trevor wood 2

Since collecting the model, t's been residing in the corner of the workshop whilst I finished a couple of HK laser cut kits. With the bench clear of clutter I decided to have a closer inspection of the airframe so I could decide what still needed completing and to plan a work schedule for later in the year. Well, you know what it's like; one thing leads to another, and before you could say "quick set epoxy" I was in to the build process. The first thing that caught my eye was the tailplane. In BEB's earlier posts he described in some detail the care he took to ensure the incidence was correct, and the surface was correctly aligned. However, a quick eyeball check suggested the RH tip was 7 or 8mm higher and further forward than the LH tip. Hoping this was an optical illusion, I got hold of a tape measure, spirit level, string and set square to double check. No matter which way I measured the alignment, the results were the same - it wasn't mounted squarely. So realising it wasn't going to fix itself, I got hold of the razor saw, put a new blade in the scalpel and took a deep breath. About 20 minutes later I had completed a successful fin and tailplanectomy. I was able to take further advantage of this situation and instal the snakes that BEB only realised he had overlooked as he applied the last pieces of fuselage sheeting. He signed off his post with the famous words " it'll be alright. Trust me, I'm an engineer". Well I'm an engineer too, and trust me when I say that installing them was a real struggle. Cutting the holes in the fuselage sides was easily achieved using a section of old aerial as a boring tool. However I wanted to ensure the snakes were adequately supported along their length to prevent buckling when compressive loads were applied. Access to former immediately forward of the tailplane cut-out was through an aperture about 3/4" wide by 1 1/2" long. An hour and multiple failed attempts later, I had a snake support bridging the former. The next former was more easily accessed through the wing cut out, but it was still located about 8 " aft of the trailing edge and so took another half hour to attach the support. However with that completed I was satisfied that there would be no unintended control slop. Apologies for the inverted photos. It just seems to be an occupational hazard of using an iPad on some sites. Any IT advice to rectify the problem is appreciated. Next time, re-attaching the fin/tailplane and finishing the fuselage sheeting.

I stumbled on this thread a couple of weeks ago whilst looking for BEB's Wot4XL rebuild info. It made great bed time reading, particularly the historical instalments. I was saddened when I reached the last page to learn that BEB hadn't managed finish and fly the model, and that it was now for sale. Out of curiosity, I looked at the eBay listing and saw that bids had only just reached £90. A quick check of the TN Design web page showed the price of the plans, wood packs and mouldings was £191. With the retracts, oleos, wheels and sevos the total was probably closer to £300, so it was fair to assume that a final auction price would be in the region of £150, particularly when the models provenance was taken into account. A quick glance into my hangar ( the upstairs box room) showed there was no more space for something the size of a Typhhoon, but caught up in all the excitement, I made a silly maximum bid of £100, expecting to be sniped during the last minute.. Long story short, the snipers must have run out of ammunition and I ended up with the winning bid. I collected the model at the weekend, and was surprised to learn that it was being sold by a non-modeller who had obtained it at another auction as part of a job lot. A quick examination showed the Typhoon condition was very much as it appeared in BEB's photograph of New Year's Eve 2013. The plan now is to carry on with the build, although initial progress will be intermittent until the 2019 building season starts in earnest later in the year.

Speaking as someone who never wins any competition, I'd just like to thank the RCME team for making me a Ruler - power at last! Season's greetings.

Except for those occasions when you need fit a large prop to a scale model, or have built a large 2channel retro design for floating around the sky on warm summer evenings, or you want to fit a 4S lipo in place of a 3S in order to reduce the current draw. There will probably be other responses giving more reasons. Bob beat me to it!   Edited By trevor wood 2 on 07/12/2018 10:01:22

BATS at Bramhall in Cheshire is silent flight and electric fixed wing only.

Victor, sorry but that's the one piece of documentation I didn't keep. I modified the wing centre section of my Hurricane and managed to squeeze in flaps and retracts, but the finished weight crept up to 55 oz. I wouldn't recommend doing this to your kit unless you can keep the final weight to no more than 3lbs as the wing loading starts to get a bit too much. One mod that is worth doing is a battery hatch in the top decking in front of the canopy. You will have to reposition some of the formers but it's not overly difficult.

I've placed a set in my photo albums. They are for the electric powered version. If you need the IC powered conversion instructions let me know. You shouldn't have too much difficulty deciphering them.

Full size and model aircraft usually have acceptable handling characteristics over a range of CG positions that is likely to cover 5% of the chord. If your calculated position is correct this time and you have found the CG sweet spot, then everything should be OK. But to minimise the possibility of another 'upset' why not move the CG to what should be the forward limit for your second attempt (perhaps another 2.5% C forward), and then fine tune its position based on actual flight testing. The worst that could happen if you use up all the of the elevator up trim is that you would need to hold a bit of up elevator on the stick. As someone said earlier in the thread, too far forward - flies badly. Too far aft - flies once.

Robert, l agree with the recent posts that that the likely cause was a CG that was too far aft. In your early posts you describe the model having a 72" wing span, and from the inverted plan view photograph in your back garden, I estimate the wing root chord to be about 10.5". In a later post I recollect that your calculations showed the CG should be at 124mm aft of the LE. If you ignore the slight sweep back of the outer wing panels and assume a "safe" first flight CG to be at or about 25% MAC, yours should have been at about 66mm aft of the wing LE. If you want to include the affects of the slight outer panel sweep back (or are feeling particularly brave) then you might consider going to 75mm aft of LE for the next "first flight". A CG position at 124 mm would be in excess of 40% MAC, which easily accounts for the vicious pitch up you encountered. PS. I wouldn't even consider trying to persuade someone to hand launch a 7lb, 6ft span, low wing, 4 engined scale model for a first flight.

The HK website lists spare prop assemblies for the Walrus from the Europe warehouse for about £6.50. The model has a 1350 kv motor and 20 amp ESC, so you don't want a prop with too much pitch. Typically, a prop's pitch is about 60% of the diameter, which means you should be thinking of something in the range of 9x4.5 to 9x6.

Excellent rebuild, but don't forget, the captain sits on the left hand side of the cockpit!

Looking at your spitfire photograph, that square lump sticking into the airflow below the starboard wing will cause asymmetric drag. The yaw/roll coupling produced by the wing dihedral would then result in a turn to the right.