Charles Smitheman

Thanks gents for the replies. The damaged bit is just the insulation, about 1/2" from the casing. I took it out of one model where it had worked fine, and noticed this.  So some coloured heatshrink would be OK. Not black. I understood that only the little bare bit at the end is the actual aerial. I was concerned that the tuned length might be affected if the protective sleeve on the inactive part was bared. Dennis you say the length, is this the full length of the aerial, or the length of the bare bit at the end? If the latter, then the covering must have some important function. Just trying to understand this newfangled stuff!   I have had another good look at it in the daylight, and will be replacing them I think. Charles Edited By Charles Smitheman on 05/03/2017 11:57:09

Hi Folks. I have one of these which has a small bit of the grey plastic insulation "skinned" from both aerials, where it rubbed on something. Will this affect the output of the aerials? Is this a special shielding or could it be repaired with heat shrink sleeving? I see new aerials are available, but perhaps fiddling with it would be worse than leaving it alone, if it is not an issue. Many thanks from Charles

I would also think about adding a rudder, and perhaps a gyro on it. The model might be side slipping erratically which could dramatically change the way it flies. Has anyone else tried the small Black Horse Cassutt? It also has a big fat nose and a small tail fin area. At low to medium speeds mine was always trying to dive into the ground in the turns rather like John describes. I had to be on the rudder all the time in the turns to keep it in the air. I fixed it by changing from 3 to 4s and flying it flat out. Then it flew OK until the sc burned out! It survived pretty much, but I got fed up and put it in the loft. Maybe one day...

https://dl.dropboxusercontent.com/u/2590535/PMA/OptiPower/Charging%20and%20keeping%20safe%20with%20Lithium%20Cell.pdf Hello Paris, From Optipower's website this is the link to their Charging and keeping lipos safe page. (under downloads) Under the last heading "Storage" it says as follows: "If you are not using a lithium cell it should be stored at what is known as the „Storage‟ charge this is 3.84v/cell or around 42% of full capacity, good brands of charger have a „storage‟ charge function. This will allow the cell to cope with temperature change whilst stored. Always try to keep cells in a fairly stable temperature environment"... So this infers that a lipo may not be able to cope with a temperature change when fully charged. Also My Cellpro charger does a "cold weather" charge and stops before full, indicating a percentage of full charge at termination. I found the page to be well written and informative for any user of any brand of lipo. Charles

On the subject of why these packs may have deteriorated, I understand that as the temperature of a lipo increases the voltage increases too, so a pack charged to 4.2v per cell could over voltage if left in a hot car or in the sun. After all we all know that dogs die in hot cars, Cars can easily get very hot, even here in the UK. So where Chris lives this would be even more of a potential problem. One of the steps that I took after having so many packs fail was to keep them in lipo sacks, in a cool bag and keep them out of direct sunlight at the field. In winter I put a hot water bottle in the coolbag with them. Perhaps Nanos fail because of their dark blue wrappers allowing them to overheat in the sun faster than their pale blue brothers? Could this be a reason why some of us have had these inexplicable failures. Paris I am interested to hear if you think this could be relevant?

Martin you may have hit the nail on the head.

Paris, Thanks for the interesting information. My experience bears out the Nano Tech sensitivity. I had very poor experience with around 8 to 10 packs from HK. In particular the Nanotechs. My conclusion then was that their QC was very poor. I changed to a better charger, (Cellpro Powerlab 6) and to Optipower and Gens Ace packs (which I think are outstanding), and ALWAYS storage charge everything, never discharge too far, and am very careful to protect the packs from heat. Since then (about 3 years) I have never (touch wood) had a problem. I regularly recharge at 2C by the way, but always a balance charge. I also have an assortment of various old packs which are lasting well with their new care regime. So my current conclusion is that a large amount of the problems one can experience with lipos is due to the way they are treated or mistreated, and that the cheaper brands have poor quality control. Perhaps others here who have had such bad experiences with Jens Ace might have been sold stock which was damaged in storage- overheated or frozen or something like that. Charles

I have done quite a lot of this, with success. It is much more difficult now than it used to be. I would check the dimensions of the package with the airlines rules. You may have to pay for the extra bag. The last time I did this BA charged me £30 extra, and the baggage handlers at T5 completely destroyed the model. The reason this happened was that the tail plane was attached to the fuselage, and consequently the package was an awkward shape. It got caught in the baggage conveyor. The couldnt give a damn attitude of everyone involved has put me off BA big time by the way. So a new ARTF in a rectangular box should be fine, if bubble wrapped and in a strong box. Expect it to be strength tested and hope for the best.

Thanks for this, very interesting!

Hi BP, Flew one of mine yesterday, it is in a Great Planes Slowpoke 20. A good match. I use a plug wire with two croc clips on the end, one to the plug, the other to a fin on the engine. Charles

Petrol V Glow: To me it is important what the engine looks and sounds like. So a Saito, OS or Enya 4 stoke is very attractive compared to a converted trimmer engine. Finally I have a Laser 150 to play with, and It feels like driving a Roller compared to an ordinary banger: I love that sound, and performance. Some of our club members have saitos converted to petrol, they sound great. Personally I really enjoy the smaller stuff, I have no desire to get anything as big as a 150 again. I guess smaller petrol engines are more of a challenge, hence my favouring glow. And really small diesels are better than really small glows. in my opinion. My favourite: DC dart.

Hi BP, Fine little engines these. I have two. Both still going strong. The older one since 1980 or thereabouts. I used to run it on castor fuel, but now using Opti fully synthetic 12%. It really likes the nitro,as it is pretty low powered. I always think of the rice pudding skin when running it! The old Saitos need more running in than the newer ones, about an hour to reach its full potential. I also have a Saito 45S. This is a real stump puller in comparison. Mine is very sensitive to fuel thank level. APC 10x6 prop is what it likes. I tried an APC 11*4 and it had a hissy fit. To start I spin it up with the starter and put a finger lightly over the exhaust; the back pressure to the tank forces the fuel to the carb. When it starts I keep the finger there until the heat gets too much. I:t needs a minute or two to warm up. Anyone remember the Somoso add on mufflers; the smallest of these makes it really quiet, hard to hear over the racket of electric models!

Hi Mr.B. Possibly there was excessive valve clearance. The hammering effect caused by this can cause breakages. I replaced the cylinder on my Saito 91 some years back, no problems. Lovely running engine. I used to use fuel containing castor, but I am very glad that I no longer do so. Even a small amount makes a mess and can cause carbon build up on the valves. I am very happy with Optifuel 12% 4 stroke fuel. Charles

see it fall in love buy buy buy! Resale? Who ever wants to sell a model plane... unless its a real dog! I think I need therapy...

I have a Sig Spacewalker II which I purchased half built. The wings are in three pieces as per your photos. But this is a modification from the kit. If you measure the tube holes you should be able to purchase carbon tubes on the web. I got some on Ebay for another plane recently. I was concerned about the strength in that instance (long glider wings) so I found a tight fitting dowel to put inside the cf tubes to prevent them collapsing. The tubes in my SW were rescued from another model.

At our club field the wind direction is critical, due to nearby hedges and trees. As mentioned above, it is the turbulence that really matters. If the windsock is flapping about it gives an indication of the amount of turbulence. I have on a few occasions had my model flipped upside down in the air, which gets the adrenaline going. In a steady breeze it is fun to try to get a light model to drift backwards downwind. Years ago in Cape Town I recall landing my model, and with the 40 engine idling, the wind would blow the model backwards down the runway, ready to take off again! Fun times. But my favourite type of wind is of course none at all.

Just make the LE blunter towards the tip, as PatMc says. The shape of the leading edge is much more important than the rest of the wing. I dont know about deltas, but it really works on straight wings, and thinner lifting sections.

Good description Shaunie. I am very happy with my one. No more overheated film going saggy later.   Temps are different for different coverings. I haven't used Solite yet. Edited By Charles Smitheman on 20/09/2016 12:48:43

Martin, that is a really nice looking model. Well done, and glad to hear that it flies well. Charles

Hello Adrian, Starters like the Sullivan have a switch which is just two metal strips held apart by the rubber grip. It is easy to open it and clean them with a bit of sandpaper. This usually does the trick. I have become too much of a wimp for hand starting, except for tiny diesels. Edited By Charles Smitheman on 16/09/2016 08:38:23

+1 for Clearcoat, on wood and film. Quick, easy, dries fast, no mixing. Does not add weight like epoxy.. Epoxy is also excellent but has a short shelf life. The stuff I bought last has a nominal one year shelf life, but the hardener is already going brown after a few months. It has to be stored correctly too. Not too hot or too cold. I hate the mess when working with it. I have also had excellent results with Poly C, but it needs many coats and is slow drying. Water based, no odour is the big advantage. Had no success with Spectrum fuel proofer some years back, but it may have been a dud batch It dissolved and peeled off where fuel got to it. But the Spectrum / Spectra paint is great. For awkward to get to areas bend a paintbrush at the metal bit to an L shape... Hope this helps. Charles

I too have recently really been enjoying some glow flying. What has made a huge difference for me is changing to Optipower fuel. The cleanliness of the model due to the fully synthetic fuel is quite remarkable. And they all seem to run ever so much better than before. I am using their 12% four stroke mix, which suits an irvine 53, small saitos and os four strokers, and my delightful, smooth, powerful, easy starting Laser 150 was airborne last weekend in my newly restored Spacewalker. (restored? dont ask...)

Hello Oldgit, The test that I witnessed demonstrated that the ammo box is quite unable to contain the pressure of gas released from a lipo. The lid just bent (permanently) open and the gas poured out. There was no explosion and no containment of the gas. What it did do was to keep the actual lipo inside. This in Trebor's instance would have given him a non scorching handle to grab in order to toss it all out of the window, I suppose. So holes for the charging leads to go through would be fine and make no difference, and the firmly closing lid would contain any non gaseous flaming or fuming matter! Yes the milk bottles sound like a great idea.

I would not worry about removing the seal. I witnessed an experiment with one of these. The lipo was punctured with a metal bar, and then the ammo box was clipped shut. Seconds later the lid bent sufficiently to allow the gas to escape. My concern with metal boxes is the possibility of a short circuit. The advantage of having the lipo in a container is the possibility of grabbing it and throwing it outside. I transport and store mine in lipo bags, contained in a soft coolbag. It also keeps their temperature stable, which is important. So far... no problems!

"How do you bend it" I have done this successfully without heat treating. The key I found was not to bend it through too tight a radius. I put a block of hard wood with a radius on it in the vice against the work piece. Possibly 5mm radius. Bending the material directly against the sharp metal vice jaw caused it to fracture, I tapped it with a hammer, and pulled simultaneously, with a cloth wrapped around the work to reduce the pain! The first one I did in 1978 or so, it is still in working order and in occasional use! The material I used then I scrounged from the scrap bin at the airport metal working shop. Those were the days. Good luck with your project, Alan. Charles