Topic: Mick Reeves Hunter

Started planing the bits and bobs that will go in the fuz.

Batts will be right in the nose.

RX, switch, servos for all pneumatics, air gauge, air fill will all be on the tray at the bottom of the pic.

Airtanks just behind with airtrap on top (off set so that I can still get at the wing bolts).

Main tank just behind. (just ordered new one from Als Hobbies)

All turbine stuff (ECU, pump, solenoids etc) will be in the engine bay just in front of the turbine.

Dave,

On the rudder setup, I'm not sure if this works better but it's fine on a 3m Airworld MB339 and what I did on mine......


Mark

I have Proskin now on my big Spitfire and Hurricane models. No problems, quick, very tough.

Mick

OK, decided to chop the nose off and attach a plywood plate to the front former. This gives me enough space to mount two RX batts, the turbine batts and possibly some nose weight. (Does anyone know if these come out nose heavy or tail heavy?)

I've gone with smaller twin air tanks, only slightly more capacity than the single tank Mick suggests, but can be mounted low in the fuz giving good access to the wing bolts and the air trap which will be mounted on the ply plate on the right of the photo.

I've been thinking about how to layout the radio in the fuz. I've decided to mount the everything on a tray low down in the fuz, this allows me to route all the wires and pipes under the tray which should look neater, plus it keeps everything low in the fuz which allows space for a detailed cockpit.

Sorted out the hinges on the nose leg doors. The rear door needs to rotate quite a long way past the 90deg mark so it was quite a challenge to get a suitable hinge. Having tried several types of door hinges the best result I achieved was by using a basic flat pin hinge.

Just need to wait for the air rams to arrive then I'll see if I can get them to open and close correctly.

Turning my attention to the ECU and other engine related stuff, I decided I wanted to make it as easy as possible to transfer the turbine to other airframes and so have mounted everything engine related on one ply plate.

Changing engine should be a case of unbolting the turbine, unscrewing the ply plate and disconnecting fuel and turbine power - everything else should be self contained.

Before the ECU goes in there is quite a bit of space around the tank for airflow to the turbine, but once the ECU and bits and bobs are in place it restricts a lot of this airflow.

...I decided to open up the holes at the sides of the former in the front of the engine bay. I don't think its compromised the structure, but has given a decent amount of area for the air to get to the turbine.

Decided to use static wing tubes in the fuz to make it easier to mount the wings. None are provided in the kit and Mick suggests making some by wrapping card round the ally wing tubes.

...I tried looking online for some tubes with an inside diameter of 1", but couldnt find any so had a go at making some. I put grease proof paper around the wing tubes and then wrapped them in glass, left them over night and the end result seems to work fine.

I've been working on the main gear doors, these arnt big and are in the fuz. Mick suggests using servos, but I've gone for small air cylinders. The rear bulk head is conveniently positioned to attach the top of the cylinder to and a since the door moves through 90 deg its quite easy to estimate where abouts it needs to connect to the door (ie approx the same distance from the hinge as the cylinder travels - 20mm in this case. (plus a couple of mm to allow for the fact that the swing of the cylinder is reducing its effective length a bit)

...I done lots of thinking and then just decided to guess - and it seems like a good guess since when the cylinder is closed so is the door and when fully open the door is at 90 deg! Hurrey!

Next set of doors are the nose doors. The front door has to open first, then once fully open the nose leg comes down and pushes the rear door down and beyond the 90 deg line so that it leans backwards slightly and gives a bit more ground clearance.

The difficulty with the front door is that the tyre of the retracting wheel virtually touches it on the way in and out so its not possible to put any kind of linkage in the middle of the door - instead I've had to offset it. Again, since this is a 90 deg door its easy to estimate where the cylinder should attach and again it seems about right. My only concern is that since the cylinder attachment is off centre it might twist the door as it moves. If this happens then I might just have to put a cylinder on the other side to to balance it out. I won't know until I attach the air to it.

The rear door is a bit harder to estimate, it is attached to the gear leg, but has to move further than the gear leg moves - to do this we have to make the distance between the door hinge point and the connection on the door less than the distance between the gear leg hinge and the attachment on the gear leg.

...A few calculations and estimations later I tacked everything in place and closed the gear - unfortunately the linkage fouls the steering spring on the back of the leg as the gear retracts.

A few more attempts and I finally got the position right - then a little adjustment of the clevis and the door was closing perfectly.

That's all I've done in the past couple of weeks! Next is sorting out the wiring and pneumatics.


This is my little airplane helper - she got this for her birthday and built it in about 15mins (with a little bit of help).

...she can't understand why Daddy takes sooooooo long to build his plane!

The final wing sheeting going on the leading edge.

Wheel well construction on the right wing. Just 1/32 ply for the main well and for the bit that covers the strut I used some spare fibreglass tube from the wing tubes.

Leading edge going on the right wing.

Right wing all sanded and *nearly* ready for glassing. I want to get all the glassing done before it gets too cold!

Final sheeting being glued in place on the right wing. (all the other posts were actually the LEFT wing! - I must learn my right from my left!)

Looks great - following this with interest - I'm sure there will be lots of lessons I can take away for my scratch build! 

What is Mick's undercarriage like - good quality?  This is one thing I'm scratching my head on for mine...

The retracts seem fine, obviously i haven't flown on them yet, but they seem ok.

...they also hold air ok (ie no leaks) apart from when the cylinder was touching the rib (see pics earlier on in this thread)

I *think* the aileron servo hatch is about here somewhere! (forgot to mark it before I done the sheeting!)

Yep, there's a servo underneath! That was a bit of luck!

Dave,

Good to see progress being made and you've got over your 'moment' LOL

What servos are you running all round?

Cheers,
Mark

Bit off topic, but Mark, that's a great avatar!! Did I forget to mention, that I love the Hunter build!

Hi Mark,

I'm using the exact same setup as in the big warbirds - HS645MG servos, they are non digital, but when run on 6v still give 9.6kgcm of torque.

My philosophy for not using digital servos is that in a full size aircraft you feel the controls getting heavier and instinctively know that if you pull really really hard against the control column that ultimately you are over stressing the airframe.

...translating this to servos then a strong non digital servo might not make it to full deflection during really fast high g manoeuvring and will therefore limit the strain on the wings etc. Where as a digital servo will ignore that fact that the control surfaces are very heavy and will use all the power it's got to get to exactly the position it has been told to go to and so over stress the airframe - just like a full size pilot deliberately pulling really hard on the elevator.

...now, if your pointing at the ground in a high speed dive then you may want that extra power, but if the first time you do a really fast pull round is when the ground is in the way then thats just bad piloting! ;-)

Dave

Mark,

I'm currently quite tempted to get a 'no hassles' ARTF sports jet for the p80 to get me up flying jets ASAP so that I can build a bit of confidence before flying the Hunter.

The Hunter could conceivably be ready next spring if I skipped a lot of the scale detail, but it would be quite fun to scratch build a scale cockpit etc so my current thinking is to get a sports jet then keep the Hunter as my scale project.

...can you keep an eye out for the YT Pantera at Jet Power as it looks pretty cool and might fit the bill!

Cheers

Dave

The Hunter standing on it's own three wheels.

All the wiggly bits are now connected to the electric bits and the wings are nearly ready to glass!

Tail surfaces all sanded and ready to glass.

...and here they are glassed. I used 25g cloth and Fibretech resin thinned with 20% methanol.

Got the heating full blast in the garage and once they are touch dry I'll transfer them to the airing cupboard for a few days.

Getting there!! Keep going 

Bit off topic, but Mark, that's a great avatar!!

He's one of those guys that women will bend over backwards for, putty in his hands

He's one of those guys that women will bend over backwards for, putty in his hands

Are we talking about the same Mark? :-)

Started glassing the wings tonight, done the top of the right wing.

I couldn't stop and take pics as didn't want epoxy all over my phone, but I started with a line of epoxy right down the centre, then a chord line half way down, then gradually work the resin out from the centre before drawing off excess resin using a credit card.

Not dry yet obviously, but it seems to have come out ok.

Next challenge is keeping it warm for the next 72 hours! Its too big for the airing cupboard so it's currently in the utility room with the electric radiator on. Its boiling in there, but will probably have to move it once the wife finds it!

...I just hope she doesn't throw it out with the trash!

Glassing the other wing.

Again starting with a line down the middle, then a chord wise line, then starting in the middle I apply the resin with my finger gradually working outwards, but stop a few inches before the edges. I then use the credit card to push the extra resin out to the edges. Then finally wrap the glass round the leading edge with my hands.

...it's not my favourite building job, but once it's fully set and been sanded it's very satisfying.

Hi Dave - looking good!  You are about a year ahead of me!  I was just looking back through your thread - there's a pic of your tank in reply 88.  Where did you get it from, whats the capacity and also if possible what are the tank dimensions?  If I can get one the same to fit inside mine, it will save another job!

I think I got the tank from Als Hobbies.

http://alshobbies.com/shop/lookupstock.php?pc=41479

...can't remember the exact dimensions (bit awkward to get at now), but it fits.

Good luck with the Hunter. Remember to double check the build sequences as some of the instructions arnt quite right.

Thanks Dave.  I'll have a look on Al's website for the tank.  I've designed my own Hunter which I'm now scratch building - no instructions other than the way I decide to do things, and I reckon I've got at least a years work ahead of me!  It's also 1/6 scale, so some of the bits may well fit, but that's where the similarities end.  I look forward to seeing your finished jet.

Cheers - Pat

Next set of doors are the nose doors. The front door has to open first, then once fully open the nose leg comes down and pushes the rear door down and beyond the 90 deg line so that it leans backwards slightly and gives a bit more ground clearance.

The difficulty with the front door is that the tyre of the retracting wheel virtually touches it on the way in and out so its not possible to put any kind of linkage in the middle of the door - instead I've had to offset it.

The front door should unlock and then the wheel pushes the door open at the same time - there's no 'sequence' to the nose leg opening   only when it retracts does it use a 'sequence vale to allow the leg to retract before the door closes, (same applies to the main gear retraction, but the extension is sequenced - if you want more info on the u/c sequencing I'm happy to help).

Also you're solution for the door jack is the same as the fullsize where the jack it attached to the left side of the door

Jumping back a page where you decide to fit a 'wheel well' - ironically the Hunter doesn't have a 'wheel well' as the undercarriage bay is formed from the front and rear spars, the leg pivot and the fuselage.

The build's looking good 


Mark

Yeah, i was aware that the front door was more of an 'unlock and push' than a sequence, but it's harder to do that on a model than the full size so I went for a sequence. In reality there won't be much of a delay so it will look like the front door is being pushed.

I wasn't aware that the mains didn't have a well, I've got a couple of pics of the main undercarriage and it looked like a wheel well, but now you mention it it could just have been the front and rear spars! Oh well!

Last of the fibreglassing done, here is the lower wing, obviously had to mask up the servo bays and UC, but apart from that it's a nice simple wing to glass.

It's been a while since I done anything on the Hunter so I dug out the sand paper, gave the wing a dam good rub down followed by its first coats of primer.