RE: CMP BF109F BUILDING THREAD
 

Well I just got the notification from UPS, the package should arrive on the 18, cant wait. i hope I'm lucky, and there is no damage on mine, will let you guys know.

Yogi,

RE: CMP BF109F BUILDING THREAD
 

I searched the net yesterday and found two retracts that might be exceptable.The first was robarts 701, 85 degrees, 18 Lb capacity, the second was spring air 551,74 degrees,15Lb capacity. Spring air also has a set with that includes a retractable tail wheel. I'm not sure, but the 74 degree pair might be more scale. Does anyone know what the approximate retract angle is?

RE: CMP BF109F BUILDING THREAD
 

To the best of my knowledge, the 109 tail wheel retract raised vertically via it's shaft only a little bit, but didn't rotate up, nor was there an enclosed area (clear of the fuse slipstream) that the wheel was ever even partly concealed in. like the fw190. By having the wheel slightly raise, it eliminated a small degree of drag, but very little.

RE: CMP BF109F BUILDING THREAD
 

RE: CMP BF109F BUILDING THREAD
 

My computer crashed and I lost my thread in Flickr to thousands of pictures of the bf109 and all its variants. It had the words honor, glory in the title and had 1 group of pics called details of the bf109e. Any clue as to the name of the thread?

RE: CMP BF109F BUILDING THREAD
 

So far I've heard 1.60 Nitro, FG36 & G38 engines may be installed in this bird. Anyone else out there have big plans to put a gasser in one of these?
This plane is probably similar in size to the nitroplanes Texan (I think) i'll have to look and see what people are flying that plane with.

RE: CMP BF109F BUILDING THREAD
 

CMP At6 is 81" span. The 109 is the same span as the 71+-" span zero or p-51d.


The tail wheel on the 109s did retract, however many went with just locking them in the extended position.

Steve

RE: CMP BF109F BUILDING THREAD
 

Scalecraft,
Thanks for the correction, so that means that a G26 should do the trick on a plane that size?
It's just that they list the 109 as a 140 size plane, and the 70" Zero is a 120 sized plane.

RE: CMP BF109F BUILDING THREAD
 

Thanks for clearing up the question if the tailwheel retracted or not. I have seen several pictures of the BF109f with the tailwheel extended. That makes one less problem to deal with.
Has anyone done any sketching as to how the scale gear and wheel could be worked in. The mains are about 4 3/4" in diameter,
while the tailwheel is about 2 1/2 ". The gear is attached to the fuselage instead of the wing and because of the main wheel diameter
slants back quite a bit. The rails installed in the wing are not canted positive enough to position the wheel forward in front of the wing.
I plan to build a mockup of the gear area to get the mechanics working right. Anyone started a layout of the cockpit changes?
www.flickr.com/photos/farinihouseoflove/sets, has a wealth of photos to get ideas from.

RE: CMP BF109F BUILDING THREAD
 

Kinda, the tailwheels on all the Bf109's up to the F were fixed. The tailwheels on the Bf 109F were semi-retractable (the same retract system was used up to the G4 which got a redesign involving a much larger tire and wheel which lead to the tailwheel being locked down). The late model G's and early K's were semi retractable as well. Only the late K's had fully retractable tail wheels...

RE: CMP BF109F BUILDING THREAD
 

I just picked one up from nitroplanes and it looks to be most like the G2-G4 versions due to the two small side scoops added to the cowl sides forward sections.

This opens up the option of using the smaller mains with the spoke hubs or the larger mains with the flat looking hubs used on early Gs

Also, I have noticed in my many books that the latter part of the war resulted in a many modifications and attachments that would give much flexibility in what one can get away with on this airframe.

Is it me, or does the spinner shape look a bit "off". Maybe if I put the cannon detail on the spinner??

Steve

RE: CMP BF109F BUILDING THREAD
 

Hello there,

According the specs, engine size starts with 1.2 2-stroke. I happen to have a 120 AX OS. Is this a good idea, or will it be way underpowered. It turns a APC 14x10 or 15x6 according to OS specs, and delivers 3.1 HP at 9000 rpm. I just want to fly scale like (but the sound, I know). But if it's way underpowered I'll wait untill I've saved enough to buy me a bigger engine.

Thanks,

Eric Schumacher, Netherlands.

RE: CMP BF109F BUILDING THREAD
 

Seems a bit odd to be listed as having 3.1 HP and only being able to spin a 14x10 at 9000rpm's. A saito 100 4 stroke at only 1.8 HP can spin that same prop at 9000.
The specs seem more like a 4stroke since the motor's practical rpm's maxes out at 9500 when most 2 strokes run up to 14000-16000.
Of course, its not a 4stroke so Im a little confused as to why a 2 stroke 120 would not be performing any better then a 120 4stroke. OS's FS-120S III 4 stroke can spin even larger props and its only 2.1HP.
Not sure what Im missing here, but it doesnt seem right.

RE: CMP BF109F BUILDING THREAD
 

9000 RPM with a 15X6 propeller produces 12.3 pounds thrust.

The HP is 1.582

If your engine can spin a 18X6 with 9000RPM then you have 3.280 HP (I doubt it)

This engine will fly that airframe - but just fly...;) forget nice loops.

Happy landings
G-Pete

RE: CMP BF109F BUILDING THREAD
 

Just for the sake of info,, the Dave platt Bf 109G6 with a 78+- span flew very well on an OS 108 @ around 18 to 22 lbs.

Steve

RE: CMP BF109F BUILDING THREAD
 

Hi all

Pic may time out. if no pic I'll post it later

an example of the idea I used on my (our, HVACMAN) full composite 48" span Bf 109F to keep the engine from sticking out.

The model can fly on a .32 size engine, but I have an OS .46VF with rear exg with a about a 1.25" alum extension to set the engine in the oil cooler scoop.

This not only adds nose ballast, but also allows a smooth and dependable idle and more importantly makes the engine rev up slower and gives the flyer a chance to control the ground loop problems that are the biggest problem with the 109 with scale gear position.

Overheating: Since the model is way over powered, I don't have to push the engines limits to get a super fast model. Also I fly in 80 degree or less ambient temps. Fuel is 15%.

Another thing about the real 109, the oil cooler scoop was made deeper to on some models to allow for the larger oil cooler, one can modify the scoop to reflect that deeper pan and help conceal ones engine.

I have an OS 108, OS 160 and a Moki 210 that may be used in this CMP 109. Hopefully it will not vibrate to death will the cheap polyester resin fuse.


The spinner is a home made composite spinner. The concept was first shown to me by HVACMAN. At this point we make a our own spinners, props, (flying and static) vac form parts, wheels, mufflers.

working on materials for scale tires.

Steve

RE: CMP BF109F BUILDING THREAD
 

Try pics now. hope it works

RE: CMP BF109F BUILDING THREAD
 

Im sure it would because the OS 108 has a max RPM range up to 16000@ 3.0hp.
That is what is confusing about OS specs for the 120AX because it lists a max rpm of 9500. Im thinking its probably a typo on their website since 9500 would be a 4 stroke max rpm for soemthing rather large.

Shummie.....if you can, mount the 120AX to a motor stand or something secure and test run the motor with a tachometer guage(rpm meter). If you get over 12000 with a 14x10 or 15x6, your good to go.

RE: CMP BF109F BUILDING THREAD
 

hi,
any cool pix,would like see how it went.

RE: CMP BF109F BUILDING THREAD
 

I got mine on Monday, open the box, and it looks like everything is in order, did no thave the chance to get everything out yet, but so far so good. Di any of you guys put landing gear on it already? if yes what are you guys using?

RE: CMP BF109F BUILDING THREAD
 

THose RPM's are for testing purposes only, Most Engines will not turn reliably anwhere near the Max Horsepower output #'s

RE: CMP BF109F BUILDING THREAD
 

The HP number you guy’s are bouncing around are break horse power numbers. I’ve never seen it done but as I understand it they rev the Pix out of the engine while free wheeling. Then apply a break until the engine dies that gives them to measure the energy in the motor. Problem is that a 2cycle will rev a lot higher than a four stroke unloaded and that is why the numbers are so squed.

If you want accurate number here is the formula for Hp:
((RPM x RPM x RPM) x (D x D x D x D) x P)/140000000000000000

(Rpm cubed)
D=diameter
(D to the fourth power)
P= pitch

Next time out get a RPM reading and find out what your favorite engine is really putting out in Hp. Some examples of my engines:

Super Tigre GS-45 12.8k 10x8 1.2hp
Rossi40 14.5 10x6 1.3hp
Super Tigre S-90 9.6k 15x6 1.48hp
OS 1.2 4C 8.75k 15x8 1.94hp

This does not account for torque, 4c have a big advantage there that 2c will never ketch them on. The best way to remember the difference between torque and Hp is. Hp keeps your car going 75mph on the highway. Torque is what got it there.

Joe

RE: CMP BF109F BUILDING THREAD
 

Would one of you guys with the ARF in hand take an accurate measurement of the cowl ? Needing to know what can or cannot be stuffed in there without chopping too much.
Thanks in advance !!:)

RE: CMP BF109F BUILDING THREAD
 

Has anyone installed air retracts yet?

RE: CMP BF109F BUILDING THREAD
 

Does Lado makes any gears that will fit this plane?