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In search of article on how to mold folding props for Mulvihill size props. What pitch and dia. would be idea ?
Thanks..Craig H[/b]
What size model are you building and how many strands of rubber will you be using?
These factors determine the diameter and pitch.Why would you want to mold your own props??
You can purchase F1B props and front ends really cheap! And they work!
These are big enough for any Mulvihill model, and builder of the model rule does not require you to carve props or make your own front end hardware.
Likewise you can purchase Kevlar motor tubes instead of stick piecing a fuselage together.
Thank you Bill for responding. I am going to build the StratoMax but on the plan it doesn’t give you the prop size,pitch nor how many strands and size of rubber to use. Any info will be helpful.
Thanks…Craig h[/b]
Attached is a link to the SAM web site that gives info on rubber model motor sizes for various models, The Stratomax is not on the list, but it’s good info to have for future projects.
http://www.antiquemodeler.org/www.antiquemodeler.org/Model%20Building%20Tips/Rubber%20Model%20Motor%20List.htm
EdQuote “Why would you want to mold your own props?? You can purchase F1B props and front ends really cheap! And they work!”
Oh dear. Maybe its more fun to do it yourself, you can change parameters such as pitch distribution and shape and find out what happens. You can optimise to the rubber you use. Its a lot of fun. Need I go on ?
There are numerous articles on prop mounding. The latest I’ve seen is in the UK Free Flight Forum 2007; available from a few places in the US for less than the price of a set of bought prop blades.
Well I am basically a power and glider flyer. So that is why I always purchase props.
Wouldn’t it be fun to carve a P-30 prop…but then it would not be legal.
So I am having fun flying P-30s, F1Bs, and F1Gs, but maybe someday I will build an old timer, and then will be forced to carve a prop.
Mulvihill models would most likely do quite well with F1B props.
I just purchased some of the most beautiful F1B front ends and props, a real simple design, made by Igor Vivchar for his Prima models. I also have F1G front ends by Bukin which have a better montreal stop system.
I wonder how long it would take me to build something equivalent to those?
Depending on what kind of unlimited you intend to build, like a StratoMax, A wake front end and prop combination would be too heavy. By the way, I think it uses a 23″ diameter prop, 27″ pitch. 28 strands of 1/8″ rubber motor 29-30 inches long.
Subject is the name of an article in the May 1978 issue of Model Aviation. by Jim O’Reilly. If you are an AMA member you can copy it right off the archives.I have used Jim’s method successfully on a version of his Tubestake design Basically , using Jim’s spreadsheets you carve the appropriateconvex mold for the undercamber in a 2X4 pine block, drill the hole for the ‘z’ hub using a jig and then sandwich two pieces of 1/16″ balsa with 1/32″ ply for the blade root reinforcment. It works slick. It is easy to balance and it s easy to make replacement blades.
Molding props?
I’m really interested in that. Has anybody here done that?
Mike Woohouse has recently published a book called something like “Free Flight Propellors for rubber ” He has a website www,freeflightsupplies.co.uk
The book has just about everything you need to know about prop carving and moulding,and lots more.Ok, I will check out that book.
Here are some new galleries of the Squirrel:
http://www.rubber-power.com/Gallery25.htm
http://www.rubber-power.com/Gallery24.htm
http://www.rubber-power.com/Gallery23.htm
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