PeterF

My BT mossie has the batteries in the nacelles, hence commoning them up would require extra full rated power cabling between the nacelles so I have left them separate. On twins with the two batteries in the fuselage then I common them up. As with Hangarqueen above, if the ESCs have enough current rating I connect through Schottky diodes so I have some redundancy.

I am with GG on this one, purchased RCMW and RCME for >20 years and only ever built one free plan.

I missed your post of last year which surprised me, but in retrospect, I was rather busy with other things at the end of April. On the retracts you said that you thought that they may be baulking towards the end of the cycle. They slow down at the end for two reasons, the first is there is a set screw that acts as a throttle on the air flow, but as the retracts go down, with the help of gravity they only need a light pressure to go down and they appear to get ahead of the air pressure, which then catches up to lock the retracts into place. Secondly, the geometry means that the oleo legs do not move much as the last part of the control arm rotation occurs. The only issue is that the mechanical lock in the down position relies on the trailing arm from the bottom of the oleo to the top rear of the nacelle going beyond 180 degree and the hinges then have a hard stop. If you do not make sure that this can occur then you only have pneumatic force holding the wheels in the down position, which can result in the U/C folding back on landing, I have suffered from this. A poor landing that causes any twist in the retracts can result in this occurring on subsequent flights, so if you have a poor landing, check the retract line up before your next flight. I have put a Turnigy SK£-5065-320kV motor through ecalc on 6S and this suggests that it may spin a bit faster than the details for my motor above, drawing a bit more power and would definitely fly the model. ECalc does not have the motors you list in its database so I chose a close match. On the 460kV motor I would have thought a 3 blade 15x8 would overload the motor, eCalc suggests that a 13x8 3 blade or a 14x8 2 blade would be better. Happy to answer any questions.

I see one of my photos from the RC Groups thread. Mine is still flying but on electric now, I did add that to the RC Groups thread. Whilst the 2 x RCV60SP is what I started out with, they caused me no end of trouble due to the excessive vibrations that they generated, ultimately ending in a crash that broke the wing beyond repair. I rebuilt the wing with electric motors. In terms of hardware changes, the thick ribs supporting the motor have been lengthened so the motors mount directly without spacers. The ESCs have been mounted on extension plates so they sit right in the prop blast coming in through the chin scoops. Battery boxes have been built into each nacelle and hatches cut into the top of the cowls. I used Hyperion ZS 4025-16 320kV motors (no longer available) with 16x12 APC E props driven by 6S 4000mAh batteries through HobbyWing Platinum 80A V4 ESCs. Measurements gave 6,450rpm at 22.3V with 47.5A, so about 1050W each = 2100W. The plane now weighs 8.07kg = 17lb 12oz which is exactly the same as it weighed in IC version without fuel, so the flying characteristics should be the same. The ESCs both have 10A BECs with adjustable voltages. I have set up both to feed the Rx through Schottky diodes with one set at 6.0V and the other at 5.5V so I have some redundancy and the voltage telemetry alarm will indicate if the 6.0V one fails. UK weather is very windy at the moment so the maiden may not occur for another week or so. The pull on the ground was tremendous and much more than the RCV 60SP engines which never reached much above 5,500rpm on 16x12 props. The RCV engines flew the model sedately, the motors give potentially 40% more thrust, which is why it felt so powerful on the ground. When I flew it for the first time on motors it was a much more relaxed time than with IC where I was always waiting for one engine out. I was happy to do rolls and loops now without the concern of losing power. It really does fly like a large sport plane once it is in the air. Someone on my thread mentioned that they had used a 4S set up but it was quite sedate, have a look at the last few pages. My build log.

I do this because I have added current sensors to all models which integrate the current with time and return used mAh to the Tx. No need to rely on timers and it means that if I want an absolute hooligan flight I can do so without worrying about running out of juice quicker than a normal flight. Really does take the major concern out of flying larger EDFs.

As with post above, I target 20% as a minimum.

One difference that I have seen is inrunners for EDF often have 4 poles where rpm can be in the 35,000 to 50,000 rpm. Whilst running at a higher rpm, the switching (commutation) frequency of the ESC is proportional to rpm x number of poles so the ESC switching frequency for EDFs is similar to a typical outrunner running at 10,000 rpm.

Early Tauben came with 4 cylinder engines but the majority used 6 cylinder engines including the Etrich D2 mine is based on, although this had 6 individual exhaust stacks rather than the combined one I printed. There were even some rotary engine versions. There was no one Taube design, Etrich's patent was refused in Germany and many companies copied the design and offered their own versions. It is a fascinating period of aircraft development.

As a follow up, and I know it is not exactly the right engine for an Etrich Taube, but it looks a darn sight better than the bits of electric conduit tubing with end plugs that I previously had for cylinders. The whole Flair Taube is definitely stand off scale so I am more than happy with the result. I would not have done this had I not seen this thread. Before the makeover After the makeover

Other than the 40-60 size range does it give a weight range or can you find the weights of models that use that size of float as some sort of guide.

Yes, I printed at 0.2mm for 7 hours, I baulked at going down to 0.125mm and a 12 hour print, but it would be worth it.

I have been looking for something better to have as a dummy engine in my Flair Taube and although this is not the right engine it looks the part. I loaded the 4 cylinder files into Cura, selected all the 4 files then right clicked and chose "Merge Models". Cura works out the shapes of the flat surfaces and groups the models together and forms them into a single model. However, it does not form them into a single entity, so when it slices, the cylinders are still printed as 2 semi circles rather than a single circle, but at least the join line fuses together. On the completed pictures below you can see a join line on the rocker shaft between cylinders 3 and 4. I then added the inlet headers and lined them up as it would not merge automatically. There is another engine file on Thingiverse, a D1, https://www.thingiverse.com/thing:2972050, this is a very large file, but I downloaded it and use Microsoft 3D Builder to just leave me the exhaust. This was imported into Cura, scaled to fit and lined up, but as this sits in the air I had to turn off the option to automatically sit models on the build plate when lining it up. All components were then grouped together and the grouped engine scaled down to 55% to fit my Taube and printed with eSun PLA+ using fairly standard settings, I used supports from the bed but not any from the model itself so I got some drooping on the underside of a few flat surfaces. By printing the cylinders vertically you avoid the problems with thin surfaces as seen above. I have an AnyCubic MegaS, I have an upgraded cooling duct which helps with some of these complex shapes with overhangs. Printed with a single 0.4mm wall on the cylinders. The exhaust was solid so that has more wall layers plus infill. Cura view of merged and grouped models The Mercedes D1 engine file

If you use something like a 1.6m small F3A plane (Sebart Mythos, AJ Acuity etc.) and you have it well set up there is a less piloting load. I took my B and examiner assessment with this type of plane in the past 18 months and glad i did. I am not sure if such capable neutral aircraft were readily available when i first started flying 20 plus years ago.

Robotics suppliers are your friends, for example https://www.active-robots.com/hardware/servo-hardware.html

Should the rectangular inlets also have rounded edges.

As has been said above anything like a discharged or broken RX battery, black wire corrosion, dodgy power connector(s) or failed power switch. There was a fly away at our club many years ago, when the wreckage was checked the flier had soldered up their own RX pack to save a few pennies.

There is talk of jammers being used, surely if there was jamming or a high power microwave transmission the RX would go into failsafe not fly away because it was no longer receiving a valid signal.

The other thing here is that the temperature is falling, you note yourself that the last flying session was 10degC. LiPo batteries give out less power at lower temperature as the internal resistance of the battery cells increases. Higher resistance in the battery means less volts at the motor, less volts at the motor means lower current. Could this be the cause of the seeming lower pick up of power.

I always thought that M S Word could open a PDF file and extract the text and formatting as long as it is not a scanned PDF. See if you can get PDF as the file type in the file open box. There are also on line PDF file converters that create an RTF file that Word definitely opens.

Heres my 1/4 scale Moth, I based mine on one of the prewar civilian planes that never had the strakes so it is correct without them. I have deliberately spun the model and it recovers OK without them. I have the slats made out of lithoplate but they are not functional.

what temperature is the location where you allow the epoxy to cure, if it is too cold this can be an issue.

The Hitec antenna is a dipole and increases the emission / reception along the axis of the antenna reducing the doughnut shape of the gain. I flew Hitec for many years without any problems, also 3.5m thermal gliders to the limit of vision. I only used the Optima 9 with twin antennas for larger / more valuable models even if I did not need all 9 channels.

When I had access to a colour laser printer I printed logos onto laser printable vinyl self adhesive sheets from ebay and cut them out using a scalpel. Great for logos with easy shapes but it would be a real pain for lettering though.

Considering a visit to Buckminster for this event.

I keep a dehumidifier running in my model workshop. Never suffered from black wire corrosion in the 20 years i have been flying. My father in law who got me into flying and had done so since the 1980s told me to do this.