RE: CMP BF109F BUILDING THREAD
 

I wonder if you ever fly in warbird fly-ins? Those are AMA events. (generally) We have a very large one here at our home field. I can promise you, if I were doing tech/safety inspections for our event, those terminations would not be allowed (other than a throttle). If someone were to lose control and put there aircraft into the crowd of spectators, it could be tragic.
It is too bad these things are even included with many of the ARF's, as they become acceptable. Just another part of the hardware package that belong in the trash.
My serious attitude comes from a desire to not destroy expensive aircraft and not pass on bad information, and nothing to do with my involvement in competition. The AMA rule book sets a standard. Just like the FAA on full scale aircraft. They have standards as well when it comes to control surface terminations. Something I am sure you welcome the next to you take to the skies.

RE: CMP BF109F BUILDING THREAD
 

BQuartucy, keep in mind the tailwheel does not fully retract. Half of tha tailwheel should be exposed when it is fully retracted. I can't quite tell in the photos you posted if it works that way...

Here is what it should look like fully retracted, damn the picture went away. Give me some time to get it back.

Here try this one:

http://www.flight1.com/images/bf109f/bf109fr4.jpg

RE: CMP BF109F BUILDING THREAD
 

Gentlemen

As we post info and opinions, (which I appreciate) it is up to the modeler to draw his own conclusion as best he can as to what he thinks is reasonable for the application at hand.

No one is saying you can't do it, its just a "heads up". You don't have to do it.

All parts can fail. Some more easily than others. Regular inspections can minimize failure. Not eliminate it, but minimize.

I have been using EZ connector for 20+ years and have not had one fail. What does that mean?? Nothing really, just lucky maybe.

Steve

RE: CMP BF109F BUILDING THREAD
 

Snappa,
Yes it's all brass tubing, music wire, brass sheet, bondo and silver solder.
Not shown was the servo mounted forward on a plywood plate.
The attached sketch gives you some idea of how it works. the original was done in full scale. So if you have the capability you can blow it up on the screen and get some idea of the sizes. Also the grid is 1/4 ".

Evil Merlin.
Thanks for the photo, I have the tail wheel on a separate channel slaved to the retract channel and haven't set the limits yet. I'll set them when the tail wheel cover is installed.

Bob Q.

RE: CMP BF109F BUILDING THREAD
 

Excellent Bob, I'm looking forward to seeing the completed airframe and retracts.

RE: CMP BF109F BUILDING THREAD
 

Evil,
Thanks, but it may be a while. I am bared from the house and the garage is colder than a well diggers butt now.
Bob Q.

RE: CMP BF109F BUILDING THREAD
 

vertical grimmace will you just let it go? you are distracting everyone from the thread with your constant whinging about the connectors you have made your point

RE: CMP BF109F BUILDING THREAD
 

Snappa,
Here's a thought, you might be able to put the control rod in without taking the elevators off.
1. The control rod goes in the holes where the inboard hinges are (were) installed. If you look closely at the pics you can see this.
2. You can cut thru the hinge and pull out the hinge half in the elevator and grind off the half in the stabilizer.
3. Only do this if you can deflect the elevator far enough to put in the leg portion of the L shaped rod with the thru the holes aft of the stab in the fuselage. This will probably reqire that the leg is fairly
short say 1/2" or so. If I were doing this, to be on the safe side I would insert a piece of brass tubing 1" long super glued in place to spread the load out.
4. Before you put on the control arm attach the 4-40 connector to it so all thats left is to thread the push rod to the connector.
5. When the rod is in the fuselage put the control arm on and continue to push the rod thru and out the other side.
6. After one elevator is attached, bend the second leg so it lines up both elevator halves.
7. I would then put several drops of superglue to bond the rod to the tube. Then fill in with epoxy MAKING SURE THAT THE ELEVATOR HINGES LINE UP.........
If up have any questions feel free to ask.
Bob Q.

RE: CMP BF109F BUILDING THREAD
 

Hello guys,

Here the pictures of the control rods wich I used. I replaced the kit ones with carbon rods. They don't flex at all. The elevator is driven by the Y setup. Only I replaced the steel Y with carbon ones. For the connection I used the metal rods and the supplied connectors. This was glued in the carbon rods, and strengthened with glas-fibre and epoxy.
The tail wheel was replaced with an earlier on this forum advised Hobbycity one.
I hope the provides pictures makes all this clearer.

RE: CMP BF109F BUILDING THREAD
 

And now the pictures.

RE: CMP BF109F BUILDING THREAD
 

And some more. Sorr, but I seem to have some upload difficulties.

RE: CMP BF109F BUILDING THREAD
 

Nice set up , that is exactly how I do mine , with the exception that I have used a wood dowl for the final pushrod to attach but the carbon fiber smaller rod is better idea and much lighter .

RE: CMP BF109F BUILDING THREAD
 

We discussed the control rods at length earlier in the thread. As was mentioned prior, no matter how stiff the rods the Y rod can lead to movement in the elevator due to flexing unless you use a U shaped rod to join the elevator halves. I added the U shaped wire, stiffened up the rods with carbon fibre tubes inside and replaced the wires with 4-40 size and terminated with theaded connectors. Adding some bracing in the center of the fuse and I have a very solid control set. I would agree that those EZ connectors should not be used on the elevator or ailerons.

RE: CMP BF109F BUILDING THREAD
 

Todd, just going through the Tower site putting things on my wish list to "restock" and came across this item http://www3.towerhobbies.com/cgi-bin...?&I=LXD904&P=V trying to work out how its set up and perhaps its for joining two elevator halves? just a thought...

RE: CMP BF109F BUILDING THREAD
 

with some research http://www.shopatron.com/product/par...161.5791.0.0.0

RE: CMP BF109F BUILDING THREAD
 

Todd,

There are different ways to get to Rome I think. Your solution certainly has its advantages, but takes quite some modefying. Weak point in every link stays the lengt of the steel rod used at the ends. Specially when you have to bend it a little, there is always some play. In this plane , one can use a perfect Y with carbon rods. The are no other angles needed. Thats why in this case the Y connection with carbon can be used without play at all. I now only have some play on the rudder, because the steel rod part connected to the servo is too long, or the carbon rod too short for that matter. I'ts clear when you see the attached picture. The advantage of the carbon Y-rod connection, is that apart from the rod itself, there is no modification needed. That can be usefull for the lesser experienced builders among us.
It's clear however that the provided system with the nylon rod, and the Y-part of 8 inch lengt of steel rod certainly has way too much play.

RE: CMP BF109F BUILDING THREAD
 

Schummie its sometimes good to do a little brainstroming with this sort of thing, you never know it might be helpfull for "the next build"

RE: CMP BF109F BUILDING THREAD
 

I couldn't agree more. Isn't that the whole idea of a forum. Not re-inventing the wheel.
A very happy and healthy newyear.
Hope all our 109's may survive 2009.

Regards,

Eric Schumacher, Netherlands.

RE: CMP BF109F BUILDING THREAD
 

I wonder if this is too light for this plane? http://www3.towerhobbies.com/cgi-bin...?&I=LXET15&P=0

RE: CMP BF109F BUILDING THREAD
 

schu , I agree , I use your set up (also my set up :D)on numerous 73" and larger planes , no problems at all .
I agree that all you need is careful placement , carbon supports ect and you will never get flutter or flex . Its that simple .

I like the homemade tail wheel set up , was the total cost under $50.00 ? not to be ignorant , just wonder the cost vs a commerical retract unit

RE: CMP BF109F BUILDING THREAD
 

another question for people who have used pull pull, what is better for say the rudder? pull pull or some decent control rods like the carbon filled sullivan ones?

RE: CMP BF109F BUILDING THREAD
 

My cost to make the tailwheel was less than $50, you need 4 sizes of nested brass tubing, 1 length of 1/8" music wire, 1/16 brass sheet, bondo, spring from a ballpoint pen, 1/8 plywood, Silver solder, 2" tailwheel. and lots of patience.
Bob Q.

RE: CMP BF109F BUILDING THREAD
 

Well I just did an order with Tower, bit of a top-up of parts actually and are using http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV43 with one for the rudder and two for the elevator, but will be jointing the two elevator rods at the servo end with this here http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXFV37 I think as long as they run up each side and come together parrallel it should be ok, KISS "keep it simple stupid" its alot better than mucking around with bearings like my old design

RE: CMP BF109F BUILDING THREAD
 

Thanks Steve, I’m finishing up a Refurb and plan to look at it by the end of the week. I’m planning to use a Saito 1.5 for power and have written Dave about a spinner but will probably end up with the flite metal spinner. I have a set of KMP fw retracts and struts that I’m hoping to squeeze in but the initial look will be at the strut length required and how much I have to remove to make them fit. If anyone has had problems with KMP retracts please let me know.

Joe

RE: CMP BF109F BUILDING THREAD
 

Bob Q , thanks , I think i will give that idea a try !!!