Smoky

Thanks for the update kahlog. sounds like you have done your homework. keep us posted.

david polley

Kahlog,
I would just love to find somebody that has authentic looking spinners, but have not found them. At leaset not 3 1/2 inch. I found several across the pond but they were for electrics or not available in the size I needed. What I have seen that is scale like have all been hand made in this forum....
I am looking though....
Can't wait to see how your model turned out...

David

kahloq

So I had promised pictures I believe. Ok so well.....here you'll see one of the 91's mounted with the cowl on and the gap space. Next you see one of the fuel tanks sitting next to the middle wing section to show size as well as the air retracts being used with fork oleo. Lastly, you'll see how the 18oz fuel tank fits. Its snug betewen the wood rails, but not causing pressure. Obviously I had to dremel down the support wood next to the wing tube shaft. This will be rebuilt later. Also had to dremel away some of the wood udner the retract mounting wood area. Again....reinforcements will be added once everythings installed and buttoned up.

david polley

Kahlog

Looking great....! It could end up going 130 mph or more if you wanted it to. What kind of retracts are you using again...
Keep us up to date... I am going to try real hard to get my new video up and running of my latest model. I just have to edit it a bit and get it to my friend who can convert it from DVD to Youtube.. Keep us up to date....

David

Hot Rod Todd

My Feedback: (1)

Mustang spinners look close enough for this plane, they're just a bit longer than needed to be perfect Mossy spinners.

I'd be very careful about going much over 120mph with this plane. At high speed the rudder tends to go into a flutter. I have seen videos where the rudder flutters and detaches causing a crash. Mine has twin OS .46AX's, and if I go wide open with the nose down it will go fast enough to shake the rudder.

david polley

Hot Rod Todd...

Nice photograph of your mossy in flight....

Oh gosh I wouldn't never fly at that speed even if the the rudder didn't flutter.... I fly mine now with 1/2 throttle with my new O.S. 46 FX engines with the 11 x 6 inch props. I am sure it will do 120 easily but at 1/2 throttel it crusies at about 90 or so....

I was just pointing our that with his O.S. 91 4 stroke engines he could go vertical all day and the model wouldn't even blink...if it could handle the stress which I think we all agree it wouldn't....
Nice photo Todd....

Hot Rod Todd

My Feedback: (1)

I run Master Airscrew 11X7 props on my 46AX's. At half throttle it scoots along, and does not burn through the fuel so fast. I also found that the engines are happier and don't over-rev with the higher pitch props. Full flaps are required to slow it down on landing though. That's the biggest problem I see about two .91 four strokes, even at idle those big props will have a ton of thrust!

I also have some side view photos.

kahloq

One thing needs to be mentioned here. The bigger the prop, the larger the disc area is for DRAG. On idle, the props will be more drag then thrust producers. This is another reason why Id like to use the graupner props as their blade size are fat compared to an MAS or APC.

Also....I have 800 feet of paved runway. I dont foresee any issues with being able to get it slow enough to land with that much room.

Now...if I wanted to go for full on speed(provided I beefed up the rudder and most other areas)....I could use 12x11 props and spin them pretty darn fast on those .91's. Ive done that on an old kyosho ME-109. fastest plane at the field lol.....but to land it, I had to actually cut the motor since the plane had no flaps.

kahloq

The retracts are Robart air up / spring down and using robart fork oleo's.
They are 510RS series retracts and the oleos are 3/8" robostrut w/fork

The oleos are rated at 6-12 pounds. However, I have a set of the straight version oleos in an 80" B-17 that weighs 14.8 pounds and they function fine. The next higher up would have requiored larger mains which I do already have, however, the length of the oleo would be too long and even though you can cut them down some(maybe 2" worth), they still would have been too long.
The 3/8" robostruts are the right size for this plane. If they somehow cant hold up over the long haul, I csn replace the springs to a stiffer strength.

Hot Rod Todd

My Feedback: (1)

I have the same robarts struts on mine. Only problem I have is that sometimes when you ground loop (as can happen with this plane depending on the wind) the forks tend to bend. I would like to strengthen them somehow but never seem to get around to it.

Hot Rod Todd

My Feedback: (1)

I believe my retracts are Robart 700RS, and they did not have enough spring pressure to lock down consistently against the airflow. I had to add some extra external springs to get them to lock properly. Even though the 510RS are a bit smaller, they seem to have more powerful springs (I have a set on a Zero).

kahloq

Maybe. The set of the 510RS's in my B-17...one of them has problems locking down.
I have a set of the 700RS series in a TF P-51 and both work just fine locking down regardless of airflow. I have another set of the 700rs's lying around not doing anything.

kahloq

After mounting both motors.....I can actually use 13x8x3 props instead of 12x8x3's. The added diameter will help load up the motors much better and the top rpm will actually be lower. Additonally, with the extra mass of the larger prop, it will allow for a lower idle speed due to more flywheel effect.

The only reason I can use larger props then all of you is simply cuz the propdriver of each motor is further forward relative to the fuse then anyone else's in the thread. Of coruse, this is only because my .91's are longer then anything anyone else is using.

I am also thinking of using blue foam from Home Depot(may be colored pink...depending on where you reside and have access to a hardware store) for the purpose of extending the the front of the cowls to mate up space wise with the backplates of each spinner.

Anyway...here's a photo showing both motors installed and the 13x8x3 props(MAS). The prop on the left motor(right side of picture) seems closer to the nose then the other side simply cuz I havent put in out-thrust yet

kahloq

Update.... I decided i didnt like the kits tail wheel/rudder wire setup. So I cut that piece down and its only being used for the rudder alone. Ive installed a dubro clone tail wheel assembly from Hobbyking. Both that and the linkage for the rudder are operated by the same servo(a 276oz torque Spektrum 6030), but using separate pushrods.

Still trying to figure out a way to make it possible to have access to the fuel tanks after the plane is flying. I dont like the idea of not being able to remove the tanks and inspect them, the fuel tubing, or if the clunks are still attached to the fuel tubing inside the tanks. Basically, I want the ability to do maintanence in case something down the road goes wrong.

Im also getting that ambitious bug where I am seriously contemplating making a functional bomb bay. I know i know....I should finish the plane and fly it first lol, but its January!!! Few good flying days come this time of year.

kahloq

Well....went ahead and cut the bomb doors out. Plenty of space for multiple bombs

kahloq

Forgot to mention....on the rudder, for the hinges, I opted NOT to use the supplied CA hinges and instead put in robart flat nylon hinges. This should beef it up a good amount and hopefully we wont see any flutter regardless the speed.

david polley

Dear Kahlog,

LOOKS GREAT....! Good idea on the rudder hinge.....Also a real good digital servo will serve you well in the rudder and elevator. The strength and speed of the digitals will really help getting the model off of the ground.. I am sure you already thought of that though.
Love the bombs too....! You have to be getting really excited about this now. Keep up the good work.

David

kahloq

The rudder/tail wheel are run by a 276oz of torque digital Spektrum 6030 MG servo mentioned a few posts back The elevator halves will be each operated by their own servo. Elevator servos do not require speed, but decent torque is good and I generally use metal gear servos on elevators so they dont strip.

Hans-Ole

Hi Kahlog, nice to see your bomp arrangement.

I have made something simular on my Mosquito DZ383, with a home made bomb door opener and -drop controlled by one servo.

You can see a video of the bomb release on our club site:

http://www.skive-modelflyveklub.dk/video.aspx

Mosquito "Query" DZ383 Bomb release

And here is a link to my Mossie, DZ383 on this site: http://www.rcuniverse.com/forum/m_20...tm.htm#8602903

kahloq

Thanks for your kind words.
Opening up the belly to make bomb doors and a release system ended up allowing me to place the onboard glow driver unit inside the wing, while the battery powering it will be in the nose. But with this configuration, I only have two servo extentions to hook up when affixing the wing at the field rather then having to solder up and extend a 4 wire Molex plug for the positive and neg wires that go from the unit to the motors.

Now my task is figuring out exactly how Im going to do the bomb release since I have multiple smaller bombs instead of one larger one. I have two channels available. One for the bomb doors and one to actuate a release. Additonally, since there are more then one bomb, reloading the bombs while the plane is sitting on its wheels is a factor as I do not want to have to flip the plane over every time to put bombs in, close the bomb doors and only have the doors themselves holding the bombs in the place.

Unless someone can suggest something different and hopefully can explain it, my current idea is to make a box inside the belly that also has doors on it. This box would be removable and held in place using magnets(rare earth). The doors to the box could be operated by their own servos not attached to the bomb doors to make use of the last channel and in this fashion, I could remove the box, unplug it if necessary and refill the box outside the plane. Close those doors manually, replug the servo connection and set the box back in the bay.

Thats alot of work though for 4-6 bombs(ie having 2 sets of doors) plus extra weight.

So...if anyone can come up with something else...ideas are more then welcome.

kahloq

While this wont work in the Mossie(or would be exceptionally hard to do considering the space available...you guys gotta check out the bomb bay and drop mechanism this guy has developed for an rc B1 bomber. He starts talking about it and shows it about 1/4 of the way into the video.

http://www.youtube.com/watch?v=TkumVCBj15c

kahloq

My Mossie is done more or less. Only thing left to do is make the cowl extensions with balsa. However, i did take it to the field last week to test run the engines.
Both .91 4strokes are turning the 13x8 3 blade props at 9100 or so.
A club friend of mine also built in and he put in two .36 2 strokes using 10x7 props.

He tried to taxi his and had issues keeping it from wanting to turn hard left on throttle up past 3/4 of takepff attempts. he never did get it in the air and hes been flying for 30+ years. I told him try to program in differential throttle, but he wants to wait to see how well it helps mine.
I was not able tog et it test flown that day as I had a couple issues arise. One glow plug went bad and then the right motor mount came loose when tuning the motor.

Both problems have been rectified and shes again ready to go.

Now heres the shocker......for siome reason, mine came out pretty damn heavy. it weighs 16.3 pounds. My friends only weighs 13.4 with his smaller two strokes, but no way the motors abnd onboad glow setup account for 3 pounds difference. Oh well. It'll fly Im sure....just land a little faster.

I have some pics of both planes at the field, but havenmt offloaded from cameram yet. Will do so soon.

PeterF

Thought I would drop in a few pictures of by recently completed Brian Taylor 81" Mossie that has now completed 4 flights. I have a build log on RC Scale Builder ([link=http://www.rcscalebuilder.com/forum/forum_posts.asp?TID=14905&PN=1&TPN=18]Peterf's 81" Brian Taylor Mosquito[/link]) if you want to chase down some more details but you need to register on that site even to view the forums.

The power is from 2 x RCV60SP engines running 16 x 12 props at around 5,500rpm giving a prop pitch speed of 62mph, which at 1:8 scale gives equivalent full scale of 500mph, but of course it will not reach the pitch speed but it does appear to fly in a very scale like manner. The retracts are the Unitracts set and work very well. I have a TwinSync on board after I had a failed engine on a go around with my DC-3. I was concerned about the characteristics in flight but I have settled in to it very quickly, it is very responsive and just looks great flying fast low passes with large wing overs.

There is also some video on Youtube ([link=http://youtu.be/vphQ8nWeyfI]Peterf's 81" Brian Taylor Mosquito flight[/link]) but the quality is not great as the sun was directly onto the camera viewing screen making it difficult to film but it still gives you a feel for the model in flight.

PeterF

failed to register new post

Smoky

Thanks for the update and the video, I enjoyed it.