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May 03, 2013, 10:55 AM
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Build Log

FW-190 1200mm - TopRC - Rating 9.5/10


This is a very nice model! It is the most complete, and simple, foamie to just take out of the box and put together in one hour, whilst having almost everything ready to go at a 'airworthy' level right away!!
Excellent paint work!
Well thought out design and mechanics.
So you COULD just assemble it and go and fly it, and I expect it would be totally fine to do just that! But.... as always, there are some things you can do.....

$136 from HobbyKing Aust, for the PNF plane.
It has 'extras' fitted - flaps, landing gear, lights. Plus the landing gear has sequenced inner doors! And they close up to form a perfect wing underside again!
The paint is excellent quality and it has a realistic camo 'pattern' - unlike Dynam's always cheap painting and 'odd' camo schemes that need re-painting to look right.
But you really want to WBPU it, to seal down the decals, and also add its good protective layer to the plane.

It is made for 3S (!!), but like most others of that intended design, you can change to a better ESC (50A or 60A) and run on 4S without any issue. Supposedly 3S is already adequate, but I will fly it on 3S to decide and then pretty surely go to the 4S setup.

ONE NEGATIVE.... they made the landing gear legs SHORT - like any other typical warbird, but not like a FW-190 has! It is probably no real issue, apart from the looks, but I will mod it to have the full length landing gear - after test flying it a bit first.

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Last edited by PeterVRC; Sep 11, 2014 at 05:33 PM.
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May 03, 2013, 11:24 AM
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Features


The TopRC FW-190 comes with pre-hinged elevator and rudder. They are not great hinges but will be adequate. The Ailerons are NOT hinged, they are just 'foam hinges'. The split flaps use just tape for a full length hinge, but that looks like it will be fine - especially if the plane is WBPU'ed, which would go over that tape and its edges.
The fin, which more or less just 'flows' on from the fuselage, is VERY THICK. Two or three times thicker than it really should be. That is a bit weird..... so I will think about if anything of use can be done to 'correct' it.

The whole nose 'cone' is a massive hard plastic unit!! I expect it would weigh a LOT, but that is exactly what FW-190's NEED !! Nose weight.... because they have such a short nose really.

The gear doors are well designed and have the shape to contour as per the wing, so that when closed the wing is just its completed under-side surface. Nicely done!

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Last edited by PeterVRC; May 07, 2013 at 04:04 AM.
May 04, 2013, 05:42 AM
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Battery area RE-DONE and 3S/4S


If the battery area was left much like the stock layout, the FW needed 130g of weight right at the very front of the nose cowl just to balance at 75mm CofG !!! That is ridiculous - plus they already have a piece of metal up in the cowl to aid balancing. So all in all that is a HUGE waste of dead weight!!
Time to FIX that issue !!!!

The foam moulding/layout was perfectly suited to a major mod of great use!
The 'hole' for the ESC is perfectly positioned and allows cutting out the foam above that, to form exactly what 2650/2800mAH batteries need to fit.
Then to get even more battery weight forwards, there is quite a bit of "free air" after the foam stops and untll the motor "fan" is reached. Maybe about 40mm. All of which will help a LOT when a whole battery can be moved that total amount forwards! About 70mm in total! Plus it gives quite a bit more room in the hatch area for RX/wiring stuff etc.

Stealing the ESC hole is no issue, as the ESC can then go down below in the prior battery area. So that all worked perfectly without need for any real modding there.

Ahead of the fuselage foam end point, I made a plywood "box" so that the battery area remains totally enclosed and supports the battery fully all the way. The box is shaped/rounded across the top so that it follows the nose cowl curve - which still allows the battery height to fit in easily anyway. To hold the box on 100% assured, it has a pair of 6mm CF tubes that go rearwards into the main foam fuselage.

All of this 'extra weight' of the box etc, which is approx 40g, just plays into being part of the balance solution anyway. Still almost 100g less than if it was left done as per the stock layout.

I had to cut and dremel down three of the ribs in the cowl, so they don't hit the new battery box when the cowl is slid back on, and the very front lip of the cowl comes right up to the battery box front face.
I will paint up all internal engine areas matt black.

Having the battery capable of going as far forwards as it can (right to the fan almost) will allow various batteries to be used, and also have 'variable CofG' ability by just moving the battery fore/aft.

A small plywood plate was added horizontally to the rear end of the new formed battery "channel" to make a "floor" to the rear end where there is no foam. Then velcro is used on the rear end floor of the tray, to lock down the battery's velcro.

The top cowl screw doesn't have a lug in the foam now - the foam is gone(!) - but once the lower two were done up I think that is all going to be enough to hold it all on because the cowl is a snug slide fit over the fuselage foam anyway, so that keeps it all in place totally fine anyway really.
But I will check it closer and might decide to add two screws in the top/side areas..... IF there is any unacceptable play found.

A 2800mAH 'square' form battery slides in to be flush to the cowl's rear end for correct CofG.
A typical 2650mAH 'flat/wide' form battery has some amount coming out into the stock battery area - just a bit - for correct CofG.

This mod also gives a LOT more RX/hatch area room for wiring and items now. So even having those a bit more forwards helps CofG control being easier.

The FW can now be balanced with ZERO weight added and has a bit of leeway to even go to nose heavy.
THIS is how the FW should have been laid out and produced in the first place!!
And it is more like 90% of other aircraft are actually laid out.....

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Last edited by PeterVRC; May 07, 2013 at 04:00 AM.
May 04, 2013, 09:59 PM
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Landing gear & Door sequencer


Hmmmm, something is rotten in Denmark about this sequencer......

I wired up the plane and found that they have labelled Ch5 on the Flaps, and Ch6 on the Gear. Not that anything has to be hard and fast rules, but normally it is the other way around - so I used them the other way around.....

BUT..... the landing gear sequencer is whacko !! It opens the gear doors, then the landing gear come out, and then go straight back in... and on and on in that landing gear retract cycle - the doors stay open.
Connecting the retracts direct, they worked properly. The sequencer is causing it.
I check the sequencer outputs, and tested them in reverse (one at a time, so as never to jam the gear again doors etc) and it still does not leave the gear extended.
One switch direction keeps the gear IN. The other way sends it out, in, out, in.. non-stop.
WEIRD!!!

To get things going I added a Lander sequencer, but its outputs send INVERTED signals to the door servo and retracts, so you cannot make them work in the correct order without also adding servo reversers in both outputs (doors and retracts). SHEEESH!!!
But it all works now.....
I will investigate more into the TopRC sequencer later on when I get a bit of time!
May 04, 2013, 10:04 PM
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WBPU'ed and all ready to fly!


I painted one coat of WBPU over the entire plane - plastic cowl, gear doors, and other parts etc too, so that they all have the same semi-gloss final sheen.
It is all very slick now, and WBPU not only toughens the foam but it also reduces parasitic drag measurably too.

I could not balance it out correctly - it is reasonably TAIL heavy, even though the 4S batteries are heavier than 3S !!

I see they have some lead weight at the front bottom inside of the nose cowl. So they were already trying to make the nose heavier. But it is going to need MORE!! It is 10mm tail of heavy of THEIR 75mm CofG, but many people say 65mm is best - and that would need even MORE nose weight added!
The plane is not that heavy in total so far (I still have to weigh it) so even if it needs 50g to 100g that should not matter to it.
May 07, 2013, 07:59 AM
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4S Test run and numbers


WOW!!! 4S.....
I guess most other typical 3S based 1100/1200mm planes have X amount of power - like, they are so-so in their 3S stock form.
I hear the FW-190 is 'very good' on its 3S, so that means it would have more power than those other typical 3S planes. The motor is about typical size, and typical 750kv area. The prop is a 12 x 8 x 3-blade so I guess that maybe that is where it gets its greater than typical 'power' from.

And then throw in 4S...... (I have not tried 3S at all). 700 Watts!! Others typically move to the 400's and maybe 500's Watts range.
700W and 2.0Kg thrust !!!! That is heading towards 1.5 : 1 thrust to weight ratio!! MASSIVE! (AUW approx 1.4Kg)
EXCESSIVE !!!

I have to dig out some of the 3S batteries (2200mAH for the most) I have and give those a try..... seeing 4S might be a big overkill !! Though I can fly it around at 30% throttle on 4S! LOL

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FW-190 TopRC 1200mm - Test on 4S (0 min 0 sec)
May 07, 2013, 05:42 PM
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Pre-flight tweaks


As usually done here, I sleeved all the clevises with heatshrink to 'lock; them closed so they can pop off by themselves ever. They are actually 'marginal' clevises and horns, as is typical on almost all foamies. Stiff brittle plastics - nylon is much better, but if they never encounter excess stress the plastics survive.

I also changed the wheels from the 49mm originals to 55mm versions of the same wheel. I have a box full of wheels and stuff and just found those type in there, so changed them. They still fit the wheel bays with tons of room to spare, and they still look 'right'. To me the originals looked a bit weeny!
Plus, at that small size they were going to make grass landings even worse than they will likely be anyway!

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May 07, 2013, 05:57 PM
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Flight Test


Hmmmm......
A very surprising flight morning with the FW-190.

The battery mod, getting the CofG right with no weight, was nice!!
700W.... this will be FAST !!!!
But NOPE!!!!..........

When I took off it was SLOW. I rolled out at half throttle, expecting that would still be overly fast, but it just trundled away and took off more like a Sopwith Camel Biplane! I added power as it lifted off away.... "Huh? Nothing is happening! It is not going any faster anyway!"

I left the wheels down, in case I was going to need to land again anyway, and just flew around at the slowish pace at about 70% throttle.
A run out to full throttle seemed to hardly change the speed by that much.
Compared to my Mustang and Spitfire (same sizes, and run on 4S instead of stock 3S) this is SLOW !! They blitz around at full throttle!

I landed seeing I thought maybe something was wrong, but the battery was cool and fine. So off I went again, and it of course flew much the same.
This time I put the landing gear up... and it did increase speed visibly, though not a lot. Again, the Mustang and Spitfire change speeds a BIT with gear up, but they can fly fast even with it down!

So anyway, now it was somewhat faster. Still not 'fast' by any means.
I did a full throttle vertical climb, and it was not 'indefinite' like 700W and 2.0Kg thrust suggest! So I think the prop is unloading a LOT in flight!
I will sort out my GPS logger and onboard power recorder and find out what IS actually going on in flight!

All in all, with wheels up it flew "OK". But if you compared 'fighters', the FW-190 is a DOG compared to the Mustang and Spitfire! It must have a lot of drag! That big nose..... and the THICK fin.....

For landing, wheels down at 70% throttle makes it "slow cruise" speed. And put the flaps down and you need 50% throttle just to fly almost! So the landing process was slow and easy to control.

On further flights, a few performance tests showed that it DOES go X amount faster per more throttle (as you would hope), but it looks to me that the prop can't utilise the higher RPM of 4S anyway. Either flexing or cavitating, and thus probably not a huge gain over what 3S would drive it to.
With a 'stronger' prop it would probably become that rocket on 4S !

Three flights in total. One good aspect of the FW is the sprung landing gear! The LG was still in perfect alignment after the three landings.
But there is nowhere near enough forwards rake to land on grass - it INSTANTLY noses over as soon as it touches down! Part of this issue will also be DUE to the sprung landing gear being able to flex rearwards notably at touchdown too! DOH! So even more forwards rake won't solve the problem I am sure.
For the third landing I decided to TRY to land on the "Mini Aircraft Carrier Deck" runway! 2.5m wide....
I can align it quite well on landings to do so, but it is very hard to run a plane STRAIGHT along such a narrow path! So as is common, it landed on the runway, at a slight angle, and then ran a wheel into the grass verge and then flipped over anyway! LOL (no damage or marks).

So ALL IN ALL I was NOT impressed with the plane's flight results....
On 3S it would be worse... or at best equal. It is just extremely draggy! And that prevents it flying like a fighter - the speed required by this scale.
The control surfaces a benign, even at high throw rates! Dull.... lack lustre response. And the ailerons at full throw go to huge angles! But it doesn't help. Though in a way, that max rate aileron roll is about the speed a real one could only roll at anyway, so you could say it 'enforces' scale realistic flying anyway - but there is just no leeway for if you want to have 'fun', or need more in an emergency situation!
The elevator authority is very weak.
I guess I would say that on 4S it flew JUST to scale realism, struggling to do so. And more like 'realistic for an FW that had no WEP ability'.... so it is not quite enough speed to be 'right'.
The 4S mainly just makes it "pull" around like a diesel locomotive... huge torque, but no speed. (or speed gain)
Maybe another prop type can cure that. Maybe an FMS 1400mm Zero or Spitfire prop.....

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Last edited by PeterVRC; May 07, 2013 at 06:24 PM.
May 28, 2013, 09:35 AM
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Landing Gear modding to 'proper' scale


I set up the FW on some 'blocks' to test what extra length the legs would need.
I decided on 40mm.
So I extended the current mount shape out a further 50mm - this is so that a plywood mounting plate could be made and have 10mm extra to go around the outer end of the retract.

Some foam hacking to seat the mounting plate into, and the retract body being now further outwards (by that 40mm).
The mounting plate is bascially a "long square U" and I used captive nuts in the wood so that the retracts are bolted in with 3mmx6mm countersunk screws. Thus no wood stripping with self tappers etc!!

Once the retract all fits in perfectly and lengths and angles etc are tested to be ok, the mounting plate is glued in.
I used GorillaGlue for the first time ever - after having some for over one year and never bothering to try it out!
I use epoxy for everything almost... and some CA here or there.
I had read the instructions, and read other people's used of it.... but it seems I forgot some of it!!

I glued the mounts in with the retract still in them! Oooops!
The expanding GG oozed out everywhere! I knew it expanded, but I half forgot... and as I watched it I thought "maybe it only epands in some cases?" - but 15mins(?) later it was oozing out everywhere!
"Get the retracts out!! And put screws in the captive nut holes!"
So 20mins of retracts cleaning later....... I will try to REMEMBER the expansion in future!

The GG is so messy, and unlikely to be any better than epoxy....so I might just stick to epoxy in future anyway!

The 110mm oleo has about 40mm of pin, with 20mm approx exposed from retract to oleo. I put a kink of a few degrees (4deg?) into that, so the legs have more forwards rake - and I made the wheel wells larger to the front direction, to take the further forwards wheel. I will match up wheel covers and doors etc at some stage later on. The small extra rake will hopefully be a useful total amount of Millimetres ahead by the end of those long legs! (15mm to 20mm on the wheel/ground point?)

I had changed the retracts to the PZ alloy trunion 4mm pin versions, and drilled the FlyFly oleos to take that 4mm pin (they were about 3.5mm before).
I also think that those FlyFly oleos have springs that are too strong - even for a 90mm 3Kg EDF jet!! They won't "absorb" a 1200mm 1.8Kg warbirds landing energy at the correct level really, so they need some modding to give them a lot less spring resistance. When too strong you get more bounce than energy absorption, and that means very easy to get a whole aircraft bounce on landing!!

Tomorrow I will solder female servo plugs onto the retract leads that I had just cut half way approx - this is so I can change a retract easily in the future, if ever required.

I cleaned up and sanded all the GorillaGlue excess, and after a bit of 'retract pin bending' I got the new legs all aligned and equal.
The FlyFly oleos are pretty lousy! They can't really slide in and out well, they are just poorly machined and set up. I will have to get some better quality ones, otherwise there will be no suspension action at all !

The wheels are 20mm or so more forwards than stock when they are in the wheel bays.
They should be the same amount more forwards on the ground too.
The extra length looks good and about right for scale.

Now I have to work out how to modify the leg fairings and wing bays to have that all back together too....

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Last edited by PeterVRC; May 30, 2013 at 06:24 AM.
Jul 04, 2013, 05:28 AM
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NEW oleos and wheels - set #2


Seeing the FlyFly oleos are really poor machining, and thus operate poorly too, I decided to find a 'good' set to fit. I have quite a lot of the various HobbyKing high quality oleos, and the best choice from what I have was the 110mm straight ones.
BUT they have a 130mm size which is the EXACT length I really needed.

https://www.hobbyking.com/hobbyking/s...Class_2pc.html

If you use 130mm then the oleo will butt up right against the retract trunion.... and you really want at least SOME retract pin in the "open" to allow for bending it to get the legs to suit the plane best. So I would really choose the 123mm version - which I also did not have.
https://www.hobbyking.com/hobbyking/s...Class_1pc.html

I have bent the 4mm retract pins to align the legs as required, and used a medium soft plastic tube as a 15mm spacer from trunion to oleo. This is mainly so that whenever the leg is put back into the trunion (after any work, alignment etc) that it will stop the pin at the exact point required 'automagically'. No need to check lengths etc.
I really want to make an alloy tube 'oleo extension cover' to make the legs all larger diameter at their top ends too - to look better than 'thinner pins'. Plus I need to make the fairings to suit the longer legs....

Because the legs do not go perfectly Vertical (looking front on) - which was a fluke of the installation, but the real FW-190's don't go dead vertical either(!) - I bent the wheel axles to make up the rest of the angle required so that the wheels ARE vertical to the ground.

For wheels I used ones I had taken off a Durafly 1100mm P-51, which are the same diameter as the ones I had used before (55mm?) but have decent plastic hubs, and pretty decent rubber tires.

I will investigate making leg fairings from DVD case plastic (softish black plastic) eventually.

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Last edited by PeterVRC; Jul 17, 2013 at 09:19 PM.
Jul 04, 2013, 05:32 AM
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Fin Thinning


I decided the trim, thin and sand down the fin to be streamlined - instead of the "Flat Faced WALL" it comes as in stock form!
WHO came up with that ludicrous design - being so thick!

I bevelled the leading edge to a point, and also narrowed down the rear end so it blends into the rudder. I left the main fin mid section the same thickness as it was. I was going to thin it all, but it was going to be too hard - for little use anyway.

I will test fly it as it is (raw) and then fill and paint it at a later time.
By then I might even thin it all a lot more anyway......

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Aug 26, 2013, 06:07 AM
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Tail end fracture


After all the nose-over flips I guess it built up the stresses over time and finally fractured the tail end just ahead of the tailplane. It fractured to one side so that shows many of the flips put sideways load onto the fin when it occurred.

I repaired it with epoxy and inserted some epoxy coated 3mm skewers to make it stronger.

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Aug 26, 2013, 06:22 AM
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Fin Mod - Balsa


I had sanded the stock fuselage FAT fin some amount, but EPO is very 'flakey' when sanded and to go down to the size I wanted to go to would mean it would be very thin and weak so then any nose-over flips would be a worry for it!
Thus I decided to replace the fin with a balsa wood fin.

The aim was to have a more realistic fin, but it still had to have the rear end to match the stock Rudder. After a bit of investigating and measuring, I decided that it could all be done to look good whilst still matching that little bit too thick Rudder.

To match that I needed almost 20mm thickness at the widest parts. I had some 6.5mm balsa wood sheet so I used three layers of that sandwiched together.
A bit of shaping and sanding..... and then a FAT slot made into the fuselage where the stock fin had been cut off.
I made it go right down to the elevator so that it had good support from the remaining fuselage sides, and a solid base under it.

I used Gorilla Glue to fit it because that stuff is pretty much equal to Epoxy BUT it expands to totally fill 'rough' areas. So you don't need gallons, like with epoxy, and it expands to fill all voids up, to form a solid and rigid joint. It has its places to use, instead of epoxy... and this is a typical one of those!

Three Robart style pinned hinges to re-do the Rudder hinging..... and all was done....

Another factor that delayed me doing this was the need to get a few colours matched to repaint the FW ! But I will get matched acrylic sample pots ($7 each for 500ml) and do it all properly matched/finished in the near future.

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Last edited by PeterVRC; Nov 17, 2015 at 07:31 AM.
May 06, 2015, 07:37 PM
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FPV setup


It has been a long time since I did stuff on the FW-190, but the FPV addition was a long time ago too! It stalled a bit before completion.... (due to other planes).

I cut a large 'cockpit' area open and made a plywood frame for that, so the foam had something else to make that base stronger. The hatch was made large so that I can get full internal access to all the space the fuselage has. It has a LOT of space in there in total!
It is also made modular so that the pilot & seat can be put back instead of the FPV equipment.

I used a Pan & Tilt unit, seeing that can fit fine in there and that is way better for great all round vision. But I might not use the stock Canopy, due to the loss of visual quality it causes. In that case it would have a 'fake frame' used - the frames with no 'glass' - so that it still looks 'right' from a LOS view and clear vision for FPV view.

The FPV setup is the same common setup I use across many/most planes.
The Surveilzone Sony HAD2 CCD mini camera and 200mW VTX, with a simple Hobbyking OSD to show Flight Battery Voltage and a Timer in the FPV display.

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Last edited by PeterVRC; Nov 17, 2015 at 07:28 AM.


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