A bit of reminiscing: my dad built one of the first of the Goldberg Shoestrings way back in the early 1960's(?) it was a step forward aesthetically versus the other porfile models of the day and did a slick job of introducing the Cheek Cowl on a profile.  A couple years later I had THE FIRST Cosmic Wind sold by our LHS and quickly had it airborne.

So here it is some 50 year's later and I embarked on a project to convert the no Brodak Cosmic Wind to electric power.  Myfirst layouts had the motor where the IC engine went - and it was a stupid layout.  The simple fact is that it is makes the most sense to locate a mounting firewall on the center of a profile.  Using one cheek cowl looked silly, leaving the cheek off completely was simply never an option.  Instead I turned the X mount (modified) into a "+" mount, aligned vertically with the profile fuselage, with one arm in the stock cheek cowl.  I ADDED a second cheek cowl to support the other arm of the firewall as well as balance the aesthetics - it looks really cool this way.  The motor is NOT internal, but it is semi-hidden in plain sight and should get spectacular cooling.

I did not like any options available for mounting the battery on the fuselage so the wing is modified to carry the pack ahead of the main spar.  The spar got a lite ply shear web added and the battery box top and bottom shells form an box structure open to the front to allow insertion of the pack through the cut-out leading edge.  This also gets the battery down on the wing center and (compared to the IC version) greatly reduces the vertical CG effect for the low wing.

Carl Goldberg was an innovator, I think he would approve.

Anyhow, the prototype has been built, and I am writing up the instruction manual.  The conversion kit will include wing mod parts, fuselage mod parts and a instruction sheet.  It should be available very soon, but that is a little hard to predict because the Brodak folks will be essentially shut down for the Fly-In next week.

Oh Denny, that's really nice!  One question, what retains the battery in it's little cubby hole?  I completely agree with your assessment that the rear mount firewall is the way to go with profiles, I have been doing that way for a couple of years now and it works.  I look forward to seeing the finished item and a report on how it flys.  I too had a Cosmic wind (or was it the Shoestring Stunt?) back in the sixties with a McCoy .35, it was fun. 

I had the good fortune to meet Carl Goldberg once at a convention in Long Beach Ca.  He was manning the company booth.  My son Greg was about five and he had lots of questions for Carl, when I tried to slow Greg down Carl turned to me and said something to the affect "he has questions for me, let him ask".  Mr. Goldberg was a real gentleman.
Andy

Dennis

Very, very good !  Are the cheeks hiding the ESC & Timer also ? 

Knowing what a PITA making electric conversions can be, you obviously have nothing better to do except practice self inflicted sadisim. What no honey do's?  Too much time on yer hands, eh?
I'm still stuck on my Electra.

Hi TY

My job situation forces me to live in a hotel weekdays and home on weekends.  So weeknights I am teaching myself CAD while I design electric installations - hopefully making it easier to convert not just Brodak airplanes but Electras too.  I send the designs off to Brodak and they laser cut the kits used for the prototype build and the assembly manual.  When I get home on weekends I build like crazy so I can take pictures and write the assembly manual.  Usually I discover a needed tweak and will touch up the design before the final release.  When the build is far enough along to complete the manual for the conversion kit, I set it aside and start on the next one.  I now have a basement full of half built airplanes!

One thing I like about doing the Cosmic Wind is that it is a nice flying simple sport model, hopefully it will help make it easier for a few more folks to discover ECL.

No doubt Profiles are the worst to do, because anything larger than a 1/2A is not designed for a firewall.  I think we need so start building up the noses for a firewall, like the Imitation - but that is gonna cause some political heartburn I'm afraid...

SO what is giving you grief with the Electra conversion?

Man them cheek cowls are the Cat's whiskers ! Looks like a home run Dennis.

That is one of the questions I have had and never asked, "How does your electric qualify as a profile according to rules I have seen for the profile events"?   I had a scale racer years ago that had an inverted engine.  But, it had engine mounts down each side of the fuse and fuse was notched out for the fuel tank and shut off.

That is an interesting question Doc - cannot say I really have an answer for you.  To start with, it is not an electric question; even the STOCK Goldberg Shoestring, Buster, and Cosmic Wind violate the letter of most contemporary profile rules by being well over 1" wide.  Tho I pity the fool CD that would DQ them from a profile stunt contest.

ANYBODY who looks at this airplane, sees the 1/2" slab fuselage with the 1/16" ply doublers will without hesitation conclude "that's a profile".  However that may change when they get to the "firewall reinforcements" - that is of course the cheek cowls that keep in theme of the original design and the full size airplane.

Part of the problem is that there really is not a hard & fast universal RULE about what constitutes a profile.  I think the Scale folks use a 1" wide rule, but note that even the STOCK Goldberg kit from 50 years ago violates that definition by being well over 1" wide.

Dick Mathis' Excaliber demonstrated how to make a profile with side doublers on both sides reinforcing the LE joint - the weak spot on profiles since forever.  Ted Fancher used a similar idea and reasoning on his Imitation, then took it a step further by finishing off the nose for a firewall so he could invert the engine - fixing the OTHER flaw common to profiles.

Then there are the Crutch style profiles like the Over Easy, Testors Freshmen & Sophomore, and AL Rabe's Mustunt 1.  NONE of these abide by the 1" guideline - would they be banned from a profile contest?

Let's get even grittier: you have likely seen any number of "modern" profiles where the builder puts a full round nose ring and blends it into the fuselage to kind of finish off the front end, maybe stiffen it a little.  They look absolutely great.  Has anyone ever stopped to think that these are in absolute violation of the 1" definition of a profile?


Profiles are intended to be simplified, easy to build, easy to service, & rugged.    Folks justify all manner of fuselage doublers & triplers to brace the wing to fuse joint, why not allow bracing for a firewall for an electric motor?  We need to rethink what constitutes a Profile, in light of the fact that we can now use power systems that require firewall mounting.


Of course let's circle all the way back to the subject of this post, the Cosmic Wind.  As you have seen lots of the posts here are reminisces about having this or one of the other Goldberg's when they were learning to fly.  These are great sport models, in no danger of ever winning the National Stunt Championships.  Instead of worrying about what is "legal" (especially when there is no clear definition) why not focus on making a great looking profile Cosmic Wind then celebrate how much fun it is to fly?

Thanks for the reply Dennis.   The profile planes I have built and seen have pushed the definition of profile.  I like the looks of the Shoestring.   I'm for getting more people flying, but at my age it has become a hindrance getting out to work with them.  Did I say I love what you are doing.