Jetfan20

My Feedback: (21)

Question for the guys that haven't built theirs yet. I purchased one of the Original Skygate Hawk in stripped down condition for a new paint scheme. The aileron and rudder pins are missing. I picked up some 2mm steel rod from my LHS. When inserted, the control surfaces have some play. I believe the steel rods maybe to small, can anyone give me a measurement on the rods diameter with a caliper? Any help will be greatly appreciated!

DUCMOZ

Hi Jetfan

Mine is reading 2mm. Maybe the holes on yours are worn out a little after use.

Regards

Behzad

Hinckley Bill

My Feedback: (569)

Colin,

Was part of the 'power' issue with the 160 size turbine tied to the original ducting setup............which was ultimately taken care of by using Marc S.' ductwork install?


Bill

Colin Gontier

Hi Bill,

There is no doubt that the Hawk is "draggy". The full ducting that Marc S was doing was beautifully designed and made but does add weight, so there is a trade off there. We would need a "real world" comparison I suppose on an aircraft with ducting fitted and a lower power turbine like a 160.

Don't get me wrong - a 160 will fly this plane and it will be enjoyable but I think most of us are used to having plenty of power on tap to do, for example, nice big loops or go from that slow and dirty pass to a long 45 degree up line. Im not a speed/ power freak myself but I suppose I always like to have it on tap if I need it.

regards

Colin

Colin Gontier

JetFan, Im not sure what was used in the original Skygate Hawks but CARF use a specific size (which I will measure shortly). I remember being stuck out at the field needing a piece for a gear door or something and nothing would fit but what CARF actually use is a welding rod used for brazing in all their jets. Maybe the old Skygate kits used the same.

regards

Colin

marc s

Colin, great job and looks superb - always a wonderful kit and glad to see it 're-incarnated'.

The full ducting kit did indeed weigh more than the standard parts but consider that the

- new tank replaced the existing with marginal weight gain but was 6.5L in capacity
- full bypass replaced half bypass supplied so only slightly heavier
- replacement main turbine formers were lighter than the originals
- ducting was heavier than original 'stumps' but was a very light layup with carbon tow reinforcement

Overall the difference was small.

I have moulds and CAD files for the main parts (bypass, ducting, formers etc) still and one tank left so can re-make the tank moulds if needed - if there is a demand for the conversion then I may be able to consider a re-make of the "full ducting/bypass kit"

Some pictures.....

marcs

c_makhija

Hi Jetfan,

I have the original Skygate kit, just measured the aileron rod and it read 2.05 mm on the caliper. 2mm rod should work fine.
Just checked for play, and there seems to be a tiny amount in the aileron, nothing that should cause any kind of surface flutter.

Regards
Chatty.

Dave Wilshere

The welding rod varies in diameter, its not normally that round! Bits I have had from CARF vary between 2.02 and 2.05mm

Colin Gontier

Just measured mine - 2.02 mm. Also took a few pieces of spare rod offcuts I have had from various CARF models and each one was 2.02mm.

As Chatty said its OK if you have tiny amount of play - you don't want them to be "binding" tight. I can move mine slightly.

regards

Colin

Jetfan20

My Feedback: (21)

Thanks guys for the info, I will see if I can find something that snugs up a bit better. It's not a ton of play but, want to minimize it.

I had the same issue with rudder, I glued a new piece of G10 with a slightly smaller hole under the old rod guide and I have NO slop at all and the surface moves freely as well with no binding.

Thanks

Ty

Doolittleraider

My Feedback: (72)

Yo TY when are you going to have that big dog done?

Peter

Jetfan20

My Feedback: (21)

Peter Wassup! Mid April should be ready to go! When will I see yours fly? This weekend at Florida Jets?

ddennison

My Feedback: (15)

Colin
Thanks for sharing this information.
Could you list what you are using for servos? I saw the YouTube elevator failure and didn't understand if that was due to variation from the standard setup?
Do you have any pics of your completed partial bypass installation?
Thanks very much,
Dave

ddennison

My Feedback: (15)

Sorry - I saw that you are using 8711. What I would like to know is if there are recommendations for servo arm lengths. One of your pics looks like > 1" servo arms. I tend to think of short distances as possible so was wondering if the instructions outline pin-pin distances at the servo for each surface?
Thanks very much
Dave

Colin Gontier

Dave - yes JR8711 all round apart from nose wheel steering where I have used the analog metal gear ES579.

I will put the servo arm lengths in the instruction manual, but here they are for reference:

Elevator - 1.25 inch - I used Secraft arms, super quality and strength. You could get away with 1 inch as I dialled about 10% of the travel out in the end.

Aileron - 19mm - I used JR Aluminium servo arms

Flap - 38mm - again I used JR Aluminium servo arms - gets you about 60 degrees of flap which is plenty

Rudder - 11mm - I used JR super servo arm.

Will post some pics of these areas when I get to the office later.

regards

Colin

Dave Wilshere

JR don't do a 42mm Ali arm I'm aware of. It is 38mm
The Hawk is known to suffer rudder flutter, I would not recommend anyone use a Nylon servo arm for rudder. The chance of the spline stripping is too great.

Colin Gontier

Apologies its 38mm you're right - bed head this morning doing things from memory.

There will be no rudder flutter here. Nylon servo arm is fine as far as I am concerned. The control horns in the rudder itself are much longer than the original Skygate version. However you can never be wrong by putting in a more heavy duty alternative if thats what you want to do.

regards

Colin

Colin Gontier

...or as another option on the rudder servo arm if one was particularly concerned you could use these nylon arms which have a metal ring around the outside of the spline area. 1st hole is at 10mm so marginally less rudder travel but not an issue.

However as above I have used the JR super servo nylon arm in my build.

regards

Colin

Mark H

I have worked on both the original skygate rudder and now on my CARF skygate and yes the horn on the rudder surface is longer giving more leverage and so rudder flutter should not be a problem , I used a cut down alloy arm , but agree with Colin on this one that the super nylon horn is ok, I am how ever using MKS 660A+ servos with 26 Kg these are all metal cases which also mount very rigid, . On the fin post I also noticed this was stiffer.

DUCMOZ

Hi Colin

When do you think your instruction manual get ready and posted by CARF?

Thanks

Behzad

Dave Wilshere

The JR arms with a ring are even worse, the material is softer. The ring was just to stop the boss splitting. The longer rudder horn might reduce the chance of flutter, but it increases the leverage and one of my main concerns on big surfaces is handling damage and the chance of a knock taking the splines off a nylon arm. The Hawk is a knife edge king and this is a lot of aeroplane loading up that little spline...
There are metal arms available with a smaller boss than a JR clamp arm, in fact the SECRAFT longer arms are suitable. I will be advising my customers to go metal.

Dw

DUCMOZ

HI all

I have used SWB arms on a large Futura and it works great. they have a one inch version with plastic insert that would work with regular clevisis without any problem although they come with a good clevis themselves. Also, the starting end and the tightening screws are small so they fit in tight places.

Thanks

Behzad

bobg

Budd at QUICK UK makes some very good quality metal horns to suit major brand servos and nice variety of sizes and colours ...

at very sensible prices too !

have been using them for a few years now .

Colin Gontier

Hi Behzad,

Working hard on it as we speak, just ridiculously busy at the moment so working all hours. I very much hope in the next week or 2 at least the main draft will appear. If you need pics /measurements /specs of any particular areas in the meantime just email me on [email protected] and I will be happy to send them through.

Kind regards

Colin

DUCMOZ

Hi Colin

Thank you. I am planning to start with the wings next week or so. Those would go fine. by then, the instruction should be ready. if not, I will definately ask you any questions that might come up.

Thanks again.

Behzad