RE: FOX COMPOSITES Bae HAWK, Build thread
 

Quick question.

With all the EDF and Jet versions comming along with this particular model. Is the Ducted Fan varient still viable/available? Or is the EDF and the Ducted Fan the same plane?

I want this kit.....BAAAAAAAAAAAADDDDDDDDDDDDDDDDDD

But, i'm not gonna fork for a turbine, and i'm not a big supporter of electric.

If I do ge this kit, i'll use this scheme.

Any replies would be appreciated. ~Ryan

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Ryan
I see no reason why this could not be buit as a DF.
The original one was but use a 91 and Ramtec. A 45 will be toolow on power for any performance.
You will have to leave the tanks out as they are too large for DF.
Use normal saddle tanks around the DF unit.
Also you would need the electric duct style to bring the air to the Fan.
Keep it light and run it off tarmac if you can.

Regards
Paul

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Here are pics of the latest development of Stu Maxwell's Stumax SM110 EDF fan unit. The shroud and rotor will be injection moulded in future.

Stu got fed up of black fan units (I don't blame him).

Gordon

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Today in England we were graced with fantastic flying weather.[8D]
6 deg C, clear blue sky and dead calm.
Well today was Hawk day for me; I wanted to check out the model, as the new season approaches (I am sure the years are shorter now!).[&o]

While visiting Als Hobbies yesterday I purchased some new wheels for the Hawk. Ali has some really nice; reasonably prices Aluminium hub wheels complete with bushes at £19.99 a pair.[X(]
You can see them on the pictures below, these are fantastic wheels for the money, a little heavier than I would like but really well made and they transformed the Hawks take of run from our less than perfect winter rutted, wet, long grassed strip.

Anyway, what a great day, the Wren 44 Gold burst into life once again with ease after its winter lay up. I have to say that I had forgotten how smooth this model is in flight, just awesome, with knife edge flight as far as you want to go.:D
Love it!

A friend of mine took some fantastic flight pictures today, once he has emailed them over to me I will post.

Paul

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Paul, also had a good day at Chalgrove electric day. Was originally concerned about the noise of the fan but should not have worried really although I will be ordering a Stumax fan for delivery a.s.a.p. as it is quieter and I beleive will deliver longer flights on a certain setup of 12 cells.
Here are the facts gained from the piloting skills of john Palmer once again.

I was disappointed with the flight time although the power was fine but not overpowered. It flew scale which was good and the loops were Just about there. I would like to fly it like this but for longer, that’s the goal and as quiet as possible anyway.

So:
Conditions : sea level @ 7 deg C no wind or 3 mph

Model weight 12 1/2 lbs

Lehenr 2250 13 wind on NEW T.Power Extreme cells 5000 10s 25c/50c fully charged to 100% around 42.000 volts

Power Jazz controller on auto detect rated @120 amp

Full throttle test prior to take off = 96 amp 3200 KW

Model took off in 50 yds and climbed 75% throttle.

Model cruised flat trajectory @ 35 amps appx 1330 KW and was nice to fly at this.

Flight time 3 mins in the air with 1min alarm in the air landed 4 mins max battery usage.
I believe 45' flaps is a bit too much for the fan version as it really does stop in the air and you require 3/4 throttle to keep things moving forward. This is at a time when your battery power is just getting to the end of its safe limits so its not a good scenario.

Temp of motor not noticeable probably due to ambient temp of 7 deg C

When landed voltage on pack showed 38.2 v

Full throttle tested on landing showed 98 amps 3200 w ("Wattmeter")

All three packs showed appx same discharge and recharge average over three was 4350 mamps returned to cells on 100% charge rate Thunder Power 1010c at 4.5 amps charge rate with balancer connected.

Need longer duration at this flight level and remembering that the wind was very light.

Will investigate the Stumax 110 on 12 cells with motor regulated via stick control.

I am sure there will suggestions so lets have em folks !

Regards

David

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Paul ,

Have a look at "Skylite" 57 mm dia wheels . Very light and certainly did 6 flights today without a hitch.

David

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Great news Dave, good model isnt it!

Did you get any pics?

Paul

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Sadly John Herman was on the video and the sun was in his eyes ( so he said) He did try but I think his thoughts were on that Gliding session he had to instruct in about an hour so the answer is NO !

David

PS he did try though

RE: FOX COMPOSITES Bae HAWK, Build thread
 

OH well, get some next time. ;)

Paul

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Got the pics

got to sort through them but here is a taster.:D

Paul

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Another couple to be going on with :D

Rough, wet, long grass take off.

RE: FOX COMPOSITES Bae HAWK, Build thread
 

A couple of close in passes. :D

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Couple of passes with the head light on, showed up well [8D]

RE: FOX COMPOSITES Bae HAWK, Build thread
 

And a couple more ;)

RE: FOX COMPOSITES Bae HAWK, Build thread
 

oh what fun:D

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Complete landing sequence.
Landing was over the trees yesterday, on one of the pics you can see I am making the final turn, low and slow.
Flaps down and 'crow' braking visible, rock steady in the turn, very controllable on flaps, beautiful :D:D

Many thanks to Tony Hazlehurst for the pictures.

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Here is a whole pass in sequence (till Tony could not pan fast enough!) using a high-speed multishot setting :):D[8D]

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Hi David

That flight time is a disappointment, and is really a function of your lipo pack size. As you know I'll be using 12S 6600 packs which I anticipate will provide around 7 minute flights at the outside. My bigger packs do come with a weight penalty of about 28oz compared with your 10S 5000 lipos, but I'm sure the Hawk will handle that.

Adding more volts isn't an option in your case as you'd smoke your existing motor. To avoid the expense involved in buying another motor or another complete fan system, probably the easiest way to get more duration in your case would be to parallel a 10S pack with your existing one. I suppose that you could try paralleling a pair of your existing packs but the weight would really climb then. Connecting a couple of 5S 3300s in series to make a 10S 3300 and paralleling that would give a 66% increase in flight time, probably even 75% as you'd have significantly more cruise time available. A 10S 3800 pack in parallel would add even more duration, along with even more weight (and even more expense - that'd be over £750 for three 10S 3300 or 3800 lipos which won't last much more than 2 years).

As we discussed on the phone, perhaps MW44 would be the better and more durable solution in the long run for this country where we don't get wild fires, and where lipos are far more expensive than stateside.

Cheers

Gordon

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Hi David

I've thought a bit more about this.

Have you found Fancalc? http://www.s4a.ch/eflight/fancalc_e.htm

It's a fan unit performance prediction program and is fairly accurate. I've put a few figures in for your setup of 2250/13/Kontronik Power Jazz/TP Extreme Lipos to show how increasing battery capacity would help - screen shots below.

The 10S1P 5000mAh is what you're using now, and the currents and durations (mixed flight time) are fairly close.

For the 10S 8300mAh, I left the fan/motor/esc combo as is, scrolled the battery up to "custom" and amended its capacity to 8300 (to simulate a 5000 and 3300 in parallel) leaving resistance and volts/cell the same. As you'll note, there's a good increase in duration.

For completeness I then modelled the 10S2P, ie a pair of your packs in parallel and you get one heck of a flight duration.

As you're committed to 10S 5000 packs for your aerobat, and will need to replace them periodically anyway, adding 3 more 10s 5000mAh packs to your collection so that you can put 10000mAh in the air in your Hawk might not be too damaging financially in the long run as they won’t all need replacing at once, and will be usable in your aerobat. Another solution would be to use 10S 3300 packs in parallel. The way that I’ve made most cost-effective use of batteries over the past 10 years is to restrict the number of pack sizes I use, in my case to 3S and 6S (or the nicad equivalents of 10 and 20 cells) at around 6000mAh capacity. This is why I’m ready to go 12S, as I already have six 6S packs to combine up into three 12S. The downside for you is you might have to shift your fan unit aft to counter the additional battery weight, which is what I'll be doing from the start.

The truth is that the Fox Comp EDF Hawk is not EDF-ready if one wants a worthwhile flight duration. To get anything near a decent duration from a plane of this size requires at least either 10S 8000mAh, or 12S 6600 (my setup) weighing about 4.5lb to 5lb and of fairly bulky proportions. So the fan is no good located in the middle of the airframe and needs to go well aft of the wing to balance a 4.5lb or so cell pack placed between the intake ducting.

Cheers

Gordon

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Gordon,
Your a star!
Thank you for your input which is considerable and I see a lot of good thinking in your recomendations, however I have currently £1000 invested in charging equipment ( S/H Honda 10i generator 2 1010 chargers 2 10 cell balancers leads and boxes). I cannot justify further cost in going to another cell setup and the time to charge between flights + the great possibilty of not making the ground in time and trashing X£ in Lipo's as you do it. This was very evident on Sunday, coupled with the technical prowess of balancing different size packs and jumping them together and getting the right plug in the right hole etc etc etc.
You may glean from this post that I am perhaps not ready for EDF just yet. I have spent most of my life in the film business doing one off's some of which cost over £100,000 but I think when I look at the BVM site in retrospect and see the phrase " Chuck Mc Llelan gets 6 1/2 minutes from 12 s 6400 !!! (cells cost $979 and I would like three flight packs) the reality comes home that I truly am not ready.
I have therefore spoken to Sara as some people do and she talked the talk of the M44 in such a sweet way I could not refuse.

I 1/2 litres 8- 10 mins with go rounds and you can warm your hands on it on a winters day !

Thats the way I am headed with this very very nice model which is great value and flies extremely well.

I think this set up will suit me well.

Thanks again for your help and interest

David

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Hi David

Don't be overly surprised if I join you guys in the not too distant future :D

Gordon

RE: FOX COMPOSITES Bae HAWK, Build thread
 

hi paul

i m very impressed with your bae hawk. After i see yours i make a decision. I will build my bae hawk of fox , but i have a problem. my model is very old maybe 15 years in the box, than i need some help to do this . my instrutions about the build is only 4 pag of machineletter of any picture with a signature of JIM . is very funy because today all is diferent. i will need to shape the wings yet. well i sad my kit is very old . i need to do all. i think today the kit is more complete but the mine is diferente. I need the manual complete. Anybody can send to my email the actual manual?....
sorry for my poor english .

Anderson

RE: FOX COMPOSITES Bae HAWK, Build thread
 

This kit is fully composite, the one you have is the original DF version you have to build up.
If i were you i would buy one of these instead ;)

Paul

RE: FOX COMPOSITES Bae HAWK, Build thread
 

I'm thinking of buying my first ever turbine-when I do, it's definitely going into this model, looks gorgeous, price not too crippling (compared with the fabulous Airworld product)

I will still have my electrics on hand too though, can't afford to fly turbines all of the time!

RE: FOX COMPOSITES Bae HAWK, Build thread
 

Matt
Good choice, it is an excellent kit that fly’s as well as it looks.;)
I am looking forward to flying nine this weekend (weather permitting).:eek:
Also in a few weeks I may get a chance to fly mine with Skywarrior who has now converted his to the Wren 44 Gold.
He has done a great job on his and somehow he managed to get it lighter than mine!:(
His is 11lbs dry.
Keep in touch when you get the kit.
Motors and Rotors stock them.

Paul