RE: Skygate Hawk - build (virtual manual)
 

Mark when your kit turns up give me a shout and I will pop over to measure up, that way I can get working on the T Hawk bypass for Ali before his T Hawk arrives with me. Are you likely to be wanting one of the 6.3L tanks as well?

marcs

RE: Skygate Hawk - build (virtual manual)
 

Cool. As for the tank, why not! In for a penny, in for a few pounds!!:)

I'm sure Al will do me a fantastic price for supplying my kit for prototyping :D

Spk soon.

M

RE: Skygate Hawk - build (virtual manual)
 

Extra £

RE: Skygate Hawk - build (virtual manual)
 

Just an extra £? Great stuff!! I knew you'd publicly show your generousity! :)

RE: Skygate Hawk - build (virtual manual)
 

Marc. Nice work... really nice work.

Between the ducting, bypass, tank and your build thread you are breaking a lot of ground for people to follow - this is muchly appreciated.

I'll be very keen to order all for my tomahawk when available.

Thanks.

RE: Skygate Hawk - build (virtual manual)
 

Good to see such attention to detail.
Jr sevo arms are the way to go with the correct clevis installed :D I am sure this will eliminate any play.
Schroedm we all know how Generous Ali is, and I also look forward to this generousity
being shown to me, one day :D

RE: Skygate Hawk - build (virtual manual)
 

As the small fill in flaps (not sure of the technical name) were over length, I had to trip the ends to length, before doing this I made a small hole in the end to be trimmed and squeezed some epoxy into the end so that when it had cured i could cut the end off and have no need to fill and make good the end.

Lined up the trimmed fill in flaps and cut three slots to match the horns they mount to leaving the outboard gap as per the FS. Used the mill to cut nice neat slots. The new horns have a small tap on top which makes it easy to get the correct position when fixing the fill in flaps, the edge sits under this tab.

Having read recent threads on the fin failure(s) I decided to add a little extra reinforcement in this area just to be safe. When you cut the exit for the rudder linkage you do weaken the fin skin, and this is further weakened by the removal of some of the vertical former to give full throw. I took a 1.5mm thick piece of carbon plate, cut a 12cm length and shaped it to fit in the area surrounding the linkage exit, a small notch was cut to maintain clevis clearance, this was then prep'd and glued in place with Aeropoxy. There is sufficient room under the rudder to allow this to be fitted.

marcs

RE: Skygate Hawk - build (virtual manual)
 

A neat UAT arrived via Als Hobbies today, worthy of a couple of pics as its a work of art, designed for high flow application with big bore connectors. Mounts vertically and has lugs fitted for this purpose.

marcs

RE: Skygate Hawk - build (virtual manual)
 

Don.t forget some Hawks had a gap (about 9 inches) at the outboard end flap vane, but later Hawks had full length flap vanes and can be identified by having SMURFs (side mounted unit root fins) fitted just ahead of the stabs. Australian Hawks, for example have full length vanes, whereas all RAF Hawks have the gap. (which cured pitch down with flap deployment) Seems Skygate has made them full length to cover both options.

Regards, David Gladwin

RE: Skygate Hawk - build (virtual manual)
 

David, unfortunately they would not fit full length, short by a few inches at least, so have opted for the shorted version as this seems more popular.

Happy New Year all....

marcs

RE: Skygate Hawk - build (virtual manual)
 

Been busy doing the second wing so posting has been slow, but now as the main surface controls on the wings are done I decided while glue was setting to take the plunge and start the canopy, which I understand is a little tricky.

There are 5 main components, front shield frame which is fitted permanently to the fuselage nose tub section, a 'floppy' front shield frame surround, a main canopy frame, main frame canopy surround and a large one piece clear canopy moulding.

I started with the front shield frame, this requires tidying up and fine sanding to get it to a stage where it is ready for fitment, then the main frame is treated in the same way. Once these two are ready you need to mount them on the fuselage tub to get the correct fit. I taped the front shield section on and then the main canopy section, the gap between the frame and the fuselage sides should be as even along the length as possible, in my case the section where the two frames meet was a little narrow so I wedged it open a few mm to get the correct gap (see pics).

Next job with the front frame securely taped in place and tacked with a few drops of cyano was to sand the frame mating loops so that an even gap was visible the whole way round, this I understand will be vital later when the canopy 'glass' is cut. This part of the job takes a good while [:o]

When the fit is to your liking the next stage requires making the canopy to front shield frame fixing, the instructions show using a bent tube for the canopy section, angled down and glued to the underside of the frame moulding, this in turn locates into two holes made in ply plates which in turn are glued into the front frame in the bottom two corners. Naturally lining up this is key to a good fit. I changed the tube for two lengths of solid rod, bent them to the correct angle (this is critical to allow the canopy to tilt up and back to remove so test before final fixing!) I scuffed and tacked in with cyano. I then cut two ply plates and shaped them to fit into the channel around the front shield frame, marked the rough location of the locating pins on them and made two slightly oversized holes. I then took some brass tube with the same internal diameter hole as the locating rod and placed them on a flat surface. I slid the ply formers onto the rods (using two collets to act as stops on the rod) and then slid the tubes on and visually angled the tube in the ply plates so everything was in line, I tacked the tubes to the ply and removed them. Once off I added epoxy to secure the tubes permanently to the ply plates and added a small ply brace to increase the strength of the tube fixing.

When done the fitting was next. I mounted the two ply plates into the front frame and clamped them roughly in the correct position, flush with the frame and seated on the fuselage lip, I applied two layers of masking tape to each side of the fuselage tub lip to give a small tolerance for the paint application then slowly offered up the main canopy frame careful not to move the ply plates. Once the main frame was in a few small tweaks had it sitting flush with the front shield frame. I slowly and very carefully removed the main frame so as not to disturb the ply plates, once removed I wicked some cyano into the ply plates to secure them, then added epoxy to complete the bond.

The frame now fits nice and snug. If there are a few gaps I would imagine these can be covered up by the frame surrounds when it comes to fitting these.

Next will be the 'glass', the instructions show this is fitted as one complete unit to both frames, and then both surrounds are then also fitted, once dry the front frame is cut with a razor saw to free it from the rear canopy section (hence the gap) - I'm not sure I will do it this way but still out for discussion!

marcs

RE: Skygate Hawk - build (virtual manual)
 

Canopy 'glass' is a thin item, primarily I guess for weight reasons, this makes it extremely flimsy until fully fitted.
First job was to cover the surface with a few layers of cling film to prevent damage and scratching. Next was to work out where to trim the canopy to get close to the required shape as there are no guide marks to work with.

So first job was to attach the front shield frame to the main canopy frame to get the overall 'footprint' of the shape required, next was how to get the canopy marked up. As it has excess areas all round it simply wont just fit on the cockpit frame while in situ, so I ended up using two 2.5L cans to which I stuck a couple of strips of aluminium angle to, to act as rests for the main canopy base frame, it was important that the support did not protrude past the edges of the frame otherwise the canopy would not seat down properly.

Once rigged up I ran some masking tape along both sides and over the front and rear hoop of the canopy frame to prevent scratching the inside of the canopy, once done I placed the canopy onto the frame and adjusted it. I took the frames (both taped together) and placed them on top of the canopy, once this was carefully adjusted to make sure the canopy was centered I held the frame down and ran a black 'sharpie' marker round the entire frame edge, marking the cling film.

Removing the frame left the canopy with a clear marking for the cut line. I use flower cutting scissors to cut canopies as they have tiny serrated blades which grip the plastic as you cut and seem to take less work to cut plastic generally than normal types.

With the canopy trimmed it was re-checked on the frame.

marcs

RE: Skygate Hawk - build (virtual manual)
 

I decided in the end to go away from the Skygate method of fixing the canopy 'glass' and fix it in two sections rather than one and then cut them apart - it might end up a disaster but I had this urge!

I took the canopy and rested it on the frame, I dropped on the front shield frame, made sure it was lined up and then marked where it meets the main canopy cover. Using the flower scissors again I cut just inside this line so the front shield 'glass' would finish just short of the frame hoop edge.
I then ran a thin bead of 20 min thixo epoxy around the frame hoop and back along the lower edges of the front shield frame for about 4", the 'glass' will not flex much beyond this point so its best left as is, I clamped the 'glass' while the epoxy was drying.

This front section seems to be the most tricky from reading posts etc, mainly because the frame which covers the 'glass' is flexible and has to sit on the edge of the frame/fuselage sides, sounds straight forward enough but the problem is there is nothing behind the frame to support it while the fixing method chosen dries. Closer to the point where the frame loop is the edges get closer to the fuselage sides so fixing is easier, its the area towards the front which is the problem, I would guess the void is 3/4" at least.

After some aborted ideas I decided to visit the local motor accessory store and bought a tube of fast setting filler putty, my idea was to add this in the key areas under the frame to bulk out the void and provide a face to which glue could be placed to adhere to the frame. So mixed up a small lump and rolled it into a thin sausage shape, I laid it in the groove along the front edge so it was just about level with the fuselage, I put a strip of brown parcel tape on the inside of the frame to prevent it sticking solid and placed the frame in position, gently squeezing down along the edge so the frame was flush with the fuselage, once happy and to keep it in place I added a few lengths of masking tape until the putty had gone off.

Once dry I lifted off the frame (which came away easily) and was left with a flattened bead of putty stuck to the front shield main frame which provided the exact support the front frame to fuselage alignment. After this I repeated this for the two corners, and will continue to do this along both edges. This should then make life much easier to fix the frame permanently as it has a ledge on which to be pressed against to glue, happy in the knowledge that it will remain flush with the fuselage sides (well thats the plan ;))

marcs

RE: Skygate Hawk - build (virtual manual)
 

Marc,

as i remember the canopy frame is too small to fit well with the fuselage sides. I remember it put on both sides 1-2mm Balsastripes between the frame and the glass, with the outer frame you get a good fitting to the outside of the fuse.
Please check this...

regards

Jörg

RE: Skygate Hawk - build (virtual manual)
 

Jorg, yes that is correct, the main canopy frame is a little too narrow to be able to just fit the 'glass' and frame, I plan to use a shim as you did, might even use a thin bead of the putty as I have done on the front shield section.
I hope to get started on the main canopy later today, it will also be having the Details 4 Scale side opening system fitted...

marcs

RE: Skygate Hawk - build (virtual manual)
 

Finally managed to get the front canopy frame and 'glass' in. Once the putty had been done all round there was a lip on which to glue the surround, to get this nice and flush I glued it in stages, first the leading edge and about 1" down the sides, while lining this up is was evident that it needed to be held in several places, not easy with only two hands! So drilled a few tiny holes in the centre of some of the screw heads moulded on the surround detailing, I was then able to glue and screw the surround nice and tight to the fuselage and frame. Once dry the screws were removed and filled with some Aeropoxy. I then did one side followed once dry by the other, the end result was neat and well fitting.

Cut slots in the flap vanes to accept the flap linkage horns and glued these in with Aeropoxy.

8511's on the flaps were mounted in the pre-cut holes inside the wing, using JR 1.5" arms for extra strength, tapped the clevis hole with M2 and bolted the ball link to this and loctited the nut.

marcs

RE: Skygate Hawk - build (virtual manual)
 

The flap linkages are all in now, if there are builders using the same metal JR servo horns on the flaps the 3mm push rod needs to be around 13.5cm long to give the right throws.

Started on the gear while I wait for the Details 4 Scale side hinging canopy kit. I am not sure if its just me BUT WHY DO RETRACTS AND LEGS NEVER FIT! I have studied the pictures on the CD supplied, and they are not clear, I've trawled threads, no joy, what seems to be the correct location on the fitted wooden formers for the retract unit causes the gear leg to rest on the wing edge without fully locking down, I have removed a little of the wing edge rebate but this only helps a little. I eventually decided to make some carbon plates to act a shims which fit over the wooden formers, these raise the retract unit and gear leg around 3mm which gives clearance - the problem now is will this cause problems with clearance somewhere else? I have not fitted the wing to the fuselage yet to see how this looks in relation to the gear doors and clearance, I guess a job for tomorrow.

If there are any SG Hawk builders out there who have done this can you let me know if you had the same problem, and if so how did you fix it?

So then I thought I will work on the gear leg scale shrouds, these must be a piece of cake, big mistake, the items are moulded in two halves, the joining faces seem to have been cut with a chainsaw, huge gaps, wavy line, just horrid. Is a shame that to odd parts seem so badly made in relation to the rest of the kit, but I guess thats life!

Rather than try to join them on the gear leg, and re-shape the contours with sanding files etc I decided to join them as best possible with cyano, then filled the seams with Aeropoxy and will now leave to dry. Once dry I will sand to the correct shape and then band saw the shrouds in half again, this time hopefully with a reasonably straight line. Fixing them to the gear leg should then be a little bit easier[:@]

Looking for something that would not be a problem I screwed in the two 8711's into the elevator servo tray - hoorah achieved something today.......

marcs

RE: Skygate Hawk - build (virtual manual)
 

Marc,

I can't answer all the questions but I definitely had to recess the wing root like you to allow the legs to retract fully.

You'll also need to shave away nearly all the material to get the flaps to retract fully.

Rgds,
Mark

RE: Skygate Hawk - build (virtual manual)
 

Hi Marc,

Here are some photos of my two sets of wings for my TWO Skygate Hawk's, I hope it helps with your set-up.

Are you sure you haven't mounted your retracts too far inwards, mine have no shims just like Mark mentioned.

Regards,

Darryl

RE: Skygate Hawk - build (virtual manual)
 

Marc, if you raise the gear with your carbon formers you become later problems with the fuse gear doors and the small doors over the gear mechanic. Here is not much space to work.

regards
Jörg

RE: Skygate Hawk - build (virtual manual)
 

Guys thanks for the pics, is there a chance one of you could shoot a picture of where the retract unit sits on the ply former plates? I need to get an idea as to where this should be positioned - the manual shows an early retract unit which differs from the later unit so a reference would be good.

marcs

RE: Skygate Hawk - build (virtual manual)
 

The latest on the main gear is confirmed that one of the legs has a slightly out of aligned weld on the 'knuckle' which has caused the wheel assembly to sit 6mm lower when compared to the other gear leg which fits the other wing, such a small inaccuracy makes a large difference further along the gear leg!

The unit is going to be re-welded to address this problem.

While waiting for the gear to be fixed I installed the main span-wise fuselage former, this runs close to the joint area where front meets back, it strengthens this area, supports the pylons for the gear door cylinders, original fuel tank and front location pins for the wings. The former in this installation will provide all the above except supporting the tank, hopefully a smoke tank will sit inside the two rearward facing rails providing 2-3L of fluid dependent on where the ducts cross over.

Ducts should be ready late this week so will start trial fitting over the weekend. To allow the ducting to be installed so it is removable the option currently looks like the ducts will be fixed to the inlet mouldings, this will allow a neat and seamless finish to the intake area, the intake mouldings will then be mounted to the fuselage in a manner which allows them to be removed, not sure exactly how this will be done yet as access to the fixing locations could be hard with the duct in the way, but I am sure there will be a way.

Hooked up the linkage to the elevator servos using the JR metal horns and drilled out M3 metal clevis with an M2 nut and bolt securing it to the arm.

Finished off the leg shrouds, these took a long while to get anywhere decent looking, after sanding and filling they are respectable now, will run through with the band saw to re-open closer to the time when fitting is required.

marcs

RE: Skygate Hawk - build (virtual manual)
 

Terrific work as per usual Marc, very impressive.

I said it when I saw Ali’s first Hawk, I said it when Mark built his; I just do not agree with that elevator linkage.

m

RE: Skygate Hawk - build (virtual manual)
 

Its an interesting one I have to agree, and possibly not the best linkage system about.

I don't know what the new Tomahawk Hawk runs in this respect, maybe an owner could confirm what system they use, I just build and tweak things, changing linkages would require a little more of a specialist brain I think!

marcs

RE: Skygate Hawk - build (virtual manual)
 

The principal is fine so long as both servos keep working; you have a double push/pull into the bell crank. From a safety angle one servo relies on the other to fail jammed, not good.

If it were mine I would introduce a “stop” to limit the rotation of the bell crank thus allowing the good servo to move the pushrod whether the other servo fails limp or jammed.

m