Seraph Posted September 3, 2016 Share Posted September 3, 2016 How do you make those beautifully neat lightening holes, Tony? Quote Link to comment Share on other sites More sharing options...
Ian Newton Posted September 3, 2016 Share Posted September 3, 2016 I look forward to hearing if the Graphenes give a noticeable difference. They certainly should be better towards the end of the flight but giving up their power more freely will potentially shorten the flight and they are of course slightly smaller in capacity to start with than your current batteries. What total current are you drawing in the hover? Quote Link to comment Share on other sites More sharing options...
Tony Nijhuis Posted September 3, 2016 Author Share Posted September 3, 2016 Seraph, I use a hole saw attachment in a drill. they are not brilliant Ian, The draw from each fan is around 60amp to hover so 120amps per pack (1 pack feeds two fan units). If reading the info on Graphene is correct, the benefit will be lower internal resistance and therefore the heat build up in the cells will be hopefully far less. If this is the case the more usable energy will be available for flying We shall see! Quote Link to comment Share on other sites More sharing options...
onetenor Posted September 4, 2016 Share Posted September 4, 2016 Posted by Seraph on 03/09/2016 07:50:02: How do you make those beautifully neat lightening holes, Tony ? Try using tubes sharpened on the inside edge and twisted into the material.You can also cut teeth or serrations into the edge as well Works well nice and clean cuts Quote Link to comment Share on other sites More sharing options...
Ian Newton Posted September 4, 2016 Share Posted September 4, 2016 Tony. That certainly is my experience. The nano tech packs that I was using in my edf's and high current draw planes were coming down very warm. The graphenes come down just warm. IR's are around 1 - 2 mOhms per cell. Some have been immeasurable on the icharger I have been using for the measurements. Good luck - I will follow the project with interest and hope to follow in your path when you have led the way. I'm really happy with the 72" Lancaster I have recently finished from your plans so have been looking for something to follow on. Quote Link to comment Share on other sites More sharing options...
Tony Nijhuis Posted September 17, 2016 Author Share Posted September 17, 2016 Just a quick update- Prototype No.3 is finished and covered in lightweight film and managed to shave 6oz off the prototype No.1 Did some hovering tests yesterday didn't seem as stable as the first one but it was quite windy in the back garden... going for a standard ROG test flight tomorrow with a bit of luck with a simple tail dragging dolly. Plan is to lock the fans in horizontal mode, dis-arm the quad board and just use the RX with an IGyro3e on ail,ele & rudder so all being well it should fly ok Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted December 21, 2016 Share Posted December 21, 2016 Hi Tony, Any further updates on how the hover & forward flight test went? I appreciate you have been busy with other aircraft, but just wondered if you could conclude whether the idea is feasible or not with the current technology? Cheers, Quote Link to comment Share on other sites More sharing options...
Tony Nijhuis Posted December 22, 2016 Author Share Posted December 22, 2016 Hi Chris and All, Things have moved on with some disasters and successes. The Mk3 (which is really only the second Mk2 of the 70mm edf version i built) crashed spectacularly on take off when trying conventional ROG. The reason was an incorrect C of G and the tailplane incidence was well out... Needless to say a new version had to be built and was retested last weekend ROG and as a conventional flying model it is superb. So much so, the plan is to release the plan as a conventional ROG Harrier (not Hover) for next years RCM&E Special. This latest Mk3 model now hovers and flies conventionally and flight trimms have all been adjusted to coincide......the only test left to do is the transition and I am only waiting for weather and the nerve to attempt....its that close Hopefully you will be pleased to know that a series of four articles have been written for the RCM&E with the first one due out in March edition and goes into the technical detail. The 5th and last article is dependent on what occurs in the next few days / weeks so fingers crossed.... Below is the final installation now flying on one battery pack and Edited By Tony Nijhuis on 22/12/2016 00:08:57 Edited By Tony Nijhuis on 22/12/2016 00:10:38 Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted December 22, 2016 Share Posted December 22, 2016 well done sir. fantastic looking model and what an achievement. Tony B Quote Link to comment Share on other sites More sharing options...
Ian Newton Posted December 22, 2016 Share Posted December 22, 2016 That's bad news about he crash but the rest is great news! Look forward to the articles. Presumably the Graphene batteries made a difference? Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted December 22, 2016 Share Posted December 22, 2016 That's awesome Tony really well done! I really look forward to reading that series of articles And good luck with the transitional flights.CheersDanny Quote Link to comment Share on other sites More sharing options...
Basa Posted December 22, 2016 Share Posted December 22, 2016 I find these forum articles about Tony,s Harrier really interesting along with the technical aspects . Looking forward to the RCM&E features in March. Quote Link to comment Share on other sites More sharing options...
Tony Nijhuis Posted December 22, 2016 Author Share Posted December 22, 2016 Thanks guys, Crashes are all part of the journey and should always be seen as part of the learning process..... hopefully will have some video to post soon Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted December 23, 2016 Share Posted December 23, 2016 Posted by Tony Nijhuis on 22/12/2016 23:19:59: Thanks guys, Crashes are all part of the journey and should always be seen as part of the learning process..... hopefully will have some video to post soon Well as the saying goes you can not make an omelet without breaking a few eggs Looking forward the videos, Steve Quote Link to comment Share on other sites More sharing options...
Steve Balaam Posted December 23, 2016 Share Posted December 23, 2016 How is Pitch, Roll and Yaw achieved in the hover and slow flight ? Steve B Quote Link to comment Share on other sites More sharing options...
Keith Simmons Posted December 23, 2016 Share Posted December 23, 2016 It's in the first post, using a quad board. Watching with interest in achieving the transition from hover to level flight & back. I feel the latter is easier. Good luck. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted December 23, 2016 Share Posted December 23, 2016 Keith, Are you sure...I think going from level flight to hover will be much tougher nut to crack. Only my view but hover to forward flight is a case of gaining forward air speed until sufficient lift is generated for normal flight...with sufficient height and into wind you stand a good chance of diving in to it if it gets ugly...but doing the opposite in a controlled way is much much tougher. Go to VTO mode with high forward air speed and its going to be a significant stability challenge as to where thrust is directed to maintain height + low air flow over any control surfaces (+ their effects wanted or not!). Pull back and nose up to flare in to it (like quads and watch their gyros go mad to fight the instability). Quad designers stick the props outboard on arms with a well distributed mass where as Tony has a concentration of mass and fans close together. I think Tony has taken on a real challenge and deserves the credit due for spending many hours work. The more I look at it, the more convinced I am that the concept (original and Tony's) should not fly (for all the technical reasons!), but the original did very successfully and I am sure Tony will get his working. Merry Christmas and best wishes to all at this festive time Quote Link to comment Share on other sites More sharing options...
cymaz Posted December 23, 2016 Share Posted December 23, 2016 A gyro is fitted...hopefully that will take some of the stress and work load from the pilot. We wait and see. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted December 23, 2016 Share Posted December 23, 2016 Cymaz, Gyro's can help...they are fast and can take workload off the pilot, but ask people who fly with them and an often complain about "less feel" Its a very fine line between control and stability, but not over control! This is like doing a headstand on a broom stick and then trying to fly a plane ! My point was that lots of designers work very hard to physically move components about to make things work, Tony just does not have that luxury which makes it a bigger challenge! I think its great there are the people out there to push things along and can't wait for another instalment...Better go off and do a bit of balsa bashing to calm down !! Quote Link to comment Share on other sites More sharing options...
Ian Newton Posted December 23, 2016 Share Posted December 23, 2016 Having flown both the Ripmax Transition VTOL and the Hobbyking Canadair CL84 Tilt Wing models I agree that the transition from the level flight to vertical landing is the trickiest as you have to judge where the plane will come to a stable hover. It is vital that you ensure you haven't run your batteries right down prior to landing as the motors need to be able to respond to inputs and provide full thrust while landing! At least with the right strip it should be possible to do a normal fixed wing landing if required. I look forward to seeing the progress Tony makes with this model and hope it is successful. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted December 23, 2016 Share Posted December 23, 2016 Using a quad board to directly control the thrust of 4 'Harrier' nozzles is a logical and technologically available solution to the problem of hovering stability. Tony as usual has made a superb job of it but of course it is not how the full size does it. I believe the Harrier achieves control using puffer jets each with about 250lbs thrust. That is less a thrust than 1% of the planes weight. An EDF provides high volume low pressure air so there is no source for puffer jets which leads to question is there an alternative way to provide controllable thrust at the planes extremities? One solution would be to use small fans/props sized not for lift but purely for control leaving the lift/thrust generation to a much larger fan(s). To put it another way how big and heavy a VTO 'plane' could say the 30 mm sized rotors of a Cheerson XC-10 control in hover given each rotor would be many times further out from the CofG? Something like this perhaps. It would still require at least two counter rotating EDFs to provide the vast majority of the lift and even better if they could be mounted inside the fuselage feeding four scale vectoring nozzles! Just a thought. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted December 23, 2016 Share Posted December 23, 2016 When I first worked for RR at Derby in 1965 they were working on separate lift engines (Alison IIRC). That was the way the so-called Flying Bedstead 'flew' back in the early 1950s (I was at school just a few miles from the Hucknall site where the tests were carried out and we always knew when the Bedstead was in operation because we could hear it even in the classrooms). RR abandoned the technique of separate lift engines after their merger with Bristol where the vectored thrust Pegasus was designed. That proved successful and hence the Harrier became operational. I hasten to add that as a mere instrumentation/electronics engineer I had nothing to do with mechanical design directly and only very rarely with any military projects. Geoff Quote Link to comment Share on other sites More sharing options...
Tony Nijhuis Posted December 24, 2016 Author Share Posted December 24, 2016 Lot of interesting comments The operation of both transitioning from hover to forward flight and back to hover is critical so I have programmed the rotation of the gimbling fans to go from Hover Vertical- switched to 45deg (still in quadcopter operation but picking up speed so you begin to use aileron and elevator control too) then switched to 90deg with the quad board switched out and an IGyro operating on the aileron and elevator...... In the year and half I have been playing with this harrier I have thought of many alternatives to the type I'm currently testing. The one below is similar to Simon's suggestion and was going to use a central single fan with 4 outlet to the true Harrier...than use four 30mm fans to the stabilisation.... 2 in the body and 2 in the drop tanks .... The complexity and weight was not practical but I'm holding this design for a Turbine version one day.... Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 24, 2016 Share Posted December 24, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Keith Simmons Posted December 24, 2016 Share Posted December 24, 2016 I only said I feel it's easier as on level flight, the lift is maintained using the wings, when you slow down towards hover the fans would be rotated 90 degs down so that it will take the plane's weight, but it will still be moving forward unless the fans are beyond 90 degs creating a braking effect, I agree now that from hover to level flight could be easier as you slowly turn the fans towards level flight as you gain speed and the wings take the load. The plane could dip into a dive if done too early/quickly. Using the turbine will have bags of power and explore the possibilities. Exciting. Quote Link to comment Share on other sites More sharing options...
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