Ron Gray

Bingo! I had the wrong settings on the scales, the fuel weighs 3.9Kg, so recalc 3900/4550x500 = 429g. So, just as Bob says, 1.6Kg plus servo. Therefore the difference isn't too scary! Back to leccy plans then. Thanks guys.

Adrian, I had exactly the same problem and it was servo arms moving on the splines, funnily enough the servos were also Hitec. I 3D printed some new ones and they are a much better fit.

Well I weighed a can of fuel, 1.8Kg for 4.55 litres. Therefore, based on a 500 fuel tank, 1800/4550x500 = 197 (ignore the weight of the can). So I was a bit out with my guess but not by that much! Intended setup is: Motor Hyperion Z4045-12 275Kv ESC 4-Max 90a Prop APC 19x10 Batteries 5000 10s Hoping for about 8 mins flight time. Regarding the potential tail weakness, I was going to mount the tail servos at the rear but was going to add some thin ply doublers to the inside of the fuse sides in that area. Edited By Ron Gray on 20/06/2020 16:58:19

There's a chap on RC Groups with an almost identical setup to mine but he's running it on 12s and he changed his from IC to leccy so I've asked him what it's like.

Defo get the spring to do the work to open the doors!

I just thought I'd weigh the powertrain I propose for this model and, with batteries (10s) it comes out at 2Kg. Now a Laser 155 weighs in at, say 1Kg and a full tank (500cc) weighs about 120g, that's a lot of difference! Am I missing something here?

On one of my Freewing models, I think it may have been the Scorpion, the nose leg doors were joined by a coil spring which held them apart (open) then when the wheel retracted it pushed against the spring which then pulled the doors closed. A very simple, if not that elegant solution which required very little force to work. In fact their Avanti uses something similar and you can buy the parts for it Motion RC Would be easy for a man of your calibre to adapt for your use.

God point Brian, Chris Foss does say, in the instructions, that if a larger engine is to be used or if the proposed flying is to be somewhat spirited then the tail should be reinforced with carbon. The tailplane was redesigned so that the elevator counter balances were removed and those pieces stuck to the horizontal stab (sorry about the use of an Americanism) as I believe that was another weak point. Mine will be reinforced!

And we're off! Following the excellent instructions and sketches the fuse was first up on the agenda and joining the balsa outer pieces using masking tape over the joints, folded back, glued then pinned onto the workbench tape side down. I'm using Gorilla Glue White for most of this build as I find that it sets quite quickly is strong and dries clear, oh and it sands very well too. Excellent quality cutting of the parts means very little sanding required to get a good fit. Once the glue had set then it was fitting the ply doublers (yes making doubly sure that I had a left and right part!). Balsa stiffeners and longhorns added together with the tail post. Quickly progressed to the formers which have to be removed from their parent sheets but you can see the quality of the CNC routed parts And this is the tool that I use on ply parts to cut them from their parent sheet Engine bulkhead and first former fitted making sure that everything is lined up correctly, lots of clamping and good use of 6s batteries! Opposite fuse side fitted with other formers temporarily fitted in position (the fuse has to be drawn in at the tail for these other formers to fit. And to support the tail whilst the glue was drying an offcut from one of the parent sheets I keep meaning to make myself a jig but progressed without one using set squares and front to back aligning to make sure everything was square. To be fair having made sure that the front end was square when I fitted the first 2 formers, very little adjustment was necessary to make sure the fuse wasn't twisted when it came round to pulling in the tail end but a jig would have made it easier (make one!!!!). And then it was a matter of fitting the remaining 2 formers and the servo tray. And that was the first day and a bit of work, coming along quite nicely.

@SR - you wont regret one of Richard's kits and the after sales service is second to none, a bit like Jon at Laser, ask a question and get an answer. now you don't get that from Hangar 9, Seagull etc and they are British!!!! Edited By Ron Gray on 19/06/2020 19:40:32