Clive Matthews

It's not unknown and probably nothing to get alarmed about. Forgive me if this is stating the obvious, but have you checked the tightness of the head nuts? Beyond this it could of course be the gasket or a warped head. This is quite easily remedied using grinding paste and a sheet of glass, but given the age of your engine, you would want to return to the supplier first.   I have to say that the picture doesn't show anything out of the expected.    Re cutting out in mid flight. I have a vague recollection of there being an issue regarding the mixture and a small hole in the carb diaphragm cover. Something to do with a drop of pressure caused by the airflow passing over the hole. Altering the mixture a tad might be the answer. Edited By Clive Matthews on 09/03/2010 17:48:06

This is serious nit picking and doesn't really relate to the 'are digital servos better than analogue ones' debate, but;   As a rule analogue by definition gives a more accurate resolution than digital. Using a sine wave as an example, analogue would be any point along the curve whereas digital is a series of sample points along the curve.   A little off topic but I get so fed up with the 'digital must be better than analogue' assumption. 

My EasyGlider copes with light winds well but I can't really recommend it as it doesn't have that 'solid' feel that you will be used to.

Some further observations (don't worry, I've actually got some work this week so will stop all this experimentation) on chargers.   I have been using a Schulze ISL6 330 for over 10 years. It is still going strong and has given sterling service.  It has two outputs, charges huge packs at up to 5.5a. Friends give me batteries to sort out which have failed to come up to scratch on other chargers. In short, it is a wonderful piece of kit which I still like to cuddle! However, it has one failing, it doesn't like AC power sources of any kind. You can use them but charging is less fruitful, with early cut offs being common.   This week, I took delivery of a brand new B6AC Dual Power charger. This is a sexy piece of kit. The display lights up a delightful blue colour, has 2 lines of info, balances LiPos and is much more programmable than the Schulze. Available from around £40 it makes the Schulze look like an expensive dinosaur!   I have now spent days just charging batteries with it (I've said that I will get a life next week!). It works very well BUT, the Schulze gives a higher capacity charge every time.   The interesting thing that I have observed so far, is that the Schulze powered from a 12v battery, is more efficient. However, if I use an AC power supply, it is less so, similar in performance to the B6 in fact.    It may be that the Schulze has more aggressive software than the B6, or that the B6 plays it safer. I think that it is the effect of using an AC power supply has on sensitive voltage sensing circuitry. Perhaps Schulze were just being a bit more honest when advising against the use of AC power sources! It may well be that the B6 is just as good as the Schulze when using a DC power supply, I haven't tried this yet.   This all said, both chargers work well, and I'm not sure that the extra cost of a Schulze makes it worth any perceived superiority. Edited By Clive Matthews on 07/03/2010 10:41:30

I would guess that 80% of the UK price goes to distributor and vendor. That's the reason buying direct is so cheap. Before getting shot down, I'm not expressing any opinion here.   I am not certain that there is a 'safe' way to buy foreign goods other than fairtrade schemes. In other products, coffee and chocolate comes to mind, these have made inroads to the problem without raising the price to the consumer by very much. These schemes are only successful due to consumer pressure. Clothing is an example where consumer pressure is not quite strong enough to have a lasting effect - yet.    Rather than just posting, we could wish for a fairtrade scheme in modelling. I would support such a scheme by only buying such products. If enough of us were like minded, a distributor will take up the challenge.Edited By Clive Matthews on 07/03/2010 09:32:44

Yes, I've had this issue with an FF7. Either physically reverse the servo or use a servo reversing lead.   You may have introduced flap trim which will increase the offset producing the other symptoms mentioned. Either inh flap trim or adjust to get the movement you require.    Sorry Frank, posted same time - great minds etc. Edited By Clive Matthews on 06/03/2010 19:05:25

They are all mostly excellent. The one thing that I would like to add is that a charger which operates on both AC and DC is a huge asset when charging at home.   My brilliant but hugely expensive Schulze doesn't like AC in any form, I've just received an AC/DC B6 and I can already see how it is going to simplify my charging regime. No more juggling large12v Pb batteries in the workshop!  

You don't have to be in a club to be insured. Clubs which are BMFA affiliated will include BMFA membership and insurance. There are clubs which are not affilliated and in their case members are often BMFA country members and insured that way.   Any individual can join the BMFA independent of club membership. Currently for an adult it costs £29 per annum. This includes the excellent insurance cover and like Erfolg, I would consider it an essential requirement for model fliers.

Posted by JayCee on 04/03/2010 19:12:52:  I'm trying to keep the cost down.   Nice as the SIG is and I would be the first to admire the quality, it's a big investment for a first model. Sadly, I fear the same might be true of the XT40. Both extremely competent, high quality models, but I think that the likelihood of a heavy arrival at some point must be considered. They will certainly fly the socks of the Jupiter which is a brick by comparison. I only suggested it for the robustness and wind absorbing qualities. The Speed Air suggestion would certainly be the cheapest at around £60.   

I'm also voting for the Wildthing 60.    It's virtually indestructible, can fly in winds of 10mph to 25mph, can be any colour you like, is responsive, and the most fun to be had by males over 50!   To counter this glowing summary,  it doesn't penetrate well in higher winds and isn't the most efficient glider.   Just to be totally offbeat, an EasyStar is suprisingly good as a slope trainer. 

If you can borrow an ESC, might it be possible to tape it to the outside just to prove whether it's that or not.   I'm not certain that you had put the prop on the wrong way round. I always thought that the writing on the prop went in the direction of travel, so I'm no wiser than you! Are pusher props different though?Edited By Clive Matthews on 04/03/2010 20:28:07

I have a Hanger 9 Pulse XT60, flies very well, but it would struggle on an Irvine 53 and may be a step too far. I'm not sure that it is worth the current price either. Agree with the SIG which is lighter.   If I wanted to match an Irvine 53 with a 1st low winger that handles windy conditions, a Thunder Tiger Jupiter comes to mind. I flew one for a couple of years at the high and windy Hexham field. It proved to be extremely robust and forgiving. The afore mentioned Speed Air and Travel Air are also good suggestions though not quite as robust.

In general terms, low wing trainers are manageable as 1st trainers. I have experience of the Calmato 40 trainer and it is quite a lively beast. I don't think that you will find the 60 any more tricky to learn on.   Irvine 53. The only way is to try it. Probably is the safest answer, but you aren't making it easy on yourself . Get an experienced flyer to test fly it and trim it out if you do go this route.

I've checked all your figures and they add up. Just to confirm it, tacho the prop. You should be getting around 20000 rpm.   Two possibilities come to mind. You are close, but not exceeding the current limits of motor and ESC. It does sound like ESC overload. It could also be the dreaded 35Mhz v brushless motor glitch.     If possible, I would try another ESC first, perhaps a 35 - 40 amp one if anyone near you can lend one. 

Posted by Ultymate on 03/03/2010 11:02:53: Clive I would always advise anyone to fly under the umbrella of a club, however I would not allow them concessions on club rules ie if the club say no solo without an "A" test then that should apply equally with electric as IC. It is fine for them to think they can fly unhindered and more than likely un-insured down at the local park until they injure a child and are facing life ruining litigation, they then don't need to come looking for my shoulder to cry on. My attitude is different. My concern is not with proving the 'likely uninsured' to be in the wrong but with the injured child in your case! We should be concerned with preventing accidents and protecting the reputation of our hobby. In any case they may well be BMFA country members. I also advise anyone to fly under the umbrella of a club and am not suggesting any concessions. I am challenging the accepted wisdom that members 'must have an A'. I'm suggesting that this could be replaced with 'are advised to have an A'. After all, how can this be realistically policed. Legally, I am advised that a club would be in a more protected position if they advised rather than insisted and then failed to ensure. There are many reasons why fliers may not have achieved an A other than incompetence.   Many people enter this hobby as park fliers. They may not initially take this hobby as seriously as we do. Neither might they recognise possible hazards. By welcoming them with guidance and advice rather than rules and hard opinions may be more productive in the long run. Above all, we should offer them a safe place to fly without risk of injuring a member of the public.   Like you, I believe that there is no difference in ability required to fly electric or ic. It's just than electric is quieter and can be smaller.  

I agree with Ultymate. No issue, electric flight and IC flight have equal status if not usage at Hexham club. But, IC is only flown at the club (or other similarly suitable place) whereas electric flight is often enjoyed at other places such as sports fields.   I am certain that there are many electric fliers out there who don't join a club because they don't need to. They may also feel uncomfortable with the 'seriousness' of a club. By this I mean that whilst welcoming, we might also be putting up other perhaps unnecessary barriers to new people joining.     Whenever we have a discussion on this subject, it tends to get heated. I appreciate that rules and safety have an important role in the running of a club. But lets consider that John Doe has bought his electric model and can freely fly it at the local public park without hindrance.  Without doubt, he would be safer and well advised to seek instruction and fly at his local club. What's stopping him and the many others? Could it be attitudes such as no A no solo? My personal feeling is that I would rather he flew without an A at the safe club environment than at the local public park. At the club he will receive guidance and tuition. I believe that we should advise rather than rule. We are not policemen.

I've been doing some more tests (forgive me it's been a very slow year so far).   The following information whilst based on tests, experience and out sourced knowledge, is purely my opinion.    Charging in the transmitter;   Whilst most transmitters have a charging socket, not all allow charging with a smart charger. This is because some transmitters have a protection diode in the circuit preventing the charger sensing the battery. Many people remove this diode. I have an old 35Mhz TX and a brand new 2.4Ghz TX which both come under this catagory. I also have a JR DX9 which allows smart charging. I believe Spektrum TXs also allow this. Fast charging in the TX is not recommended due to heat and gas emission.   LiPo v NiCd v NiMh   This is where it gets a bit opinion biased. I am attempting to be objective, so please bear with me. NiCds, most wall chargers supplied with TXs are designed with NiCds in mind. They are happy to receive a low rate charge and 'float'. They will suffer from the so called memory effect and to counter this need cycling every so often. A TX with a protection diode will prevent this and so they will have to be removed to achieve this. NiCds have a 'slow' voltage drop which is ideal for use in TXs. Unfortunately they are no longer available on the market due to the use of cadmium. NiMhs, These are now the most common rechargeable battery in cylinder form. For their size they generally have a larger capacity than NiCds. They are not suitable for charging by typical wall chargers. Whilst in practice, they can be charged in this manner without obvious problem, they are at risk. A smart charger is highly recommended and they are best charged at 1C (source Schulze and Panasonic). They should not be charged at this rate in a TX. If the TX allows smart charging, they can adequately be charged at a lower rate with reduced capacity. NiMhs have quite a steep voltage drop and for this reason should not be used when 'low'. Both NiMhs and NiCds self discharge. This can lead to cell imbalance in packs. This leads to cell failure when the pack is subsequently recharged or discharged. They both need regular cycling. Low Discharge NiMhs, Becoming more common, these cells reduce the problem of cell imbalance due to there charge retention characteristics. When new, they are charged ready for use. Can be left for long periods without charging and retain good capacities (about 2100mah for an AA cell). They have higher internal resistance and should not be recharged at more than 0.5C. They also require smart charging, though it is possible to get away with using a wall charger with care. Their characteristics should result in a longer life due to requiring fewer cycles. Other characteristics are similar to NiMhs. LiPos, With a cell voltage of 3.7v, they do not add up to ideal voltages for TX and RX use. This will change in the near future as TXs and RXs will be designed to utilise these excellent batteries. They MUST be carefully charged using a dedicated smart charger. Incorrect handling and charging can lead to combustion. Whilst it is possible to charge in TX, it must be with a smart charger and a low current. I would prefer to charge on the bench. The minimum discharge voltage is 3v per cell (source Kokam) beyond this, the cell will be damaged. Many TX low voltage warnings will be to late to prevent damage. LiPos have a sharp voltage drop towards the end of their capacity. The biggest advantage of the LiPo battery is it's capacity/weight ratio. They are often less than half of the mass of similar capacity NiMhs.   My opinion;   If you've got NiCds, hang onto them, they are ideal for TX use though tend to have relatively small capacities. If you need a new battery for your TX or want to fly all day on one battery, the new Low Discharge NiMhs are ideal and cheap (£9.95 for an 8 cell 2100mah pack). Just take care on the rare occasions that you will need to recharge, and don't recharge for the sake of it. Whilst LiPos will increase in popularity and usage (until the next type arrives) using them in a TX is at the moment is pushing the boundaries slightly and you need to take extra care. In an RX, you will either use a voltage regulator or be prepared to replace servos regularly (the RX itself will probably be fine). This extra complication doesn't make sense to me for now but I know that higher voltage servos are coming. NiMhs, probably the most common battery for now, use a smart charger to cycle them occasionally and don't keep topping them up.      

Wot 4 wot 4s   Sorry, couldn't resist! 

Sound and eloquent BEB. Thank you.

Soar Ahead Sailplanes    

I have used an FF7 35Mhz set buddied up to a 2.4Ghz FF7 and 6EX as well as a Spektrum DX7 and JR DX9. The only set that won't work with it (up to now) is the DX6i due to no PPM output. Futaba recommend that 2.4Ghz sets are not connected to round plug sets.    For JR to Futaba I use a HAN173 which is expensive and a HAN174 which is ludicrously expensive! This lead only work with the JR/Spektrum as master.   I have only been successful with a basic set up. Mixing is beyond such a mixed setup.   Edited By Clive Matthews on 01/03/2010 19:35:39

The 2.4Ghz is very similar to the 35Mhz version in operation if not identical. It's an excellent radio (as you already know) and is probably all the radio you'll need. If you decide to go gliding or get into helis, you might find some limitations.   Just be aware that the Spektrum DX7 is also very highly thought of and has the advantage of a more comprehensive and cheaper receiver range.

I've been doing some experiments with a 2200Mah 3 cell LiPo (well the weather has been miserable). The LiPo is in good condition and is at it's stated capacity.   Timbo is taking reasonable care in landing when the voltage reaches 11.5v. When my LiPo reaches that voltage at a low load (50 milliamps) it requires  a charge of 0.91ah to bring it up to full charge. I must stress that because of the time this takes, I have only been able to do this experiment once and with only one battery.   My conclusion so far is;    11.5v cut off is over cautious.    Utilising less than half the battery capacity is counter productive.  

Absolutely Martin, they are all good. Horses for courses! I have used Acomms, Sanwa, Futaba and JR. They all worked well for their cost. We've never had it so good!

Just to add to Martins post; If you do have NiCads, rejoice, they are superior to NiMhs in all aspects but capacity.   The trickle charge issue is good advice. In practice, I've been leaving my TX NiMhs on a trickle charge for years and the batteries seem to last a long time. That said, I do take them out and cycle them occasionally.    Chris and Martins advice is certainly best practice. Edited By Clive Matthews on 28/02/2010 12:42:29