ticketec

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Thanks guys!

They are perfect pictures. Have got a whole heap of non-visible work done on the Hawk this week. Got ready to attend the first jet event for the year with our jet association, but I did get landing gear swings done with the help of a mate yesterday so good to see all working great.

now that we know that the tip stalling issues can be addressed I'm getting excited to get her finished.

thanks

dave

ticketec

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Not got a whole heap done of late...

I've covered the wiring in the rear of the airframe with aluminium tape to protect it a little if there is release of heat in the wrong place

And have started to do the calculations in order to scale the fairings and fences etc correctly. the Skymaster website states that the wingspan is 70" or 1750mm, but when I put the ruler onto my model, I measured 1850mm... The full size Hawk has a span of 9.94m (32ft 7in) so based on wingspan alone, the scale is 1:5.37 . close enough to the stated 1:5.5, but i'll use the correct scale factor to make up the fences.

The large fence looks to be is 95mm tall, 640mm long on the top and about 200mm long on the bottom. So the scale sizes for the skymaster hawk should be:

17.7mm tall
119.2mm long on the top
37.2mm o the bottom

So I will just carry out the same calculations for the rest of the items on the wing that I need to produce till I have all the numbers and then I can start to make the bits.


Thanks

dave

ticketec

My Feedback: (2)

So the first of the larger wing fences has been cut from some clear polycarb. Net result from all the measurements.... lengths top and bottom are good from skymaster, just needed to make it 3mm taller all the way around. I used the original kit piece to trace around so that it would match the wing nicely.

Both are now made prep'd and primed so I will move onto the smaller ones next. You can see were the previous owner aka 'ole mate went wrong when he installed the wing fences. Firstly he did not align them correctly to the airflow, and second, he used CA to glue them on! I got pretty lucky on one side because I was able to pick away at the glue residue and remove it all easily. The other wing suffered from the paint lifting and so played hardball a little more, but we'll sort that out later when all the other bits are made.

I have very graciously been offered all the "missing" bits for this hawk by the president of our local Jet association. His Hawk was also in the Saudi scheme which is all the better until he realised that I was building the smaller skymaster hawk and is was the larger one. No matter! I will take him up on his offer and will either cut and shut the larger items to get them to work or they might not be all that far off the right scale as it is! For example the sidewinders that come from skymaster are about 1/7 scale in length, not 1/5.5. So stay tuned to see what we can use from the factory to dress up this Hawk. There was no point trying to use the wing fences from the larger hawk as they need to conform to the shape of this wing.

Thanks

dave

ticketec

My Feedback: (2)

I did manage to go to the not so local LHS and pick up a powerbox Competition SRS for the hawk. This was holding me up from being able to finalise the radio gear installation. Ole mate was flying the model around on just a dual powered JR 12ch R/X and so no redundancy at all. I have moved over to DMSS about a year ago and so this will be getting a pair of the x-bus infinity R/X to complete the radio install. It also had a pair of 6v NiMH packs powering the model which I moved away from a while ago, so am in 2 minds whether to use them or not.

I'll post more pic's as I learn how to use the powerbox and complete it's installation

Also, most of the bits for my new 1/6 pilots have arrived!! I borrowed a body just to test fit the pilot into the cockpit and I have to say I am much happier with their fit! no more of that 12yr old junior flying the hawk around look for me. Both the pilots will be anamatronic so just waiting for the conversion bits to arrive and I'll get those completed and squared away soon hopefully. on the plus side, the skymaster pilot is a little porky at 225grams. My completed anamatronic pilots come in at about 120-130grams so next to no gain in weight at all for the model and I'll have 2 pilots!

Thanks

dave

ticketec

My Feedback: (2)

All the bits have arrived for the pilots so I have been busy making them up and now re-teaching myself how to program their control board. Hope to have them knocked over and correctly installed in the next few days...

I have been making great progress with the setting up of the powerbox and I have to say that it hasn't been difficult at all, but have worked out that one the extension leads to an elevator servo has failed. it's going to be a right pain to get it out and replaced. I reckon it's a few hours work just to get it changed out, but it has to be done. The only other problem left to deal with to complete the electrical installation is that one of the flap servo's seems to not be setup at all mechanically when plugged into the powerbox. I was perfectly rigged correctly when I was just plugging directly into the r/x before the powerbox arrived. Will have to ask powerbox what the go is there.

Thanks

dave

DocYates

My Feedback: (102)

The maiden on my SM Large Hawk 100 did not go as expected, nor as I wanted. With a fellow pilot at the helm, with over 500 flights on his SM Hawk (shorter version), we spent several hours doing a preflight, using throws similar to his own. Mine, powered with a Evobooster 160, and his with a Kingtech 170. I used the given C.G, and it only required about 5 ounces of weight in the nose to balance with the UAT full and the tanks dry. It was powered by Royal SRS powerbox and EV5 Pro air valve system. The take off looked goo, but was made with no flap since it was a maiden and he was so used to the plane. It climbed fine and when he got up a few hundred feet and began the circuits he needed some up trim on the elevator. It then flew nice and level for about 3/4 of a circuit, then needed more elevator trim, eventually after about three circuits the trim was at the max. With the throttle at about 70% it was not too slow, nor too fast, but the elevator constantly began to give way. There was no flutter. After the trim was expended things went worse more quickly, thankfully we shut the turbine down about 2 seconds before it went thru a local stand of trees into a swamp about 8 inches deep in water. Nothing much survived, but the tail, and we were able to check the servos and everything worked fine with the servo tested. The new A123 batteries were fine and had plenty of power. Plenty of witnesses and experienced people there, and we were at a loss for words as to what caused it. Needless to say I have a few landing gear parts should anyone need them for their Hawk. Good luck with yours, I certainly wish mine had survived since I think they are beautiful planes.

wichet

Very Sorry to hear that Doc

DocYates

My Feedback: (102)

ticketec

My Feedback: (2)

Oh no!!! So sorry to hear that mate.

I guess there is no comfort in not knowing what caused it either. Did the Stab attach area survive the crash? I wonder if that was starting to rattle loose, just a stab in the dark though. Dont' know what I'd feel like it that happened to me. Was the turbine a total loss as well?



I have been progressing slowly on my hawk. Mainly my fault as I have not had as much time of late, but all the flight controls are up and working. Just need to do the final neutral position check and throws and that's done. Came to the conclusion that I will be buying new battery packs to power the powerbox rather than the Ni-Mh packs ole mate had in there. I have been using them for setup and testing and they ran out of steam way too quickly.

The animatronic pilots are also almost done. Just have to properly secure the front seater and then it's adjust his programming to suit. The guy in the rear has a little more work left to do, and the waving arm will require a re-engineer to make it work the way I want it too.

The landing gear jobs had been pretty much finished but during testing of the landing gear and brakes the EV5 Pro valve brake side failed mid test!! It seems like there is something jammed in the pneumatic block, because I can still here the solenoid clicking, but the brakes are not working correctly anymore.I tried some silicone spray in there to see if it would loosen up but no luck. Wasted a few hours trying to sort it out You cannot get these fixed anymore and they factory that they were made in burnt down some time ago, so no replacement available as yet for it either. I will bypass the brake side of the system and use a xicoy single action valve in the mean time to get it up and lfying but am trying to get another one to pull apart and see how easy it might be to fix before I damage mine that is working other than brakes.

Thanks

Dave

DocYates

My Feedback: (102)

ticket,
We still have no idea. I was in the process yesterday of breaking down the remnants and salvaging what could be salvaged, and the tail mechanism was still soundly attached. Loctite on the screws and nothing was lose. I think it was some sort of electrical issue failure, whether it was the Powerbox or the two elevator servos, I do not know. The servos are on their way back to the factory for an assessment, but that is just because I don't want to trash them since they were so expensive. At this point I cannot find anything wrong with them. I am just perplexed as to the fact that I cannot find anything that caused it. It makes me want to just give up jets altogether. The Hawk was a beauty and I have yet to see one that did not fly nicely. Would like to have had the opportunity to put a few flights on it myself.

paulhat

Sorry to hear about your loss DocYates.
That seems like a particularly bad scenario with elevator control slowly diminishing.
I was thinking..do you reckon it could have been incorrectly splined servo arms? It is just interesting that both elevator servos went at the same time.

In any case I think you should buy another one

Paul.

DocYates

My Feedback: (102)

paul,
The arms were replaced with the metal ones, HD, and they were securely attached. Testing them afterwards revealed no slippage nor bad gears. Well at least I still have an intact set of gear...

ticketec

My Feedback: (2)

Well I hope you get an answer soon from the servo factory and hopefully shed some light...

I have been steady making headway on the hawk. The flight controls are rigged and ready to go. Worked out how to do a mix with the XG-14 that stops the nose gear from turning when it's retracted, and have made the clear lenses for the anti-collision beacons because we had a slow day at work and so I just polished them while we were standing around. I've also finished making the smaller of the wing fences and so will move onto the VG's now.

As you can see in my pic below, the Vortex Generators are 40mm long and 15mm tall on the fill size. That translates to 7.5mm long and about 3mm tall, and there are 15 per wing. also important to note that they are sided. I.e. the lower section of the L angle faces inboard. Off to the LHS to buy some evergreen plastic L angle!

Thanks

Dave

ticketec

My Feedback: (2)

I prepared a little bit of a rig to make all the VG a consistent size and shape. I linished the angle onto them with a guide on the linisher and then prepared this with my demel to cut them all off to the same length.
Now with all the VG's made and cleaned up I gave them a quick hit of primer and they are now ready for the final colours to be applied.

I worked out using my pictures the locations for the wing fences and I have added them to the picture below if anybody else was looking for the same information. I masked up the wing location and then marked out the correct location for the fences, and then with a borrowed an idea from one of the previous posters on this thread, I put down 2 layers of glass cloth, and placed the fences on the wing. This will give the ability to pre-paint the fence once ready to go and a bit more surface area to attach the fences more securely.

Next off is to do the spacing calculations for the VG's.

Thanks

Dave

basimpsn

My Feedback: (5)

I was about to buy a SM or a Fb HAWK when I notice some unexplained crashes due elevator not responding. Checkout this video.
https://www.youtube.com/watch?v=Z-mO1b_SUfI
https://www.youtube.com/watch?v=Pm1dCwC0N9Q

jws_aces

My Feedback: (33)

This was a Skygate not SM hawk. The reason for the crash was determined to be the shaft that on this earlier version ran from the top of the fuse behind the cockpit to the elevator. It was about 28" long and was 3 pieces. The builder determined it failed not the elevator or servos.

The second crash I can't comment on other that it looked more like lose of total control because the plane starts to roll before diving.

I have both 1.5 Xtreme Hawk first version SM 1.5 hawk. and have no issues with the elevator. I have not seen anyone else. I lost count on how many flights I have on the both. I am running a single servo on elevator on both. I did have one small at KY jets with my Xtreme hawk elevator I made a repair the it. I had drop something on it and cracked the top part of the joint. I repaired and order a replacement. I had about 10 flights on it when the repair failed at KY jets and the right side started to flap up and down. I managed to bring it around and land it with one side still working. I have the new on it now and will be flying more this year.


Doc sorry for your lose.

ticketec

My Feedback: (2)

Im with jws_aces on this one as well, It would be like going car shopping but saying I'm not going to buy an SUV because I saw a couple of them crash.....

basimpsn

My Feedback: (5)

Cool glad to hear that...I was thinking "HAWK" in general was having problem with flaps blanketing the elevator or something of the sort since both crash with flaps down, Sry if it sounds like I was singling out SM or FB

Just my opinion.

jws_aces

My Feedback: (33)

Nobiggie..
I was told the same about the flaps on my first one I bought from the builder.I agree you need down to about 3/4 speed or less before deploying the flaps. Ialso will tell that Crow will help prevent tip stalls on landing. One lastthing is a lot of people including me start out real nose heavy due to all thetip stalling reports. I have been moving weight back on the one I have now and Ihave even pulled one pilot figure out after balancing it at the factory spec.Now if it bounces on landing like them seem to do if you don't nail theapproach it will recover without bouncing uncontrolled and knocking the gearout. Again CROW is need to prevent it from falling over on the bounce

ticketec

My Feedback: (2)

A little more progress to report.

I masked up the canopy on the inside to paint all the frames in flat black as per the full size. It makes a fair difference once installed. The canopy edge repair that I had done broke again while taping up, so I used some hysol and glass fillaments to properly strengthen up the area. all good now.

The L/H wing now has it's fences and VG's glued on. I cut out some masks to assist in the alignment and spacing of the VG's. Just need to come round with the correct colours and touch them up. you can also just make out I have started post-shading the wing upper surface. That's the first step of the weathering treatment she will have.

All the bits are made for the r/h wing, just have to install them

Thanks

Dave

ticketec

My Feedback: (2)

Little bit of having fun, but I built these for my nephews when they come up to visit and always want to help me with the jet.... just have to attach the remove before flight tags when they arrive.

Also glassed and filled the hole in the nose 'ole mate had made for the landing light... that will be moved to the correct location.

Thanks

dave

ticketec

My Feedback: (2)

Started work on the fuel system...

The first pic shows what I pulled out of the Jet.... So this required a trip to the LHS for supplies...

The next pic's are what I put back into the Hawk, I bought new brass tube so that I could deal with all the kinked tube and also silver solder some barbs onto the tubes. I always lockwire the lines with 0.020" stainless steel lockwire.

I have put an order in for the last things I need for the Hawk including some new festo fittings from Intairco for my air trap, so by the end of next week I will have everything here so I can do the final placement of items to get the correct CoG. Our Jet association's next even is the 19th June so I have booking in my accomodation and pit crew so the target completion date is now set!

Thanks

Dave

ticketec

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To strengthen up the strake mounts I glued in some hard balsa blocks and then added 2 more pins on each strake. Some hysol and a good few hours of drying time later and they are good to go!

The nose detail was replace and repainted, so another job ticked off.

I have also done the repair to the speed brake and have hooked that all back up.

I decided to throw all the components into the Hawk and see how we are tracking for CoG. Because the thrust tube is the length that it is, I have to mount my turbine almost to the back of the mounts. It then means that I have to look at placing the LiFePo4 cells almost beside the nose gear retract to get close to balancing out correctly....

I wonder how much of the thrust tube need to be sticking out of the rear of the airframe?

Thanks

dave

ticketec

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The final bits I need for the hawk have arrived!!!

the 2 Xbus R/X's and the new airspeed sensor from JR.... Should be interesting.

thanks

dave

ticketec

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Turbine and thrust tube are in!

Just plumbing ing up the fuel system to the turbine and I should be able to start the turbine up in the next few days!!

thanks

dave