PeterGregory
CrossThread Industries
While electric foamies from FT got me back into the hobby/sport/obsession of model building/flying in early 2014 - and how it did - I am now running parallel foam and balsa programs.
I thought I would write up a build thread on this balsa model in case there is any information that is helpful to someone just thinking about trying their first balsa plane - whether electric or fuel, which this one will be.
The genesis of this build started as a response to a build-off challenge on another site. I chose to find a plane that isn't covered that much or at all. The build-off challenge basis was to build a plane appearing in a US publication up to and including 1965. My sense of nostalgia has been raised from having a ball on the outerzone.co.uk site that SteveWMD runs, reviewing all the old plans that he is posting up there - the earliest plan I've found going back to 1911, a Wright Flyer only 8 years after it first flew. Imagine that - a plan that is 104 years old.
In the world of smallies - 1/2A and A engines up to about .10 ci displacement, a few prolific designers are found on the outerzone (OZ) site. Ken Willard's designs emerged as a bunch of fun-to-build-&-fly planes that take modern miniaturized RC very well.
I actually got started unofficially on this build well back some 7-8 months ago, starting to build up tools for a bench that will get me good results and speed my progress. A mini table saw and a scroll saw from Dremel have really helped out, cutting out patterns and parts. The table saw let's me buy sheets of balsa locally and rip them to sizes I need. The big benefit is I can buy the hardness of balsa I need, make sure it is a straight piece, and cut many straight pieces from it - rather than sorting through balsa for many straight pieces. Also, I had to get a CA glue, CA kicker, wood glue, and a metal building surface. I went to Harbor Freight and got a bunch of magnets for the sheet metal building surface - I had never built this way before but reading up on it, I thought it sounded fast and easy. No sticking pins through and aside balsa pieces into a soft building surface like cork or pine. It turned out to be a good investment, it is really fast to build this way, and very adaptable as you can move magnets around fast to accommodate whatever you are building.
As I started building, I started computing when the last time I built a balsa plane was - and it was at least 24 years ago. I have that unpowered sailplane sitting in the corner of this room, right now - used to get a fare amount of use, took a few repairs well, and is ready to fly.
If you want to learn a something about balsa, I was pointed to a really interesting place on the Sig site, that you may be interested in, too, that has tech information about the different cuts of balsa you can buy - different cuts are good for different things. A really good article on balsa:
http://www.sigmfg.com/cgi-bin/dpsmart.exe/IndexInformVideosF.html?E+Sig
You have to get used to identifying the different cuts, and gauging its thickness and strength. I needed hard balsa strips as spars for my wing, but soft balsa for wingtips. Soft is generally lighter and easier to shape, hard is heavier and stronger.
The plane I chose to build, and now is partly done, is the Ken Willard Duranita from 1953, printed in Model Airplane News (MAN). It is a funky biplane, with a flat (no dihedral) smallish lower wing, and a gull upper wing. I thought that was unusual. When I did some googling about the plane, I found virtually no coverage of this plane, whatsoever. That really got me interested - hopefully, no coverage does not equate to not fliable(!). I wish we still had Mr. Willard with us so I could find out more about this design from him. He is in the AMA Hall of Fame.
The desig was originally designed for a .049 diesel engine, as a Free Flight model (FF). There was a lot of skill in designing, building, and then trimming an airplane like this back in the day to get about a minute of flight from it. More than that and it might fly away on a thermal or gust of wind. That seems unbelievably common in the accounts I read about FF flying, which is still active today - just not in populated areas. FF is still big in the UK - great videos on youtube.
Anyway, here is a scanned photo of the plane from the original article:
There will have to be mods to take it from FF to RC as it does not have a true rudder, elevator, or ailerons. I am scaling up the design to 115% and so will have to strengthen the spars, leading edge, and trailing edge.
In the next entry I will post a screen shot of the plans, and what I had to do to get a copy of them in order to build on the bench.
My build criteria for taking plans of OZ is to build planes not covered at all and possibly don't even have a photo of it on the OZ site - plans only. As mentioned, this fits the bill.
The Duranita is an interesting crossover plane from the time with FF was still going gung-ho to the advent of better small engines, especially the ubiquitous Cox engines. So some of the lines have an old-timer look I want to preserve. And, RC gear was gradually becoming more available.
That's it for now, let me know if you have any questions along the way.
Cheers,
Peter
I thought I would write up a build thread on this balsa model in case there is any information that is helpful to someone just thinking about trying their first balsa plane - whether electric or fuel, which this one will be.
The genesis of this build started as a response to a build-off challenge on another site. I chose to find a plane that isn't covered that much or at all. The build-off challenge basis was to build a plane appearing in a US publication up to and including 1965. My sense of nostalgia has been raised from having a ball on the outerzone.co.uk site that SteveWMD runs, reviewing all the old plans that he is posting up there - the earliest plan I've found going back to 1911, a Wright Flyer only 8 years after it first flew. Imagine that - a plan that is 104 years old.
In the world of smallies - 1/2A and A engines up to about .10 ci displacement, a few prolific designers are found on the outerzone (OZ) site. Ken Willard's designs emerged as a bunch of fun-to-build-&-fly planes that take modern miniaturized RC very well.
I actually got started unofficially on this build well back some 7-8 months ago, starting to build up tools for a bench that will get me good results and speed my progress. A mini table saw and a scroll saw from Dremel have really helped out, cutting out patterns and parts. The table saw let's me buy sheets of balsa locally and rip them to sizes I need. The big benefit is I can buy the hardness of balsa I need, make sure it is a straight piece, and cut many straight pieces from it - rather than sorting through balsa for many straight pieces. Also, I had to get a CA glue, CA kicker, wood glue, and a metal building surface. I went to Harbor Freight and got a bunch of magnets for the sheet metal building surface - I had never built this way before but reading up on it, I thought it sounded fast and easy. No sticking pins through and aside balsa pieces into a soft building surface like cork or pine. It turned out to be a good investment, it is really fast to build this way, and very adaptable as you can move magnets around fast to accommodate whatever you are building.
As I started building, I started computing when the last time I built a balsa plane was - and it was at least 24 years ago. I have that unpowered sailplane sitting in the corner of this room, right now - used to get a fare amount of use, took a few repairs well, and is ready to fly.
If you want to learn a something about balsa, I was pointed to a really interesting place on the Sig site, that you may be interested in, too, that has tech information about the different cuts of balsa you can buy - different cuts are good for different things. A really good article on balsa:
http://www.sigmfg.com/cgi-bin/dpsmart.exe/IndexInformVideosF.html?E+Sig
You have to get used to identifying the different cuts, and gauging its thickness and strength. I needed hard balsa strips as spars for my wing, but soft balsa for wingtips. Soft is generally lighter and easier to shape, hard is heavier and stronger.
The plane I chose to build, and now is partly done, is the Ken Willard Duranita from 1953, printed in Model Airplane News (MAN). It is a funky biplane, with a flat (no dihedral) smallish lower wing, and a gull upper wing. I thought that was unusual. When I did some googling about the plane, I found virtually no coverage of this plane, whatsoever. That really got me interested - hopefully, no coverage does not equate to not fliable(!). I wish we still had Mr. Willard with us so I could find out more about this design from him. He is in the AMA Hall of Fame.
The desig was originally designed for a .049 diesel engine, as a Free Flight model (FF). There was a lot of skill in designing, building, and then trimming an airplane like this back in the day to get about a minute of flight from it. More than that and it might fly away on a thermal or gust of wind. That seems unbelievably common in the accounts I read about FF flying, which is still active today - just not in populated areas. FF is still big in the UK - great videos on youtube.
Anyway, here is a scanned photo of the plane from the original article:
There will have to be mods to take it from FF to RC as it does not have a true rudder, elevator, or ailerons. I am scaling up the design to 115% and so will have to strengthen the spars, leading edge, and trailing edge.
In the next entry I will post a screen shot of the plans, and what I had to do to get a copy of them in order to build on the bench.
My build criteria for taking plans of OZ is to build planes not covered at all and possibly don't even have a photo of it on the OZ site - plans only. As mentioned, this fits the bill.
The Duranita is an interesting crossover plane from the time with FF was still going gung-ho to the advent of better small engines, especially the ubiquitous Cox engines. So some of the lines have an old-timer look I want to preserve. And, RC gear was gradually becoming more available.
That's it for now, let me know if you have any questions along the way.
Cheers,
Peter
Looking forward to this build for sure!
