Saturday, January 31, 2015

Official SEMROC Announcement

News Release
January 31, 2015

eRockets is proud to announce the acquisition of Semroc Astronautics Corporation.
eRockets will relocate Semroc to their facility in Dayton, Ohio, and resume full production of  Semroc flying model rocket kits.
Semroc was originally founded in the 1960’s by Carl McLawhorn to enhance the options for flying model rocket enthusiast.  The remaining family members decided it was going to be impossible to continue the company without Carl and ceased production.
eRockets was founded by Randy Boadway in 2009.  eRockets sells model rocket kits via the internet and ships to customers around the world.  eRockets boast the world’s largest selection of flying model rocket kits with over 700 kits in stock.  eRockets entered an agreement to take over Totally Tubular in 2010 and purchased A2Z Hobbies in 2013.
Randy Boadway will remain at the helm of eRockets and launch them into the next phase by enhancing the experiences of model rocketeers around the world by operating Semroc as a manufacturer.  Semroc will continue to produce some of the highest quality model rocket kit in the marketplace under the Semroc name.  eRockets will continue as an internet retailer while sharing resources like space, administration and shipping facilities with Semroc.
The plan is to have production restart sometime in February with flying model rocket kit re-releases beginning shortly after start up.  Boadway indicated that the first kits produced will be the popular kits where we can get parts through the pipeline quickly.  In its prime Semroc produced over 150 different kits.
We have a good team of people that will be an important part of producing parts and kitting the models at Semroc.   Every member of this new team has a lot of experience building and flying rockets.  Each has already been an inspirational help to the hobby and will provide great incite towards making the Semroc kits even better.
The facility in Dayton, Ohio will provide more space and efficiency that could be provided in North Carolina.  This will also allow for better buying and storage opportunities.
Our thanks goes out to Bruce McLawhorn, Sheryl McLawhorn and the late Carl McLawhorn for creating such an exceptional company and product of Semroc.
eRockets can be found at
Semroc will soon be available again at
Questions may be addressed to

TLP Pershing #K046 Build, Part 25, More Scale Data!

Thanks to links from Eero Fluge, I have a good scale drawing of the Pershing! This is from the January 1970 issue of  Model Rocketry magazine -

Looks like I'm going to have to remake the fin vane pads. I was pretty much guessing and going by what I could see in the Estes instructions.
I might also do the rear fins again, thicker this time.
Interesting too is the rounded tip on the nose cone.

There might not be a Pershing build post for the next few days! The cruise used up many of the posts I had in draft form and now I'm going to remake the fins and fin vane pads. I'm also busy with land shows.
There should be posts, but they will be on other rocketry subjects. 
Just give me a few days to get the Pershing back on track.

The Big Fix, Crimped 3 Ply Card Stock Fin

My new carded downscale Black Brant VB landed hard on the basketball court asphalt.
One red fin was crimped on the tip.

I thought about steaming it, but was concerned it might smear the printer ink on the outside layer.

The fin was set flat on a clean countertop.
Some white glue (no yellow glue here, the yellow could discolor the red print) as applied and allowed to soak in for a moment.

A Sharpie pen barrel was pressed and rolled (don't rub, roll over the glue) over the wrinkles, flattening them.
Here's the repaired fin.
The wet white glue softened the crimp bends allowing them to be pressed flat. The glue also strengthened the bent fin tip.
Not perfect, but ready for another flight.

Want to build your own carded Black Brant VB?
Email me at:
And request the Black Brant VB PDF art. It's Free and the model is dirt cheap!

Friday, January 30, 2015

TLP Pershing #K046 Build, Part 24, Rear Fin Shaping

The upper and lower tapers are sanded first concentrating on just the edge.
The blackened edge gives more contrast making it easier to sand the knife edge evenly.
So far I've only sanded a taper about 3/16" off the leading and trailing edges.

Now sand towards the penciled center line. Don't thin the black edge! You'll be constantly checking its thickness. Keep the width consistent from top to bottom.
You'll end up sanding off some of the pencil line and the outside edge will be thinner than the root edge. This is typical of many real rockets and missiles.
I've drawn the pencil line down to show how the sanding removes the wood.

The other side is sanded.
The center line will end up back in the middle and should straighten out. It might take fine sanding under a strong light source to clean up the line.
The center line wedge shape is easy to see near the outside edge, not as sharp as the root edge.

On the left is the diamond shaped root edge, the inset shows the small outside edge.
The ink down the leading and trailing edges is removed with a few light passes of 400 grit.

Each fin takes about an hour to get right.
Anyone can get this result with practice. You've just got to go slow -
Sand a little, check the ink line width, sand a little, check the ink line width.

Asking Permission Might Be A Good Start!

If you follow the blog, you might recognize this rocket.
It's my two engine cluster model called the Big Girtha. It was adapted from a Quest Big Betty kit.

I took this picture before it was launched at the Tampa TTRA monthly.
Then I saw it in a EBAY listing. Maybe I should be flattered, but I'm not.

A vendor was selling his 808 "Spy" cameras using my picture. Farther down the Ebay listing is a link to my YouTube video from the flight.

I didn't buy and build the rocket, buy the camera, fly it, edit the video and post it for somebody else to make a profit. Build your own model, fly your camera and post your pictures.

Just because you can "Right Click", "Copy and Paste" doesn't mean you own or have the right to profit from somebody else's work. Don't assume "Oh, he's one of us, he won't care!" This is a business and part of my income.
I wrote the vendor twice and he did pull the pictures and video link.

Thursday, January 29, 2015

TLP Pershing #K046 Build, Part 23, Rear Fin Shaping

The rear fins on the Pershing are tapered.
The instructions show the center line of the taper in one drawing but don't mention to shape them.

I've been looking online for more scale data but didn't come up with much. The face card picture shows the fins flat and squared. I'll take extra time on the fins and get it closer.
The 1/8" stock is thinner than actual scale.

The balsa would be very weak at the thin tapered edges so I cut more out of 1/8" basswood.
The 1/8" thick balsa fin weighed .02 oz.
The new, stronger 1/8" basswood fin was .08 oz.
My shaping method is described in more detail in a Apogee Peak Of Flight newsletter article:

The outside edges of the fins are marked with a wide point permanent marker. This gives you a high contrast to better gauge the taper thickness when forming the "diamond" shape.
The outside edges of the fins were "sealed" with CA glue applied with a Q-tip. This prevents the ink from a marker from soaking into the wood. After shaping the fin tapers the remaining black ink is easily sanded off.
The marker is quickly passed over the edge. Go quick using just enough ink to darken the outside edges. Don't mark the root edge.

Crepe Wadding Update

Wadding alternatives come up on the forums and on rocketry FaceBook pages. I've done quite a few blog posts about cheaper wadding in the past.

Lonnie B recently wrote:
"I finally made use of the bag of yellow crepe paper wadding you gave me a couple of years ago. I was getting fed up with how my new 'chutes were quickly getting burned, even with extra sheets of conventional wadding, so I tried yours and it was fantastic! It made a perfect seal that better protected the 'chute. I would love to purchase/find/make more."

He added the link on an old blog post is no longer valid. (I've gone back and fixed the link.)
Here's the new link to Crepe Paper wadding SHEETS -
Notice I specified SHEETS. These are 20" X 7.5' sheets. This is not the party rolls you find at the Dollar Store. Party rolls do work as wadding but are not very wide.
(Note: Some party rolls might not be flame resistant! Test them to see before using them in your rockets. You don't want to have flaming paper raining down on the field!)

I prefer cutting 4" squares, smaller than the 4.5" treated toilet tissue squares from Estes. Crepe Paper wadding is stiffer than the Estes and is easier to pack when it is slightly smaller.
TIP: With the crepe paper wadding (and the stiff Quest style) you crush up the sheets into a small ball then reopen it before going in the rocket. This puts many creases in the paper and softens it up making for easier packing and a better seal.

The colored crepe paper is easy to find on the field. Usually the first piece (closest to the top of the engine) is burnt and not reusable. The pieces right above it look like new and can be used again.

If you buy crepe wadding from the you should buy more than one package or the shipping charges will offset any savings over buying Estes or Quest wadding.

Right now, the crepe packages are $1.12 each.
Buy 5 packages for $5.60
Add shipping at $8.05 (Florida destination)
Total for 5 packs is $13.65
You can get more than 100, 4" squares from each package
Pictured above is the Canary Yellow color crepe paper.

Estes list price for wadding is $5.49 or 7 cents a square! (No shipping charges added)
Cut your own Crepe Wadding (with shipping charges) is under 3 cents a square!
(Even less if you buy more packages to offset the shipping charges.)