jacksonretlaw-RCU

My Feedback: (16)

I am building this kit.I am in need of a low profile retract for this model.Not happy with Aviation Design retract.Protrudes out of wing.Want to install gear doors.Tried using my Robart 635 retracts.Frame rail depth to deep.About,1.25 inch from rail.Also retract has to retract away from air cylinder.I am using Aviation design nose gear.It has direct drive steering.Any responce will be helpful.Thanks all in advance.

HarryC

My Feedback: (1)

But the retract is AD's one that they sell specifically for the F-100. You mean the one that doesn't even sit on the pre-installed mounting rails? Who'd have thought it, AD stuff that doesn't work. Just don't use the AD jet pipe, whatever you do. [sm=cry_smile.gif]

BVM makes a special low profile unit for his F-100, you could try that.

olnico

Are you sure that you have the right retracts? Because I have never heard or seen something like this on the AD F-100.
Anyway, the guy who can help you on that matter is Barry ( u2fast ). Just send him a pm. He built a very nice F-100 not so long ago.
Cheers.

HarryC

My Feedback: (1)

You didn't read my review of the AD F-100 in RCJI then. The main leg retracts they sell with it simply do not fit the bearers pre-installed in the wing, and I mean by a long way like they are for a different model entirely, and the retracts and main legs sit proud of the wing. Main leg doors are not possible. Let's not mention the swarf trapped between the trunnion and the frame. The air rams for the wheel doors were all different sizes, and had plastic end caps with nipples so crude that even FEJ would have rejected them. The noseleg retract's brass nipple was so big it needed tygon not normal air tubing, and anyway it came apart when tested! And lots of other minor issues with the retracts and wheels and brakes.

The fuselage had deep long furrows where the cloth had folded back on itself in the mould, lots of other areas on the prepainted silver model had flaws which AD had thoughtfully filled in - with white filler and red filler on a silver model, yeah that worked. And when you take this up with AD because that's not what you paid for, the reply is personal abuse!!!!!!!!! The wing would not attach to the fuselage because they put they misaligned the anti-rotation pins compared to the main joiner tube.

Oh, and the inadequately thin jet pipe (30% thinner steel than other brands) collapsed in flight causing total loss of the model, £6,000 down the drain on the 10th flight.

But apart from all of that...........

mark hinton

Harry have you lost yours !
I now have over 100 flights on mine. The outer gear doors will fit mine but lost them both over time as my attachments on to the leg
Were not good enough. My uc does sit inside of wing just enough to get skins back on.
The model is a builders kit but in the end you do get
A superb flying machine that is both light and strong.
I have had several AD jets and they are all great fliers.
SU27 twin single seat and twin seat Raf and F100.
My kit was great no filler was needed. And it came out at 13kg.
Regards Mark Hinton.

HarryC

My Feedback: (1)

Yes, I was gutted, because in the end it was a gorgeous aeroplane and flying it was a very great pleasure. But suddenly there was a loud pop, loss of thrust, and 2 or 3 seconds later total loss of control. The inner pipe had sucked completely flat, the hot exhaust then melted the inside of the model, servo wires, pushrods etc and it went down vertically from 400'. I liked it so much I want another one but I won't be giving another penny to AD! They were lucky the mag review was published just before the jet pipe collapsed.

mark hinton

Sorry to hear that H.
Pipes are not sucked in , the are pushed in by the outside pressure , this is caused
Because the pressure inside the pipe has been lowered because the turbine spacing at the front
Is wrong so causing not enough air to enter the front of the pipe to equalise the outer pressure. (15 lbs per square inch. Or one bar)
Or not enough air was flowing through the model.
I once had a pipe (bifurcated ) start to do this and when I tuned the turbine to the pipe it was fine.
I have flown my F100 with standard pipe with a G Booster 160+ and even a 180plus I now fly with
A Jetcat 160 all have been no problem. I also secured the front slightly different as I have also seen pipes move.
Usually if the pipe collapses the engine stops pretty quick but if the pipe had moved then the pipe could of blown in
With the motor still running.
Sorry for you loss but it can happen any time the plane is not on the ground. It is part of the hobby. We have to grin and stick with it.
Regards Mark h.

HarryC

My Feedback: (1)

I appreciate what you are saying Mark, but in this case the distance was that given by the instructions of the engine maker, there was nothing in AD's instructions about the distance, so what else can one do? After the destruction of the model I put my calipers onto the jet pipe and found it to be substantially thinner steel than my other pipes from 3 other brands, 0.1mm instead of 0.15mm from other brands.
H.

HarryC

My Feedback: (1)

Returning to Walter's original post, tbh the lack of leg doors, and the slight protrusion of the trunnion block and leg outside the wing is not a visual problem if you fit the drop tanks. When I received the kit I was gobsmacked that they say to fit the flap servo on the outside of the wing and I went to a lot of trouble to cut hatches and fit it internally, but again if you fit the drop tanks you will never see it in flight. Lozza, whose photos are much admired on many forums, took lots of stunning photos of the model in flight and you would never really know there are no doors over the main legs.

SJN

I remember one of the guys here in Denmark also had problems with the gear on his F-100


some of his build pics here: http://www.modelflyvning.dk/forum/sh...ighlight=f-100

HarryC

My Feedback: (1)

Walter, when you come to drill a hole in the bottom skin of the wing for the M3 bolt that holds the wing to the joiner tube, do not follow the instruction manual! It tells you very precisely to drill the hole Xmm out from the root. Chances are you will be drilling through nothing more than the skin and that won't take any load. Somewhere near to where the instructions say to drill the hole is a 1/4" ply rib, on mine it was about 1/2" away from where they said to drill the hole, drill through that all the way down to the joiner tube and you have a very solid mounting for the M3 bolt.

H

HarryC

My Feedback: (1)

I also felt that the AD noseleg spring was far too powerful, I think it is a main leg oleo unmodified, so it never absorbed up any bumps and it skipped along the ground. I did dome calculations to determine an acceptable range of spring rates and static loading, and then measured the actual oleo supplied. This showed the spring rate wasn't too far out but the static load was far too high - in other words it was an acceptable power of spring but the spring was already so compressed that it was putting out several multiples more force than the weight on the noseleg and thus behaved like a solid leg. Since the spring rate was about correct (force required to compress it a unit distance) the spring itself could stay, all that was needed was to reduce the initial compression which I did by cutting a calculated amount off it. That worked beautifully, now the leg just started to compress by a couple of mm at rest, and could be seen absorbing the bumps during ground running.
This problem isn't confined to AD, I have seen it on virtually every jet I have bought, they use main legs as noselegs.

olnico

Oh, I am so sorry to hear that you lost it. It was such a beautiful model.
I did read your review of course. I enjoyed it along with the beautiful pictures made by Laurie.
BTW, I am reading every review as a part of my job. However, forgive me for forgetting things after more than half a year.
I did build an F-100 for a friend in Luxembourg about 7 years ago. The kit did all come together nicely, just as Mark mentioned. Certainly a builder job though.

Regarding the takeoff roll instability, I added a gyro on the yaw axis, coupled to the steering servo. That completely sorted out this issue.
Regarding the unexpected stabilizer position that you had on level flight, I believe that it was due on your model to the fact that you somehow ended up with the wings at the "wrong" angle of incidence. I realized this from the pictures of your plane in flight.
Your plane looked like it was flying level with a higher tail attitude than with the recommended setup. It was actually looking much nicer like this!
So I think that you somehow found a more scale wing incidence. If I was to build another of these planes, I would certainly give it a try and add a couple more degrees of positive incidence to the wings ( this would also help in reducing the takeoff roll ).

jacksonretlaw-RCU

My Feedback: (16)

Thank you HarryC and every one else for your responce.HarryC,sorry for the loss of your stunning aircraft.Still need sugestions on low profile retracts.Who makes them.The kit does have its flaws.But all I here is how well it flies.Again,thanks to all.

HarryC

My Feedback: (1)

Golly, that would not inspire confidence in the factory build! The wing alignment should be very consistent. I'm convinced, more than ever, that I was sent a whole load of reject parts that should never have been sent to a customer.

The misalignment in mine was that the holes for the anti-rotation pins at the leading and trailing edges were created a bit wrong in fore and aft distance, there was no hint that they were rotated off line. So without the main joiner tube, the wing would plug into the fuz as the anti-rotation pins fitted perfectly into their 2 holes, but with the main joiner tube in place the anti-rotation holes were 1 or 2mm forward of the pins on the wings.

As to the steering instability on take off, I didn't have a gyro at the time but was advised by someone who knows F-100s incredibly well, that they are prone to it and the trick is to start at say 1/2 throttle, keep it steady and once it has some speed and is tracking true the fin will work and full power can be used. I tried that and it worked, though in future I would use a gyro from the start. I never noticed it, but another flier told me that sometimes in the turn he could see a slight fishtailing, so it seems a yaw gyro is an all round good idea.

H

HarryC

My Feedback: (1)

BVM for his F-100, quite a different design to the norm but probably difficult to fit into the AD wing, or check the dimensions of this robart unit http://www.robart.com/products/90-de...obostrut-ready

mark hinton

As for u/c to get back on thread, go with what is supplied and put in blocks at the back. These are very strong units , if drop tanks are mounted you will never see the missing doors. Also these units are strong as the Hightower of them makes for good gear. Never had a single main problem. Yes you are right about the aircraft , it flies on rails like a bandit landing is simple and with the large flaps and speed brake down , make sure you keep the power on as this induces a lot of drag.
To keep mine light I metal coated all leading and trailing edges then sprayed with alloy paint with no primer. Each panel was rubbed in different directions to give the metal look. Paint and decals from Ralle at Taylor made.
Keep pilot and cockpit light. The only thing I miss on mine is more fuel as 6.5 mins is max flight time.
Regards Mark Hinton.

HarryC

My Feedback: (1)

I agree with Mark, the supplied units are low profile for this size of retract, just not quite low enough for this wing, but as I also said earlier with the drop tanks fitted you will never see it. If I built it again I would even just mount the flap servo on the outside as per the instructions, anything in that area inboard of the tanks is so well hidden. I doubt you will get a retract that is significantly lower unless you spend a fortune.

jacksonretlaw-RCU

My Feedback: (16)

HarryC.Those Robart units look like my best option so far.Thank you for help.Also think Tams Jets might have low profile units.

HarryC

My Feedback: (1)

Walter, I finally got my scanner working today and was about to do the instruction manual for you when I remembered it is on the AD website! http://adjets.free.fr/adjetsv6GB/notices/F100.pdf

thunderceptor

I have dozens of flights logged on my AD F-100, no problem with the stainless steel pipe and P120, and I customized it with Airpower legs and AD retracts.
Model is very forgiving in flight, and very stable. I installed nose and main doors, but no way to install side doors on main legs, wing is too thin for them.



Regards

jacksonretlaw-RCU

My Feedback: (16)

Thank you HarryC for manual.