Being a compulsive builder I have had much assistance from the Forum in obtaining plans, this being the latest. I built an original size Powerhouse (80" span?) some years ago but fancied a smaller version! This one is resized to 44" span, a nice "handleable" size! It`s a simple budiling process for anyone used to building from plans and I`ve enclosed some pics. showing the progression of building. I have been building and flying for many years and seem to have stuck in a time warp at the 40`s and 50`s as most of my efforts are of this vintage! I`ve always thought that vintage style models are very relaxing to fly and make excellent trainers, far more so than the overweight, overpowered offerings from the trade. Just a personal thought! I`ll post more pics. as the model nears completion and hopefully of it`s maiden flight! PS. seems like the pics. have posted in the wrong order, but you can see the progress!

Nice Bob, I look forward to seeing it come together. I agree with your comments on vintage as trainers. Set up right you can just take your hands off and they sort themselves out. They were free flighters after all.

All the best for the New Year.

Allan

Cool!
Regarding scaling down to 55% - How much did you reduce the thickness of your balsa? Are you just building everything smaller, or are you also reducing the number of formers etc.?

KNS:I believe he scaled up the Model Builder plan of the .020 size Powerhouse. The original plan from Model Builder sported a 36" WS.

The Model Builder plan suggests 1/8 sq. balsa for the fuselage framing, wing tips, tail frame outlines. Now I also have the 42"WS version of the 1/2A Powerhouse from Bob Holmann Plans and that one suggests 5/32" sq. for the fuselage framing and the wood list for the tail and wings is the same as the 36" version. Basically everything cut in half from the original 84" Powerhouse as designed by Sal Taibi.

Hope this might help;

Greg

Originally Posted by Greg Knipp

KNS:I believe he scaled up the Model Builder plan of the .020 size Powerhouse. The original plan from Model Builder sported a 36" WS.
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Greg

Look like it. Same thing Bucky did

Thanks a lot Greg and Ryan!
I was asking to get to the thinking behind scaling model builds. The strength (density) of the balsa remains the roughly the same, but its dimensions/volume changes a lot in the process of scaling (or are you using loads less dense balsa on the smaller versions?).
Well, sorry to bother you - if there is a good book on engineering/construction principles for balsa/wooden model airplanes then please let me know and I won't pester you here any more. Just wanting to pick up a gem or two along the way .
-Kai

Originally Posted by KNS

Cool!
Regarding scaling down to 55% - How much did you reduce the thickness of your balsa? Are you just building everything smaller, or are you also reducing the number of formers etc.?

Being quite an experienced builder ( nearly 70 years! it`s not clever, you could teach a monkey to do it! ) I rarely follow plan building methods religiously as over the years I have evolved my own methods which work for me. This being so I never claim that my efforts are what the purists would call "real" vintage models! I use the basic plan outline and build in my own manner; quite sucessfully I might add! I used medium grain 3/16 for most of the fuselage frames and wing spars and 3/16 sheet for wing and tail tips This is quite an economical way to build as it only involves 3/16, 1/8. and 1/16 sheet stripped as required.. I could possibly gone smaller but I wanted to avoid "flimsy", there`s nothing worse than a model you`re afraid to handle!

Perfectly stated imp.bob as I follow the same building practices and theory as you do. In fact the 1/2A version I have is literally a 50% reduction from the original 84" version as I mentioned. That being said, the plan calls for 5/32 " sq. balsa for the fuselage. Ever try finding that size? I utilize standard size wood ( in this case 3/16" sq.)and change construction methods to ones that work for me as well. I too understand light can be better but I don't want to be affraid to fly the model either.

Greg

BTW. I am just loving your progress!!!!!!!!

Originally Posted by imp.bob

Being a compulsive builder I have had much assistance from the Forum in obtaining plans, this being the latest. I built an original size Powerhouse (80" span?) some years ago but fancied a smaller version! This one is resized to 44" span, a nice "handleable" size! It`s a simple budiling process for anyone used to building from plans and I`ve enclosed some pics. showing the progression of building. I have been building and flying for many years and seem to have stuck in a time warp at the 40`s and 50`s as most of my efforts are of this vintage! I`ve always thought that vintage style models are very relaxing to fly and make excellent trainers, far more so than the overweight, overpowered offerings from the trade. Just a personal thought! I`ll post more pics. as the model nears completion and hopefully of it`s maiden flight! PS. seems like the pics. have posted in the wrong order, but you can see the progress!

This is the latest situation with the model. The weight has come out just about as I wanted and after a bit more "fettling" it`ll be ready for covering. Most of my previous models in these later years have been larger than this one, and I`ve normally used Solartex with which I have become quite familiar! I don`t want to go back to tissue and dope and I`m not sure which of the lighter more modern coverings would be best. I`ve tried Litespan but I`m not too keen on it. Any suggestions would be gratefully received! More pics. when more happens!

For a plane that size I wouold suggest Nelson Litefilm or Stevens Aerofilm Lite which is the same type of material. It is like Monokote but much thinner and lighter but with fewer color options.

For my Powerhouse I am contemplating using the transparent yellow for the main color and the solid red for trim to keep with the original color scheme.

Greg

Originally Posted by Greg Knipp

For a plane that size I wouold suggest Nelson Litefilm or Stevens Aerofilm Lite which is the same type of material. It is like Monokote but much thinner and lighter but with fewer color options.

For my Powerhouse I am contemplating using the transparent yellow for the main color and the solid red for trim to keep with the original color scheme.

Greg

Thanks for taking the time to answer. One problem I`ve discovered with modern coverings is that they have different names in different countries so you`re never quite sure what is what! In the UK the one that comes closest to what I would like is called Litespan but I`ve tried this and wasn`t too happy with it. I think there`s something called fibafilm(?) which looks like doped tissue. Anyone familiar with this or something similar?

Originally Posted by imp.bob

Thanks for taking the time to answer. One problem I`ve discovered with modern coverings is that they have different names in different countries so you`re never quite sure what is what! In the UK the one that comes closest to what I would like is called Litespan but I`ve tried this and wasn`t too happy with it. I think there`s something called fibafilm(?) which looks like doped tissue. Anyone familiar with this or something similar?

I've heard that what Coverite sold as Micafilm was actually repackaged Fibafilm. It had no adhesive of its own and was ironed onto the structure after an application of their Balsarite. It's not bad to work with, just a little more finicky than Monokote, and getting it to go around compound curves is what I would call "technique-driven." My only complaint was that it seemed to required continual re-shrinking before it finally settled down.

In the UK you would want to look for Nelson litefilm and it comes in 2 meter rolls. If you come across Solite it is the same stuff.

Honestly I think the only thing that changes is the manufacturers name and label but the plastic itself is made in the same factory.

Greg

Originally Posted by imp.bob

This is the latest situation with the model. The weight has come out just about as I wanted and after a bit more "fettling" it`ll be ready for covering. Most of my previous models in these later years have been larger than this one, and I`ve normally used Solartex with which I have become quite familiar! I don`t want to go back to tissue and dope and I`m not sure which of the lighter more modern coverings would be best. I`ve tried Litespan but I`m not too keen on it. Any suggestions would be gratefully received! More pics. when more happens!

Here`s the latest on the mini Powerhouse build. Just about ready now, it`s only my extreme aversion to the current cold weather`s effect on my ancient bones that`s holding up it`s test flight! I decided to go with Solartex in the end, the weight penalty against other coverings must be minimal taking into account Balsaloc and/or dope. I`m comfortable with Solartex and the all up weight is still only 24oz. for a wing area of 2.5 sq.ft. so I`m quite happy with that! It`s the sort of model that always flys well, after all, it was a free flight model originally and flown as radio assist should be calm and relaxing to fly as are all my other vintage types. Flying pics. to come when it happens!