rbtonet

Hello everybody. I was reading the topics and seeing everyone's enthusiasm for this model so I wanted to share with my colleagues what I liked these days and take some opinions. Do I buy or not?

limodune

Buy it
You might want to check out this thread it has 94 pages of information for the cmp 109

CMP BF109F BUILDING THREAD

Mike

David R

Hi I am surprised that they are still for sale,
I bought one about 10 years ago so the design may have changed since then and my comments may be out of date. I talked to many other builders at the time with similar issues and I might be able to find the threads from the or send you some pixs.
Beautiful looking plane but a couple of places on the fueslage were very fragile and I chose to glue thin ply inside to stiffen it (hard to get to as they were near the tail).
The coating on the wings tears easy so be careful, it was not as strong as the shrink films on the market then or now.
I was not happy with the push rod assemblies to the tail, they are good solid tubes but with plastic terminations to insert wire ends to go to the servos. 1 end broke and I found that the push rod flexed which resulted in the elevators walking a bit like ailerons. In the end I glued the pushrods through the bulkheads ( there was plenty of meat to do this) and used then as outer tubes for flexible pushrods worked a treat.
I forget why I was not happy with the tail wheel but I found one from another supplier of undercarriage pieces that did the trick.
The undercarriage has two problems, one I didn't think was solid enough but also if you mount it as designed the wheels are too far back to the COG and the plane has a tendency to tip easily, you have to keep back stick all the time when taxiing. I modified the wheel mounting to be similar to the Topflite spitfire such that as they descend they go forward, I did this by putting tapered shims under the retrack mounts.
Other builders indicated that they had the same concern before or after testing but solutions differed I was building the Spitfire at the same time so it seemed like a good option and shifter the wheels about 50mm forward.
The wing takes a lot of work, the air brakes are optional and are not air brakes but in real life dampers for the radiators. I made mine work but it is fiddly. depending on how much movement you give them I am reliably told that if you open the dampers at low speed the plane will drop out of the sky but they will really help slow it down on landing as it is slippery.

The engine mount as supplied is a permanent horizontal ply plate suitable for a large Nitro (1.20 or 1.60) or DLE 20 flat mount. if you want to install a DLE 30/35 there is a lot of work to redo the engine bay noting that the engine mount provides rigidity for the Fues front and from memory access to the back of the firewall is limited.
I installed a OS 1.2 nitro, I am told by another who also used the same it was fast.
Cooling the engine is problem and the only way to do it is to cut most of the bottom cowl out. the large spinner and cowl design means that there are no ducts from the front of the plane.
Finally the spinner was brittle, I was advised not to use it and they were right, I found it cracked in the spares box before ever running it on the plane.

If you wonder why I use anecdotal comments it is because I was never happy about butchering the front of the plane for the engine cooling so other than installing and running the engine it has never been finished or flown. I moved homes modifying the front and everything was dismantled for the container, it looks great on the wall. tell me if you want photos I will see what I can do.

regards
David R

[]TEX[]

I picked up one of these ARFs NIB with a TY spinner and Sierra retracts for $250. One issue is the TY spinner has no cut outs for the prop and no center hole drilled for a bolt.

What did you guys do about that?

ticketec

My Feedback: (2)

The Spinner not having cutout is not an issue, that's pretty normal for low run or one off spinners, and more importantly, It doesn't restrict you. It allows you to use it with either a 2 blade prop or a 3 blade prop. It's only aluminium, mark out where the blades will go and cut the ali out.

No need for a "center hole", And in fact with spun dome spinners, it is not the best place to attach the spinner to the backplate... around the outside edge where the spinner passes the backplate there should be screws that attach the dome to the backplate. If there isn't any there. (can't remember its been so long since i last had a TY spinner) then you will have to drill and tap holes around the perimeter to fasten the dome to the backplate. I would suggest you will need at least 8-10 holes to do this safely.

there is another more active thread on the 109, here on RCU. look at the post from limodune about 3 posts ago for a link.

thanks

dave

[]TEX[]

Thanks, I'll check it out.