Stephen Jones Posted September 25, 2020 Share Posted September 25, 2020 How I make Autogyro blades for Rc Models I am sure there are different ways of shaping a piece of wood to a airfoil having tried a few myself. Take a full sheet of Balsa 36” x 4” x 6mm and glue to both edges a length of 36” x 6mm x 6mm spruce strip. A good strong wood glue or epoxy will be best to secure the hard wood to Balsa. When the glue is fully dry mark up the sheet into four by measuring the centre of the width and length like so . Alternatively if you can get hold of pine beading 900mm x 6mm x 6mm from your local hardware store then that will save you a bit of work sanding it to profile. Once the glue has fully dried cut the sheet into four Blade blanks . Now you need to sand them to profile like this. You are looking at getting all four blades to the same profile and thickness . Steve. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 25, 2020 Author Share Posted September 25, 2020 How I make Autogyro blades for Rc Models Cont........... Start by plaining the trailing edge to profile then the leading edge to somewhere near the desired profile as this will reduce the amount of sanding you will have to do. You may want to cut a hole through some ply to the desired profile to act as a guide for checking the thickness of the blade is even running the length of the blade. I figured I will brake a fair few Blades in the process of learning to fly Autogyros and so will need to make a fair few blades if I am to pursue making and flying Autogyros. And as I already have working blades I decided to copy their profile by sticking sandpaper on top of one of my blades and running it back and fourth under some hard foam to copy it`s profile. And then sticking sand paper into the formed profile of the foam block. Steve Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 25, 2020 Author Share Posted September 25, 2020 How I make Autogyro blades for Rc Models Cont........... You may want to try this method for yourself. If so concentrate on getting one blade as good as you can so that you can copy its profile.. But before you start sanding weigh all four blades. You are after three that are very similar in weight so chose the odd one out as your profiling blade. I made my profiler out of spare wood I had laying around in my shed so it only cost me the price of a pair of drawer runners. More on this later… Steve. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 25, 2020 Author Share Posted September 25, 2020 How I make Autogyro blades for Rc Models Cont........... So once you have all three Blanks sanded to profile you will need to prepare the anchor point by cutting away so that the blade can swivel around the anchor bolt in case of a ground strike and reduce damage to the blade. Now you will need to find the center of mass and the Blades balance point. Balance point first, I use a long steel ruler that it longer than my blade and place my blade on top of the edge of the ruler to find where it will balance. But you could use anything similar like this. Mark it`s balance point and glue on some thin ply to strengthen the point around where the anchor bolt will be fitted . The flat bottom of the blade will need a shim adding later so for now just glue in place . The long oblong ply sits on top of the blade centred over the balance point that you have marked up. Now drill the mounting hole through the ply and blade. Now all three blades have their ply mounts fitted weigh all three and mark up as 1 being your heaviest and 3 being your lightest and 2 the final blade. Steve. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 25, 2020 Author Share Posted September 25, 2020 How I make Autogyro blades for Rc Models Cont........... Now it is time to find the centre of mass of each blade which will most likely differ from each other Now bolt blades 1 and 2 together in order to balance them with each other. If the difference between them is only small then apply a coat of Ez dope to the lighter blade as this will add weight while sealing the wood. Pay attention to the centre of mass and try to get them as close to each other by applying the dope to one side of the blade allow to dry and re balance. Keep doing this until they both balance pay attention to the centre of mass to try and match remember you can always sand back if you have added too much of the dope or varnish if you prefer. Once you have got blades 1 and 2 to balance repeat the process with blades 1 and 3. Hopefully all three blades will now be very close in weight and balance to each other so it is time to cover them you can use heat shrink film or as I did use colored tape. First seal the edges with tape then you can start to cover the blade starting at the trailing edge. Last to cover is the leading edge so that none of the over laps are facing into the air flow. Steve. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 25, 2020 Author Share Posted September 25, 2020 How I make Autogyro blades for Rc Models Cont........... Now re check the blades balance with each other if not you can add a small piece of tape to the lighter blade to make them balance add the tape somewhere around the centre of mass location. Now you will need to add a shim to give the blade negative angle of attack when fitted to the Delta plate. I find that if I tempory bolt the delta plate to the underside of the blade I can mark where the edge of the Delta plate will be. As we do not want the shim to come off the delta plate when knocked we will fit are 1/64th ply just forward of that line and treat with Ez Dope or varnish. Now we can bolt all three blades to the Delta plate for the final balancing you may want to try the blades in different positions to get the best balance ie order as 1,2,3 or 1,3,2 . Some more tape maybe needed to get the perfect balance with all three in place. Steve. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 1, 2020 Author Share Posted October 1, 2020 Here is a quick video of me using my profiler. excuse the mess in the yard. Steve Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted October 2, 2020 Share Posted October 2, 2020 great info Stephen, thank you. ken anderson..ne..1...blade dept. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 3, 2020 Author Share Posted October 3, 2020 Posted by ken anderson. on 02/10/2020 08:31:43: great info Stephen, thank you. ken anderson..ne..1...blade dept. No problem, For years i have wanted to fly Autogyros . So anything that makes it easier for me may well help others also get into Autogyros. I think the fact i made one out of a Lidl Glider that bounces has allowed me to keep practicing. And Finally fly autogyro . If anyone would like more detailed info size dimensions on my profiler then just ask. although i think it is pretty self explanatory. Cheers Steve. 1 Quote Link to comment Share on other sites More sharing options...
Richard Franks Posted October 30, 2021 Share Posted October 30, 2021 Hi Steve A question about chord wise balance point if i may please.when i check the chord wise balance on my blades they seem to balance further back than shown on the plan[ el bandito). so do i add weight to the leading edge to achieve nearer the plan spec or go with what i have ie balance point a few mm rear of plan? regards Richard franks Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted November 7, 2021 Share Posted November 7, 2021 Rich, As long as it's not passed the 50% mark you will be fine. Our old friend Tom Wright flew some of his earlier models with a mount point almost at 50% and they worked fine. Though these were lighter models than the Bandito. Rich Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted November 14, 2021 Author Share Posted November 14, 2021 Oppps, Sorry for some reason I missed the last two posts. Luckily Richard has replied. Steve ? Quote Link to comment Share on other sites More sharing options...
Big T Posted January 16, 2022 Share Posted January 16, 2022 Hi Stephen, I am interested to know if you have experimented with the span wise CofG position. In particular the effect of moving the CofG further towards the tip and if so have you found a sweet spot? 1 Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted January 16, 2022 Author Share Posted January 16, 2022 Hi Big T, All my blades I have made with the CoG being central I know some of the other guys put tip weights on the outer ends of their blades But I have never tried it TBH. Something I must try along with narrowing the blade to the tip. Steve Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted January 17, 2022 Share Posted January 17, 2022 Be careful with how much you use, it slows down the spin up rate dramatically ! 1 Quote Link to comment Share on other sites More sharing options...
Andy J Posted January 17, 2022 Share Posted January 17, 2022 Stephen, notice you drill the pivot hole prior to covering. Is this an issue as adding the covering will change the chord balance position? I made this error on my Panther blades and found the position of the hole to be about 1mm in error. 1 Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted January 17, 2022 Author Share Posted January 17, 2022 9 hours ago, Andy Joyce said: Stephen, notice you drill the pivot hole prior to covering. Is this an issue as adding the covering will change the chord balance position? I made this error on my Panther blades and found the position of the hole to be about 1mm in error. Not a issue for me as I allow 1mm behind my balance mark plus I find a shiny surface harder to balance on. Just how critical is + - 1mm ? Steve. Quote Link to comment Share on other sites More sharing options...
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