Boeing 727 build
12-21-2018, 09:45 PM
#1
Boeing 727 build
Hello I have not posted in a long time. I am currently building a 62 inch wing span b-727. I reduced the planes from a 100 inch model. The original planes call for two 90mm edf's. I am seeking help on what edf's I should plan on using. I want to keep the no 1 & 3 engines as close to scale as possible. I know weight and balance is of great concern. I will need advice on thrust requirements and battery size. The original planes do not call for landing gear but I plan to put retracks on it.. Also the original plans call for tissue or silk covering, I plan to balsa the wing and Fuselage.
I have cut out all the fuselage formers and am close to assembling the fuselage. I plan to do a building blog as soon as I figure out how to upload pictures. I am a retired airline pilot with over 9000 hours as captain on this aircraft and an experienced R/C modeler for over 55 years.
Thanks for your advice and input.
John Castronover
I have cut out all the fuselage formers and am close to assembling the fuselage. I plan to do a building blog as soon as I figure out how to upload pictures. I am a retired airline pilot with over 9000 hours as captain on this aircraft and an experienced R/C modeler for over 55 years.
Thanks for your advice and input.
John Castronover
Last edited by jfcgnv; 12-21-2018 at 09:48 PM. Reason: spelling
12-22-2018, 10:46 PM
#3
Join Date: Nov 2010
Location: Coffs Harbour NSW, AUSTRALIA
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Hello I have not posted in a long time. I am currently building a 62 inch wing span b-727. I reduced the planes from a 100 inch model. The original planes call for two 90mm edf's. I am seeking help on what edf's I should plan on using. I want to keep the no 1 & 3 engines as close to scale as possible. I know weight and balance is of great concern. I will need advice on thrust requirements and battery size. The original planes do not call for landing gear but I plan to put retracks on it.. Also the original plans call for tissue or silk covering, I plan to balsa the wing and Fuselage.
I have cut out all the fuselage formers and am close to assembling the fuselage. I plan to do a building blog as soon as I figure out how to upload pictures. I am a retired airline pilot with over 9000 hours as captain on this aircraft and an experienced R/C modeler for over 55 years.
Thanks for your advice and input.
John Castronover
I have cut out all the fuselage formers and am close to assembling the fuselage. I plan to do a building blog as soon as I figure out how to upload pictures. I am a retired airline pilot with over 9000 hours as captain on this aircraft and an experienced R/C modeler for over 55 years.
Thanks for your advice and input.
John Castronover
12-23-2018, 04:49 AM
#4
Thanks Joseph, You are the second person top recommend 70mm fan units. I was hoping to get away with 50 or 60mm units as this would keep the engine nacelles close to scale in size. Do you think this is possible? What about three 64mm engines? Is there a high performance 64mm set available? Is there a formula for thrust to weight for EDF's. I have flown prop electrics and use the formula of 150 wats per pound as a guide for sport flying. Thanks for the input.
12-23-2018, 07:22 AM
#5
Hello I have not posted in a long time. I am currently building a 62 inch wing span b-727. I reduced the planes from a 100 inch model. The original planes call for two 90mm edf's. I am seeking help on what edf's I should plan on using. I want to keep the no 1 & 3 engines as close to scale as possible. I know weight and balance is of great concern. I will need advice on thrust requirements and battery size. The original planes do not call for landing gear but I plan to put retracks on it.. Also the original plans call for tissue or silk covering, I plan to balsa the wing and Fuselage.
I have cut out all the fuselage formers and am close to assembling the fuselage. I plan to do a building blog as soon as I figure out how to upload pictures. I am a retired airline pilot with over 9000 hours as captain on this aircraft and an experienced R/C modeler for over 55 years.
Thanks for your advice and input.
John Castronover
I have cut out all the fuselage formers and am close to assembling the fuselage. I plan to do a building blog as soon as I figure out how to upload pictures. I am a retired airline pilot with over 9000 hours as captain on this aircraft and an experienced R/C modeler for over 55 years.
Thanks for your advice and input.
John Castronover
I also have a type in the 100. I’m building a turbine version with an 81” ws. The design and plans, which are kind of non-existent are in German. I bought the fiberglass plugs of the nose and tail, along with the retracts from Germany. The center section is of hollowed foam to make the fuse, balsa sheeted for a total length of 120” for the 200. The guy was sick that used to cut the wings, so cutting my own, then sheeted. There’s now an ARF out for the turbine version, there wasn’t one when I bought the short kit. With electric you aren’t too concerned about an engine loss. With turbine, they have only figured out how to have two engines operate together in the last couple years. The biggest issue was one engine would read the rpm’s of the other engine and causing it to shut down. So, long story short, the turbine version is a single one in the center. Keeps cost down and the KISS theory. Plus, when the kit was designed, small enough turbines weren’t available for #1-#3. Expected weight will be about 25-30#, and will be using around a 20# thrust engine. As you are aware with full scale thrust to weight is approximately 1:3. And you know how that is on a hot day. With models, the closer that you are to 1:1, the better. I wouldn’t go any less 1:2, or 50% of GTW. Also take in consideration of your flying field whether it is a grass or paved runway.
If you decide to go with one in the center, I have a BVM VioFan 10s that I bought from an estate sale. It’s new, but was mounted in a BVM F86 that wasn’t finished. I have tested it, and it works as described.
Boeing 727 ,Maßstab 1/16 - GRUMANIA JETS
Electric Power
12-23-2018, 06:04 PM
#6
Join Date: Nov 2010
Location: Coffs Harbour NSW, AUSTRALIA
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Thanks Joseph, You are the second person top recommend 70mm fan units. I was hoping to get away with 50 or 60mm units as this would keep the engine nacelles close to scale in size. Do you think this is possible? What about three 64mm engines? Is there a high performance 64mm set available? Is there a formula for thrust to weight for EDF's. I have flown prop electrics and use the formula of 150 wats per pound as a guide for sport flying. Thanks for the input.
I used to fly two similar size "777s" foamies on 64mm/3S fans but it was a floater. tho very scale lookalike.
12-31-2018, 06:51 AM
#7
OK, I need help. I have taken several pictures of my 727 build and progress. Now how do I up load them to this thread. They are successfully transferred from my camera to a file on my computer but for the life of me I don't and can't get them transferred to this thread. Also how do I edit my first thread. the original plans call for a 90 inch wingspan not a 100 as posted. the reduction still will be a 60 inch wingspan
12-31-2018, 12:47 PM
#9
Join Date: Aug 2012
Location: Dallas, TX
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Thanks Joseph, You are the second person top recommend 70mm fan units. I was hoping to get away with 50 or 60mm units as this would keep the engine nacelles close to scale in size. Do you think this is possible? What about three 64mm engines? Is there a high performance 64mm set available? Is there a formula for thrust to weight for EDF's. I have flown prop electrics and use the formula of 150 wats per pound as a guide for sport flying. Thanks for the input.
Last edited by 11blades; 12-31-2018 at 01:20 PM.
12-31-2018, 04:22 PM
#10
I tried your advice and my computer is telling me my pictures are in an un authorized file or format. I am so frustrated. I can open them on my computer so I know they are there and work. I took the pictures on my I phone and sent them to my e mail on my computer.
12-31-2018, 04:51 PM
#11
Yeah, I understand computer frustrations. I to have an iPhone and have found your exact problem. It does work if you upload them from your iPhone to RCU. I just uploaded pictures to Market ads with no issues. Try from your phone.
When responding, there’s a “Current Attachments” under the response box. Wait until 3 selection boxes appear. Use the link that says “My Device “, this will allow you to choose from the pictures on your phone. Do not use “My Album “, it is for pictures that are already uploaded to RCU.
When responding, there’s a “Current Attachments” under the response box. Wait until 3 selection boxes appear. Use the link that says “My Device “, this will allow you to choose from the pictures on your phone. Do not use “My Album “, it is for pictures that are already uploaded to RCU.
