John Dennier

I have flown two twins both had contra rotating props and both tend to yaw to the right on initial take off power application requiring left rudder input until speed builds up. I cannot recall whether the tips moved inboard or out board at 12 o clock.

HK posted spec for this motor is maxed at 57 amps. Use a watt meter to check your amp draw with a selection of props and batteries up to 5s until you find a comfortable arrangement. Minor short term exceedences from a fully charged battery probably won't hurt . Note that the voltage spec quotes 19 volts max

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A fellow club member is working on a Halifax kit of TN design. He is at the point of agoniziing over battery, motor and prop combinations. It would be of great assistance if a succesfull Halifax builder could share his experience on these issues. Our builder anticipates a weight of 24 pounds plus or minus a margin. He would particularly benefit from experience of AUW for a flying model with details of battery power, motor/ ESC details and prop details . Thanks in advance for your thoughts J Dennier

Many thanks for your constructive comments gents. In checking the RC groups thread offered by Cymaz I can confirm that my CG was at the spot indicated by the red box. This location is at odds with the general drift suggested by the other responses. I wonder if the online calculator suggested by Denis will correspond with the rearward preference? Could you send me the online calculator web site please Denis? The model I am building is made from blocks of pink insulating foam sculpted with various foam cutting wires around ply templates. The wing section was basically flat bottom curved upper surface and quite thin with zero degrees angle of incidence. Power is from two 70 mm fans powered by two 4s batteries. Another issue the plane exhibited was very twitchy aileron response. I had full span elevons and plan to reduce the span of these on the next effort. Thanks again to you all, any further discussion on the above would be welcome. Cheers JD

I am building a second Avro arrow from scratch with help from a three view drawing plus a few cross sectional views. My first effort was overly nose heavy. I had used a geometric plot prescribed on a website to estimate a CG location which was obviously in error. I am appealing for some wisdom on the subject of acquiring a CG location on delta wings and would be obliged to hear from any modeler who has used a process successfully. Cheers JD

Here on the wet and windy Vancouver Island there remains a glimmer of interest in Trad building although the sentiments expressed generally in this thread are undeniable. Foamies are by far more popular than home builds but in their defence I for one would not be an aeromodeller if it were not for ARTF's . It is the wetness that inspires me as the rains commence in October and persist well into the new year providing the perfect conditions for extensive model building activities. In my case I have completed a Traplet plans Fairey Firefly which I would have hoped to fly by now in it's birthday suit but have been thwarted by the incessant rain. consequently I have finished the aircraft and it remains in my hangar awaiting the arrival of a dry spell. As winter refuses to relent I have had to turn my hand to further building this time utilising the salvaged corpses of pranged ARTF's, in an ironic twist, and have produced from a sheet of insulating foam an Avro Arrow mounting twin 70mm motors powered by twin 4s batteries. For the benefit of the sceptics out there a comparison between prices might be in order: My Arrow has cost no more than $50 as the parts were already available, in stock as it were, but my hangar contains an SU35 from Motion RC which, by the time dollar exchange rates, shipping and customs duties are paid, costs in the region of $800! This makes a compelling case for home building in cheaper materials. A fellow club member builds and modifies designs created by RC Powers. These again are easy builds in foam board mostly of park flier style propjets . These aircraft have impressive performance and can be seen on You tube postings in the name of E3Scott. I would be surprised if any of Scott's planes cost more than $40. This suggests that the case for home builds might be evolving but is not yet a reason for despair. Especially given the interest generated by the mass builds and the gliding fraternity so heartily encouraged by the RCME Cheers JD

Since re subscribing I have been locked out of access to the digital RCM&E Magazine. Despite whining about it to a couple of websites no restorative action has been offered apart from them acknowledging that I have sent them an email! Has anybody else suffered this inconvenience? I wonder if the problem is at my end. Edited By Pete B - Moderator on 04/02/2017 08:02:56

I sometimes locate balsa parts by spot welding with CA during a gluing operation.

Great graft job Colin I have a few graftings you might enjoy! Cheers JD

How about taking the plans to a print shop and asking for a copy plus a PDF file. Then you can print any part you want to make into a template for transfer to the balsa. You will then have fair and a working full size copies and the ability to duplicate any part. If the plan is copyrighted ask the supplier for permission to proceed.

Perhaps you should consider the liklihood of your final circuit becoming a go around and set voltage warning at a level that will keep you in the comfort zone to handle a missed approach. If you do arrive with charge remaining your next battery recharge will be quicker.

Concerning canopy making check out my posting of 2014. I followed internet concepts to make both nose and canopy glazing for a JU88 model. My plugs were made of plaster of paris built up on a one sixteenth frame substrate. A toaster oven warmed up the canopy material. (Same stuff pop bottles are made from.) After some trial and error it worked satisfactoriily. John Dennier

Hi Ady what a luxury to have a Ju88 kit to work with. I had to scratch build mine. I am intrigued by the build materials and concept. Are you planning to install retracts? How about propulsion, electric or ICE? From my experience I would advise a serious effort to keep the rear end light as there is not a lot of room to put ballast in the nose. Mine is powered by three 4S batteries (in parallel) all in the forward section under the canopy and they are accompanied by a lead weight . Mine is an A4 but with your Nachtjager you might have some additional space in the nose for ballast. Looking ahead to flying I quickly discovered that despite having props running in opposite rotation there was serious yaw instability in the early phase of the take off roll. This necessitated a rudder gyro which can be switched off once airborne as once trimmed and the plane fly's fast and true. Landing is also pretty hot, probably because mine is a bit heavy due to my overbuilding a few areas. Looking forward to seeing your results. I have some pics in one of my posts if you are interested.

I have read some of his books and it is clear that Captain Brown is a captain in more senses than just that of a Naval Officer. Also I met him briefly many years ago at RNAS Brawdy when as a young Leading Air Mechanic I strapped him into a Hawker Hunter of 738 Sqdn. Good luck with the capaign. Cheers John Dennier (Signatory to the petition)

Thanks Cymaz it makes sense. I received the wing in two parts with some light skin damage so have the advantage of eyeballing the underlying structure. From this i envisage a flap installation cum repair/wingjoin operation. Cheers JD

Interesting points and questions gents, thanks. In order to provide a better insight for your consideration I have weighed the model parts and the total including an extra pair of servos for flap actuation and a 4s battery is 3 pounds 12 ounces. After beefing up around the repair area it is unlikely to exceed 4 pounds. Floating on and on has been the bane of the previous owner's life, however he is in his eighty's and might be less in touch with tricky models than in the past. I understand the proposal by Martin Harris and have seen it done locally with the benefit of a stabilizing gyro on a small mustang. Here, that style of landing is called dragging it in. The big ïf"you referred to earlier would be highly endorsed in the flying culture in our club Martin nevertheless it remains an avenue to be explored. The main message I am getting from your suggestions is that flaps are likely to present the best physical option to proceed with. I will make it so and am now brainstorming a repair scheme and flap installation mod. Cheers JD

Many thanks to all contributors to my question. As I am now the owner of this aircraft it seems that I need to build in some flaps. The wings came off and separated neatly in the middle during the last owner's final landing which has led to his despair and passing on the model to me. So this would present the best opportunity to installing flaps during the repair. Images of the Mew Gull on google suggest that split flaps are the norm. I would be grateful for opinions on that concept. The aircraft has a 48 inch wingspan and the airfoil I suspect is scale, as the builder /former owner has a reputation for accuracy to drawing. I am not sure yet whether the model is scratch or a kit/artf. I will glean this from him as time progresses. His propulsion system swung a 10X7 prop but apparently even this was not enough to slow the model. His landing style was to chop power on the downwind leg and fly more or less deadstick to finals and landing which was still a perilously speedy and lengthy affair even on our 800 foot grass runway. Once again thanks for your helpful suggestions I will proceed with the repair. Feel free to make any further comments especially concerning flap design and I will advise results later. Cheers JD

An electric model Mew Gull is posing problems in our club because of the landing speed which is proving hard to bleed off. The model does not have flaps and we have a grass runway.. I wonder if there is any experience from which we might benefit to help the owner to bring the plane to a safe landing. Also if in the opinion of other Mew Gull owners if flaps make any difference. Looking forward to some qualified insight, J Dennier Comox BC Canada.

Thanks for this BP I expect improvements to be achieved a little at a time. I am currently flying the stock aircraft so that I can evaluate changes as I make them. Cheers JD

Hi Steve if you check out https://www.youtube.com/watch?v=E5dQVqPivXY at minute 11:06 a caption comes up advising that both Radian and Radian pro have the same decallage issue. Thanks Buster P for your input did you notice an improvement over the stock condition with you mods? Cheers JD

Mr. Naton of Radio carbon art.com has a tuning video (see youtube) in which several changes are applied to his Radian pro. They seem fairly reasonable and I wonder if any of the glider fliers have any experience of the effect these changes have on the Radian Pro. Especially interesting is the proposed change in Horstab incidence coupled with CG shift. As a new glider flier I would be interested to hear of any changes deemed successful by the UK gliding community. I fly in British Columbia Canada in the Comox valley and rely primarily on thermal action to maintain altitude. My glider enjoys the full repertoir of control tweeks courtesy of a taranis control system. Looking forward to input from the expert glider community. Thanks JD

Please advise what a maintenance mode is Cheers JD

I seek wisdom on the setting of crow braking on a taranis x9d radio. I am using open tx programing version 2015 and my receiver is x8r. The intended recipient of this is a Radian pro glider. I hope I am not the first with this problem,,, Thanks in advance John Dennier

I seem to have got the pics in but not the text. So here it is, an update for those who were kind enough to take an interest in my project. I hope to post a video when I get a decent one together in the mean time let me describe the points which were of some significance regarding this model. Sharp eyed observers will note the rather gangly legged stance this was due to the need for the retracts to get the wheels aft of the wing rear spar. An error in Mr. Scott's drawing shows wheels neatly tucked into the space occupied by this spar. You might also notice the overscale rudder. This was added after the first test flight when yaw instability led to snakey tracking just after tail wheel lift off during T\O roll. I also added a gyro to help get things into line. otherwise this model is rock solid in flight and is very fast. I was surprised at how fast it is and need to work on getting my head in front of it. It is electrically powered with contra rotating props pwered by three 4s batteries. The weight is around 15 pounds as a consequence of the lead which needs to be placed in the stubby nose to achieve CG. I originally had only two batteries but discovered space inside the canopy for a third which alleviates the "range anxiety" associated with two batteries. I chose a desert scheme for visibility as we fly among huge Douglas firs here in Vancouver Island not to mention a lot of other lush vegetation in the summer so a green camo tends to lead to sighting disorientation. This a/c is my first build and I chose a JU88 because of the challenge and that it is undermodelled and it is a twin, which are almost none existent here in a hobby dominated by allied single engine types of warbirds. Thanks again to those who helped me with issues like canopy pulling which as you can see was a reasonable success.