flightprep
Posts: 33
Joined: 8/27/2007
From: bridgewater,
NJ, USA
Status: offline
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Hey Slim, welcome back!
Sounds like you may have a bit of time to build going forward.... anyway, there's still a bit of work to do on the cherokee, but we're moving ahead now with an Ultimate Bipe .40 - already about 1/4 of the way there, it's a fast build. Field is a mess anyway, so we won't be flying anything with wheels for a while.
So - I will get a few closeups of the OS .35, it is mounted (temp) in the pics above, but it is hard to see. It is a sideways mount (that's how it was set up, we will keep it). I'll describe it below, then when I post some pics (weekend?) I'm sure it will be easier.
Coming off the firewall there is a 1/4" spacer, to which a Tatone 29 cast aluminum mount is attached (the mount is received in the firewall, 3 bolts, blind nuts). The mount itself is tapped for 4 mm mounting bolts, the spacing is for the .35 but would in fact fit a .40 LA. Based on the plans, this all looks pretty conventional for the time it was first built.
With a sideways mount, the muffler exhausts to the bottom. This engine came with a Tatone Peace Pipe, it's a 2-piece unbaffled muffler that bolts on. By reputation I don't think it's much of a muffler - we'll hear it soon enough, because we plan to use the original setup - sort of a period piece. We had to rebuild the cowl, a friend made one via the lost foam method. It has carved out nicely with an X-acto knife and dremel tool, easier to work than many original plastic parts. The original cowl had been cracked and had a few missing pieces. I'll get a pic of both cowls as well. One thing about the new cowl, the "diameter" at the mounting area it was made a bit larger than the original, so we built up the edges of the fuse with some lite ply - which we did to strengthen the fuse. We will probably mount the cowl with 6 screws, that's because the back of the cowl is ported in two places, once for the muffler and once for the nose gear, so better to have a strong mount.
Your last question got me thinking - always a dangerous proposition - so I went and looked at the .35 and an LA 40. Engine block is similar, but there is an important difference, and that is the muffler geometry. On the LA, the distance from the block to the expansion chamber is fairly short, and the muffler runs at about a 90 degree angle to the block - so you may be inside the cowl/hitting the fuse. The .35 / PeacePipe assembley has a longer muffler stand-off, and the muffler is angled away from the block. Even so, I had to carve a bit of my "extra" fuse reinforcing lite-ply to get the muffler in place.
So, be sure to check it soon. if it's a problem, you have a few options; I know there are extensions / inserts so that mufflers can be pushed out from the block, they probably have them for a .40 LA; or, you could go to a Pitts style muffler. I will send some pics of both engines, that way you can see the issue for yourself.
Thats it for now, glad you're back in the thread, let us hear about your progress!
brgds
Flightprep
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Printable Version
All Forums >> RC Airplanes >> Vintage & Antique RC >> RE: Recent VK Cherokee Babe build 
RE: Recent VK Cherokee Babe build - 
That Ultimate Bipe sounds like a good looker....I also use the Monokote Black/White checkered sheets, cut to appropriate size, and fit to the bottom of the wings and stab on my planes/trimmed in Black Monokote striping. Looks real nice in the air.
