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Old Mar 23, 2012, 12:59 PM
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McQueeney TX
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Thanks to all for the compliments gents!

I do not have a good scale, my digital just quit working, but I think my plane ready to fly with batteries (6s 5000's) all the ordinance, tanks and probes is about 8lbs. I actually prefer it a bit heavier, I can't imagine flying this thing at 5lbs or something.

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Originally Posted by Eddie P View Post
One more question, what size aluminum tubing are you using for your refueling probe and your nose probe? It's very frustrating not having a hobby shop n town anymore, I have to mail order EVERYTHING that I can't source in hardware stores. I have to mail order some K&S tubing on my next order of "whatever" I'll need. I was assuming the nose probe was about 3/16 and 1/8 diam and the refuel probe was about 5/16 inch.
The refueling probe is 3/16", all it has for extra strength is a balsa dowel in the first bit before the bend coming from under the wing. My club mates were teasing me about my improvised wind tunnel, I attached the refueling probe to the outside of my pickup truck and took it down the road at 85mph to see what it would do!

I made the end of the probe on my mini lathe out of pine.

The Pitot tube has a base of 7/32" and the 3/16" slides nicely into that for the middle bit, then it's just 4-40 wire for the end. I'll post some pictures of the detail, I made an indent into the 7/32" base so that when it is folded up it will not fall to the side, kind of locks into place. I used a small Robart style hinge, it is actually a smaller Chinese copy, I filled it with CA and kept moving it so that it would become stiff, worked really well.
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Old Mar 23, 2012, 02:06 PM
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Quote:
Originally Posted by Dionysus View Post
Thanks to all for the compliments gents!

The refueling probe is 3/16", all it has for extra strength is a balsa dowel in the first bit before the bend coming from under the wing.
The Pitot tube has a base of 7/32" and the 3/16" slides nicely into that for the middle bit, then it's just 4-40 wire for the end.
Thanks man! That is a great bit of help, I can gather some bits and pieces now. I'm like you also on weight preference with these EDF's - light is very important but if you want to fly scale the model can't be "too" light - it has to have a reasonable wing loading for grace, gust penetration and energy retention in maneuvers. And then to still have the punch, it need the total power / thrust and efflux speed to be there. I know some guys are of the opinion that "lighter flies better". Well, it DOES. But lighter doesn't fly like a FIGHTER all the time. Goldberg Gentle Lady, yes, but fighter... well... Being that 90 percent of the time the problem is too much weight rather than not enough wing loading the generalization can be randomly applied... well most of the time

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Originally Posted by 4stripes View Post
Nice Details Dionysus!
What does your plane weigh? I'm curious how much weight was added with the fiber-glassing.

Yesterday was another great day here in Southern Ontario so we flew another 10 flights on ours (16 in total). Not one technical issue so far and I can't get over how well this model flies. It flies like it is "on rails". The take off run is around 75 feet and it tracks easily down the runway centerline. On a couple landings I flared a little too much and it would just hang very nose high and settle onto the mains without any nasty wing drop. The large servoless retracts have a nice controlled movement compared to our previous air driven retracts. We flew it with the large fuel tanks and they do reduce the performance. They weigh 130g total which reduces the vertical performance (but then that is what the real aircraft would do as well). With the tanks the nose pitches forward slightly when power is added (which doesn't happen without them). It will still do loops, Immelmans etc. but they are not as large. We made our tanks removable using strong velcro in the channel which holds them well. Will post some photos when the cockpit is finished.
Cheers Eric
Cool write up, thanks for that. What's your battery, motor, ESC, fan again? I've recently read "F-100 Units of Vietnam" and it's a dry factual account mostly but has a lot of information in it. I also have "Bury me Upside Down" the story of the Sandy F-100 pilots - a much better read and a must for anyone interested in the hay day of the F-100. Anyhow one of the things that comes out right away is the F-100 was not an agile butterfly with the tanks on though it was probably the best close in support bomber, with the tanks on, of the Vietnam war. As far as heavy ACM, Huns had to pretty much be clean if they got into a squabble with anyone and wanted to even think about turning for 2 seconds with them. So your model is doing better than the real deal with the tanks
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Old Mar 23, 2012, 03:02 PM
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Canada, ON, Burlington
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Zippy 6S 30C 5800mah
Turnigy Xk4074-B-1400kv
RED BRICK 125A ESC with 5A BEC
CS 12 blade 90mm fan
Cheers Eric
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Old Mar 23, 2012, 08:55 PM
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Dionysus,

I am glad you are back and showing off your F-100 flying and all. I followed your build and bought the kit from hobby king last year when they first started carrying them. I have not built it yet but I will someday and hope that it looks and flys as well as yours.

Tom
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Old Mar 24, 2012, 12:51 AM
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i always wanted to know how they operated the pitot tube on a F-100 ..it must be a cable or something.they would stow it while taxiing in.
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Old Mar 24, 2012, 05:30 AM
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Australia, VIC, Melbourne
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Some of my latest F-100 work bits done....

First is the cut-down CS12.... as per 4stripes mentioned(was it?), cut down with a hacksaw!! lol
But I was careful and got it really accurate anyway... plus a bit of sanding off to clean it all up.
I took 6mm off the front (note the spinner coming out more on it) and the rest off the rear. This was to keep the fan mounting plates positioned where the provided stock plates are.

About 10mm of foam had to be "dremel drum sanded" out, to the rear of the stock fan area. So the fan's front lip sits right where the stock fan would sit.
The ESC is ahead of the fan and the wiring runs past the fan in the standard channel that is cut out a bit more to allow that. I want the least airflow restriction AFTER the fan as possible, for the cleanest efflux possible. Even the motor wiring (3 wires of course) have a cover to keep them three-in-line so they present the narrowest streamlined profile to the airflow.
There will be a heatsink on the motor(s) too. It is the length of the exposed can and has fins about 2.5mm off its 'base ring' so it should be negligible 'view' to the fan exit FSA.

The fan mounting blocks have an extra piece added seeing the CS12 mounts are offset more than the stock fan. I glued them on, but afterwards decided I should not have glued them and just place them in as spacers in case I change to another fan housing one day. Too late now! Oh well, no big deal.

For now I have the XK3674-1400 in the CS12, seeing I am awaiting delivery of a 40mm (and 41mm) diamond tipped holesaw so I can fit in the XK4074-1400
On 6S I am getting 2.1Kg thrust so far, but either via a better battery, or going to 7S, I should be able to get to 2.5Kg or so.
But maybe the 4074 is overkill anyway.... I will test both to see what they can each do when I have them both going.
I am seriously thinking I might even run 7S anyway, just to get some more RPM from the 1400KV's. (A few ESC's I have are 7S rated.)

Then the rear vertical mounted servos and their ply mounting plates. I would have re-mounted them that same distance AHEAD of the elevator blocks, but I had aready put them in the stock positions and run the wiring, so it was far easier to just rotate them to being vertical where they were. I guess a bit more rear end weight could be good seeing balancing out the battery is often a need to get it as rearward as you can... and now it will have a fraction more leeway to be forwards more. Hopefully the take-off and landing AoA won't drop the tail to hit the servos on the ground!! I will be adding a nylon skid on the rear end centreline in case!

The elevator pushrods are 2mm threaded end rods, and the other end needs to be braised onto the "threaded end". The nylon clevises fit the servo arm and elevator control horn perfectly with zero play. I hate having any play in any mechanics! There are enough other 'wavering' factors in model aricraft (eg servo play etc) that you don't need to be adding more yourself in any other ways. And the aileron and flap pushrods are the same method/parts.

Paint-wise, my only aim is to add the engine area discolourations and tail cone 'soot' if it seems applicable.
I will add the pitot and might make up some of Luke's nice looking bombs too!

I agree with the idea that "Most foam planes are too light" !! I pretty well always have 'things' to raise the flying weight.... usually via a larger power system (battery, motor etc).
Foamies just get 'blown around' too much and I am sure their wing loadings are almost always way under what a true scale aircraft would have. And even if that is not quite right, maybe due to a scale aircraft still dealing with "full scale air", it still seems they don't fly 'right' (lack lustre penetration and stability etc) because they are too light. So from all the reading I expect it will be too light, which could be a perfect match to running 7S instead - with the required two large batteries then. Of course you could run two 6S batteries too, for more weight.... and both cases give a bit more (??) flexibility in where to place weight in the F-100's "double storage space" up front.
.
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Old Mar 24, 2012, 09:19 AM
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Canada, ON, Burlington
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Here is a shot of our fan and ESC installation. The ESC is ahead of the fan to help keep the battery leads shorter.
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Old Mar 24, 2012, 10:46 AM
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This shows our HXT-900 rudder servo installation located just below the rudder behind the hinge line. A simple Z bend into the servo arm and the typical wheel collar/set screw pivot going through the control horn. Positive and easy to set up neutral. We use similar linkages throughout the model and all our other models. On wires that may bend, we add carbon fiber tube over top of the wire to provide the required stiffness.
The servo wire was routed under the vertical fin prior to gluing it on.

The yellow and black was spray painted and the stencils are vinyl graphics provided by Callie Graphics. They were very helpful by making the stencils from a simple photo of the plane I was trying to make. They are far superior to the markings provided in the FF kit as there is no clear material between each letter or number.
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Old Mar 24, 2012, 05:21 PM
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Quote:
Originally Posted by PeterVRC View Post
Some of my latest F-100 work bits done....

First is the cut-down CS12.... as per 4stripes mentioned(was it?), cut down with a hacksaw!! lol
But I was careful and got it really accurate anyway... plus a bit of sanding off to clean it all up.
I took 6mm off the front (note the spinner coming out more on it) and the rest off the rear. This was to keep the fan mounting plates positioned where the provided stock plates are.

About 10mm of foam had to be "dremel drum sanded" out, to the rear of the stock fan area. So the fan's front lip sits right where the stock fan would sit.
The ESC is ahead of the fan and the wiring runs past the fan in the standard channel that is cut out a bit more to allow that. I want the least airflow restriction AFTER the fan as possible, for the cleanest efflux possible. Even the motor wiring (3 wires of course) have a cover to keep them three-in-line so they present the narrowest streamlined profile to the airflow.
There will be a heatsink on the motor(s) too. It is the length of the exposed can and has fins about 2.5mm off its 'base ring' so it should be negligible 'view' to the fan exit FSA.

The fan mounting blocks have an extra piece added seeing the CS12 mounts are offset more than the stock fan. I glued them on, but afterwards decided I should not have glued them and just place them in as spacers in case I change to another fan housing one day. Too late now! Oh well, no big deal.

For now I have the XK3674-1400 in the CS12, seeing I am awaiting delivery of a 40mm (and 41mm) diamond tipped holesaw so I can fit in the XK4074-1400
On 6S I am getting 2.1Kg thrust so far, but either via a better battery, or going to 7S, I should be able to get to 2.5Kg or so.
But maybe the 4074 is overkill anyway.... I will test both to see what they can each do when I have them both going.
I am seriously thinking I might even run 7S anyway, just to get some more RPM from the 1400KV's. (A few ESC's I have are 7S rated.)

Then the rear vertical mounted servos and their ply mounting plates. I would have re-mounted them that same distance AHEAD of the elevator blocks, but I had aready put them in the stock positions and run the wiring, so it was far easier to just rotate them to being vertical where they were. I guess a bit more rear end weight could be good seeing balancing out the battery is often a need to get it as rearward as you can... and now it will have a fraction more leeway to be forwards more. Hopefully the take-off and landing AoA won't drop the tail to hit the servos on the ground!! I will be adding a nylon skid on the rear end centreline in case!

The elevator pushrods are 2mm threaded end rods, and the other end needs to be braised onto the "threaded end". The nylon clevises fit the servo arm and elevator control horn perfectly with zero play. I hate having any play in any mechanics! There are enough other 'wavering' factors in model aricraft (eg servo play etc) that you don't need to be adding more yourself in any other ways. And the aileron and flap pushrods are the same method/parts.

Paint-wise, my only aim is to add the engine area discolourations and tail cone 'soot' if it seems applicable.
I will add the pitot and might make up some of Luke's nice looking bombs too!

I agree with the idea that "Most foam planes are too light" !! I pretty well always have 'things' to raise the flying weight.... usually via a larger power system (battery, motor etc).
Foamies just get 'blown around' too much and I am sure their wing loadings are almost always way under what a true scale aircraft would have. And even if that is not quite right, maybe due to a scale aircraft still dealing with "full scale air", it still seems they don't fly 'right' (lack lustre penetration and stability etc) because they are too light. So from all the reading I expect it will be too light, which could be a perfect match to running 7S instead - with the required two large batteries then. Of course you could run two 6S batteries too, for more weight.... and both cases give a bit more (??) flexibility in where to place weight in the F-100's "double storage space" up front.
.
I rather improve and modify the foam especially those flimsy little fan formers then butchering the EDF unit, Joe.
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Old Mar 24, 2012, 07:21 PM
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LOL... it is not "butchering". It is "modifying".
It will work 100% the same whether shorter or standard.
And I would much rather leave the plane suited to still fit any fan size - seeing all others are shorter than a CS12. Plus shortening the CS12 means more motor body is outside the fan and can have a much longer, and thus far larger cooling area, heatsink then. I have heatsinks that are the exact match to the motor length I now have clearing the rear of the CS12 housing.

So I think the CS12 shortening method has a lot more benefits than modifying (butchering) the plane itself too much. hehe

The fuselage internal exit ducting looks pretty good - clean - inside, but I still think a thrust tube would be of use. I will make one up and then try it with and without one anyway.
It will be interesting to see what changes it has on static thrust, and in-flight thrust and speed.
I guess I will have to sort out my Eagletree and what sensors I have for it, or need to get. Though maybe my GPS datalogger unit is good enough for the main measurements.
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Old Mar 24, 2012, 07:27 PM
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McQueeney TX
Joined Oct 2005
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Quote:
Originally Posted by FoamieFlier View Post
Dionysus,

I am glad you are back and showing off your F-100 flying and all. I followed your build and bought the kit from hobby king last year when they first started carrying them. I have not built it yet but I will someday and hope that it looks and flys as well as yours.

Tom
Tom, get to work on that plane! You'll love it when you do fly it, anyway thanks I'm glad I inspired you! Keep us posted when you do start the build.

Quote:
i always wanted to know how they operated the pitot tube on a F-100 ..it must be a cable or something.they would stow it while taxiing in.
I could see how it would be done with a pushrod and a spring loaded hinge, but I think I'll stick with my way for now! Maybe if I build the BVM F-100!

4stripes nice work on your HUN, I like the ESC in front of the fan myself, your install looks clean.

I'm not a fan of your elevator servo install however, there is enough foam there to dig in a little deeper and keep just the servo horn on the outside of the plane. This puts the elevator pushrod right where you need it.
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Old Mar 24, 2012, 08:50 PM
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Thanks Dionysus
Perhaps the picture doesn't show it but my elevator servos are indeed recessed! I just haven't trimmed the top servo arm off yet. The servo will be covered and only the working arm exposed. We were just anxious to fly it ASAP. Finishing touches will come soon enough.
Cheers Eric
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Old Mar 24, 2012, 09:02 PM
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For those of you who are not glassing the model, the horizontal stabilizers are pretty flexible. We added flat carbon fiber strips along the trailing edge and most of the flex was eliminated. This same method stiffened up the upper vertical stab with little effort.
Cheers Eric
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Old Mar 24, 2012, 09:07 PM
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United States, TX, Grand Prairie
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Pete, have you tested thrust with the shortened CS 12 blade?

After hearing Dionsys I'm thinking of putting mine back in the F100 with the T 1400kv motor...

Should sound nice on 8s
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Old Mar 24, 2012, 10:49 PM
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The CS90 with an 8s on 1400kv (HET 700-68 for example) works out to just over 2900 watts.

Great pics of these Huns guys. Keep up the work!
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