RE: CMP BF109F BUILDING THREAD
 

I'm getting a Dave Platt spinner for my cmp bf-109 and am told that the spinner backplate hole is 12mm.  How do I mount this to my os 1.60 engine which has a crankshaft size of 3/8".  Nothings easy !  Thanks

RE: CMP BF109F BUILDING THREAD
 

Circular sleeve/tube if its too big. Have it bored out to size needed with lathe if too small.

I had a Platt 109. the spinner is injection molded, so try not to nose over much.

steve

RE: CMP BF109F BUILDING THREAD
 

Scalecraft,
Thanks for the reply. What's a circular/sleeve tube? and where can I get one?,

Messer
</p>

RE: CMP BF109F BUILDING THREAD
 

I made one out of a piece of copper tubing, cut it to fit the height of the spinner back plate then slit it up n down so it expands to when placed over the engine prop shaft. I had the same issue with the os 160 and the Dave Platt spinner. Would have preferred the spinner backplate had a small center hole so you could drill it to fit instead of the large hole it comes with. Over 20 flights no issues to date.

RE: CMP BF109F BUILDING THREAD
 

Thanks Asanders for the info. Will give it a try.

RE: CMP BF109F BUILDING THREAD
 

All,
      I'm thinking about making the radiator cooling flaps stationary on the plane, since I assume they were not utilized for anything else on the original.  Has anybody utilized these in flight for any reason?  This would mean 2 less servos on the wing which would make the plane lighter.  I guess I could accomplish by gluing the hinge points and flaps together.   What do you guys think?,

                                                                                        Messer </p>

RE: CMP BF109F BUILDING THREAD
 

I made my cooling doors stationary but you still need the servo to operate the lower flap part of the radiator. This 109 has two flaps per wing. the inner which is the flap under the cooling door, then the outer flap which is next to the aileron. A couple of servos on the wing are not going to make that much of a difference with the weight. I fly my plane with a SAito 150. This plane would fly well with a 120 4 stroke. A 160 2 stroke makes this plane a rocket which is not needed. I am flying at about 4200 feet asl.

RE: CMP BF109F BUILDING THREAD
 

Asanders,
Are you saying that thelower vent flapis deployed in conjuntionwith the conventional flaps when landing on your plane? And the upper vent flap remains stationary ? Is this how they were utilized on therealAircraft?,

Messer

RE: CMP BF109F BUILDING THREAD
 

the lower flap vent is a primary flap, it works also in conjunction with the radiator vent on top. On many landings the upper vent will come downwards when the flaps are deployed for landings. This is a good video to see flaps fully deployed.

http://www.youtube.com/watch?v=HCRnQTsAPw4


This model looks awesome on landing approach with the flaps down and gear down.

RE: CMP BF109F BUILDING THREAD
 

http://www.youtube.com/watch?v=PQU0MkMjV8o

Mine flies with an OS 108. This was my test version for CMP's 109. I have still have it, but when time allows will build my second one with scale corrections.

The only improvement to this one was an aluminum back plate with original plastic spinner, and a more secure engine mount system. The gear are a complete air retracts system to add the weight of the gear.

My new one will have electric retracts and a scale 3blade prop system, ect. All flaps were connected but not used.

When i get to it someday.

Steve

RE: CMP BF109F BUILDING THREAD
 

The lower half of the radiator cooling flaps ARE used fof landing flaps along with the pair inboard of the ailerons as noted already. The top cooling half flap does not do much on the model. Its supposed to add drag to ahlp slow the plane down, but doesnt really do much good.

You WILL need all four sections of the actual landing flaps to function, especaialy if the plane weighs over 16 pounds like mine. The upper cooling flap things can be glued in place and it wont harm anything.

I did make the upper halfs functional, but by separate servos from the flaps all together and a separate switch. So I could control tbhem independent of the flap function. I never used them except as "hey look at this: on the ground.

RE: CMP BF109F BUILDING THREAD
 

Thanks for the info kahloq. Do you think that if I glued the hinge points for the upper flaps, that that would be sufficient to hold them in place?</p>

RE: CMP BF109F BUILDING THREAD
 

Asanders,
What type of plug are you using with your OS 1.60? It comes with a number 8. I'll be using an onboard glow driver also so I guess the heat rating of the plug won't matter much. I've had success with an OS A-3 (A-6) on smaller OS engines.,

Messer

RE: CMP BF109F BUILDING THREAD
 

I believe it is a #8. I have changed out that engine and put the Saito 150 in it now. The 160 is a powerful engine for this plane! I had problems getting it to idle well mounted inverted. It died on me on final. I hear the onboard glo will prevent that.

RE: CMP BF109F BUILDING THREAD
 

I used pieces of wood like match sticks and put them in the holes where the hinges would go and also glued the inner part of the flap to the wing. They have held well. This is a pic with the OS 160. I later got an inverted pitts muffler for it and got rid of the large standard muffler.

RE: CMP BF109F BUILDING THREAD
 

Asanders,
Could you tell me the weight of your plane? I'm also using the 160 for power with an 18 X 8 prop and my plane weighs in at 16lbs. Honestly, I have been disappointed in the performance. I expected the thing to be a rocket with the 160 but it flies very scale like. I'm not sure if this performance is typical with the 160 or if I'm doing something wrong. Thanks in advance for any help.

RE: CMP BF109F BUILDING THREAD
 

Just got back from the field, I will weigh it and send you the info. I used a 15x10 with my 160 and also with the saito 150. The 18x8 may be too much prop to get much out of that engine. Maybe others have had luck with that but I think that is too much for that airframe and engine combo. I use an 18x8 or 10 with my 40-50 cc gas engines.

RE: CMP BF109F BUILDING THREAD
 

Thanks for the help. The 18 X 8 is within the prop range that O.S. specifies so I figured it would work well. The 16 X 8 that I tried turns more RPM but it generates less thrust. I figured it was due to the huge spinner diameter blocking a lot of the blade surface of the smaller prop.

RE: CMP BF109F BUILDING THREAD
 

I'm using an OS 1.60 in my 83 inch span, 16.5 pound Midwest Harvard and with an APC 18x6W it is a rocket ship. Definitely not scale unless I'm throttled waaaay back! You don't say what type of prop you are using but I would suggest that if it's a Zinger or Master Airscrew they are generally better used as paint stirring sticks than as props on high performance models.

RE: CMP BF109F BUILDING THREAD
 

Yep, MAS 18 X 8 Classic Series Prop. Although, even with the reduced efficiency it shouldn't be as piss poor of a flier as it is. I'm guessing I have other problems. For more info, I'm using 15% Wildcat fuel, a #8 plug with on-board glow, and the engine is turning 8600 RPM with the 18 X 8.

RE: CMP BF109F BUILDING THREAD
 

Ok..well the reason your getting piss poor performance is the prop isnt suited for your motor...at least not at the moment. 8600rpms on an 8 pitch only gives you a MAX of 65mph. With drag factored in, your probably only seeing 55-60.

Drop down to a 17" diameter and use a 10 pitch. I did that on a 80" H9 P-51 150 size that was using an 18x8 on a saito 220 and it flew like a dog. Once the 17x10 was on it, it did much better.

Even if you get slightly less rpms..say 8400 on a 17x10.....your max speed will be 79mph. This is quite a bit of a difference.

Also, if you can get a prop with wider blades, they do better at producing thrust.

I use turnigy cherry type E props even on glow or gas motors.
take a look at this prop...its only $5 but far surpasses most other props for thrust:

http://www.hobbyking.com/hobbyking/s...propeller.html

Ive got a number of these types of props on large electrics, large glow and even a 50cc gas motor(20x10)

In comparison to an MAS, Xoar, etc, these turnigy cherry wood props put out usually 25-40% more thrust, but are also light so rpms are pretty good even with fat paddle blades.

An example.....on an electric e-flite160 motor installed in my CMP me-109......18x12 APC and an 18x12 turnigy cherry wood.......I get the same speed on the cherry wood prop at 2/3 throttle as I do on full throttle with the APC. Same as with an MAS.
I can also run a 20x10 turnigy cherry wood on that same motor for more thrust(slightly lower top speed, but longer flight time)

Give the prop a shot...its cheap, but it works wonders.

RE: CMP BF109F BUILDING THREAD
 

Thanks kahloq! I know you're always ready with good info. I'm going to start shuffling through props and will give that Turnigy a whirl. I hate that it's wood though. Probably won't last long on our bumpy grass field where warbird noseovers are a common occurence.

RE: CMP BF109F BUILDING THREAD
 

Maybe...but then again...a prop strike on grass may not break it. Since they are so inexpensive at $5ea...buy several

RE: CMP BF109F BUILDING THREAD
 

Yes indeed, quantity orders from Hobby King are a habit I have formed. :D

RE: CMP BF109F BUILDING THREAD
 

Guys,
Wondering if I can get some advise. I'm going to use an OS 1.60 2 stroke on this plane, Bisson Pitts inverted wraparound muffler. Engine was broken in on the bench using Wildcat 10% Nitro, 24 % oil, 17x10 APC prop, #8 plug. After break-in the follwing values were obtained using Wilcat 10% Nitro 18 % oil:

17x10 APC prop, Platt Spinner backplateattached (no spinner cone) 7800 rpms

18.1 X 10 APC prop, Platt backplate attached ( no spinner cone) 7200 rpms


Have not flown the plane yet. How dothese RPM values look? and which prop should I use for flight? would prefer a shorter take off run. Also,I didn't attach the spinner cone because I haven't yet received the proper screws to attach the cone toth backplate. Thanks guys. Any advice would be appreciated.,

Messer