RCU Forums - View Single Post - Ziroli 1/7 (120") B-25 B scale build
View Single Post
Old 07-21-2014, 04:42 AM
  #44  
bentwings
 
Join Date: Dec 2001
Location: St.Paul, MN
Posts: 474
Likes: 0
Received 4 Likes on 3 Posts
Default

Here is one of the few shots I took with my iPad of the b25 exhaust.
this picture up load has changed since I last used it, hope it works.
The exhaust system was built using copper fittings. Sounds heavy but I carefully trimmed over 60% of the weight off each fitting. The whole system is TIG welded with exception of the flange which is TIG braved with silicone bronze. It actually is very light considering the material.

there is also tuning effects built in. This is the reason for the large loop on the left side. We explored this extensively during the design and build. This is the third and final generation. We had no problems with this system vibrating loose. It probably had 10-15 hours of full throttle run with nothing coming loose.

it survived the crash.

Between you and me Ziroli said not to reduce throttle on engine out. Fly it away. Personally I strongly disagree, and my son and I have had numerous heated arguments about this. I flew model twins back in the 70's when twins were not cool. I had many engine out and the only plane I lost was an AeroCommander. Had I chopped the throttle and left it ther it would have lived another day too. In the bomber case he tried to fly and turn away from the dead motor but it was a downwind turn so airspeed dropped faster than the plane could keep up. Chop the throttle, nose down, get control and land straight ahead is the rule I use. It's better to take some rash than lose the plane.

we also have Flight sim and I have tried this with the B25. While not perfect you can at least sim getting control.
Stepping off the soap box. Haha

Byron Nelson
Attached Thumbnails Click image for larger version

Name:	image.jpg
Views:	248
Size:	1.11 MB
ID:	2015930