Friday, December 23, 2016

True-to-the-name Estes Generics...

Duane recently dropped off the remaining Make-It-Take-It kits from the October Rocket City Blast Off; while in the process of putting them away, I discovered a poorly built Estes Generic buried in the pile. The pathetic thing had a loose fin can, and you could practically hear it screaming "Fix me! Make me worthy to fly!"

So I did...

I re-glued the fin can, filled the spirals with diluted Fill N Finish, filleted the launch lug, and applied two coats of primer. While the last coat was drying, I contemplated what to do with this almost ready to fly (ARTF) Estes model - the standard paint scheme involving the "peel n' cuss" stickers was abhorrent, and I found myself taxing my single creative atom in an attempt to come up with a simple d├ęcor that would match the rocket name. After an hour or so of banging my head against the wall, I did what I should have done in the first place - scan the Internet.

Which brought me to a superb blog - Blast from the Past - by Edward Mitton. In a strange cosmic coincidence, he and I were struggling with the same conundrum at roughly the same time. However, Edward obviously has some creative chops, for he came up with a simple and very obvious solution that I can only ascribe to a flash of creative genius.

Paint the rocket white like a generic package, with the appropriate label.

So simple, yet so inspired. I had to create a Generic for myself.

And here it is, with the waterslide decal label. I changed the wording a bit, but the gist is the same as on Edward's model.

My version of the Generic (Click to enlarge).
A closer view of the label (Click to enlarge).
Now THESE are true Generic rockets.

Paying attention, Estes?

Thursday, December 22, 2016

What to do on a rainy day...

From a rocket perspective, rainy days kinda suck - can't launch, can't paint, can't sand. You can start a kit build, but have to stop at the sanding parts - not very satisfying, unless you are putting together something with plastic or fiber fins. These go together in like 30 minutes, leaving quite a few hours needing something to do. Such was the situation this past weekend, and I found myself online searching for a subject for my next build (yeah, I know I have a list, but that's for 2017, which ain't here yet). Glancing away from my monitor, I noticed the Centuri Stellar Hercules clone over in the corner, and I realized that it was high time I built another in the old Stellar series. A few seconds later, I was perusing the Centuri catalogs - I did not like the looks of the Loadlifter, a payloader with a minimum diameter main body tube. The engine hook was on the outside, held in place by a mylar ring, which seems a bit on the tacky side. However, the Stellar Photon Probe was a different beastie - it exhibited a futuristic style, with two part fins and reactor vanes. Classic Centuri... So classic that Estes later adopted a simpler version of the design in their early 1990's Solar Probe model.

The 1970's Centuri Photon Probe and the 1991 Estes Solar Probe
(Click to enlarge).
Before starting any clone build, one must first make sure one can actually build it. This entails searching the Net for plans, parts lists, and decal scans. The plans were easy, as they were located on Ye Olde Rocket Plans, the best source of rocket instructions after JimZ's site. The parts list was more difficult, as the instructions did not specify the part numbers; fortunately, there were a couple of threads on Ye Olde Rocket Forum (my favorite hangout) devoted to this model, and these listed the parts. A quick comparison of this list against my inventory showed I had all the parts needed for the build, including the laser cut fins (Thank you Semroc/eRockets!).

Which left the decals...

They were nowhere to be found - no scans anywhere. The authors of the YORF threads had whipped together their own based on the cover art and kit instructions (which were not in agreement, by the way). I was going to have to do the same, so I pulled out my ruler and started measuring the dimensions of the markings on the model's screen images relative to the body tubes and fins. Once I had these numbers, I fired up the Pixelmator software on my Mac and got to work. It turned out that I did not need to draw everything, for I had some of the markings in scans of other decals. In the end, I only had to create the bottom roll pattern, the numbers, a few lines, and the "NASA" and "United States" markings. The upper roll pattern came from the Centuri roll pattern decal sheet and the hatches were obtained from a scan of the Estes Solar Probe decals. Thus, after about an hour and a half of effort, I had a fairly reasonable reproduction of the Stellar Photon Probe decals.

A few hints for those of you who wish or need to make your own decals:
  • Always scan your kit decals - you never know when you may need to reproduce them for a repair or use them on another model.
  • The convention is 300 dpi resolution - use this when scanning decals and in creating the canvas in your art program. Also helps to place a ruler in the scan to confirm the dimensions.
  • I also set the canvas size to that of a standard 8.5 x 11" sheet of decal paper, so I can tell how much space will be occupied. Any free space is filled with other kit decals or markings, maximizing the use of the paper.
  • If using an ink jet printer, be sure to spray a clear coat on the decal sheet after printing to avoid smearing when they are applied. My HP Envy inkjet sucks at decal printing, so I use Bel decal paper for laser printers and print them out on the office color laser. No need for the clear coat and the quality is acceptable.
Below is my decal sheet for the Stellar Photon Probe, which also includes a scan of the Estes Challenger 1 decals and some markings for a Generic kit bash. I also show a decal sheet created by PaulK on YORF, so you can see the differences in interpretation. I followed the plans more than the kit art, whereas he did the opposite. No right or wrong here, though I do wish someone would post a decal scan from an original kit. Trouble is that these Stellar kits are fairly rare, and it's hard to imagine a collector opening a pristine box just to provide some rocket noobs a scan of the decals.

Paul's decals posted to YORF (click to enlarge)My decal page (Click to enlarge).
The build can now commence...


Sunday, December 4, 2016

Easy interchangeable motor mounts...

Folks sometimes ask me why I like clusters so much - while it is true that I like duplicating reality (practically all launch vehicles of size make use of clustered engines), it is also true that the variety of black powder (Estes/Quest) motors has decreased with time. No longer do we have the "port-burning" B8, B14, or C5 motors, capable of propelling heavier models off the launch rod or serving as the 1st stage booster in 18 mm 3 stage rockets, such as the old Estes Farside or Centuri Arrow 300. This is why the Estes Comanche-3 uses the 24 mm C11 in the 1st stage - no 18 mm motor in the current line up can safely lift the model. So when I need heavy lift, I often resort to 18 mm clusters (yeah, I know - there's the Aerotech D21, but a) it's a composite and b) is fairly expensive). Besides, clustering adds a bit more suspense to the launch and the rocket definitely looks cooler riding multiple pillars of fire into the sky.

My RX-16 blasts skyward on 2 C6-5 motors (Click to enlarge).
So you can easily see why I was intrigued when Centuri released their "Rocketry Exploration Power System Outfit" back in 1977. Designed to teach "advanced" rocketry, it featured a 18mm 2 stage minimum diameter payload model (the RX-7) and, wonder of wonders, a ST-16 (BT-60) based payloader (the RX-16) with interchangeable single and dual 18 mm motor mounts. The motor mount setup, called "Plug and go" was simplicity itself - A JT-60 coupler was glued into the main body tube at a depth corresponding to the length of a JT-60 coupler. Then the end of a motor hook was inserted into a slit cut just below the coupler; this was held in place by gluing a piece of paper-like material (Tyvek) to the body tube over most of the length of the hook. The motor mounts were constructed the standard way using JT-60 couplers. All you had to do was pull back the hook, slide the motor mount into the tube, and release the hook, which prevented the mount from separating at ejection - just like inserting a motor. My youthful self was all over this - I ordered one of these sets, which unfortunately did not last a year (I was pretty hard on rockets back then).


Pages from the Centuri Power System manual showing the construction of the RX-16
Click here for the full size scans.

Flash forward to summer of 2011 - While looking for a new project, I ran across the Power System manual on Ninfinger's site. I remembered how much I enjoyed the versatility of the RX-16, and after confirming that Semroc had all the parts (Balsa version of the plastic cone and laser cut fins being the most important), set about building a clone. However, this time I would add a 3rd motor mount - for 24 mm motors - in addition to the two that were part of the set. Because of its versatility, the RX-16 soon became the workhorse of my fleet, lofting cameras and altimeters to a range of altitudes and testing stuff like the Jolly Logic Chute Release. I love this rocket - I can choose a low impulse B for small fields, cluster A motors for school demos, or cram a D into it for altitude or payload lofting. It is incredibly flexible.

The "easy peasy" motor mount retention system
(Click to enlarge).
The motor mounts (Click to enlarge).
So flexible in fact, that I decided to include the "Plug and go" concept into Beulah, a Big Bertha derivative with a payload section. Good thing I did, for Beulah is built for survivability and turned out to be a bit on the heavy side - I have to resort to C's or D's to get decent altitude out of her, even with an empty payload section. 

Beulah - Bertha and Betty's big sister (Click to enlarge).
There are other schemes for interchanging motor mounts, like the twist and lock approach used in the the Semroc SLS kits and the MRC Concept Series. The Centuri approach has the advantage of simplicity and is very easy to implement - even for novice rocketeers. Give it a try if you want a versatile mod roc.