Seagull Hurricane

[Tim Flyer]

Cheers chaps . The oil cooler will go on now and I will epoxy it after light sanding the covering. Regarding gear doors . I also used zip ties rather than the old metal jubilee “hose clips” supplied . However I agree that they are too twisty. I will make small but about 1cm wide aluminium bolt on straps out of some thin plate I have . I did that on my P47 and it worked ( photo to be added later) . These are easy to make and reduce twisting and look way better . I will leave the zip ties in while I fix them to hold all in place .

[Tim Flyer]

Here are my wheel brackets made tonight and fitted . Made from .03” Aluminium sheet. And secured with modelfixings.co.uk M2 bolts. I roughen the oleo legs before tightening the straps and use thread lock on them . The gear doors are now totally stiff and won’t turn in wind/ grass. I left the zip ties on while fixing and drilling the gear doors . That made it easy. I will grind off excess bolt length later.

[neil martin 1]

Wheel brackets look good, will make some for mine. Do the wheels miss the brackets once the Oleo's are fully compressed?

On rcgroups "seagull hurricane" page, a guy says that when the Oleos compress, the wheels can hit the gear which causes a nose over. He stated that he had to angle his gear forward to also help, I have already added a 1/8th piece of packing, hope that will be enough.

[Jon H]

one thing you could try is to crank the axles a little as well. This gives the wheel better clearance to the leg and its scale (see photo).

I was going to recommend an 8th under the rear u/c mount as hurricanes have very vertical legs if scale. One thing that can help is slowly make the model more and more tail heavy, with a corresponding reduction in elevator rate, until you get the best balance of flight and ground performance. Many of my models are 'tail heavy' but fly very well and are not at all prone to spins unless abused. Clearly dont go mad with this, but a great many models have very conservative c/g positions on the plans and excessive rates recommended so i move both.

[Tim Flyer]

Hi Neil funny you mentioned that . I was just thinking today that I would dremmel a bit out to ensure clearance at full travel , and is important otherwise the wheels might force the gear doors out of position when taxiing on our bumpy strip. . My Permagrit Dremmel drill piece will make that easy and I won’t have to undo anything. You might have also noticed I also left the top zip tie on that was partly as it’s not very visible plus will be a slight shock absorber if they get caught in long grass. Cheers Jon I have already angled the wheels forward by 1/8” with a ply fillet under the rear of each retract unit.

Edited By Tim Flyer on 25/09/2018 14:31:57

Edited By Tim Flyer on 25/09/2018 14:32:12

[Tim Flyer]

One other thing I wondered is whether to bother with the landing lights . I will install the bulbs and wires and covers but I don’t think they are worth connecting. I will be adding a good extra coat of clearcoat fuel proofing too in the landing gear bay as it could easily act as an oil trap given that the wheel bays on the Hurricane are set close together and straight behind the engine. I cut an extra 10mm or so from the gear doors’ axle slot last night to allow for full wheel travel. I also started colour coding the servo wires to make assembling at the field easy. I am using coloured insulating tape flags secured with small zip ties on the wires.

Edited By Tim Flyer on 26/09/2018 10:36:36

[Jon H]

You can always hook up the lights at a later date Tim. As long as the wires are accessible its easy enough.

[Tim Flyer]

Cheers Jon agreed. I put then in on the P47 and even when on were not very noticeable. After finishing wiring and locating the receiver and clearcoating, I have to balance it . That will govern position of my three batteries ( two for RX and one retract) . . I’m going to try a balancing cradle this time.

[Ron Gray]

@Tim - servo connections - that's where S-Bus comes in handy, on the RR, 4 wing servos, 1 Rx connection!

[Jon H]

Posted by Tim Flyer on 26/09/2018 12:57:54:

I put then in on the P47 and even when on were not very noticeable.

You just need to stop flying in the day :D

[Tim Flyer]

Hi Ron . That SBus does look good . There are a few things on my Radio Futaba (14SG)I don’t yet use...I never found SBus explained properly. I do have the very good Malcolm holt Book so can use most functionality but have never touched SBus as I was wary of having to use decoders for non SBus servos etc. On this model to keep it simple I bought Futaba’s very pricey top of range receiver with 14 sockets for servos!! So lots of cables but hopefully totally reliable. I will probably leave the centre wing permanently connected so I will just need to connect the 2 aileron servos at the field. I might just have to build a transport cradle for the car so the radiator under the wing doesn’t get squashed.

[Tim Flyer]

Here she is put together outside my garden workshop. Hopefully I will get her balanced this weekend an then start Engine tests etc .

[Jon H]

really nice Tim. I like the neat cowl cut outs too.

My only question is where will the hot air escape the cowling?

[Tim Flyer]

Cheers Jon . What I have done is open out the three exhaust stack exits on both sides of the cowl. It can’t be seen in the photo as they face rearward. The exhaust outlets are quite big and facing backwards in the air stream plus being above the inlet should help extract hot air. I was initially going to add an extractor spoiler of aluminium underneath but this looks like it should do the job ....I hope

Edited By Tim Flyer on 04/10/2018 14:20:34

Edited By Tim Flyer on 04/10/2018 14:22:44

[Ron Gray]

Looks good Tim.

My only observation on cooling, I was told that it should be 1 in to 3 or 4 out.

[neil martin 1]

Looks really nice Tim. I've got my cooling going through the bulkhead and coming out of the retract wells. Having looked at yours I can see that your fuel tank would obstruct this.

[Jon H]

The 180 is pretty tolerant of heat so you might be ok. Just to cover bases though what you could do is fit a small block of wood to just hold the lower cowl off the wing slightly. If you fit the block in the middle you would only notice if you looked at it from under the belly so it would not spoil the looks. Even a 3mm gap will take quite a bit of air out with the venturi effect

[Ron Gray]

This is what I’ve got on mine and the 180 runs fine

Edited By Ron Gray on 04/10/2018 16:04:33

[Tim Flyer]

I think the cooling ratios also depend on Venturi effect as mentioned above in planes that works well as air is high speed. My Spitfire worked with quite a small spoiler . On this plants there is a lot of frontal engine showing and a fair bit of air will pass over and around the head and not enter the cowl. However the exhaust stacks have superb Venturi effect as are right in the main horizontal air stream there is about 6sqcm of vacuumed exit of air which I would hope should work

[Tim Flyer]

Hi guys I took a look at the plane tonight after returning from my trip and staring to set up a balance harness. The cowl does have a decent sized gap venting into the wheel well ( similar to Jones idea of opening it) the manufacturer might have allowed that in their design. I include photos of that and the exhaust stacks . I’m happy running it asit is as the outlets added together will be of good enough size.

[Jon H]

that gap in your 2nd photo looks ideal Tim. I think it will be fine.

When is the big day?

[Tim Flyer]

Haven’t got a date yet for maiden. I’m going to get balance finished this weekend and put switches and batteries in then I will wait for some ideal weather 😊

[Tim Flyer]

I tried making a balance cradle hanging plane from ceiling. Was interesting but didn’t work well. I ended up using my normal “upside down finger method”. I estimate it needs about 240g of lead upfront for the recommended 140mm from wing root c of g. That gives C of g about 10mm in front of the wing main spar.

[Tim Flyer]

The maiden flight has been completed. I was lucky to have had Jon around ( he kindly agreed to visit our nearby club for the test flight) or it might have been its last. Taxiing and take of was ok but once the model gained speed it was apparent that the elevator was way out of trim despite looking ok on the ground. This plane is very very elevator sensitive and we ended up using almost half the recommended 12-15mm travel. After take of the nose raised up to point right up and I needed lots of down elevator just to keep it steady. The ailerons were also way out of trim. Whilst turning back into wind I got into a spin and couldn’t seem to get out . I throttles up and Jon quickly took over and retrieved the plane managing to pull out magically! Jon then trimmed the plane and landed it . After trimming the plain still tries to stick its nose in the air on full power . Landing it seems fine on the approach etc but it has a very nasty habit of nosing over despite our fairly firm grass runway. I did not land it but Jon made 3 very good landings with it but the darn plane still flipped and nosed over . We went through two props and a canopy and bent olio in testing ( which needed hammering back ...luckily we have a vice on site !). My conclusion it’s a difficult plane to avoid nose overs but flying is fine . I think I will practice more with my trusty P47 before this plane’s next outing! Thanks again Jon for a great day 😊

Edited By Tim Flyer on 22/10/2018 11:17:33

[Jon H]

No problem Tim, we had a great day all in all even if the heart rate was up a few times!

Just to add my 2 cents on the Hurricane situation as there is a great deal to learn from Tim's experience.

Firstly as already stated the elevator is extremely sensitive. If you look at the travel you have, and think 'thats not enough', halve it, and then you might be close to the correct setting. The maiden voyage was done on 70% rates (which gave travel lower than the kit stated) and following more flights i am recommending Tim use 35% in an effort to tame the beast. Long story short, the instructions are wrong.

So, while Tim's misalignment of the elevator was very small it had a big impact on the flight. The excessive rate combined with the trim made the model extremely difficult to control and frankly i think he did extremely well to collect it all up after the near vertical climbout from take off. Following this his workload went through the roof and ultimately this lead to a spin. Due to the circumstances Tim was unable to recover the spin and frankly i was damn lucky to be able to recover it myself from the position it was in and with only one hand on the tranny.

If anyone reading this thinks this was simple pilot error on Tim's part and they could have done a better job i recommend they keep that to themselves as i suspect most pilots would have been caught out by the situation. It was a serious handful and anyone who was there to see it will confirm that. If it were not for my many many hours of experience with warbirds like this and more than a bit of luck i would not have been able to save the model.

In any case, once the trim was corrected i found the model pleasant to fly but very sensitive due to the excessive rates. The model also turns into a lawn dart with the gear down so my landing was not perfect and the model lifted back off just enough to stall and bust the prop/oleo.

To cut the rest of the story short we altered a large number of settings, added an elevator flap mix and despite the final landing running off the runway edge (my fault, not used to the site ) and a nose over both causing damage i feel we were able to get the model set up quite nicely.

My view overall is that it is a great looking model that looks fantastic in the air, is fun and rewarding to fly but requires total respect or it will bite you hard. The tip stall to the left is vicious but happens at a very low speed so you should be able to fly round it with a little care and proper landing technique. A 180 4 stroke is plenty of power, the ailerons are soft and it rolls beautifully with no elevator needed for scale barrel rolls. Axial rolls are not an option. With the elevator flap mix now set and low rates landings are easy and at a very comfortable speed. Takeoff is a challenge due to poor rudder authority (more deflection needed) and no mix on elevator. We are going to change the ele/flap mix to ele/gear/flap. This will give +15% elevator with gear down, and + another 10% with flaps. This brings us to the 25% we have set now on the flap mix. The nose overs were mostly my fault, but these settings will help prevent them in future. The only other thing to be aware of is that the model is impossible to trim in pitch. You just have to get it about right and then fly the rest. When it comes to flying you just need to nudge it round the sky. If you give it the bank and yank treatment its not going be at all fun to fly. Keep everything big, smooth and sweeping.

I hope nobody is put off getting one of these models by reading this. I was really enjoying flying it and would gladly buy one myself having flown it. I just hope that the above means that anyone who does get one is not caught out by a few issues with the instructions and by a few of the handling traits of the model.

Edited By Jon - Laser Engines on 22/10/2018 12:36:58