By continuing to use this site, you agree to our use of cookies. Find out more

Member postings for David Davis

Here is a list of all the postings David Davis has made in our forums. Click on a thread name to jump to the thread.

Thread: Seagull E-Pioneer
17/07/2019 07:54:51

That Seagull E-Pioneer looks very much like a Boomerang. No wonder the Pioneer flew well with a 46 in the nose!

boomerang.jpg

Thread: Which Servo Sould I Use?
14/07/2019 14:05:18
Posted by Sparks on 14/07/2019 09:18:47:

Hi David,

A dab of threadlock, such as Loctite, on the nuts is a useful precaution.

Thank you Richard. How are things at Forton?

Thread: Newbie with some starter trainer plane balsa IC questions please.
14/07/2019 06:54:45

You could always keep your basic transmitter as a slave transmitter for when you become an instructor yourself!

Thread: Which Servo Sould I Use?
14/07/2019 06:42:44

I'm going to risk the Coronas to get in some flying practice. I will order another HS 5085 just to be on the safe side.

Thread: Newbie with some starter trainer plane balsa IC questions please.
13/07/2019 11:49:25

I have one of those Prolux irons and it's excellent, well worth the extra fiver.

Thread: Which Servo Sould I Use?
13/07/2019 11:46:25

Thank you gentlemen.

13/07/2019 08:24:36

Introduction.

I am repairing my Baron after the rudder pushrod unscrewed itself in flight. This was the first time that I had fitted carbon fibre pushrods and did not realise that you had to secure them in place with locking nuts! blush

bertie 2.jpg

The Baron is a simple 1.55 metre wingspan three channel trainer originally designed for a 15-19 sized engine. I intend to compete with this model at La Coupe Des Barons in September. In this event there are four flying rounds flown in concert with up to nine other models. Two of these rounds are flown close to the ground while the other two, a pylon race and a "fox hunt" require an element of speed. I had planned on fitting an OS 52 FS, this being the largest sized four-stroke permitted in the competition rules but it was damaged in the crash so I've replaced it with an OS 48 FS Surpass.

Two standard Hitec HS 311s are mounted at the rear of the fuselage. When checking the cg earlier this morning I found that the model was tail heavy though it did not seem to fly too badly on the two flights prior to the crash. Not wishing to take a risk, I have decided to replace the servos with smaller ones in order to move the CG forwards.

The Nature of the Problem.

I do not recall having fitted servos smaller than standard size to any of the models which I have built but a trawl through my souvenirs revealed the following:

  1. Two Hitec servos: a Hitec HS 81 and a Hitec HS 5085MG.
  2. Five smaller Corona CS-939MG Micro servos bought for some long forgotten project which was never even started.

The Hitec HS81 is rated at 3kg.cm torque at 6 volts with a speed of 0.09.

The Hitec HS 5085 is rated at 4.3kg.cm and 0.13 speed.

The Coronas are rated at 2.5kg.cm and 0.14 speed.

Questions.

  1. Are the Coronas powerful enough for the purpose I have in mind?
  2. If I fit the Hitecs, which one should I use for the rudder and which for the elevator or should I buy another matching servo?

Picture of the starters in last year's event for your delictation!

group photograph.jpg

Thread: Newbie with some starter trainer plane balsa IC questions please.
13/07/2019 05:38:28

OK Nu Me 1, just a heads up about Futaba servos. They are excellent servos but they have a little tag on the connector designed to prevent you from connecting the servo the wrong way round. Futaba receivers have a slot in them corresponding to the tag on the plug. If you want to fit a Futaba servo to any receiver other than a Futaba reciver you have to cut away the tag with a sharp knife. Not exactly a difficult task but I prefer Hitec HS311s myself. The negative wire always goes to the outside of every receiver I've ever used.

PS I've had three Honda 400Fs and a 350R when I was touring the USA.

12/07/2019 10:08:39

I am currently building a large model on plaster-board. This is the first time I've used plasterboard. It works a treat and is as cheap as chips.

lenthening plasterboard.jpg

fuselage framed up.jpg

12/07/2019 07:20:58

Nu Me 1

I think that you should adopt the mode which is used by your instructor.

In 2015 I retired to France. 85% of French pilots are Mode 1. Out of the 31 members of my club only three of us are Mode 2 and the other two don't turn up very often.

It is possible to learn to fly if your instructor flies on a different mode. I am currently teaching two blokes: a Frenchman who flies Mode 1 and an Englishman who has opted for Mode 2. To turn a model aircraft you use the ailerons to bank the model and you pull a little up elevator to prevent the nose from dropping. Using Mode 1 you would have to push the right-hand stick to the side and pull the left-hand stick towards you. A Mode 2 pilot uses only the right-hand stick for this manoeuvre, push to the side and pull towards you. With the Frenchman I have to TELL him what to do, with the Englishman I can demonstrate the process on my own transmitter.

Thread: Good news thread.
11/07/2019 17:32:04

England bowled out Australia for 223 in the Semi-Final of the Cricket Woirld Cup then proceeded to score 226 for 2 in only 38.1 overs!

They face New Zealand in the final.

Thread: Newbie with some starter trainer plane balsa IC questions please.
11/07/2019 13:59:38

As regards radios, I would choose the same make as used by your instructor. Once you are able to fly you will be able to choose something else if you want to.

Futaba are the industry standard, you won't go wrong with a Futaba radio.

Spektrum are the new kids on the block and are very popular.

Multiplex and Graupner are German makes and enjoy an enviable reputation and there are a number of newer producers like Taranis which are becoming more and more popular.

Hitec servos are well-regarded. I nearly always use Hitec servos.

PS. I recommend Aliphatic glues for building.

Triumph Sprint RS

triumph sprint st.jpg

I wish I'd never sold the yellow one. The red one is getting a bit too heavy for my seventy-one year-old knees.

Edited By David Davis on 11/07/2019 14:01:35

11/07/2019 11:17:24

You will not go wrong with an OS 46AX. My club has a couple of trainers fitted with those and they have proved to be excellent. Several new members have gone on to buy their own ARTF trainers and all but one have chosen the OS and he would have bought an OS if he had had the budget.

These are very fine engines if a little expensive. Your LT40 is larger than the average ARTF trainer but you won't find yourself lacking power if you go with one of these, neither will it overpower the model.

Edited By David Davis on 11/07/2019 11:20:33

Thread: Never throw anything away!
11/07/2019 10:30:46

Last year I built a Baron. This is a simple three-channel trainer and I entered it in a competition, "La Coupe Des Barons," or the Barons' Cup, in which you fly four rounds. Two of these are at high speed, the other two are flown close to the ground and all four rounds are flown in company with up to nine other models, so it's not unusual for sixty percent of the entry to become seriously damaged during the course of the day. More details here for those who are interested: scroll down to "Video Coupe 2018." **LINK**

I damagerd my first tailplane in practicing for the event last year so built a second tailplane using basswood to reinforce the leading and trailing edges of the tailplane instead of balsa. The picture below shows the original all-balsa tailplane under construction but you get the idea.

baron tail (small).jpg

Since building my first Baron, I've built a second incorporating some modifications to save weight. As this year's rules allow for the use of a four-stroke motor up to a 52 I fitted an OS 52 in the nose and used carbon fibre pushrods for the first time.

bertie 2.jpg

I did not realise that you had to fit locking nuts to the clevises when using this system and the rudder pushrod unscrewed itself. I had no directional control and the model crashed. blush I had substituted basswood for balsa fuselage longerons so the fuselage was undamaged and the wing was only superficially damaged at the trailing edge of the centre section. The engine however, suffered a damaged cylinder head anybody got a spare one they would like to sell?

The tailplane didn't look too bad at first but further examination revealed that considerable surgery would be required. So I stripped off the covering, then my eyes fell upon the original tailplane. "Surely" I thought, " I could scarf in some of the old tailplane into the new one." The picture below shows one half of the old tailplane still covered in checkered film, the other half stripped of its covering and the model's tailpalne taken down to sound wood.

bertie tail repair (2).jpg

Having cut a couple of 45 degree lines on the leading and trailing edges of the old tailplane I matched them up to new tailplane and cut matching 45 degree lines on that. Then I drilled four holes into the leading and trailing edges of the structure to accept short lengths of carbon fibre rod to reinforce the joint. The picture below shows a dry fit before I used half hour epoxy to glue the wood together. The trailing edge carbon fibre rod is just visible.

bertie tail repair (1).jpg

A little sanding and the tailplane structure is repaired.

bertie tail and elevator repair (1).jpg

The elevator was also damaged in the crash and I resorted to scarfing in new wood over the plan.

bertie tail and elevator repair (2).jpg

A little more work with the sanding block, some hinges and covering film and the job's a good un or at least an acceptable one! The model will probably get wiped out in La Coupe anyway!

bertie tailplane the jobs a goodun.jpg

The cognoscenti will say that the diagonals of a scarfed joint should be four times the size of the wood. E.g. with 1/4" sq balsa the joint should be 1" long but using carbon fibre rod I think I'll get away with less and I won't forget to use locking nuts either!

Thread: Newbie with some starter trainer plane balsa IC questions please.
11/07/2019 08:47:46

Nu Me 1, welcome to the forum!

I learned to fly on the Junior 60, in fact I've built two, and I've still got the original model though it's a bit like Trigger's broom these days. I love its slow flying characteristics and massive stability.

junior 60 in flight.jpg

junior 60.jpg

That said, I agree with Percy that the Super Sixty is a better r/c trainer. It may be built with or without ailerons, it goes where you put it and handles gusts of wind better. I've had two of those.

super 60 squadron 2.jpg

However, my favourite vintage aircraft for training beginners is the Radio Queen. They are larger than the other models so far discussed, they are easy to see and don't require a great deal of power. I've seen one fly on an Enya 40 four-stroke.

radio queen and T240, Forton, 2007..jpg

Strange that the Boomerang has been mentioned. This is my favourite ARTF trainer, its semi-symmetrical wing section allows it to fly in a stiff breeze, and you can finish it with a tricycle or conventional undercarriage. I was going to suggest that you buy one of those, put a good 46 in the nose and learn to fly on it while you built a vintage model. I'd forgotten that it was available as a kit. If I were in your position and you didn't want an ARTF, I'd give this model some serious consideration.

The SIG Kadett LT 40 has a good reputation but I've never flown one. I think an old friend had one but I never got to fly it because I am a Mode 2 pilot and he was Mode 1. He died of leukaemia in 2004 and after all of this time I cannot be sure that it was in fact an LT40.

A brief note on engines. I love fourstrokes but even experienced fliers sometimes crash. I crashed a simple three-channel model a fortnight ago. I was using carbon fibre pushrods for the first time and didn't realise that you needed to secure the clevises with locking nuts. blush As a result the rod unscrewed itself and I had no directional control. Lesson learned. However, my much-loved OS 52 FS was damaged in the crash. Anyone got a spare cylinder head for an OS52? So, I'd recommend that you started with a two-stroke, they are more cheaply replaced or repaired.

Final note. Please join a club and get an experienced pilot to train you on a "buddy box," a system which links two transmitters. The instructor holds down a sprung button or lever to give you control and regains control once you have started to make a horlicks of things and believe me, at first, you will. Later on you will be able to recover from your own mistakes without the instructor's intervention unless he leaves it too late of course! blush

enya 50 and boomerang.jpg

Best of luck to you whatever you decide to do.

Edited By David Davis on 11/07/2019 08:50:27

Edited By David Davis on 11/07/2019 09:16:19

Thread: What does your wife or significant other half think of your hobby?
10/07/2019 07:03:53

We met for the first time on 12th January so it's early days yet but Trish likes to be involved in club activities, thinks that my ability to build a model is marvelous, (my ability to bodge more like!) and she likes to carry my models down to the runway! laugh

One day I'll teach her how to fly!

trish and me at the ulster memorial on the somme 1st july 2019.jpg

Thread: The demise of. ASP/SC
08/07/2019 15:01:46
Posted by Paul Marsh on 07/07/2019 20:24:51:

The only engine make now, is really only Saito. Thunder Tiger are gone as well. If we all want Saito to keep going, support them by each of us buying a brand new Saito this year...

No! Buy a Laser!

Thread: Frog Jackdaw resurrection.
06/07/2019 12:41:03

Is that an Irvine Mouse on the silencer?

Thread: Soft Mount
06/07/2019 12:31:20

I found this mount among my souvenirs. It has obviously been driiled for an engine but I don't ever recall having used it and it looks brand new and unused. I must have picked it up at a bring and buy.

I am thinking of using this mount in a model. As you can see in the pictures the front is an adjustable structure made from aluminium. Four set screws go through the firewall then there are four hard-rubber washers, four "threaded donuts" which I assume compress to absorb the vibration, and four nuts with washers to hold the mount in place.

  1. Do the hard-rubber washers fit in front or behind the firewall?
  2. When drilling holes in the firewall for the mount, I assume that I drill 4.5mm holes to match the set-screws rather than 10mm holes to match the donuts. Then I assume that you tighten up the donuts as tight as you can by hand, then tighten the nuts against them, in order to compress them.

Any advice gratefully received.

engine mount.jpg

engine mount (1).jpg

engine mount (2).jpg

engine mount (3).jpg

engine mount (4).jpg

Thread: The demise of. ASP/SC
06/07/2019 05:31:57

I agree with Geoff Sleath wholeheartedly!

Our club was given a trainer fitted with an MDS 48. I took it under my wing if you'll excuse the expression. I know how to tune a model aircraft engine. I could get it to start and run at moderate revs but then it would cut out at high speed. I could get it to start and run at all speeds but when you throttled back to tick-over, it would cut! In despair I gave it to a Rolls Royce, note a Rolls Royce-trained engineer, who altered the taper of the main needle on his lathe. It made no difference. I solved the problem by contributing a Thunder Tiger GP 42 which ran like the proverbial Swiss watch and the MDS was acquired by the club chairman to add to his collection of model aeroplane engines. As far as I know it's lived out the rest of its existence in a glass case.

We had another pilot, curiously also a trained engineer, who had the largest MDS in a Precedent Druine Turbulent. It had only had a few flights when the big end failed in flight.

I could go on. Suffice it only to say that watching other peoples' experiences of MDS ownership put me off them for life. In fairness, the 38s were alright and I believe that the little 18s ran well too but I've never even seen one of those. The later silencers were pretty effective too. I've got one fitted to a Webra 40.

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Revoc
Slec
Pepe Aircraft
Wings & Wheels 2019
CML
electricwingman 2017
Motion RC
Gliders Distribution
Advertise With Us
Sarik
Latest "For Sale" Ads
Does your club have a safety officer?
Q: Does your club have a safety officer, or is the emphasis on individual members to each be their own safety officer?

 Yes we have a SO
 No, it's down to everyone

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us