Jonathan M

If you're going to use the supplied wire linkages (with z-bends at the servo ends), then the simplest method would be to solder on an extender with a screw-on clevis for adjustment at the control-horns: https://www.rcworld.co.uk/acatalog/M2-Clevis-and--Solder-Extenders-Pk2-5508041.html#SID=59

I had a quick fast-forward through VMC's own build video - I wouldn't be happy either with their standard method of connecting the wires to the horns (used the same for the servo arms), bulky and easy to lose the model if anything slips!

Crisp-looking Lacy! Should be able to get at least a minute out of that indoors!

Cowling malarkey: This is the bit I wasn't particularly looking forward to. The flimsy plastic cowling had already had several layers of cloth and Poly-C to help stiffen it and, although it wasn't up to the standard of a proper glass cowl, it was much better than before and I felt confident enough to proceed to hack jolly great holes in it. The measuring and guessing and hacking all went fairly nicely, and finally had the whole thing accurately taped down to both the fuselage and the spinner-disk, except that where I came to drill the holes and drive in the self-tapping screws (from my own collection) the cowling seemed to pull slightly down! Is it "good enough"? Although it won't of course make the blindest difference to my very average flying skills, I know in my perfectionist's heart that it isn't really good enough, and will no doubt want to re-do it again properly tomorrow!

Carbon Capture: Decided to remove the cylinder head from the Irvine 46 (mainly just to make life a little easier cutting and fitting the cowling, which I did next), and found that it was... a well-used engine! Not troubled at this stage as I've already had it on the test-stand and it starts easily and runs very well. I can always do a probably unnecessary strip-down and clean-up later on if I feel like it.

CG business: Having realised last week that my cunning plan to plonk the RX battery nicely aft so to ensure the model wasn't going to be nose-heavy resulted in... a tail-heavy situation with the CG at 5" from the LE. So hacked out the original balsa bedding and made a new side cot for the battery in the next bay forward, and CG now happily right on 4". (Instructions state 3" but this is the usual excessively cautious advice, and Andy S tells me that his is just over 4", so happy with 4" as a starting-point for myself.)

Only if you insist on flying it as a conventional power model in half a gale! ?

In which case 50% differential as you've done is a good starting-point! ?

Re your initial settings - surface travels, differential, etc - are those as given in the manual? Are you going to programme in flaps as 'flaperons' (i.e. with up/down movement at a proportion of aileron travel in normal flight)? Does the manual say anything about this? On a non-scale four-servo wing competition thermal glider the following is normal: Flaps normally move as a proportion (say 50%) of aileron movement. In Thermal Mode an equal amount of camber is applied to both flaps and ailerons. In Cruise Mode both flaps and ailerons are flush with the wing root, i.e. in a neutral position. In Speed Mode an equal amount of reflex is applied to both flaps and ailerons. The amount of camber (say a few mm max) or reflex (just a mm or two) is normally specified by the designer/manufacturer as a starting point, then can be tweaked by the flier to suit their own flying style. Selecting between flight modes is normally done using a 3-position switch, although some fliers like to then have the exact amount of Thermal Mode camber further adjustable via a slider (but only active when that mode is selected). With crow-brakes (aka butterfly) for slowing down for (spot) landings, the amount of down-travel on the flaps is much more than the up-travel on the ailerons. So some down-elevator needs to be mixed in to stop the nose from pitching up, and this is usually on a curve (found by trial and error) where the down-elevator compensation is greatest initially, then continues but at a lower rate as more braking is applied. Most competition flyers put braking on the throttle stick (rather than a slider), where normal flight is carried out with the stick fully up (think of it as 'full-throttle') and maximum brakes with the stick fully down (i.e. similar to 'idle'). As braking is on the throttle stick, it is then normal to put throttle on a slider (on the same side of course as your normal throttle-stick). While this gives less physical range than a stick, the fact is that throttle is only normally used for launching where (after a soft-start) you want maximum beans until you reach motor-off altitude. This is how the TX then looks - based upon the setup I'm using with my Taranis, developed for Open TX by RC-Soar: template for F5J class electric sailplanes with 6 servos + ESC All this might be much more than your own model is designed for, but I hope it gives you a helpful overview - from which you can pick and choose the basics.

Re the slight twist on the starboard side - can you check whether it is in (a) the flap, (b) the aileron, or (c) the wing itself? If it's in one of the control surfaces then you might be able to work (or bully?!) it out somehow, if it's in the wing that'll be a bit more difficult. A small residual error shouldn't be too problematic but, just like on a regular power model, the trick will be to initially manually trim the twisted control surface to an average position, then tweak it via the trim on the RX while test flying. You'll lose a teeny bit of efficiency due to drag on that wing but not sure you'd notice it in practice.

Very neat development Delks. Presume the wing photographed above will get cap-strips on the exposed ribs?

It depends. For FW power using 3 or 4s, I always bought from 4-Max or Overlander. For very lightweight thermal soarers like DLGs and bungee-launched 2mRES, I've always used 1s Nanotechs from HK. For my latest foray into electric-launched thermal soarers using 3s batteries, I've gone for Overlanders from here and 3s Hackers from Germany. The key thing for me is that in all cases none of my LiPos have ever failed or become doddery - simply because I almost never run them below about 35% remaining capacity, and always return them to storage voltage after use (or if not used). So I think it's more a matter of care and good housekeeping really - which more than offsets the cost of buying relatively expensive ones in the first place.

Good point John. The servo tray in the nose of my Auri DLG came loose early on after a particularly hard landing because I'd omitted to degrease that area inside the carbon fuselage. With the old CA cleaned off and the whole area roughened slightly, and an extra shoulder of epoxy after CA'ing the tray back in place, it is now fit for... future pilot-error! BUT I wouldn't worry overly about your spar/rib joints. Yes degrease the carbon tube before sliding it in, but that'll be more than enough.

Adrian Its not actually that hard learn to feed in rudder manually as you need it (after having set up the right amount of differential of course) especially as your rudder thumb should already be quite proficient from your power aeros experience. For thermal model flying: 1. Roll gently into turn using ailerons, plus a bit of same rudder to iron out any adverse yaw, and as much elevator as you need. 2. Maintain turn using rudder (and elevator as needed), apply some opposite aileron as needed (won't be much) to prevent rolling any further in - also a lightly banked wing will obviously be more efficient in terms of generating upward lift than a tightly banked one. You'll see from the above that if you have rudder coupled to ailerons (CAR), then your turn-direction rudder input will be countered by the opposite-direction rudder (via the ailerons) and you won't know where you are at all!

Chris, that looks ideal for the job! There is in fact a downloadable English version of the instructions from their website: http://hoellein.com/Anleitung/gruener-cnc/Introduction-E.pdf I've got a slightly smaller 2.54m FXj bought second-hand. It has barely been flown, but I need to recover it (the builder used Oratex which is unnecessarily heavy for a thermal model!) and convert to electric-launch with a Hacker A10-7L. Enjoy the build! Jon

If the spar and ribs are a snug fit (and in my experience most of the engineered German kits are very precise), then slide everything in place, pin everything down over the (plastic-covered) plan in their exact positions, then zap each joint in turn with thin CA, which will wick right through. A mistake with CA can always be rectified later with CA de-bonder, but this won't be likely if you follow the above sequence. I almost never use medium CA these days, and only use epoxy for high-strength areas (e.g. wing-root joiner tubes or ballast tubes) where gap-filling extra strength is needed. PS - just seen your reply as I was typing mine - go for it! What's the model by the way?

Good lateral thinking, but for a model of this sort - weight, size, fuel residue everywhere - I'd personally prefer an adequate number of hinges buried in balsa, rather than surface-applied film which could lift and deteriorate over time.

NB I'm now using the above sequence of photos as an aide-memoire to myself to programme the same on my other IC models. But as in some of these the Throttle Input does not equal physical Throttle Stick travel (e.g. 100% travel = 60% Input on my Boomerang), it's now clear that the Logic Switch must be based on the physical Throttle Stick travelling 25%, else the timer won't cut in until higher throttle Input (i.e. 25/60 = 42% throttle)! This is the correct way it should look:

I've got it now! Thanks so much Matty. As I only use Companion for backup purposes, I've done it all on the TX, which I much prefer as I can make changes at the field etc. Also I've only dealt with the timer being activated over 25% throttle as per my original quest. Re-setting the timer I always do via the menu button on the TX, as this is how I deal with all my flying - thermal soaring as well as FW power - so don't want to have two different methods or I'll wind up getting confused! The photos below present the order in which I tweaked the programming. The reason for this order is that there are no Logical Switch options on the Timer 1 line on the Model Setup page until one is actually set up first in the Logic Switch menu page! (1) Throttle mix is only ever active when SB is in the UP position, otherwise the output is held at -100, i.e. no throttle output at all, called here ThrHld. (This was already programmed in all my power models.) (2) A Logical Switch (LO1) was programmed to be TRUE (i.e. 'on' )when the throttle is above 25% (the range is -100 to +100) AND switch SB is in the top position. (3) Note that in the above Logical Switch programme line I could have chosen either the physical Throttle Stick or the Throttle Input, as the relationship between the two is entirely linear, i.e. 100% Stick = 100% Input, and this is also reflected in the Mixer line for throttle in the first photo above. (This won't be the case for the other mixes for this model - i.e. aileron, elevator and rudder - but I've yet to actually programme the desired surface travels in the Mixer Page and tweak the Expo in the Inputs Page for this new model.) (4) Finally I could then go to the Model Setup page and find Logical Switch LO1 (now that it's been programmed in!) to trigger the countdown timer. Physically the thing looks like this:

Hi Matty, haven't yet got round to the actual programming - work, family, dog, 3rd vaccine, chiropractor, club AGM, finishing off the Gangster Lite build, etc - but its on my 'learning-achievements' list for the weekend! ?

If you've already glued in your elevators then simply slice the hinges off and clean up, then put two new ones in each elevator half in approximately these positions:

At 800g flying weight you'll have a wing-loading of 13oz/sqft which is in fact quite manageable for a 42" span model. But keep it two mistakes high until you're comfortable with its stall characteristics at slower speeds.

Meanwhile back at the ranch... Opted for Nigel's bellcrank suggestion. There's no inline shock-absorber as per Andy's setup, and the bellcrank arms are of equal length. But the 'gearing' via the much longer steering-arm at the nosewheel compared to the servo arm - plus a modest degree of play via the bellcrank connectors etc - should hopefully prevent any sudden shocks from damaging the rudder servo. (If practice proves me wrong, then its another £12 for a new servo plus a shock-absorber for my sins!) But going back to the CG business, with the U/C completed and the motor in place, this is now showing at about 5" which is way too far back! No alternative then but to hoik the battery out from its cosy rearward position and construct a new berth for it under the turtle decking just below where the throttle servo is.

Andy, is the spring-saver a home-made or off-the-shelf item?

RB - its not that moving the throttle servo is such a big deal (after all I do seem to enjoy playing with small bits of balsa!), its more that I just really want to get this long-running build finished as soon as possible! Excellent thinking Nigel - love the simplicity of the bellcrank solution, which will also go a long way to reducing the floppiness. How, if the nosewheel was fixed, would one turn the model while taxiing?