david Osborne

Thanks for the tips. The wires to the motor are quite stiff and 5mm diameter each (approx 12 swg). I was going to cover them in two layers of heat shrink with some RTV at either end to seal it. I think this would be stiff enough?? Cheers Dave

A bit of advice please. I have to seal the motor wires for an EDF system where they pass through the exhaust duct. I was thinking of using RTV sealant to provide some flex and the ability to remove it if needed. Any experience or tips. One thing to bear in mind is that I have to install the fan and exhaust duct as an assembly but the wires will have to inside the duct until its in its final position, then fed through the hole in the duct because there is insufficient clearance to put the assembly into the model with the wires already on the outside of the duct. No problem getting to the motor wires after final positioning as its a 120mm fan and I can get my hand all the way in. Cheers Dave

Thanks for the info. Interestingly all my chargers have a max delta voltage setting of 20mv. If NIMH are not as easy to detect by the delta voltage method what is the best way to ensure correct charge?   Cheers.

I was hoping that someone could provide me with some info on charging NIMH batterries, specifically a 2000mah 9.6v pack for a transmitter. I know about most of the process such as forming charge for the first charge at about 1/10th C and not to let the pack get too hot or sit on the charger for too long. I also know about delta temp (best method) and delta voltage for determining the full charge point. my question is regarding these delta points as I have not been able to find out any actual values. My chargers have the delta capabilities but I do not know what values to set. I would also like to know about discharging the batterries so I can cycle them a few times.   what is the best delta voltage value to set for charging the example battery pack? what is the best temperature to set for cutt off? what is the correct value / rate for discharge Discharge should terminate at 1 volt a cell I believe?   Cheers.

Try Krumscheid, they have a large range of aluminium spinners of good quality. Hope the link below works http://www.krumscheid-metallwaren.de/neu/shop.php?lang=EN   Cheers Dave Osborne

Can anyone tell me where I can buy some resin casting materials, silicone, latex, resin etc suitable for a scale exhaust? Is it possible to buy a "kit" of materials rather than seperate items? Some hints / advice on a good brand or source would also be useful as there seems to be a lot out there from different producers.   Thanks Dave Osborne

Oh and forgot to add.   If a structural failure occurs in flight and the model becomes uncontrollable causing damage or injury who is responsible? if you can prove the model structure was at fault would the BMFA insurers reclaim the money from the manufacturer as is common practice in other such compensation cases?   Cheers again Dave Osborne

While I can see the point about landing technique I do not believe it to be the end of the story.   I firmly believe that it is your responsibility to learn to land correctly, and then put that knowledge into practice. but there are a few other things to consider.   1. We are all human and typically the human being makes a mistake 15% of the time. this increases depending on stress and pressure or the situation etc. Therefore in theory about 1 out of 9 ot 10 landings will be less than perfect regardless of outside influence.   2. Outside influence such as a sudden gust of wind at the wrong time can lead to a less than perfect landing.   3. A certain level of abuse is usually taken into account by many manufacturers and there are requirements to meet standards and pass tests for such things as shock, topple and general handling abuse. Granted this does not apply to everything but in general consumer goods are tested and designed to meet the standards - why should ARTF be any different? If you bought a phone where the cover kept falling off you would take it back wouldn't you, even if it did not affect the function. If youre car wheels collapsed when you accidently hit a kerb then the car would be in serious danger of being removed from use, ok not the best example maybe but the principle is there.   3. Light is one thing not strong enough is another. The avaiation industry goes to great lengths to make aircraft as light as possible and they are, to all intents and purposes only built as strong as they need to be. However, that does require the inclusion of reserve factors to take into account the unknown, abuse and life requirements etc. OK I know it is not quite the same thing but the principle is the same we want the lightest aircraft structure to do the job so the rest pays of in economy and payload.   Cheers. Dave Osborne

A general theme seems to be undercarriage. While we all want things as cheap as possible the terms value for money and fit for purpose come to mind. Is it really value for money if we have to keep repairing, sometimes with almost as much expense and the original model? Is it fit for purpose if typical flying sites are grass and normal landings result in immediate problems or problems after a few landings? Surely some design life expectancy is not too much to ask in the frame of normal wear and tear. I for one would be prepared to pay a bit more for  a model that is built for the real world where some level of abuse is inevitable. After all an extra 20 quid on a 250 quid model is not that much more and would buy plenty of quality ply for the u/c areas, particularly if it saves you 40 quid for a couple of repairs you don''t have to make. After all most people build from kits or scratch build this way don''t they?   Cheers Dave Osborne

Just noticed I should have started a new thread so I have placed the P-47 stuff in said new thread   Cheers Dave Osborne

Just noticed I should have started a new thread   sorry for the repeat posting   Dave Osborne

    I have had some problems with ARTF undercarriage on my P47. I had a perfectly reasonable landing (I have witness) and the undercarriage came out. While I confess this was not the first landing and others were not perfect I do believe that the poor construction in this area contributed to the problem / failure. I repaired the damage and in the process uncovered other areas of concern within the wing structure. Again I cannot be 100% sure about the origins of the damage but suffice to say there was a lack of glue and no external indication of problems. Since the repair and reinforcement I have not had any issues. Work included beefing up the ribs in the u/c area, glueing all joints in the wing, using birch ply instead of the standard light ply u/c mountings ( a common fault on ARFT). I am working on a P-51 ARTF and customising it but I did notice similar construction issues with this model as well, including a rib that is completely cracked through in the u/c well area, and this is straight out of the box. No point  trying to get a warranty replacement as I am ripping it apart for modification anyway and thats how I found it. Still goes to show that even expensive ARTF suffer. other problems include tailplane joiner tubes that need to be bent to allow a flush fit making incidence setting a nightmare. I have mentioned some of this to the retailers but they are not always enthusiastic about such matters, often quoting the value for money thread. however it does not matter how little it cost if it is not fit for purpose but again this is a difficult argument.   On the plus side I have had good experience with some makes with no construction or failure issues and the general finish is very good.   Are we allowed to name names?   Just in case images do not work I have uploaded a load to my photo album.   Cheers Dave Osborne 

The P-47 u/c and wing ribs was from YT. On the plus side the glass fuselage has worn very well. The tailplane joiner was on the same model.   The P-51 cracked rib is on a Topflite giant ARF, not cheap and I am going to reinforce the whole u/c area as it too uses a lighter type ply rather than good Birch ply. No other problems found with this so far although I do believe the wing structure looks a bit light in general in the wheel area for such a large model.   Good experience with a Hangar 9 Sopwith Camel. It went together really well and has taken some ground handling abuse with only minor deformation of the u/c to show for it.   E-Flite Funtana has been good as well.   Other issues in my experience are "custom" retracts not up to the job or than need a great deal of maintenance, extensive mods to fit said undercarriage, tail wheels that fit into the fin but there is no block inside to secure it to.   Cheers. Dave osborne

    I have had some problems with ARTF undercarriage on my P47. I had a perfectly reasonable landing (I have witness) and the undercarriage came out. While I confess this was not the first landing and others were not perfect I do believe that the poor construction in this area contributed to the problem / failure. I repaired the damage and in the process uncovered other areas of concern within the wing structure. Again I cannot be 100% sure about the origins of the damage but suffice to say there was a lack of glue and no external indication of problems. Since the repair and reinforcement I have not had any issues. Work included beefing up the ribs in the u/c area, glueing all joints in the wing, using birch ply instead of the standard light ply u/c mountings ( a common fault on ARFT). I am working on a P-51 ARTF and customising it but I did notice similar construction issues with this model as well, including a rib that is completely cracked through in the u/c well area, and this is straight out of the box. No point  trying to get a warranty replacement as I am ripping it apart for modification anyway and thats how I found it. Still goes to show that even expensive ARTF suffer. other problems include tailplane joiner tubes that need to be bent to allow a flush fit making incidence setting a nightmare. I have mentioned some of this to the retailers but they are not always enthusiastic about such matters, often quoting the value for money thread. however it does not matter how little it cost if it is not fit for purpose but again this is a difficult argument.   On the plus side I have had good experience with some makes with no construction or failure issues and the general finish is very good.   Are we allowed to name names?   Just in case images do not work I have uploaded a load to my photo album.   Cheers Dave Osborne