RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Great info re balance etc Scott. Cant wait to hear about you test flight. Good luck with all.

Cheers

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hey Scott - any news on a test flight mate?

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Finally will tomorrow!!
Scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Good luck!

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Managed to fly the Tomahawk.
Few things to note:
If you gain to much speed on takeoff, the gear struggle with closing. The incoming air through inlets pushing out through wheel wells makes for a bit of a struggle for the retraction. They will finally managed to get inside but often not before doors shut. I have a very long delay on doors closing and they beat gear over and over. I even tried rolling inverted and retracting without an luck. After one gear gets inside then the other is fighting all that air. I kept having gear hanging on doors, gear closing on doors, etc. Well the doors are servo driven so this puts them in a bind which could be big trouble.
Of course the gear work perfect on ground and the door delay seems a bit on rediculous side.
Next I tried to manage a slow takeoff in hopes the air bowing through door would be minimized. They went in and doors closed behind them! Finally! This is the fourth light and I'm finally flying about clean winged. First thing I noticed is it needed no trim! I couldn't believe this especially with the flying stab.
BUT, on a flyby I noticed the dang gear doors blowing open! Ugh! I have some graupner 8811 on the doors and those servos are 250 oz torque! Wth! So now I have two 250 oz servos fighting the entire flight! This isn't good.
So now I will have to consider some options.
1. Install 400 oz torque servos on doors, which may still be under considerable load during flight. 2. Switch to air cylinders on doors. 3. Switch to actuator on doors, if there are any that are strong enough and will fit
The most obvious scenario to me would be to have inlets and a bypass and I wouldnt be having any issues.
They aren't available so idk yet what to do. I might try to modify a scully set from SG and make fit.
I really think intakes would also help the flying characteristics. This airplane is big and light and the unbypassed setup made it a bit of a kite. Backing off power a bit slows the hawk really quickly. The SG without intakes didn't seem to be as effected. It was very noticeable with the TH. I kept climbing when trying to do slow rolls or four points. It seemed to want to climb on it's side. It being really big, really light and no intakes made it feel light I was fighting it a bit.
It ground handles very nice. Seems a bit better even than the SG. it will even roll around at idle.
It takes off in no time and it light weight is obvious. I think I had a bit too much takeoff flaps and it lifted by itself once! Lol!
Landing was a breeze. Full flaps and off the power will scream to hault, so a lot of power on landing is necessary. Cones in nose high like all hawk at a slow speed.
Next problem is the springs in the mains. They are too soft. One side worse than other. Two landings managed to compress springs to the point that the leg door touched ground and knocked it off. It needs some stiffer springs. The landings were not hard but one was in a crosswind and I was flying sideways til touched down.
It is so big and so light that a crosswind will effect it significantly. Still very predictable in crosswind and easy to manage with no bad tendencies.
This aircraft could use some intakes and bypass and be fine or could use some extra weight somehow.
The Hawk is a monster and it has great presence on the ground and in air. It flew great, but needs a bit of tweaking.
It really would be nice if the kit was available in a heavier layup and be about 10-20 percent heavier.
A bit of tweaking and it will be one of my favorites.
I probably will try to fit intakes and bypass first. If unsuccessful I will Try to find actuator for doors. I probably will send gear in to be converted to electric. Definitely Get some stiffer springs for main struts.
Scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hello Scott,

It is good to here ( especialy for me ) that it fly's.
Congrates with your maiden.
Damn , that is crap with the gear doorshttp://www.rcuniverse.com/forum/js/f...ngry_smile.gif.
In my L39 i used the same servo's and no problem with it.
When we take of , we fly a round and came back almost on idle and then pull the gear in.
The doors don't open in the air.

Are you happy with the plane?
Do you have anyvideo or pictures of its maiden?

Best regards Maikel

ps , what was the reaction from the guys overthere?

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hi maikel!
Yes I am very happy with the plane. You did a wonderful job on the build and the paint and weathering is fantastic.
It flys very true with zero trim which is a testament to your work as well. . The paint is very light and very durable. I worked on it a month without a single scratch or chip!
The jet had a very overwhelming response. It is very impressive! I love it and love the scheme.
I'll get some pics and maybe some video.
Cheers and thank you!
Scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hello Scott,

I am verry happy that everything is ok.
Looking forward to see the pictures and movie.

I think i know the answer for the geardoor problem.
On my L39 are the servohorns vertical up when the doors are closed.
So there is no force on the servo's when you are flying.
It is a overcentral lock.
so you have only to make 2 new ( longer) pushrods between the servo and door.
I hope you understand what i mean, because my englisch is not so goodhttp://www.rcuniverse.com/forum/js/f...sn/biggrin.gif
If you don't i can make pictures for you.

Rg Maikel

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

What we do here is that the doors are on another channel finetuned with a matchbox (u have to get it as tight till u hear the servo humm quite a bit) and the three doors are on a seperate switch that u activicate only when u confirm the gear is gone up that takes a good 8to 10 seconds at 140 psi. provided u have orbit valves with 4mm fittings.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

rcu

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

This is crosswind landing. The plane is flying sideways, not im coming in at that angle.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Look at how far open the doors are being pushed!!!

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Scott, brilliant. Great to see your shots! The model looks really impressive.

The 'doors not closing' thing has been on my radar since day one - I cant remember who complained to me heavily about this but it seems to be a relatively common thing with the SG models too.

I agree the fully ducted system is the way to go and am in the process of making my own for my TH. I'm using a carbon comp arf bypass that fits between the turbine mount perfectly at 154mm diameter. I'm making custom ducts in a similar to marc s's SG bypass kit. I'm making male moulds at the moment - a left and right. These will then be Vaselined up and glassed from the outside. From there they will be split on the inside flat face and seamed. I am not sure if my system will be fully ducted or stop a third of the way down the engine - ie: semi ducted if you like but the airflow will be ducted to the front of the engine, and not throughout the airframe. Best case will look for a fully ducted system and change the bell housing on the front of the thrust tube to suit the Comp Arf bypass - its yet to arrive for me to be able to check the fit etc. I hope it does!

This could be a simple system to custom fit to yours if you like the format.

This is the link for the Comp arf large carbon bypass: http://www.carf-models.com/public_ca...art&proId=1570

Cheers, and well done with the test flight! Nice work.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hey Tobba!
I think even a partial duct will be much better than stock setup. The air comes in and straight out wheel well. I will try to make scullys inlets work with some modification. I am also going to try to use his bypass as well.
I thought about you tonight when i cut this hatch. I used an exacto! Yikes!! kinda thin!!
I bought 50 yards of 3" carbon Im going to use to stifffen up the fuse.
Scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Sounds good Scott. So are you doing a second TH Hawk..??
Will post pics of my ducting setup as i go.
Good luck with your updates. Yep pretty thin glass wall on the fuse eh, feel like the 20kg rule has a fair bit to answer for.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

I couldnt resist!
Scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

A 100 - Bloody brilliant! Very keen to keep on eye on that mate.

Spent last night on the lip for my hatch - worked out really well. Will post some pics this evening.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

I thought i would mention I changed out door servos with 8711 and changed the leverage. Shouldnt be a problem now. I used some 1.5" servo arms and made a 107 mm pushrod out of 4-40 stainless all thread. This allows the door to open and close fully. When closed, it cant be opened period!! Pulling on the door doesnt even put a strain on servo with this geometry.
also converting to electric gear. Sent them to Down and Locked last week.
The new kit will get intakes, a bit too much trouble to try and instal some on this one.
see pic
scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Scott,
seems like you have the doors shut now :D
I was looking at linear actuators from Firgelli (http://www.firgelli.com/products.php?id=42), wondering if they would do it, especially if they would fit in the room available...?
Expecting to pick my Hawk up at Tomahawk end of april (together with a friends F5) so currently trying to collect as much info as possible [8D]

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hey Scott,

Will be very interested to see how the 8711's go. This is what I am running.

A few progress shots from me. Hatch finished using the tried and tested nyrods BVM style... all tack glued at the moment but a nice gap free hatch. Molded a carbon lip which helps everything sit perfectly. Access via the top intakes.

Been working on the rear chute hatch making some custom hinges and a mod to the fuse molding using wood and filler.

Spent a fair while on the custom ducts... taking a pile of measurements etc. I have a friend here with a 3D prototyping setup and he is making me molds from CAD files. Amazing process which means I will end up with molds ready to paint. Using a Comp ARF bypass for s semi ducted setup.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Carsten,
Ive been playing around with the Firgelli and Lado actuators. I have about a dozen of each!!
Lado doesnt make a larger than 20-30 mm stroke and they are not linear either. They are end point to end point, no in between. So they might be a challenge because of stroke and end point adjustment. They are great for robart 1" cylinder replacent though! most doors and speed brakes.
Firgelli makes a L12 Linear servo actuator that is a plug and play servo/actuator. They also come in different stroke lengths. They have a 50mm. This might be the only problem. I think the required stroke is closer to 60mm. I will try and fit one eventually as this is the way I want to go. The next size up is 100mm and that will be too big. They are really cool and very strong. I have an L12 that is 50mm stroke with 100:1 gear ratio that would probably be very close to perfect if not just barely on short side. Its very strong and the speed very scale! They will mount very easily and the end points can be controlled with a matchbox or whatever.
Quote from site:
(The L12 -R Linear Servos are a direct replacement for regular hobby servos and use the standard 3 wire plug. They are compatible with most Radio Control receivers and most USB servo controller boards and use either 5 or 6 volts. Lower gear ratios have higher speed but less force. Higher gear ratios have higher force but are slower. )
The smaller ones will fit the nose door no problem! I think they are 20mm stroke??

Tobba,
Man, thats some beautiful work! Amazing job!!
If you decide to make some doubles of the intakes, Id be happy to buy a couple sets from you!! Might could offset some of your cost!
I have a Dan Gill Chute system in my SG Hawk in case you could use some pics. Im going to have him make me a chute system for the Hawk 100 as well.
If you go with the 8711 on main doors, use a similar setup with linkage, and have intakes, you should be doing really good!
If you stick with air on retracts, then double the air volume!

Scott

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Carsten,
looking at it further and it might be perfect!!
pics

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hey scott - love some shots of the chute setup on your SG. Dan did my chute and components - slight up size from the SG in yellow as I am doing a similar scheme to Mark S's.

Yep 8711 for me and similar setup to yours. Very nice.

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

scott, keep the info coming. i will be in thrash mode for top gun. my hawk arrives late this week or next week. the gear door tip looks great. barry

RE: Tomahawk-Design Bae Hawk 1: 3.5
 

Hey Barry,
I dont know what level of completition yours will be in, but get ready for some clearance issues if your using P200(or similar) and stock fuel tank. There being no hatch is even more challenging.
Ive mentioned what ive ran into so far and I think ive gotten all the bugs worked out.
suprisingly theres not much chatter about this bird in the air!
this kits been out for a while and i feel like there would be more.

I messed around with my main struts some more and while they seem a little softer than my new kit, i was unable to compress them straight and get the strut cover to touch ground. I must of came in angled to be able to knock it off. There was a crosswind that day and i must have touched down the same side first catching the same strut cover. so struts are fine, just my landings bad! lol!
Scott