F-22 Raptor Parkjet by Hans-Joachim

[Veloc-E-raptor]

First, this is an adaptation of the design by Hans-Joachim, which can be found in the Jet-Pushers section, along with his templates and videos, here;

http://www.rcgroups.com/forums/showthread.php?t=373397

Secondly, I am posting as I go, this is not a documentation of an already built and tested model!! So I apologise if this takes some time or does not work/fly at the end!!

Ok,

WingSpan should be 630mm,
Length (Nose to tip of rear middle bit) 825mm

AUW approx 650g (23oz)

Twin WeMoTec microfans, powered by Air Craft VL DIY kit motors, on 4S lipos (to keep current low), giving approx 160-170Watts per motor, approx 280grams thrust per fan after ducting (I hope.....???)
Servos and Rx yet to be decided on, (depending on how this works out!!).

************************************************** *****
It all worked out fine!!! (Saves having to read the whole thread!!)

http://www.rcgroups.com/gallery/showphoto.php?photo=24374&sort=1&cat=500&page=1


Thought I'd put together a few hints and tips (in hind sight) to speed a successful build (although I'm sure most of you have done all this many times before...):

Cutting out parts: a little thought into which way the 'grain' runs in the depron sheets (and marking it on the sheet for future parts) will help give the best/stiffest results eg grain/stiffest direction vertical on the tail fins, nose to tail on top/bottom keels, nose to tail on rolled parts etc.

I would suggest using tailerons, you save weight (and power) on the servos and linkages, and don't need a complex radio setup. It would be very easy to add aileron control later if you want to (just keep in mind where the servos will go).

Mark but don't cut out the tailerons (or ailerons) until you are ready to do the pivot points (ie after the reinforcing carbon tubes are in and the bottom skins etc)

Don't cut out the area where the fans go until the bottom keel is in place.
Don't cut out the area where the duct transformation pieces go until the fan mounting former is in place. ( If your household is like mine you will get fewer 'who broke this' moments.....).

I would cut the main bottom (front duct) skin from 6mm foam, then you don't have to double up the bottom front edges of the intakes, and it will take a bit more landing abuse (won't weigh much more than the 3mm skin).

Most of the 3mm parts are oversize, as in the thread the flat pieces get trial fitted, glued in place, and then the oversize edges sand/cut back to the airframe. Curved pieces are hot water shaped and then trimmed to fit in certain places (like the join between upper skin), then glued and final shaping. This should allow for slightly differing airframes....
Follow the order of fitting in the thread........

Instead of using lightweight filler/spackle to smooth the inside lip of the duct transformation pieces, you could use the method I used on the exhaust cones: make the round end slightly too small to fit over the fan (by trimming a triangular slither off the seam edges), and sand the inner surface of the foam until the fan fits with no step. This should also speed up the build.

Glueing: I started by using PU glue on everything, and a trial with UHU POR on the bottom nose skin. Unfortunately the PU doesn't stick 'very' well to the depron surface-skin (even after cleaning with alcohol etc). Sticks ok to the cut or sanded edges, or where you need the foaming properties (holding the rear/tail support carbon tubes).
The POR works OK, but only if the skin is reasonably closely moulded to shape, otherwise it is a ...... and keeps pulling away (learn't this on the bottom nose skin...)
What does work really well is ZAP 'O' and kicker spray (the type that doesn't disolve foam and that you let dry on one surface before using). This is a bit more expensive (£5 a bottle + kicker), but really bonds well to the depron surface-skin, and really speeds up the build. Alot. Very good on the outer skins too; spray kicker on the skin (let it dry) dribble a little ZAP 'O' on the appropriate bits of frame and bring the parts together. Dribble a little more frame, press down a bit more of the skin...

Try not to use tape (as a temporary gluing hold) on any joint that will show, eg wing surface, joins between skins etc You will loose the nice shiny depron surface when you peel it off, and will have to fill/smooth the surface before painting.
On a similar note, try not to sand the outer surface of the depron skin (eg joints between skins)....
Sometimes it is unavoidable..... :(

Motors: if you don't fancy winding your own AirCraft VL motors, Razor 300 look good (from what I've read same sort of power, but lighter, and on 3 cells not 4 (but slightly bigger cells), don't know if they will both run of one controller...)

************************************************** ***

Thank-you for your support.

************************************************** ***

[Veloc-E-raptor]

I have slightly changed Hans' cross-sections to give the slightly drooped nose of the F-22, and to arrange the ducting to the fans, whilst still keeping the one piece carbon spar. Hopefully the ducting losses will not be too great...
Ok, marked and cut depron yesterday, glued spar over-night.
On with the build......

[Veloc-E-raptor]

You can see the change to the nose profile.
Ok, next I've glued the bottom keel and most of the bottom formers, plenty of pins, and I've kept glue off the formers where the ducts will be cut.
Spar joint ended up being messy inspite of plenty of tape to stop the glue leaking out!
Former E needs modifying to angle it back as Hans suggested. I've cut an additional strip of foam with one edge at an angle, and glued it to the top of E. I will trim it when set.
Former I will be a repeat of former H. I needs reinforcement for the fan mounting, and H still needs a shaped hole for each duct as it transitions from square to round. These still need doing, as does a figure of 8 shape for J (somewhere near the elevator pivot...)
I think I might have been better leaving the ailerons intact at this stage, it would have given me the choice of an all flying tail.....

[RCParkflyer]

Signing on, I wouldn't miss this for the world :)

[Hans-Joachim]

Signing on, I wouldn't miss this, too ! :)

Hans-Joachim

[RCParkflyer]

If anyone is interested, I have some plans for a Single microfan F-22 Adapted from Mr. Boogie's F-35 Plans, by Dr'e.
There on my RCHomepage site http://www.parkjets.com/free-plans.html

[Dré]

The F22 plans on parkflyers site are for a singel edf40/Feigao.
Thanks again for hosting them parkflyer.
Dr'e

[Veloc-E-raptor]

Hi there Dr'e! I was looking forward to your modified nose design on the micro F-22, but this happened first..!
Don't think you got enough recognition when you first posted your bird in the F-22 design thread. Seems like everyone ignored it first time round, even when you said you had flown it!!! It took the second time (a couple of weeks later) before people showed any interest!!!
Never mind, I liked it, and have a couple of EDF 40 and Feigaos waiting!!!!

[Veloc-E-raptor]

Ok, so far things have been pretty much the same as the pusher design, now the part where it could all go horribly wrong!!!!
(Still, I could always convert it back to a pusher...???....No????.....OK....)

[Veloc-E-raptor]

On we go....

[Dré]

Hi there Dr'e! I was looking forward to your modified nose design on the micro F-22, but this happened first..!
Don't think you got enough recognition when you first posted your bird in the F-22 design thread. Seems like everyone ignored it first time round, even when you said you had flown it!!! It took the second time (a couple of weeks later) before people showed any interest!!!
Never mind, I liked it, and have a couple of EDF 40 and Feigaos waiting!!!!

Veloc-E-raptor
Thank you.Good luck on your edf convertion.Here are some updated pic's of mine and video's can be found here.
http://www.rcgroups.com/gallery/showgallery.php?cat=500&ppuser=21848
Dr'e :cool:

[Hans-Joachim]

Wow !!

Great job boys !!

:)

Hans-Joachim

[Hans-Joachim]

Hi Dré,

AUW 200g, WS 42,5cm

COOL !!

? what kind of kokams are you using ?

Greetings
Hans-Joachim

[Dré]

Hi Hans,
3S1P kokams 340's with a EDF40/feigao 5800kv
fly's great,lots of fun.
Dr'e

[Hans-Joachim]

How long can you fly with this setup?

[Dré]

Usally land after 4 to 5min with throttle management.If I'm flying all out after about 3min.Don't have a small lipo safe esc yet so I don't take chances but have allways had plenty left after landing.
Dr'e

[Hans-Joachim]

The White F-22 on the picture looks perfect !!!!!! :)

Hans-Joachim

[Dré]

The White F-22 on the picture looks perfect !!!!!! :)

Hans-Joachim

Thanks Hans.
The white one's the "updated" version.Only the nose is different.
Wasn't happy with the older(grey one) nose so I re-did the plans.
I'm really happy with how it came out.Also fixt a few mistakes I made in the first plans,mostly fitting of the parts.
Dr'e :cool:

[Veloc-E-raptor]

Not much to show for today, a good coat of 'looking at', and lots of thinking.......

**In the end, the 'spectacle' approach for the elevator pivots (last picture) was dropped**

[Veloc-E-raptor]

That last bit should read 'keep thinking to myself 'strong but light', don't know if it worked though...'
Wonder if a Rhinocerous filled with helium is strong but light.....
All work stops for the weekend now, see you all on Monday!!!!!

[RCParkflyer]

Wonderful Job your doing on those formers and ducts. When you have everything finished, can you publish the former tamplates so we can duplicate your build?

I'm just wondering how much larger we would have to make this to fit two mini-fans :)
That would be the ultimate!!!!!!!

[Veloc-E-raptor]

Would guess about 1.36 times larger!!!!

[Veloc-E-raptor]

From rectangle to offset circle.......

[Huckebein]

Looking good !!

[Veloc-E-raptor]

Quick progress report:
Now on Mk3 version of the duct change of shape. Just have to keep adjusting for the amount the depron shrinks/stretchs as I fold/curve it.....but nearly there I think....

[roccobro]

Signing on. Can't believe I've missed this much F-22 fun!!

Justin

[RCParkflyer]

Hi Ya Justin!!

You haven't missed too much yet :) You'll need a set of plans from the pusher-prop thread http://www.rcgroups.com/forums/showthread.php?t=373397

[Hans-Joachim]

.. be careful with 3mm depron!

My experiences with minifan and mega 16/15/2 on F-16C,No.2 are:
.. it snapped in :D. So I´ve used Thomas Nelsons bathroom number
and preformed 6mm depron under 60°C water.

Red hands, but it works perfect!

Greetings
Hans-Joachim

[RCParkflyer]

I have Hans Parkjet Plans printed up, only 36" long I'm afraid, not quite sure what I'm going to do about that yet, maybe just trace the plans larger on the Depron or FFF (Using a Compass) that might work. I really want a twin mini-fan jet, so I'll have to improvise a bit lol.

[roccobro]

Veloc- Are you making the inlets out of rolled 3mm depron? I have some 1mm and it is what I would use. Very light and easy to manipulate. Or some overhead projector plastic sheets. If I'm just clueless ignore this post! :D Got me thinking now...

Justin

[RCParkflyer]

The plastic sheets look like they would be easiest to use, once ya get the pattern down that is.

[Veloc-E-raptor]

Hi guys! (and any girls as well....!)
Yes, 3 mm depron is what I'm using for the duct so far. I have some 1mm and 2mm depron (well the 2mm is Depron and the 1mm is just the same material), but as the thickness goes down, relative weight goes up a little! (More 'skin', less foamy filling)
Also, at 1mm there is little strength in the duct walls (against the vacuum created by the fan), so things start collapsing, reducing duct size etc, so then you strengthen it, eg carbon tow, which adds weight........
I'm using 3mm depron. People can get it easily, overall not too heavy (ok, I retract that until this flys....!), and will add strength to this heavily loaded/thin part of the fuselage. As for forming; tape on outside of tight bends, take time to increase curvature on gentle bends and it all seems to work.
I will post some more pictures of this ducting in the near future....(have new puppy to settle in/house train etc

[Veloc-E-raptor]

A few more pictures on the (slow) progress.
(Puppy sitting has been taking all my time (and most of my sleep....!), unfortunately where I am building this aircraft is a couple of miles from where the puppy is...)

[Veloc-E-raptor]

Now you can see why I am useing the duct to help strengthen this end....
(The Force might be strong, but as for thin-section bits of depron...)

[Hans-Joachim]

... (Use the force Luke, switch off the targeting computer... I need more sleep.....)

LOL !!

You are doing a great work !!

I can´t wait to see her in the air !!

Hans-Joachim

[Veloc-E-raptor]

Sorry for more delays. I will hopefully get Thursdays to continue the build, so this will probably be a weekly slot!!!
The conversion of Steve's F14 to twin micro-EDF and 4S lipo gives me added insentive, but home life has to come first at the moment.

[RCParkflyer]

Don't feel bad, I just got back home from a 300 mile round trip to a Casino, only to loose $100.00 over the course of the day, in the slot machines. Not to mention the $30.00 in gasoline :mad: Lots of fun when you win, but most of it ends up back in the machines :sigh:

[Veloc-E-raptor]

At last, a little more building. Second duct is being glued in place, and, now that more supplies of 1/32 ply have arrived, the spectacles/elevator pivots have been started. I have allowed the option to put a rod across the ducts (with a centre bearing) if things appear to be a bit too flexible later (doesn't seem to have drastically harmed the F14......). The brass tube is being used to align the pivots as they glue, but will only be used to sleeve some carbon fibre rod at the bearing points. (Still possible to have tailerons at this point!!)

**'Spectacles' approach dropped (last picture)**

[RCParkflyer]

I'm having horrible luck making formers that are the correct size :(

[Veloc-E-raptor]

A little more done. Hopefully things will go a little faster now.....

**Spectacles approach to elevator pivots dropped**

[RCParkflyer]

Veloc-E-raptor I just wanted to tell you what a fine job your doing on the F-22!!!! I was wondering about the wiring, are you planning on running all the wiring down the center of the ducts?

Tom - Milwuakee

[Veloc-E-raptor]

Hi Tom, thanks for the compliments!
I take it that you are asking about the motor wiring. I plan on having the wires exit the back of the fans, at the inside/top of the model, and then run them forwards, on top of the wing/deck/plate, if that makes sense? Hopefully I can put all the radio gear on the top as well. This should keep the ducts nice and clean (apart from maybe having to run the elevator pivot rod across at the back.....)

[RCParkflyer]

duhhhh, I forgot about the "Top Part" LOL Do you have any drawings of the formers you made? I sure could use some.

Tom

[Veloc-E-raptor]

Hi Tom,
I have used the formers posted by Hans, and altered where they are cut to get the nose 'droop', cut out pieces where the ducts run, etc, but essentially the same formers. Unfortunately I only have paper drawings of the changed bits....

[RCParkflyer]

I just need the ones for the front and discharge side of the EDFfans, I'm having the most trouble getting the angles right, for the under the rudder area. I'd still have to size then up to the minifan size 71-72mm hole dia.

The rear end taper down of the fuse height my other problem, I'm assuming that your former templates are larger for the fan intake, than the exhaust area.

[roccobro]

I understand what your talking about Tom. Like seen here.

Justin

[Excogitate]

Looks great so far!

Can't wait for flight video ;)

eX

[Veloc-E-raptor]

Ok, I think I understand what you mean, please correct me if I'm wrong:
you are talking about the former that the fans are fixed to, and the former that I have called 'spectacles', which is at the elevator pivot point, not the nose formers?
If so, I used Hans former 'H' for the mounting plate (microfans just fit....see post 9), and the spectacles are based on 'I' and 'H' (see last photo post 19, you will see the outline of 'H'). As you can see, not much change in overall height at this stage, just shape, but I needed some strength for the elevator pivot points, and this is not very far back yet! The exhaust holes in the spectacles are still the same size as the fan inlet/outlet. I will be attaching cones directly to the back of the fans, to reduce the effective exhaust area to 85%-95% of fan swept area, which will pass through the spectacles.
It is difficult to see in your photo, but I think most of the height reduction/taper that you are looking for happens after the elevator pivot point, where the thrust vectoring happens with the triangular pointy bits (not technical, but descriptive :D ) (and there have to be some comprimises for this to work, I never claimed this would be perfectly scale :) , couldn't find any good photos of this area, more excuses etc :p ), and so far this follows Hans outlines at the rear, as near as I can tell......
Once the exhaust reduction cones are done, I was going to use a shroud to replicate the thrust vectoring and cover the fans etc (ie all the dark and triangular pointy stuff at the rear in Roccobro's 3 view), but this is still a little way off. I still need to finish the forward ducting, wind the motors, see if I can get away with 1 speed controller, test for available thrust (probably rewind the motors again.....maybe change the exhaust cones.....), decide how to run the control links to the servos, balance etc top skin....the list goes on...... :(
I don't know if thats been much help, and after all, this is a conversion of Hans design with as few changes as I can (at least, his one flys!!!), as I said at the start of this thread, I'm doing this as I go, and it might not work!! :)
Glad this has made it this far..... :D

[RCParkflyer]

If so, I used Hans former 'H' for the mounting plate (microfans just fit....see post 9), and the spectacles are based on 'I' and 'H' (see last photo post 19, you will see the outline of 'H'). As you can see, not much change in overall height at this stage, just shape, but I needed some strength for the elevator pivot points, and this is not very far back yet! The exhaust holes in the spectacles are still the same size as the fan inlet/outlet. I will be attaching cones directly to the back of the fans, to reduce the effective exhaust area to 85%-95% of fan swept area, which will pass through the spectacles.
It is difficult to see in your photo, but I think most of the height reduction/taper that you are looking for happens after the elevator pivot point, where the thrust vectoring happens with the triangular pointy bits (not technical, but descriptive ) (and there have to be some comprimises for this to work, I never claimed this would be perfectly scale , couldn't find any good photos of this area, more excuses etc ), and so far this follows Hans outlines at the rear, as near as I can tell......

Thanks for the description :) I'm hoping to increase the size of Han's plans by "Over tracing" his templates by about an inch on all sides, when I cut them out.

Hopefully that will be large enough for me to use Minifans.

I suppose I should build a smaller version first, but I've never been one to take the obvious "normal steps" easy way :eek:

IF that rear "Triangular" area ends up being large enough, I'm going to try and mount the servo's in there to control the elevons. I'm going to try and duplicate as many of the control surfaces (Alerons, flaps, leading edge slats, maybe even rudders) as I can, and add mechnical retracts too. I'll have to buy a UBC to power all of that stuff. (This will be no ordinary parkflyer LOL) But, we'll see what I "end up with". I may have to build several versions before hitting the final design. as I said at the start of this thread, I'm doing this as I go, and it might not work!!
Glad this has made it this far..... I'm VERY Happy you made it this far too :)

Tom - Milwaukee

[Veloc-E-raptor]

Lower front skin has been carefully hand moulded over the formers using a contact glue (UHU Por), and the edges bonded to the wing/deck with pu glue (loads of pins and elastic bands used to keep the edges in place....).
A few wrinkles are evident at the nose end. Probably should have cut out a little V down the middle at the front, as Hans did, but I wondered if I could do it in one, with no seams....
Still, not so bad that I want to start again!! (I think I can smooth these out, or fill them.....)
Duct sides have been trimmed to height, and the front end cut to the correct angle.
The rear end has been cut off in preparation for the spectacles to be glued. This also allows better access to the fan mating area in the duct, so the lip created by the front end of the fan can be smoothed out with light weight filler. At the same time, all mating areas/edges in the rest of the duct can be smoothed/filled, and the bottom of the transformation pieces sanded down, ready for the rest of the bottom skin/duct bottom.

[Veloc-E-raptor]

I have just noticed Tom's link to this thread in www.parkjets.com ..........the pressure to finish this is mounting!!! (Next people will be asking for kits...!!!)

[rcjetpilot]

I understand what your talking about Tom. Like seen here.

Justin

I know that picture :D

FWIW, here's a full version...
Bob

[Hans-Joachim]

Oh, what an awesome work!

For me, I have not the patience to work on a bird so long.

You are doing a very great job
and I hope the fans are
swinging like you want!!

Hans-Joachim

[Veloc-E-raptor]

RCjetpilot,
Only a single fan?.......

Hans, thanks. I would work faster by choice, (but I don't think this one will fly without the skins like yours did!!!!!!!)

[rcjetpilot]

RCjetpilot,
Only a single fan?.......


Yep, at the time I built the plane I planned on using 12 FAUP 1950's, thats a lot of weight for foam:) So I opted for a single fan. Turned out to be 52oz's so I shelved it.

I might try to fly it now on a 4s1p polyquest 3100. Its been itching me for over a year :D

Bob

[Hans-Joachim]

RCjetpilot,
Only a single fan?.......

Hans, thanks. I would work faster by choice, (but I don't think this one will fly without the skins like yours did!!!!!!!)

Fans and props have a 1 to 2 difference of power for me now.
But the sound of the fan(s) is so cool, that I wouldn´t miss this experience.

Best Luck my friend!

Hans-Joachim

[RCParkflyer]

Hi guys,

Bob, I think your Raptor will fly great with a 4S Pack Give it a whirl :)

Hans, sorry for no progress on my end yet, I'm so far behind on things, I feel like I'm going backwards :( Props will always be more efficent, at least compared to the size of fans we are using now.

Things may improve with large fans, I'd have to do some research on that (when I win the lottery LOL) but generally high voltage - Low Amps coupled with a perfectly balanced fan will get you the best results (along with good ducting).

If you can find a thread (3D Jets or something) by Joe "WireIt" he ran a wemotec microfan up to 55K rpm and it produced some amazing power for it's tiny size.

My new website is starting to take shape, but with as slow as I type it will take a while to complete LOL

Tom - Milwaukee
www.parkjets.com

[Veloc-E-raptor]

Some more pictures of progress.
Motor is wound with 5 strands of 0.3mm wire, 7.5 turns, and is drawing 8 amps on full throttle with the 4s batteries and Castle Creations 25 controller. Controller was getting very hot, even on low throttle settings. Having read the thread in the vendor section (I like all this information, what a great group this is...) with others getting similar problems, I uploaded the latest software for the controller (supposed to help with problems due to high iron losses), and switched on again. Even hotter even quicker!!!! Quickly downgraded to lowest level software available, and it seems OK now. How strange......
I have yet to measure voltage under load and thrust produced, but I think I should be getting a higher current draw (approx 11 or 12amps), so will try some different winds......

[Veloc-E-raptor]

Have measured voltage at controller under load as 15 volts (one motor at the moment...), and thrust at approx 240g with no intake lip/exhaust tube. Then tried balancing the impeller; current down to 7 amps, thrust about 250g.
Wound the other motor 7 turns, 6 strand 0.3mm. 8 to 9 amps, thrust a little higher maybe... still not the current figures I expect (this motor should give 160w input on 3S with 6 turns of 6 strand 0.3mm....)
So still a little short of my target of 280g per fan after ducting, but close, and thats with no intake lip (20%-30% maybe????).
Unfortunately the cc25 controller is still getting too hot (can't hold it after a few seconds of running), and it should really only be barely warm at these current levels, so have ordered a cc35, which is supposed to be a newer design, and not prone to this problem. We will see.
In the mean time, I have a lot of careful rubbing down of filler in the ducts to keep me busy........

[Veloc-E-raptor]

The cc35 controller has arrived, and it has made a difference; it doesn't get hot at part throttle, but the thrust and current have remained the same!!!!
So, on to the next wind, 6 turns, 7 strand 0.315mm wire. This is now drawing 11amps, and giving 265grams static thrust with no intake lip/duct or thrust tube, approx 154 watts......
This should be good enough for the moment. Hopefully this will not get reduced too much with the odd shaped intake ducts, and may be improved by rounding the intake lip....
Bottom skin of the duct is in place, and have reassembled the tail.

Then I held up an elevator.
And rechecked Hans drawings.
And tried to find as many drawings/photos of the real thing.
Should the elevators really be pivoted that far forward?????
According to the details I've found on the web, I think the pivot point should be back, near the exit tip of the thrust vectoring triangle (roughly where the white pen is in the last photo).
Really I should have noticed this much earlier.....

Hans, could you confirm where you have the pivot on your F-22 elevators??
Perhaps you moved it forward to stop the tips of the elevator breaking off in the grass?

[Veloc-E-raptor]

I suppose the question is;
do I cut off the tail end again, and re-do the elevator pivots (in the style of Tom Nelson's F-16, with two carbon tubes providing the support) in the correct (more scale) place, which would also give a better side-on profile (Tom.... :) ), but possibly introducing some extra slop and flex to the elevators (no spectacles or rod connecting across the two halves), or...

do I keep with what I've done already, which would add (IMO) extra strain to the elevator servo.....

By the way, all up weight is looking like 580-600 grams, including TP 4 cell 2100mAh battery.... (Hope the ducts work well..... :) )

[RCParkflyer]

Keep the elevators the way they are for the present time, and see how she fly's. You should be able to get away with less control throw at the least, and if I recall Hans's first flights he had to lessen the throws. 600 Grams (21oz.) is not too heavy for a twin EDF :)

She should fly good as long as you have decent thrust. If your pitch control gets too crazy, you can always re-design the #2 bird :D

She looks fantastic!!!!!!!!

Tom - Milwaukee

[beanie]

veloc-e-raptor,
i've always had the understanding that you get the least servo strain if you position the pivot at 25% of the mac of the taileron/elevator. that is what keith shaw taught me and that is what i have done on my mig-23. works well for me so far. hope that helps.
-beanie
ps. GREAT build by the way! thanks for all the documentation! best of luck

[rcjetpilot]

Hi Veloc-e-raptor,

I just reviewed the pen location, I'd really suggest "NOT" using that point for the pivot. It's a good bet that at full travel the load on the servo will be very high and stall the servo. Also, the 23-24% mac is really a better spot for the pivot. Take a look at my earlier post (cad drawing) you'll see where I marked the pivot point. Due to the clipped tail, the 24% location is further foward then one would expect.

Bob

[Hans-Joachim]

Hi Veloc-E-raptor,

yes, I moved it forward to stop the tips of the elevator breaking off in the grass. The AUW of my F-22 is 410g. My little 9g servo is doing the job for
a long time now and I haven´t got any problems till now.

You say, that your AUW will be around 600g. I think it´s not a bad idea
and you are on the saver side, when you place the pivots 1/2 inc back.

Your F-22 is looking very nice!!

.. can´t wait for the maiden flight video!!

:) Hans-Joachim

[Veloc-E-raptor]

So many replies! Thank-you all!
RCParkflyer: It is tempting to get the plane flying first, and redesign later for a mark2 (how long will that take!!!!!)
Beanie: thanks for the input from your Mig experience.
Bob: I assume the 'clipping' that you did was to take the front tip off your elevators, in line with the trailing edge of the wing, requiring your pivot point to be further back than mine.
With reference to the mac; I presume (as it is a 'complex' shape and couldn't find a calculation program that would deal with it ! ) I find the cg point of one elevator (while it is still a uniform thickness), mark out the chord at that point, measure 23%-25% back from the leading edge along that chord, and thats where the pivot line should pass through?
Hans: thanks for the confirmation on your reasons behind the positioning,and that the servo is doing ok. I'm looking forward to getting as far as the maiden!!!

It looks like I have a bit of measuring to do before I make any changes.....

[rcjetpilot]

Bob: I assume the 'clipping' that you did was to take the front tip off your elevators, in line with the trailing edge of the wing, requiring your pivot point to be further back than mine.
With reference to the mac; I presume (as it is a 'complex' shape and couldn't find a calculation program that would deal with it ! ) I find the cg point of one elevator (while it is still a uniform thickness), mark out the chord at that point, measure 23%-25% back from the leading edge along that chord, and thats where the pivot line should pass through?

Hi Veloc,

The clipping I refered to is the trailing edge, and yep the MAC location formula is a bit complicated but CAD works its magic:) If the pivot point is too far reward you end up having a situation where the deflection force (center of pressure) overtakes the servo resulting in sudden pitch up. The reverse situation is less troublesome as the deflection with simply load the servo to a point where it can't pivot anymore.

Which ever point you pick, I'd add some carbon fiber length wise (top and bottom) at the root.

Bob

Bob

[Veloc-E-raptor]

Thanks for that Bob, from your drawing it looked like the front tip.
Yes, I certainly understand the danger of the elevator 'flipping' from being pushed by the servo to pulling on it if the centre of pressure crosses the pivot line. Even if the servo is up to the job and doesn't overshoot/break gears(small servos....), any back lash in the linkage system results in a less than satisfying sudden pitch change... not nice if you are landing!!!!!!
Any comments as to whether my 'manual' (lack of suitable cad program...) approach to finding the mac on this piece will be sufficient?
I certainly agree with adding strength to the elevator to stop flutter etc. I was planning on epoxying carbon tow top and bottom after a little shaping.

[Veloc-E-raptor]

Ok, I have just found a multi-panel calculator for the mac (yippeeee!)
http://perso.wanadoo.fr/scherrer/ma...nglish/mce.html
and after working out how to use it, 25% mac puts elevator pivot about 3/4" to the rear of the current position (approx the top edge of the pen in post 60, so my gut was close!!), so Hans guess of another 1/2" was good, and we are about scale as well! Now, do I want to do the work..........

[Hans-Joachim]

Ok, I have just found a multi-panel calculator for the mac (yippeeee!)
http://perso.wanadoo.fr/scherrer/ma...nglish/mce.html
and after working out how to use it, 25% mac puts elevator pivot about 3/4" to the rear of the current position (approx the top edge of the pen in post 60, so my gut was close!!), so Hans guess of another 1/2" was good, and we are about scale as well! Now, do I want to do the work..........

Good Luck My Friend!!
I can see her in the air!!
Greetings
:) Hans-Joachim

[Hans-Joachim]

.. but :)

[Veloc-E-raptor]

Yes, I took those out after glueing the bottom skin on!!!!
Interesting picture, I can't see any diverter plates.....I'm sure they are on the '3 views', and I was thinking of putting them in....
Have a look at:
http://www.globalsecurity.org/military/systems/aircraft/f-22-pics.htm
interesting site with photos of YF-22 and F-22 (these seem to have the diverter plates.....how strange?)
(over 5000 views of this thread, I'm amazed....)

[roccobro]

(over 5000 views of this thread, I'm amazed....)

If you build it, they will come...

Justin

[Ed Waldrep]

Hans-Joachime's pic is of the F-35 full size static display airplane, not the F-22. That's why there's no diverter plates!

[Veloc-E-raptor]

That explains it!!!
Thank-you..

[Veloc-E-raptor]

F-22 woke up feeling strange....not its usual self.....something was,.....
different!

Surgery has been performed with the aid of some light 6mm 'Breeze' carbon tube (kite stuff by Avia Sport) and foaming PU glue. Seems ok so far, not quite as rigid as the spectacles, but there is still a little more structure to be added when I start the top side of things.
Centre of rear has been 'channeled' (now that I've seen photos of the underside!..would have gone a bit further back, but already had that part of the bottom skin firmly glued in place (maybe next one.....)), and the rear of the bottom skin/arrester hook area has been hot formed in water, using a pen as a moulding tool for the tight curves, and glued in place.
Side panels were fitted around the wing area, trimmed to about 1/4" over size (except where they are chamfered against the wing), then the ends treated with a hot water bath, twisted 90 degrees, and left to cool (springs back to about 45 degrees).
Rear 'arms' have had the foamed pu glue trimmed to shape, and half the thickness of the outside edge chamfered to take the side skins.
Skins glued, and sanded to size, giving a nice side profile (RCParkflyer.. :) ), and a nice looking bottom on this girl!
Have also added skin doublers at the bottom of the intakes, giving the thickness for a nice lip, and the look of the gap that diverter plates would give... :D
A little bit of sanding, and I will have to start thinking about the top of this bird......

[Veloc-E-raptor]

just to finish off.... :)

[RCParkflyer]

shes starting to look like one sexy beast :D

[bajaflyer]

I Can't Thank You Enough For The Amazing Details You Are Giving Us On Your Adventure......................wish I Had 1% Of Your Skills And Patience....................a++++++++............. ..cant Wait To See It In Air...................thanks For Letting Us All Come Along W/ You....................keep Up The Enginuity

[Omnius]

wow that's just amazing i realy love it great job keep it looking that nice.
i also wish i had a bit of your skills.

niels

[Veloc-E-raptor]

Many thanks for the comments, I'm glad its starting to shape up. I seem to be making changes to every part of this bird (sorry Hans, I did originally start out with the intention of just putting the fans into your design, but little things kept popping up, and changes made here and there.......).
I have made a start on the top, more changes...... :eek:

[Hans-Joachim]

Many thanks for the comments, I'm glad its starting to shape up. I seem to be making changes to every part of this bird (sorry Hans, I did originally start out with the intention of just putting the fans into your design, but little things kept popping up, and changes made here and there.......).
I have made a start on the top, more changes...... :eek:

:) Let´s see what you have done!

[Veloc-E-raptor]

The top is starting to take shape. Former shapes are being modified to give a more scale appearance. Extra pieces have been glued in above the inlets to allow for the shape of the down angled nose. The layering at the cockpit base looks a bit thick/heavy, but once the top skin is done, the cockpit base/support plate will have the middle cut out, allowing access for batteries, but still supporting the edge of the skin.

[Veloc-E-raptor]

a few more pictures

[RCParkflyer]

This jet is looking more magnificent all of the time :) I hope your tracing the parts for a future plans or a kit. Wonderful Wonderful stuff!!! You are really nailing down the lines of the 22 :D

[Veloc-E-raptor]

I was wondering if plans/kits might be an option. Perhaps a donation system similar to Steves F-14 plans.... I had better wait until we know this thing works!!!!

[RCParkflyer]

I'd donate my left kidney for one of these :)

[Hans-Joachim]

AWESOME WORK!!!

.. like Tom said:

" You are really nailing down the lines of the Raptor "

Great Job!!

Hans-Joachim

[Veloc-E-raptor]

More work on the upper formers (can I please stop sanding now???.....SOON....) :)
Takes a while to shape new formers to the correct profile, but it is getting there.
(Yes Tom, I am keeping a copy of the formers, which will make future ones a doddle..... As for the offer of a kidney, what blood group are you?? :D I don't know what the going rate for a kidney is these days, but I could do with the cash equivalent; I've been unemployed since before Christmas, and the funds are running very low. Of course, buying all this depron, servos, motor kits, fans, speed-controllers, tiling software (Tileprint by www.Blackflight.com , Very handy for scaling up 3-views to full size), plastic model kit etc hasn't helped, but I fancy the idea that one day people will pay me to do something that I enjoy!!! Any donations for development work gratefully appreciated!!!!!!!!!! :) )

Back on the F-22, the last photo hopefully shows the nice contours starting to develop, and how close I am getting to skinning the top.
I've also been working on the tools to do some vacuum forming, so hopefully a nice canopy will result! (When I've got the technique right and a good plug/mould :) )

[Veloc-E-raptor]

Both side of the upper formers are now in, and I have been working on the new elevator pivots.
The discarded 'spectacle' approach had the advantage that the bearing tubes could be easily aligned on a tube or rod before gluing, the new design has a bit of the tail in the way, so I had to think of a good way to get the outer bearing tubes aligned, supported and glued, without needing 3 hands etc.
As with the first (spectacles) design, I am using an outer brass tube (part of an antenna approx 3mm outside dia.), an inner close fitting brass tube to act as a bearing, and a 2.5mm carbon rod (no carbon on metal rubbing).
I first used the outer tubing to tunnel through the foam in roughly the correct alignment. I have never found this very accurate though!
To stop the tube ripping out through the thin foam under flight/mis-handling loads, I am using 1/32" ply supports at each end, drilled to a tight fit to the outer tube.
The inner support fits into a slot cut in the foam, with a little bit of PU glue squeezed into each end (so it doesn't get near the pivot hole....). The outer tube is then inserted (whilst the glue on the ends of the support is still liquid), and the inner support moved in its slot untill you get the range of adjustment needed (up and down, front and back). The tube is then carefully removed without moving the inner support (tight fit in slot), and the glue left to foam and cure.
Two small holes are drilled through the top of the foam, into the channel where the outer tube fits.
The outer tubes are cut to length to just fit through the inner support, allowing an extra 1/32" for the support on the outside, scuffed for keying, and then glued flush into the outer support (I used CA).
Whilst that lot is curing, I tackled putting the carbon pivot/support rods into the elevators. First I tunneled through using a thin steel rod with a sharp, flat end (a piece of 2mm control clevis rod that I had cut off using heavy duty wire snips). The thin, but stiff rod allows you to dig around a bit, so tunnel a little, check/correct alignment, tunnel a little more etc.
Once you are through (in the right place!) it is easy to feed the slightly larger carbon rod through, and it is correctly aligned, with no breaks in the surface of the elevator! Remove the rod, squeeze a little glue into the hole and re-insert the rod with a twisting motion to distribute the glue.
Time to go back to the pivot tubes, now that the PU on the inner supports has cured. Insert the tube/outer support assembly into the foam and into the inner support, no glue yet... Use a rod to align the bearing tube (up, down, front and back), hold in place, and apply a little foam safe CA to the back end of the outer support to tack everything in place. Check alignment is OK, and glue the rest of the outer support, and the rest (middle) of the inner support ( I again use foam safe CA for this as it wicks better than pu). Now, squeeze a little PU glue into one of those two holes made earlier, and as it foams, it will feed along the channel and out of the second hole, locking everything perfectly aligned and solidly fixed.

I hope I haven't been too long winded on this, I guess most of you have your own methods for doing the pivots, but this is one of the few areas where careful alignment and a solid fixing with no excess glue in the working bits is important!
Time for bed (1a.m. already!!)

[reusty2k5]

Veloc-E-raptor-


Outstanding work, I have been following this thread for about 2 weeks now. Maybe I missed it but could you post a paypal address so that we could make small donations to help you with your progress?

Again, excellent work and good luck with the next few stages of development.

[Veloc-E-raptor]

Veloc-E-raptor-


Outstanding work, I have been following this thread for about 2 weeks now. Maybe I missed it but could you post a paypal address so that we could make small donations to help you with your progress?

Again, excellent work and good luck with the next few stages of development.

reusty2k5, I'm glad that you are enjoying the build/development. It seems to be taking a while to complete, but I think we are nearly there. It no longer looks like a couple of flat depron sheets! A second machine would go a lot quicker, once the templates are done. (I usually shape a former for one side of the aircraft, which takes time, and then use that as a pattern for the other side, which is really quick!)
You didn't miss the address, I simply hadn't posted it! I didn't think anyone would want to consider donating, at least until we had a complete and flying machine! (And it seemed cheeky to ask in the first place :) )
Do you think I should edit some of my earlier posts (eg the first), to include my address?
Very many thanks,

[Veloc-E-raptor]

OK, no takers (well, givers actually...) so far!! (I quite understand!!)

The glue has foamed and set on the pivot points and elevator rods, and they have now been trimmed. The elevators have been shaped, and carbon tow epoxied to the upper and lower roots.
Whilst that is curing (I've used the 12 hour epoxy, as I find the 5 minute stuff doesn't seem to go off really hard), the vertical (ok, 'inclined') fins have been chamfered on the bottom edge to the appropriate angle, a notch cut out to clear the fan mount former, and glued in place.
Ailerons have been shaped, and are ready to fit with diamond tape.
I decided to do the top skin from 3 pieces, as there are some compound curves to deal with. The first piece covers the nose, from tip (which will be cut off and replaced by epp foam at some stage....) to the back of the cockpit. The next piece covers from the back of the cockpit to former 'F'. The last piece doesn't have any compound curves, so is nice and easy, and will be done last, after fitting radio etc.
The first and second pieces have been formed in hot water, and quickly (whilst still hot) held onto the fuselage to help with the shaping. After a rough trim, I've traced their outlines, which will make repeating this alot easier!
The nose piece has been glued into place, starting with the centre/profile former, followed by formers A+B together, then C, then the cockpit bracing piece and a half lap on 'D'. Finally finishing with the join along the edge of the lower skin. This was all done with foam safe CA and a long nozzle.
The second piece is trimmed and ready to fit, but I will wait until the radio etc has been positioned for correct C of G.

[RCParkflyer]

OK, no takers (well, givers actually...) so far!! (I quite understand!!) Gotta wait till payday :(

[reusty2k5]

I did what I could for ya :-)

Love the progress, very nice work!!

[roccobro]

My PP balance is negative until they give back my money (or my account gets closed). I won't forget ya when it is (hopefully) fixed.

Keep up the good work! Looks like the nose skins are nice and tight! Me likes!

Justin

[Veloc-E-raptor]

Many thanks to you all, you don't know how much this means to me.

[Veloc-E-raptor]

Today has mainly been used to sort out positions of radio/servos/batteries etc
The good news is; bare airframe, including yet-to-be attatched skins (ie no servos/RX/esc/batteries/motors/linkages/fans) comes in at 190grams (oh, and no canopy as yet).
1 motor and fan: 59 grams
Airframe, Rx, 3 HS-55 servos, 1 CC35, 2 Wemotec micro-fans, 2 Air Craft VL motors and 4 steel pushrops/clevises: 400grams
4S 2000 Kokam(no connectors): 231 grams
but 4S 2100 ThunderPower, including connectors: 200grams!
So we are on target for a 600gram aircraft, there abouts, and a wing area of about 1.25 sq.feet (not including ailerons, although I don't know how effective the wing/body will be), which gives a very acceptable wing loading of just under 17oz/sq.ft!
Even if only 1 sq.ft of the wing is effective , this still gives 21oz/sq.ft, so I think we will have a flying machine!!
The bad news is (although it is not all that bad...), the cc35 instructions say that it is only good for 3 servos at upto 12 nicads, so with 4 lipos I am starting to push things a little. The way the elevators are arranged, I will have to add some sort of mechanical lever assembly to drive them from 1 servo :( . Now the good bit, adding another servo to drive the elevators will only add another 8 grams (and will allow me to experiment with elevons and flaperons, so we are getting towards RCParkflyers goal of all control surfaces!!( Just rudders, front flaps/slats, separate ailerons/flaperons, thrust vectoring...........!!!)) The 4th servo would definitley mean using a separate bec, and so add a further 11 grams (for the Firmtronics SBEC I just happen to have sitting here!!). Changing from the steel pushrods to 1.5mm carbon ones saves me 10 grams....
Looks like the batteries will be centred just behind the cockpit (with about an inch difference between the Kokam 2000 cells and the TP 2100 cells), so I have a bit of carving to do in that area before the next bit of skin can be done.
I have again removed part of the tail!!!(Well, just part of the upper spine at the tail. Funny, that piece just keeps on getting cut out...) This time it is to become the home of the CC35. Keeps the motor leads short, and gives a good ventilated position. Hopefully it won't spoil the looks too much.
Elevator (elevon!!) servos will sit ontop of the duct transformation pieces, with the push rods running along the inside of the vertical(ish) fins.
Aileron (flaperon) servos: have thought of mounting them in/under the wing, have thought of mounting them in the bottom side walls, but they all seemed a little untidy. So I have put pushrods through the wing/deck, so the servos will be in the upper fuselage, and only the rod ends protruding underneath the wing. Seemed neater somehow....

Again, many thanks to you all for your support. I hope I am doing your contributions justice and in a professional manor.

[RCParkflyer]

Again, many thanks to you all for your support. I hope I am doing your contributions justice and in a professional manor.

Your Doing A FANTASTIC Job!!!!!

[roccobro]

There is a lighter switching ParkBEC that is 6.4 grams and is $17-18. That is pretty cheap for peace of mind, but your is even cheaper- FREE! Looking good, keep at it!

Justin