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Caelus New F3A design by Top RC Model

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Caelus New F3A design by Top RC Model

Old 09-01-2021, 07:49 AM
  #501  
mgosson
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The first photo was the original location of the battery pack, after repairing the landing I ended up moving the tray and esc back.
As you have figured out the rudder servo is designed to be installed in the fuse.





Old 09-01-2021, 11:32 AM
  #502  
husafreak
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Thanks, everything on mine is well forward of your early set up. So something is different. But Iíll put the CG where it needs to beÖ
Old 09-01-2021, 05:10 PM
  #503  
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I got the Roaring Top 4300 35C packs today. 500g each, really light. My old Gator 5200 packs are 620g. So two pics here, With the light batteries and positioned as shown and everything else as far forward as possible this gives me a CG 225mm back, thatís about 20mm behind the spar tube rear face. In comparison is the Gator pack location for the same CG. So it looks like if you have very light packs and prefer a forward CG you might need nose weight. Iíll fly then decide. I will add some structure and Velcro up front to actually mount everything and reinforce the battery tray so that will help a bit.

1240g battery

1000g battery
Old 09-01-2021, 05:18 PM
  #504  
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Also I have a question about the stab mounting. With the design it looks like the stabs could be individually adjustable but with a screw into the spar tube on each side that is not so. Getting those holes drilled through the CF tube even slightly off would be a disaster! Do you recommend adjusting each stab with an incidence meter, eyeballing the results, and then drilling the holes? Or is there a better (safer) way?
Old 09-01-2021, 06:08 PM
  #505  
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On the early models I thought the stabs were adjustable, but latter versions omitted that option. This is from memory of a few years ago.

Normally the stabs would set at zero with the wings at .5 degrees. Keep in mind once you trim the elevator halves you will adjust the stabs to keep the everything even.

I would set the stabs by eye and use a digital meter to set the wings and T Can.

Also, make certain you replace the wood dowel in the CF tube. The supplied dowel is usually too short and is crappy wood.
Old 09-01-2021, 09:03 PM
  #506  
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My version has a cf rod maybe 3mm through the fuselage, each stab has grub screws above and below that rod, so I thought you can adjust the incidence of the stabs by adjusting those up or down. Now you have me thinking those are only to retain the stabs? Iíll have to have another look at that tomorrow. Each stab has a pre drilled hole out at the end of the stab spar tube on the underside. I figured that was for a screw through the stab into the tube to retain the stabs. Yes I intend to have the stabs at 0 so any adjusting is just to make it that. Iíll call Mike. You are right about the wood inserts, mine fell out even covered with glue.
Old 09-03-2021, 07:23 AM
  #507  
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Originally Posted by husafreak View Post
I'm fishing for comments here. But I am puzzled why my Caelus is so tail heavy?
The tailwheel wire is at least twice the diameter needed and there is no need for that huge spring.
The tailwheel looks too big as well.
Replace the wire with smaller diameter and make the wire come straight down then angle back.
The rest of the bracket shape etc is good......if the bracket is steel....replace it with aluminum.
There was a huge steel bolt in the tail used for the stab incidence....hopefully that has been removed.

Old 09-03-2021, 09:13 PM
  #508  
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Hmmm, the tail wheel from the kit seems pretty light and small to me but if I need to move the CG forward I could get aluminum turnbuckles and try to lighten the linkage. Thanks to you and Mike I understand how the stabs are held, itís not complicated but it is different than the original. Iíll add some pics. Iíll have to admit to a lot of Hysol in the tail which was required because the hinge holes were completely ridiculous and after opening them up I was more concerned with a safe linkage than sparing glue. Plus I glued a modest plywood plate in the tail for a rear mount rudder servo which Iím no longer using.
And who knows (not me I havenít flown the complex F3A patterns in many years) but 1000g batteries may not be adequate?
Built as intended with an 1100g battery on the tray it would be close to perfect average CG. Somehow I convinced myself it would trend nose heavy and built accordingly, not so!

Servo installation

Slot for adjusting stab

Screw into spar tube

Grub screw adjusters top and bottom

Spar tube and 3mm rod
Old 09-04-2021, 03:14 PM
  #509  
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In the end you have done the correct methods to complete the airframe. If you are flying Sportsman, Intermediate or Advanced class a set of (2) 5S 4300 - 4500 25-30C lipos will complete the entire schedule. Early on I used 5S, 4400 Thunder Power , 25C rating. These weighed in at 520 grams = 1,040 in total, plenty of power to spare.

Changing from stainless to aluminum turnbuckles will gain you nothing in the end, the rods are too short to make any difference.

Keep the questions coming

Mike
Old 09-04-2021, 06:45 PM
  #510  
husafreak
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Thanks for the positive rienforcement Mike! I'm getting excited to fly this plane.
Old 09-05-2021, 06:39 AM
  #511  
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Originally Posted by husafreak View Post
Hmmm, the tail wheel from the kit seems pretty light and small to me
I was referring to the tail wheel WIRE....not the wheel.
The wheel looks to be light enough.
More than likely....you will have to find several things on the tail that need to be removed or replaced with something lighter.
As an example.....on your pix of the stab....it looks like there is a 'plate' on the root of the airfoil next to the fuselage.
Is it wood or what?
Perhaps you could remove it from both stabs. If you want something to take up the gap...I have used 1/8 light foam from Hobby Lobby.
It is very light and you can use 3m 77 contact glue to hold it in place.
There is no picture of the prop.....you can use a APC prop....they weigh a lot more than most others.
You can move the rudder servo and mounting plate forward to just behind the wing incidence adjusters.
Old 09-05-2021, 06:56 AM
  #512  
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The blue ďplateĒ on the stabs is thin factory applied foam. This is on the wings as well, a nice touch on this kit. I agree that the spring coil on the tail wheel is probably not necessary. Prop is a Falcon 20x13 and they are very light. I imagine a Tru Turn spinner would be heavier than the Gator (or a Falcon) spinner too.
Old 10-06-2021, 02:50 PM
  #513  
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Default Caelus PDF manual?

Does anyone have the Caelus PDF manual they could share?
Seems no longer to be found on the TopRCModel website.
Can't seem to find the manual anywhere and I just bought an unbuilt kit.

Thanks
Old 10-31-2021, 09:03 AM
  #514  
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I finally got mine airborne with multiple, "just for fun" flights" last Thursday and a half dozen trim flights yesterday.

Thursdays session was cut short when the tail wheel "tiller" wire was lost. Prior to that I was having issues taxiing due to it flexing allowing the tail wheel to not follow the rudder. Back in the shop I drilled out the collar to accept a piece of approx. 1.5mm music wire and the repair worked fine yesterday with solid control.

Of course now I have trimming or rather set up questions which may be better answered in another pattern related thread but I'll try here first.
I set mine up with +0.5 degrees on the wings and T-can. But my T-can is not true so I get +0.5 on one side and +1.0 on the other. My ailerons are also both warped. I started with the CG 1/2" behind the spar tube and found this too far forward, I'm about 1" back now or 225mm as someone else had settled on. This produces a gentle drop of the nose inverted or using the 45 degree climb method. I have been flying IMAC and 3D planes for so long I am not sure how a pattern plane should feel.
But even this far back the plane trims out with about 1 mm of up elevator deflection, after mixing in down elevator with throttle off for vertical down lines that position (throttle off) is exactly centered or elevators matched to stab. So I don't think my incidences are correct if it flies level with 1mm up elevator but I'm not sure what to change. The thrust line appears to be good, the spinner is perfectly matched to the fuselage and there is no pitch with power. In K/E mixing there is almost no roll coupling but there is a strong pull to the canopy in both directions. I mixed in quite a lot of down elevator in both directions but it its getting to the point where I'm afraid it will cause unwanted interactions in rolling manuevers? Interestingly, moving the CG back 1/2" did not affect elevator trim for level flight or noticeably affect the K/E pull.
I did end up with a tiny bit of aileron trim, probably due to them being warped and the giant T-can not being true. Or it could be a normal anti torque requirement? Not much I can do about that.
Any advice or observations would be welcome!


Old 11-01-2021, 06:42 AM
  #515  
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Pulls to the canopy on knife edge because you're carrying up trim on the elevator. Try moving the c/g back even more..1/4 inch at a time. If it starts to wander, put the c/g foward a bit and try adding more positive wing incidence.

Last edited by big_G; 11-01-2021 at 06:46 AM.
Old 11-01-2021, 07:38 AM
  #516  
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OK thank you, I'll let you know how it goes.
Old 11-01-2021, 06:10 PM
  #517  
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I put a Castle ICE2 HV120 in my Caelus. I'm not sure if the brake function (type and strength) can be used to create drag on downlines. I set mine to 20% initially but it accelerates rapidly on downlines. The manual is no help and if I call them who knows who I'll get to talk to. So I'm wondering about that. I had Jeti Mezon before on another pattern plane and with that it was a little clearer on how to apply the braking function.
Old 11-02-2021, 06:26 AM
  #518  
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Originally Posted by husafreak View Post
OK thank you, I'll let you know how it goes.
In addition to what Big G mentioned.....
Considering that the T-Can is warped/crooked I would remove it and try to trim the airplane even with the crooked ailerons.
At least this way the T-Can is not complicating the trim exercise.
Try to straighten the T-Can on a flat plate....off the airplane.
Hopefully each aileron is warped the opposite direction...if so try to split the difference with them.
I would fly it without the T-Can first before you make any additional c/g changes then continue with Brian Heberts Triangle Trimming procedure.
Speed is also a consideration....trim test at your normal pattern speed not full power or too slow.
The faster it goes the worse it gets.
Old 11-02-2021, 06:31 AM
  #519  
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Originally Posted by husafreak View Post
I put a Castle ICE2 HV120 in my Caelus. I'm not sure if the brake function (type and strength) can be used to create drag on downlines. I set mine to 20% initially but it accelerates rapidly on downlines.
I beat my head against the wall for over a year with those Castle ESC. They are just not good for Pattern where the brake function is needed.
Stop fighting it....get something else.
I like the OS and Futaba ESC....no drama and the brake is very effective.....and they don't burn up.
I have 4 of them, one of them has about 1200 flights on it....the other 3 have several hundred each.
Old 11-02-2021, 07:34 AM
  #520  
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Thanks for your advice DH. Iíll look into the ESCís you mentioned. Better to just move on in cases like this!
Iíll fly it without the Tcan today and see if it changes the roll trim. Itís a funny warp, Not really a warp, thereís no twist, rather a change in incidence at the root. Iím not certain about my Hangar 9 Angle meter accuracy and the fuselage ďwater lineĒ below the canopy edge is not ruler flat either.
Iíll remove the Tcan, move the CG back to neutral then forward again, and trim the wing incidence to get the elevator and ailerons (as close to balanced as possible) centered and then put the Tcan back on.
I did try to straighten the ailerons but they split along the trailing edge. Iíll just try to balance everything out.
Good point about trimming at constant speed. I realized pretty quickly that I am not doing a good job at that! Constant speed, radii, angles, timing. Itís been so long since I really tried hard, LOL.
Old 11-02-2021, 09:03 AM
  #521  
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I'm not finding the Futaba or OS ESC in stock anywhere, I'll keep looking, but am assuming it is the Futaba MC 9100A ESC? And that the OS is similar? If I find one I assume I will also need a programmer for it... If anyone knows a reliable source I am not opposed to ordering from overseas or placing an order with a company that will be able to get them when they are available. I did notice that the local pattern flyers are using Futaba ESC's. But I've never seen one outside of a pattern plane.
Old 11-02-2021, 03:48 PM
  #522  
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Did a dozen 4 minute trim flights today. This plane is blowing my mind! Or maybe all pattern planes are like this. But Since getting her airborne last Thursday I have moved my batteries back 3"! Now I'm moving the Rx packs back. I still have not got it back to a neutral CG point, the nose still drops when inverted. But it is getting a little loose feeling so I am not anxious to go back any farther. I also increased the wing incidence a bit, 1 1/2 turns on the wing adjuster bolts up from the measured 5 degrees. I'll have to take some measurements later. But the weird thing is how little the trim or feel of the plane has changed.
I found removing the Tcan to have no effect on pitch or aileron trim.
I was able to remove mostl of the down elevator trim by moving the CG way back and increasing the wing incidence slightly, but there is still a tiny bit. So I went from 1mm of up trim to 0.3mm. Not much difference!
The aileron trim has not changed through all of this. I may try adjusting the wing incidence independently to remove it. But as is it doesn't roll unless I tell it too.
It still pulls to the canopy in K/E. Not as bad now but still having to correct it with down elevator, even with a mix. Here I have to learn more about my radio though. I have a relatively new Powerbox CORE Tx. I spent a lot of time with it today on the rudder to elevator mix curve but it is not right. Basically the Caelus needs very little rudder in K/E, so I need the down elevator mix to come in with the first bit of stick travel and then stop increasing. I think the curves are based on full travel not the actual reduced rates. My problem to solve.
Do most pattern planes use aileron differential?
Another thing I need to learn is how much travel is necessary. I have my low rates at 50% on aileron an elevator and even less on rudder. So I'm losing a lot of precision there. I won't know how much high rates I need until I start flying really demanding pattern maneuvers I guess. One quick question for you all is should I be able to get a crisp snap roll on low rates? As is is now I cannot, there is not enough elevator authority. But on medium rates I get a nice snap with the pitch noticeable to start.
I'll look at "triangle trimming" too. But so far I'm changing lots of stuff and Caelus just goes about its business largely unfazed, LOL.


Old 11-02-2021, 04:00 PM
  #523  
husafreak
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Oh, I spoke to someone at Futaba USA Today. They told me the MC9100A 100A ESC which listed for 219.99 has been discontinued. Its replacement is the MC9130 which is a 130A beast and retails for 359.99. It is not available yet. Who knows wether this ESC will have the same F3A friendly properties as the MC9100? It looks a lot like my big Hobbywing Platinum 160 ESC in my 800 size heli.
Old 11-03-2021, 04:37 AM
  #524  
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I use the Jeti Spin 99 you can get through F3A unlimited. It is a very good ESC,but does require Jeti programmer
F3A Unlimited Jeti Spin Pro 99 (with braking) JSP-99-O -F3A Aircraft
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Old 11-03-2021, 04:40 AM
  #525  
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They all pull to the canopy, threres really nothing to do put mix it out, I had one that I flew for 4 years, its a nice plane but does have some bad tendencies.
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