Brodak Smoothie Kit - Inverted Engine?

[Bob Sowder]

I am getting ready to build the Smoothie kit from Brodak.  I would like to invert the engine.  Would this be a mistake? Any how-to tips or things I should consider? Thanks.  Bob

[Steve Helmick]

Some of the Veco kits with upright engines also showed inverted engine installs in sketches, but I don't recall if there were instructions or details on how to go about it. I'd keep one eye on a set of plans for a Nobler or similar inverted plane. I'd do it in a heartbeat. Steve

[Steve_Pollock]

Bob, Tom Dixon already did it in a design he called "Smoother" and he has the plans.  The article is in the March 1985 issue of Model Aviation.

[Dennis Leonhardi]

I have Veco Smoothie instructions (as provided in the kit) in pdf form.  It actually shows 2 inverted engine installations - one cowled in, one with the engine "sticking out".

Anyone who wants a copy of this file can send me an email and I'll send the file out.


Dennis

[Balsa Butcher]

Not a good picture but the only one I could find of my Smoothie with an inverted engine. Easy to do. This was built from a Brodak Smoothie kit. I used the plan view from the original Veco Smoothie for the outlines but updated the construction technique. John Miller liked it so much he drew plans on how it's done. He is on this forum and more than likely will send or sell you a copy if you contact him. He is the draftsman who drew the plans for the Brodak Smoothie kit so the detail will just be for the front of the fuselage to show the mods necessary for an inverted cowled engine version such as this one. 

[Mike Scholtes]

Hi Pete:

I had a feeling you would join in here. That Smoothie is/was a real peach. Did you keep the same thrust line with the inverted engine as would have been with the as-shown-on-plans upright installation?

Anybody interested in the Smoothie should search the archives here, there is a ton of material on the history of the Smoothie. Also anyone considering building one needs to be aware the Veco/Dumas version is far different from the "original" Smoothie, really a completely different airplane. Palmer blessed the Brodak version as true to the original Smoothie (and I do know about the thin-wing vs thick-wing thing).

[Balsa Butcher]

Hi Mike, if I did it was unintentional-really didn't take that into consideration. I just notched the top of the F-1 and F-2 bulkheads to accept  1/2 x 3/8 maple motor mounts, kind of like what is the norm for just about every classic 35 sized stunter ever built. Seemed to work OK. Space between the mounts was filled in with balsa and aluminum mounting pads were added under the engine as per current practice. My version had a V-Splitter front end, Windy U style. I don't believe John incorporated this in his version. I have only seen his drawing once but remember it as being a very workable solution, one that Bob Palmer would have approved of. 

[Dennis Leonhardi]

Nice looking Smoothie!

Mike, I've never compared - are there significant differences between the Smoothie published plans and the Veco kit, then?

I have been impressed by the windy weather reputation.  I've judged stunt many times here, and the performance put in by a not particularly dedicated stunt flyer on a very windy day with a kit-built Smoothie powered by an OS .35 still stands out as one of the best "under the conditions" flights I've seen.

Dennis

[Mike Scholtes]

Pete: You lost me with the "V-splitter front end, Windy U style." What is that? Cowl intake? I am considering building yet another Smoothie so am interested in this detail. John Miller probably has the right answer to whatever needs to be done structurally.

Dennis: Not sure what the "original" plans might be but the Veco kit is a smaller airplane with weird airfoil that is not any of the Palmer airfoils. If you want a "real" Smoothie get the Brodak kit or ARF/ARC. I built a kit Smoothie, then got an ARF and built it as fully take-apart for airline travel. The Smoothie does have a reputation for performing well in wind. Check the archives here and maybe on Stuka Stunt for Smoothie lore.

[Balsa Butcher]

 V-splitter front end was popularized by Windy with his ST-60 stunters back in the day. It is a way of making a strong front end with good airflow and not having to use a large F-1 bulkhead. One pic worth a 1000 words, unfortunately I don't have one I could post.
As far as the Smoothie story, it had been told here before but in brief two plans were drawn, one with a thick airfoil, one with a thin. He was out of the office when the thin wing one was chosen. When he got back, there was no turning back. That became the Veco Smoothie.  The Brodak kit has a thicker airfoil which is the one he preferred.

[EddyR]

Palmers Smoothie was a building article in a model magazine before there was a Veco kit. The plans show the odd airfoil not a thick one like Brodak sells. The tail is smaller also. None of his pre T-Bird models has a thick airfoil.
Ed

[Randy Cuberly]

V-splitter front end was popularized by Windy with his ST-60 stunters back in the day. It is a way of making a strong front end with good airflow and not having to use a large F-1 bulkhead. One pic worth a 1000 words, unfortunately I don't have one I could post.
As far as the Smoothie story, it had been told here before but in brief two plans were drawn, one with a thick airfoil, one with a thin. He was out of the office when the thin wing one was chosen. When he got back, there was no turning back. That became the Veco Smoothie.  The Brodak kit has a thicker airfoil which is the one he preferred.

Actually the original designer of the "V deflector front end" was Big Jim Greenaway.  Windy picked it up from him.  Jim designed an airplane called the Pattern Master which was sorta the beginning of Windy's V deflector front end.  It was designed to control the vibration of the ST 60 "shakers" so popular during that time.  It worked pretty well and makes a very stiff front end.  Along with 1/16" Plywood doublers  and fiberglassed front fuselages.
Not a bad idea for Fox 35 paint shakers either!

A lot of the designs used that construction during the 70's 80's etc.  Big Jim was also a "Guru" of great running ST 60's and a good guy in general.

Randy Cuberly

PS: also the Smoother was a very modified Smoothie/Nobler combined concoction Smoothie looks with Nobler airfoil and moment.  Good flying airplane.  I built two of them in the 80's.

Tom Dixon has plans if anyone wants them.

[De Hill]

Bob Palmer told me (and several others) that the veco kit was the first smoothy. However, when Bob flew the original smoothy it did not perform to his desires. He quickly redesigned the smoothy  flew it , liked it, and brought the plans to veco.  The dies had already been made, and Gil Henry, the owner of veco refused to remake the dies.

Bob told me that the revised smoothy (the Brodak smoothy)  is the one he flew in competition.

[Avaiojet]

I am getting ready to build the Smoothie kit from Brodak.  I would like to invert the engine.  Would this be a mistake? Any how-to tips or things I should consider? Thanks.  Bob

Bob,

I see you're a new member, welcome!, and this is your first Thread.

A good Thread actually.

There are advantages to having an engine mounted upright. You'll never have to turn the model over to start the engine. 

All kidding aside, I'm not sure if there's any evidence of a model flying better with the engine upright or inverted?

Certainly one difference is in the appearance, obviously. The eye of the beholder.

IMHO. To me, there's just something fitting about an engine in the nose of a well designed model airplane sitting upright. 

Especially a model originally designed for an upright engine.

Be interesting to see what you decide?

Welcome again!

Charles

[Bob Sowder]

Bob,

I see you're a new member, welcome!, and this is your first Thread.

A good Thread actually.

There are advantages to having an engine mounted upright. You'll never have to turn the model over to start the engine. 

All kidding aside, I'm not sure if there's any evidence of a model flying better with the engine upright or inverted?

Certainly one difference is in the appearance, obviously. The eye of the beholder.

IMHO. To me, there's just something fitting about an engine in the nose of a well designed model airplane sitting upright. 

Especially a model originally designed for an upright engine.

Be interesting to see what you decide?

Welcome again!

Charles

Thanks Charles for the welcome.   Seems to me that most designs of that era did have upright engines. This is my first CL kit in years. Gas FF for the past 10 years.  Lots to learn from CL fliers that are great building techniques for FF guys.

[Dennis Adamisin]

Bob
WELCOME to Stunt Hanger.

One of the members here is John Miller.  I believe John did the CAD work/engineering of the Brodak Smoothie kit and also has a drawing showing how to convert the Brodak to the inverted engine variation.  He moderates the CAD Forum on SH.  Also, go to the Vendor's section of SH look for CAD Classics plans - that's John's business header...

[Mike Scholtes]

Back to Bob's original question, the photo of Palmer's Smoothie on the box and the plans (or sketches), and the sketches themselves, feature an inverted engine just like Pete's yellow and black model in the photo above. I pulled my Veco Smoothie kit box down from the rack to have a look at the photos and sure enough, the box art and "plans" show the inverted engine. AirClassix posted a picture of the "plans" above. The plans show two versions of inverted installation, one that drops the engine in from above so it rests on the top of the motor mounts. I am sure whatever John Miller penciled out is a better idea. Thrust line for the three variants all seem to be different from each other, so it must not make much difference on this model. The box says the Smoothie is "designed for windy weather" but that's in terms of what was known about stunt design in 1951.

[Avaiojet]

I purchased a Smoothie as far back as the early 60's. It was the thin wing model with the engine sitting upright.

White and orange, built by my friend's dad. He had many models hanging in his garage but all I could get was the Smoothie.

It didn't fly well at all with the thin pointed wing.

Compared to the Thunderbird I built from a kit, which, BTW, I inverted the engine, the differences in flight were many.

The thicker blunt airfoil on the T-Bird, was probably the difference?

I had a great time with my Thunderbird. All black with white trim and the white trim was outlined with a thin green line.

I remember the model and the building, but I cannot remember what happened to it?

It's on my bucket list, the bucket with the hole in it.

Charles