the brand of paint you are using. This was done on well cured Rustoleum Gloss White Painter's Touch 2X Coverage spray paint.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/23    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 12 Band Gluing

Here's the doubled band at the top of the body tube. Note there is a raised edge where the band ends.






While gluing the band on the fin side, I was double checking the fit with the fin recess. Here, the first wrap is glued down. I've yet to add glue to the second narrow wrap and smooth out the glue bead with a toothpick.





While the glue is still wet, any that may have squeezed out was picked off and removed with a toothpick point.

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/23    | توسط: فیروز قوچ داشی    |    | نظرات()

Rocketry Golf!

I received an Email from Doug Frost - a.k.a. Frog Dust.
I knew Doug in the late 1970s when I flew with a Santa Clara area NAR section.
Doug was our section president.

That's Doug on the right. The picture was taken from the Centuri Magnum Jayhawk instructions.



After a twenty year hiatus from rocketry, Doug has resurrected ROCKETRY GOLF!
Check out the website HERE

I can just hear the countdown:
Five, Four, Three, Two, One . . . FORE!

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/22    | توسط: فیروز قوچ داشی    |    | نظرات()

Semroc IRIS Build Part 11 Gluing Bands

The fins, body tube and nose cone were sprayed with gray primer and sanded.

The tape was removed before sanding the body tube. (You'll have to add back more tape strips before painting the white and black on the body tube.)

I layed a thin bead of white glue to the flat finish side of the band.
That bead was spread out and smoothed with the flat side of a toothpick.

I only applied glue to the widest side of the band first for a single glued wrap.
After the first half of the wrap is in position, glue will be applied to the narrower second half.

While rolling the band, the flat side of my sanding block was used to be sure the band side was flush with the end of the tube.
Any flat surface could be used here, a sanding block is probably not the best choice. It's simply a flat surface to be sure the band is being glued correctly without a "step".

منبع:
http://modelrocketbuilding.blogspot.com

نوشته شده در تاریخ 1390/04/22    | توسط: فیروز قوچ داشی    |    | نظرات()