Thursday, March 26, 2020
Tom Boice has worked for a number of years with the old O.S. .60 open rocker four stroke glow engine converted to spark ignition for SAM Texaco events. A number of mods to get 33 minute motor runs on 28 cc of fuel. Special fuel tank as seen in photo. Head shim to decrease compression for gasoline fuel. Remote O.S. .20 four stroke glow engine carb used (see photo below). Special fuel formula and probably other mods I am not aware of. I can verify the 33 minute motor runs as Tom let me fly his 1600 sq. in. Bomber in Texaco last year at 3 SAM contests in the Mid-West. Three contests and three 1st place in Texaco with Tom's big Bomber.
At the last of these three SAM contests at Fort Wayne, Indiana Chuck Hutton offered me his old O.S. .60 open rocker four stroke glow converted to spark for Texaco. I accepted Chuck's offer and he mailed it to me after the contest. I cleaned it up and sent it to Tom with two spark plugs and two ignition modules. Spark plugs may not be the brand that Tom uses. Tom said it looked new until he checked it out and could see it had been run a lot with carbon on exhaust valve. Tom said it is a very good engine and he did his mods and gets 33 minutes with a 18/10 prop turning 2,500 RPM. With that prop that is all the RPM you need for a regular size Bomber.
Friday, March 20, 2020
Tuesday, February 18, 2020
Click HERE to comment. Please!
I am writing to express my disapproval of proposed regulations to substantially limit, hamper, and interfere with a time-honored hobby, namely that of RC (Radio-Controlled) Model Aviation. My brother and I found great fruit in the construction and flying of model airplanes, ever since our childhood, and my brother himself was partially inspired by the hobby to go on to pursue a degree from Notre Dame University in Aeronautical Engineering, and subsequent career work with an aerospace contractor - all beginning with this noble hobby. Both of us obtained pilot licenses, which again were pursuits inspired originally by involvement in the venerable pastime of model aviation. How many American innovators, engineers, scientists, technicians, etc. associated with such aviation-related American corporations such as Boeing, McDonnell-Douglas, Cessna, Piper, Beechcraft, etc., etc. had similar origins of their careers in this admirable hobby of model aviation ? Hence, please do not waste time and government resources to unnecessarily regulate a perfectly self-governing pastime, which does not pose, nor has ever posed any kind of threat to the safety and well-being of American citizens.
- Fr. Joseph C. Klee
I have been in modeling since 1936 and a member of the Academy of Model Aeronautics for most of those years. We have had in effect all these years safety rules and insurance to cover membership. If you will look at the record if the AMA you can see that the vast majority of members are followers of the safety rules. There is no instance that I am aware of, where modelers have been a risk to national security. I know noting of drones and do not own one.
The adoption of a rule governing UAS all modeling in general is unjust and unfair. At age 93, I fly only old timer models designed n the 1930-1950 era. These are balsa and light film covered models which are built by members of The society of Antique Modelers.(SAM). SAM is a specie interest group within the AMA and follows all rules plus SAM has specific rules regarding which models and engines can be used. Most SAM models weigh < 8 pounds. SAM models are inherently stable, meaning that they were designed long ago for free flight. We now use radio so that chasing is reduced to a minimum.
SAM competition is primarily climb and glide. The power of engines is designated related to the size of the model and only certain models are approved ( only those from the era noted above) . Engine runs are limited by rule, corresponding to the model size ad weight. Most events involve models of 8-12 ounce wing loading per square foot of wing area. Thermal recognition and flying skill are involved.
From the above description of SAM, it is obvious that the 400 foot limitation of altitude will do away with this segment of the hobby and associated distributors and many shops which make up the model aircraft industry. I realize that other modelers have different views and comments, so I repeat that one set of rules does not fit all. We would like some compromise which will protect our airways, but at the same time allow modelers to continue what we have been doing for years.
I am now age 93 and a retired physician, a Life Member of the AMA, Member of the SAM Hall of Fame and belong to the Model Engine Collectors Association. I would like to remain an active modeler as long a health permits.
Dr. George Shacklett
Sunday, February 16, 2020
Friday, February 14, 2020
I stumbled across your blog and saw you had a resource section on the left. I work with Fintech Industrial Abrasives. They're a family-owned abrasive provider based in Michigan. They'd love to be able to provide abrasives for your readers. Is there any way they could be added to that links section? You can learn more about Fintech here: https://www.fintechabrasives.
Tuesday, February 4, 2020
Sunday, February 2, 2020
Tom, Late 1950's a fellow I knew made a single channel R/C model of the Stahl Fokker D-VIII. It flew well and I wanted to build one. I did for the 2006 SAM Champs. See photos. Now a 1/4 scale model using Stahl plans... I have acquired a fiber glass cowl, Wheels and vinyl markings. Plans enlarged by AMA Plans Service. Probably years before I get it built. A home for the Laser four stroke .80 diesel. Jack Hiner
Friday, January 24, 2020
Polyspan and Spunbonded Polypropylene From Mike Myers.
Rudy Hewert asked: Gents; In following this discussion, I am getting somewhat confused by the names of the vari- ous products. Anyone know who actually makes "Polyspan Lite"? Polyspan, Polyspan Light (sold by Larry Davidson and maybe Mike Woodhouse), Salzer Tissue, and SAMSpan (polyspan sold by SAM 27 in Northern California) are all vari- ants of the same thing - spunbonded polypropylene. It is an industrial product and it's made by a lot of people. (In my old work life I was a lawyer who helped form a joint venture and gave ongoing business legal advice to a world scale polypropylene plant that was built in Southern California.)
Here's what Dupont has to say about "Spunbond Polypropylene": DuPontTM Spunbond Polypropylene is a non-woven fabric composed of thermally bonded, continuous polypropylene filaments. The structure gives it good filtration properties and tensile strength even in diagonal direction. In addition, it is made of 100% polypropylene, which makes it resistant to moisture and chemical attack. It is a unique composite media that combines polymer technol- ogy with DuPont nonwoven manufacturing expertise. The polypropylene based material is an exceptionally strong yet light, pleatable material with excellent drainage and permeability properties. It is manufactured by a unique inte- grated process in which continuous filaments of polypropylene are spun and then immediately formed into a multi- directional arranged web that is heatbonded at filament crossover points.
Polypropylene comes out of the reactor in the polypropylene plant as a white plastic pellet about the size of large rock salt. It's then shipped to fabricators. Fabricators melt that plastic pellet and do lots of different things with it by running it through extruders, moulding machines etc. It shows up in plastic deck chairs, flower pots, medical trays, in a clear film wrapping cigarette packs and CD's - and in various "spunbond" forms. That spunbonded polypro- pylene is a fabric. It's made in as many different weights as there are manufacturers and end users. We sold a lot of it to people who made disposable diapers. It gets rolled up and used in filters - cigarette filters, water fil- ters, automobile oil filters, for all I know. It also gets used in sheathing or interlining or facing material that you can buy at your local fabric store. In thicker fabric weights it gets used to make disposable lab coats, Hazmat suits etc.
The manufacturers have large capital investments in these machines - one of our customers was making clear film in China. He had the film coming off the machine at about 2,500 fpm - or close to 30 miles per hour in a roll that was 10 feet wide. You'll note on Mike Woodhouse's earlier post that when he got some light polyspan from a manufac- turer in Austria, he had to buy a 2.5 kilometre long roll of the stuff.
Since spunbonded polypropylene is a plastic, it doesn't react to water - and so doesn't shrink when you spray it. It does react to heat, so you can shrink it or set a different warp in a wing through use of a heat gun. And because it doesn't react to water, it doesn't sag on a damp morning.
For our modelling purposes, we want it in the relatively lighter weights. You can buy "Polyspan" from the usual sup- pliers - Woodhouse, Davidson, some of the local hobby dealers and cottage industry people. That stuff is all good, and a lot of us use the material in just a single coat with nothing but dope.
But if you can't find a polyspan supplier and you're in a pinch you can go to the local fabric store (they still have a few of those around) and look for dress interlining or interfacing. That material is spunbonded polypropylene. The sewing and tailoring folk use this stuff to thicken up colours, cuffs, coat lapels etc. It comes in white - any colour you want, so long as it is white because after all it's going to disappear inside the finished article of clothing.
It comes in several different weights so you need to look around. The lightest stuff is probably not useful, so go for the medium or heavier weights. Most of the stuff that I've seen is light - a bit lighter than Larry Davidson's "Light Polyspan", and would take a lot of dope to fill. But if you are going to double cover with tissue or silk over the material, then there's a lot to be said for it. The polypropylene fibres run in all directions and are bound to each other by heat - so you add tremendous tensile strength to whatever you already have in the tissue or silk where the fibres tend to run at right angles to each other.
As long as you're down at the dress or fabric shop, you might also look at the coloured dress sheathing material. A lot of this stuff is made from polypropylene or other plastics. I covered a Peerless Panther in red and silver grey dress sheathing in the late '80s, and flew it with a Mills 1.3. The red and grey was heavier than silk, but it was hell for stout and that was just fine for a sport model. Unlike silk the colours never seemed to fade much in the sun.
You have to be careful with the coloured dress sheathing when you put it on, because it doesn't shrink with water, or much with tautening dope for that matter. It does shrink with heat. I still have some of it - as I recall it was like $3 a running yard of material that was 50 inches wide - when I was paying $10 a square yard for Esaki silk. Cheap is good!