Rick Tee

Any one know of a good supplier of coloured dope? can only find clear and thinners apart from Flair who don't trade direct.

Ref the model crash; the pilot now believes this was caused by installation, the receivers being in front of the controller, battery and 2 EDFs , thus when the model was pointing directly away from him the signal was masked by the equipment.

He flew another model after the crash and had the same thing happen but control returned before the model went in. I wasn't watching at the time though. Batteries tested before and after. Hopefully i will see him again tomorrow and get full info on batteries, RX & TX etc.

Timbo: I agree not brown out. The model that was written off last Sunday was being flown by the guy the runs one of the local model shops, though i neglected to ask (will do next time i see him) i'd expect he was using QC receivers. The model was at 100 - 150 foot altitude and around 100 yards from the pilot when the motors (2xEDF) shut down and all control was lost. This is very close to the same place the other model went down. The only ground object between us and the model was a piece of hedge row about 8 - 10 foot tall which ends just short of line of sight, so he could see the model all the way down. Visibility was good but as with most of this summer, the ground was fairly wet, time approx 16:30hrs BST. Location

I've had a reply from the site admin he says the directive only effects NiCads.

On 2 occasions i was there watching, i heard the motors shut down and the pilot say 'I have no control', and was present at the after crash testing. Definitely not pilot error. All models were electric though i don't think that's relevant, most of the pilots who have switched to 2.4GHz are leccy fliers or fly both ic and electric. I think we only have 2 pilots who have switched to 2.4GHz and fly IC only, both use Futaba. Apologies for the MHz GHz error, that's what happens when i try mixing too many TLA's. 

I've had the same problem as Eric, with the addition of arcing as the breaks went unnoticed until the plugs were removed. The plugs were used on my Pro Peak charger so non critical and relatively low current.

Thanx again to Timbo for the testing, very interesting reading. I have unfortunately to report that our club has had 3 models using Spectrum 2.4MHz gear go into fail safe for no apparent reason, one damaged, one written off, one control returned before terra firma interrupted flight. Though models are occasionally lost on 35mg given the number of regular pilots few are using Spektrum gear, making this disproportionate in comparison ie. there have been no unexplained losses reported this year on 35MHz. All equipment not damaged in the resulting crash functioned as normal when retrieved. Like Timbo some users report no problems whatsoever, I'm beginning to suspect this may be a QA issue and as 2 models belong to the same person, the only common item was the TX.

It's the 'other batteries' part that bothers me, is this another price fixing scam?

meme

Sorry about that Eric, was just following the previous posters abbreviation of the term.

I have tried a scroll saw from Machine Mart priced around £50 it was rubbish. A good quality band saw is likely to be of more use then a cheap or even a good quality scroll saw IMHO. If your budget is limited its better to buy good quality hand tools then cheap power ones. A good dovetail saw will set you back about £30 and is ideal for cutting 1/8 or thicker ply, 1/16 ply or under cuts fine with a Stanley knife. To cut holes in ply formers either use a hand fret saw, a coping saw or dremel.

What Gordan says is more or less what i discovered by doing some research on the Internet. With DC an additional decoder stage exists in the RX it's only purpose is to prevent the remote possibility of harmonic interference which may occur between transmitters on channels at the 2 extremes of the 35MgHz band. This is so unlikely that the extra costs and increased complexity (more to go wrong) is not warranted. At our site the upper frequencies 81+ are allocated to a near by helicopter flying site so the problem does not exist. Roughly though i can't remember the exact channels, 62 or under could produce/receive a harmonic to or from a RX/TX on channel 83 or over. Channels in between are unaffected as the frequency needed to produce the harmonic is outside the allocated bandwidth.

Lol, bad form old bean.

I wonder what hardwood it is that's been supplied, i use beach as there is still some knocking around here from the pre plastic engine mount days, it has never split. I would expect spruce  to split though.

Hmm ok it's been a long time since i was taught electrics and soldering but IIRC you can solder aluminium just need the right flux.

Andy there's never any need to feel embarrassed, no matter what others may say, there is NOTHING you can do that most of us haven't done at some time or another.

The addition of washout is usually used to reduce or eliminate tip stall, its side effects are to increase drag and reduce lift efficiency effectively increasing wing loading, flying speed and making inverted flight unstable. The exception is where a wing is specifically designed to have some washout, in which case the aerofoil section at the tip will be different to that of the wing root (aerodynamic washout.) I believe it's mainly used on thermal gliders as tip stall can be the result of highly tapered, high aspect ratio wings and inverted flight is not a major consideration with this type of model.  In this case we are talking about a free flight rubber powered model (I think) so inverted flight is not a consideration, but the wings lifting and drag characteristics are. Though increasing the dihedral does reduce the wing's effectiveness, it should not increase the drag. I'd go with Eric's post, if instability is the problem, increase the dihedral by cutting the wing or building a new one.  If the wing is twisted then pin down and re-dope, if your lucky the twist will be gone, if not it will be back in a few days. I remember having this problem with rubber powered kits, i bought a balsa stripper and replaced spars, leading and trailing edges (mainly spars) with ones cut from the same piece of wood, as inconsistency between them seemed to be the main cause (all looked fine untill the dope dryed.) If i've not got this right i'm sure someone will correct me.

Grats, well done.

Ah ok, my bad. No idea then none of my stock is marked.

Try Balsa Cabin, prices are good but the postage is bad so make it a big order.

Well i would fuel the model first then peg on, that way i have the peg for the minimum time.

Super Rieti: Not quite the quality i had expected. The plastic fuselage, tailplane and rudder had a lot of flashing from the moulding process. It took over 2hrs to cut and scrape it all off. in addition the plastic parts are off white, meaning it required painting. The instructions are pictorial with very brief text in 6 languages, i.e. a picture of 2 components with text which says 'glue' i only figured out what glue to use as in one image the glue bottle is large enough to make out 'Cyan' on the side. The flying tail is fixed to the control axle by a grub screw screwed into a plastic collar, this is all that holds the elevators on. Another grub screw fixes the axle to the plastic control arm inside the fin. i think this will prove to be inadequate, grub screws have a fine thread and are not suitable for self tapping into plastic. The control system for flaps and ailerons consists of brass tubes, one inside the other. With the inner one operating the outboard ailerons and the outer the inboard air brakes. These are then epoxied to the control surfaces and function as hinges. While the control system seemed like a good idea at first, fitting it requires great accuracy. Too much clearance will produce slop, too little will result in unacceptably high friction. The routered slots outlining the cutouts for ailerons and flaps proved to be a little inaccurate, so some time and a great deal of care needed to be taken trimming back the cutouts before fitting the ply backing against which the brass tubes rest. Some scrap wood needed to be added to the front edge of the flaps and ailerons for them to fit correctly in the wing. Having connected up the controls as per drawing there was .5" slop in the ailerons, so the 'R' clips that fitted in the ends of the brass tube were lengthened and ball links fitted to the servos, this reduced the slop to around 2mm. 10oz of lead was needed to get the C of G where shown on the drawing (no dimension given.) Flying: First flight showed rudder was needed to turn and any use of elevator in a turn resulted in tip stall. Mixed 30% rudder to aileron and tried again. Much better in the turns, put on some speed for a loop then a bit more speed for a roll, the ailerons fluttered badly at speed and despite aileron movement of .75" each way control was very sluggish. The deep short ailerons are not very effective, according to the book i have on model aircraft aerodynamics that's expected. Another time i would fill in the gaps routered for the ailerons, cut strip ailerons up to the air brakes and fit servos in the wings. Sold on Ebay.  I have now bought the CMPro Ventus.

Great stuff Timbo, many thanx for your hard work.

Some model shops stock the clear stuff, i use it to make canopies.