J.N.

I know that there is a thread running about how to correctly state servo output, please excuse me if I have made a mistake. I fly a Flair Magnatilla in a steady manner along with an occasional slow loop or gentle roll and need to build a replacement wing. The wing has inset ailerons and the original was fitted with a single Futaba S3001 servo driving the ailerons through long and short pushrods, bell cranks and ball joint connectors. The whole installation took many hours and was a long and tedious process, and,  I never did manage to obtain equal throws on the ailerons, not that it appeared to effect flying.   In the new wing I intend to fit a servo for each aileron. For ease of fitting I want a servo physically smaller than the Futaba S3001 but powerful enough to control each aileron. The Futaba S3001 has a Torque of 4.1 Kg/cm and a speed of 0.19sec/60 degrees. Can someone please advise as to what Torque and Speed output from a servo would be suitable to drive an aileron in the above circumstances to enable me to chose a small servo.  I am very happy with Futaba and would like to continue using their kit.  Thanks.

  CUTTING BALSA SHEET TO FIT PLAN Having built one open frame model from a plan suitable for novices I have just started on a another model built from a plan, in balsa sheet. This balsa sheet model has given me a problem. With the previous model, lengths of balsa strip glued and pinned down onto the plan formed a frame and any infill was shaped to fit. The outline of the plan was visible and accessible during the construction. My difficulty is, how can I cut the fuselage sides true to plan. I cut out one fuselage side by marking the six cutting lines with a pin pushed through the plan into the balsa sheet. Then I cut along the waste line with the aid of a steel rule joining up the pin holes, leaving sufficient balsa to sand back to the plan and finish up with a square edge. I then intended to mark out any reference points onto the fuselage side that would aid construction. After carefully sanding one of the six cut sections to match the plan I would start on the next section. The difficulty I have is matching the fuselage side to the plan. Although there is only a small amount of material to remove on each cut section I cannot see the plan underneath the balsa. It has become a juggling act to try to match up the sections without the danger of going “over the line”. I may be making a mountain out of a molehill or made a mistake and prepared to start again however I need to know where I went wrong. Can someone please point me in the right direction. I did consider cutting along the outline but this would leave no margin for error. Furthermore, how do I cut out the other side of the fuselage.   Having cut one near enough side, do I transfer this outline onto the other fuselage sheet, then cut, then finally treat both as one unit and  sand back to plan. Thanks

Dear Timbo, Thankyou for the prompt response.   It is always the same, no matter how many times I look at what I have written as soon as I press the send button I think, oh dear.   I should have stated that the receiver will be powered by its own switched battery and will be switched off on landing (as I do with I.C.).   The question I should have asked was, in the above circumstances is it a safe procedure ?     An indirect but most  important reminder in your email was for me to ensure I can easily get at the motor battery and connections.  I have just started to build from a plan and already earmarked a place for the RX battery and externally operated RX switch.  At this early stage of construction your timely reminder gives me the opportunity to make any modifications necessary to ensure easy access.   I have re-read this a number of times and altered it twice and yet, I still hesitate to  press the  button. Here Goes. Thanks. Posted by Timbo - Administrator on 23/02/2010 10:53:40: On all  but the very largest or highest powered setups ( where heavy isolater switches /bridging plugs etc can be deployed )  the easiest and safest way is to simply unplug the main flight battery immediately after landing. Switching off the tx should NOT be relied upon, and besides, the model should be always be switched off before the Tx.....just as with IC.  

I have read through this thread and if the answer is there, I have overlooked it. No matter. It will be some weeks before my first ever electric flight model is ready and my question is about isolating the motor.     I have never flown electric and with my I.C. engine when the engine stops, it remains stopped.  In the case of an electric motor, is switching off the transmitter a sufficient way to ensure safety or should an on/off switch be fitted in series with the motor-battery.   I understand that it is good practise to keep joints and connections to a minimum.  Thanks.

Dear Worden, You appear to be pleased with the undercarriage you fitted to your Whizzza`s.  Will you please let me know the size/type of wheels and undercarriage, and where you got them from. Thanks. Posted by Worden on 22/03/2009 20:56:47: Hi Birdy   I'm sure you will end up building planes much better than mine with a bit of practice and experience, you have plenty of time for that yet (but don't neglect the homework!).   The piano wire u/c as shown on the plan is quite heavy and very permanent.  I wanted to keep everything as light as possible so used carbon legs and thin, lightweight wheels.  The legs are fitted with nylon bolts into threaded inserts in a 1/4" ply plate built into the bottom of the fuselage.  The advantage of this is that is that the legs can be removed in a minute or two (for rough strips or extra speed!).  The legs I used are very light, strong and were quite reasonably priced (direct from H. Kong).  They come in 2 parts and do need careful drilling but worth the effort if you want wheels.  My first Whizzza (the one with blue wing tips) started life with an u/c but I took it off as it was getting a bit weak after some less than perfect landings.  It now hand launches with no effort at all, easy with 325W of power.  My second electric one has twice the power, 650W making it 300W/lb, plenty quick enough for me!    Easter Holidays soon!                Edited By Worden on 22/03/2009 20:57:36 Edited By Worden on 22/03/2009 20:58:22  

Thanks again,   Yes did`nt realize.  Your -  "sure, PM me if you like, though others might benefit from the same info" - makes a lot of sense.     Others will benefit from offers to resolve problems.  I like many inexperienced builders am only a "mere mortal" and no doubt someone, somewhere will have the same question.  

Twinstar, Many thanks for the prompt and comprehensive reply, the photos I found particularly helpful,  a picture is worth a thousand words.   I will take you up on your offer to help with further advice and willing to exchange correspondence through this forum.  However, if agreeable to you, may I contact you through a PM rather than add to this already long running and very helpful thread.    May I throw the following open to anyone.  Having built the wing I have finished reading all the small print on the plan and the Whizzza article in RCM@E.  The plan states that the two panel wing should have the leading panel Medium to Firm Balsa and the main Wing panel Medium to Soft.    The RCM@E Whizzza build article states that both wing panels should be Soft and the Lightest available which is what I have done.  Does anyone know who is correct, the plan or the article in RCM@E. Thanks.    

I am building the Whizzza from the RCM@E plan.  I have moved onto the fuselage and a little puzzled as to the order in which it is assembled even though I have the RCM@E write up (Apr 06) and another building article.    Will someone please advise as to when  the upper fuselage sides are glued in place.  Is it before joining the fuselage sides together or towards the end of completing the fuselage. Thanks.

Posted by Pete B on 18/02/2010 21:22:40: Slec UK do 152mm sheet...........   Pete   Dear Pete, Many thanks for your prompt contribution,  just looked at the site and will be placing an order.   This forum is a mine of information.   Jeff 

Does anyone know if 6 inch (or metric ) wide, 3ft long balsa sheet is available in the U.K. Thanks. 

Thanks. It is early days yet and I hope for more contributions as the snow is likely to be around for some time with the worst month (Feb) yet to come.   No matter, yes it is for flying off snow and yes I considered a float plane.  However I am  of the un-qualified opinion that floats are a second best with regard to flying off snow. I am not experienced enough (hence my frequent recourse to this forum) to identify the cause of some of the more un-usual flying characteristics that are encountered when "making do",  and in order to stand the best chance of progression think it better to find a dedicated model. 

Does anyone know of an off the shelf model with ski fittings, that is currently available, be it build up, ARTF, or RTF. Thanks.

Sorry if this turns out to be like asking how long is a piece of string but it is a result of reading threads on keeping the all up weight of a model to a minimum.    My Flair Magnattilla is complete and ready to be covered  (I may use Solartex).   Is it possible at this early stage to determine what the likely effect on the current point of balance will be after the covering has been applied.   Or put another way. As a general rule, is it possible to work to a point of balance when building; such as where to fit servoes and RX battery, or choosing heavier/lighter undercarriage wheels.   Thanks

Dear Simon, Thankyou for your contribution explaining the  physical forces a push rod is subjected to.   Now knowing the cause and effect of such things I can easily make a judgement as to the cause and effect of components I work on/with in the event of wanting to make a change.  Thanks.   

I have used various materials to make up the control surface pushrods on my trainers;  snakes, square balsa, square spruce and hard wood dowel.  I switched from square balsa to round  hard wood dowel when I had great difficulty in preventing the pushrods from fouling each other at the tail end of my Flair Cub.  By reducing the cross section dimension of both rods I was able to resolve the problem, however,  I now know that  I could have shortened the balsa push rods and made up a longer piece of metal rod at the end of the push rod.  I continue to use dowel or spruce  when a wood push rod is needed in the believe that these are more suitable as they are less likely to bend/flex in use.   I recently read through a thread on building a Magnatill and noted that one contributor stated that dowel for push rods should not be used, one reason was that dowel is subject to setting up a vibration that would not be found using balsa.     I have searched the forum and cannot find the answers to the following.  What other reasons should I stop using dowel/spruce for push rods. If I feel the need to replace a wood push rod is carbon fibre rod the way to go.  

I am the bloke who submitted the original request on a Count Down Timer and  considered the posting to be a sensible query.  To those comedians who poked fun and took a dismissive attitude, move over,  you have taken up more than 66% of the thread and contributed nothing.   Thanks to those who submitted a constructive reply however I still have not sourced a count down timer that is small enough to mount on the transmitter and gives an audible signal when the dialled elapsed time is reached.  I hope there is still someone out their  who can point me in the right Pound Land is an  80ml round trip away,  I have tried a cooks timer but it is bulky and inadvertently pressing one of the keys will alter the setting.   Due to living at the back of beyond most of my model parts and equipment are supplied by mail order.  Thanks

I need a small countdown timer of around 30mins to fit/attach/stick onto my transmitter.  I have searched the internet but so far not found anything that I would want to use.   Does anyone know of a suitably small timer that would emit an audible warning when it has reached a dialled in time delay . Thanks. "

I would have expected this topic to have been covered in the past but after carrying out a search cannot find the answer. I will be fitting my first 4 stroke, an OS52 surpass, into a partially enclosed engine bay.  The glowplug may prove to be very difficult to remove in situ, the venturi to the inlet valve, and the carburettor,  can only be accessed by removing the engine from its mountings.  I have yet to bench test the engine and have no idea how much oil will be expelled from the crankcase breather nipple.  I recall reading somewhere that a piece of flexible tubing can be fitted to the breather to direct the expelled oil into the slipstream and that a "T" piece union should be used.  The "T" part is open to atmosphere and allows air to flow into the crankcase on the piston up stroke when the lower part of the "T"  is full of expelled oil.   Can someone please tell me if I have got the above right.    Normally I apply after run oil through the carburettor however it will not be possible in this case, in addition I may not be able to easily access the glow plug.  I recall reading that after run oil can be applied through the crankcase breather.  Can someone please put me right. Thanks.

Dear Bruce,   Thankyou for the welcome. You have found me out, I failed to let you all know that I was a newcomer to the site, no matter, duly reading the "joining instructions".    The site has a wealth of information with many helpful contributors and I should have availed myself of it when it first came into being.  If David Ashby and the wizard from Oz read this, I have returned to the fold to support the RCM@E.  I left RCM@E when the "E" side of model aircraft was dropped, one article that will live with me forever was the glow plug voltage supply project, however, after many years wandering through other model aircraft periodicals I am back.  Regards

Dear Tony,   Thanks for the prompt contribution, you have put me on the right track.  I have just done a search on the internet and found not only Archimidean drills but collet holders similar in size to a pin vice.  One Archimidean drill that particularly appealed to me had a return spring incorporated into the design and in another case found drills of varying diameters with a standard shank to fit into a standard collet.  I looks like I will be able to have my cake and eat it.   

From time to time I need to drill from 1mm too 3mm holes in tight places, such as mounting rails for servoes and use a pin vice which allows me to offer the drill bit up to the work.  However in hard material it is very difficult to tighten the pin vice jaws sufficiently to hold the drill bit in place during the drilling operation.   I believe the way to go is to use collets but finding a suitably small and compact collet holder, similar to the pin vice is proving to be difficult.  Can anyone please advise ?