CL-415 group-build thread

Michael · November 30, 2018, 09:56:02 PM

Nacelle tops sheeted.

Next step: clean up my table.

Michael · December 01, 2018, 08:27:46 AM

I have not yet glued on the firewalls. I'm waiting to measure with the motor, prop, spinner, etc.

Lower front triangle stock and sheeting done.

Cowls cut to size, and a bit of extra balsa glued on top for a nice fit on the cowls.

Sanding and shaping is next.

Michael · December 01, 2018, 08:29:28 AM

If anybody wants, here is a similar one being advertised, almost finished, with motors, speed controls and servos.

https://www.rccanada.ca/rccforum/showthread.php?t=572689

electroflyer · December 01, 2018, 08:51:37 AM

You guys are doing great!
I am on vacation for a week and am not sure how often I can check in. I look forward to seeing the progress when I return.
I have been thinking about the wing and have decided to use 1/4" square spruce with shear webs fully sheeted. The plans call for 1/4"x1/8" so very minimal effort to change the ribs to accept square stock.

Rob, good choice to get the servos out of the tail. My linkage is buried in the tail and will be hidden. The only trick was to allow a hollowed area in the rudder to accept the belcrank.

octagon · December 01, 2018, 08:57:44 AM

Have a great trip Glenn. Be sure to have a couple of cold ones for us poor schmucks here. See you when you get back. Hope to have the fuse mostly done by then.

Michael · December 01, 2018, 02:18:21 PM

Nacelles shaped and (mostly) sanded, and cowls cut open.

The plywood firewalls in the kit fit exactly to the mounts on my motors, but I would have to use bolts and T-nuts.

The problem with that, is if I later want to use larger motors, the T-nuts will be glued onto the back of the firewall, and drilling new mounting holes might be difficult.

I may use new plywood and use wood screws to attach the motor mounts.

I'm thinking about what to do, and how to do it.

octagon · December 01, 2018, 04:12:58 PM

Michael, a more simple solution to making new firewalls. Why not just turn the motors 45 degrees, drill pilot holes and use wood screws on the existing firewall?

Michael · December 01, 2018, 04:27:51 PM

That is a good and simple idea.

Michael · December 01, 2018, 05:25:04 PM

Firewalls glued on upside down, in order for the motor to be centered in the cowl.

Formed and beveled blocks glued at tops and bottoms for a snug fit for the cowls.

Test fit on the wing.

My next tasks will be to hinge the ailerons, install servos, install the motors, and finish the most of wing, except the parts where it will attach to the fuselage.

Michael · December 01, 2018, 07:10:56 PM

One aileron hinged with Robart 1/8th inch pin hinges, at the top of the aileron.

A small channel was cut out, and holes drilled.

I've only done two hinges, and it's very solid. Does anyone think a third (in the middle) would be needed?

Easily swings up and down.

Michael · December 02, 2018, 12:09:52 PM

Front of wings outboard of the nacelles are sheeted; overall seems structure is much stronger.

In preparation of sheeting the section between the nacelles, motor wires are installed, and blocks are shaped to form solid areas, later to be drilled to screw the wing onto the fuselage.

Michael · December 02, 2018, 01:38:31 PM

Center-front-top sheeted.

Leading edge glued on and shaped/sanded.

Tip ribs added for aileron clearance from winglets.

Next, aileron servo installation.

Michael · December 02, 2018, 03:15:17 PM

I forgot to take into account mounting the tip floats, before sheeting the wing.

Oh well, a bit of surgery has begun.

Frank v B · December 02, 2018, 04:54:19 PM

Michael,

re: your I've only done two hinges, and it's very solid. Does anyone think a third (in the middle) would be needed?

I always put a minimum of 3 on a primary surface. The reason is very simple: with only 2 hinges on a surface, if one hinge fails you have a catastrophic failure. If you have 3 and one fails you still have a working surface. Critical on a primary surface (elevator, aileron). Live dangerously on a rudder or flap.

I have had 3 aileron and 2 elevator hinge failures in 25 years and not a single loss.

Rule of thumb- the more complicated an airplane the greater the need for 3 hinge points. Murphy's Law. Your call

For what it is worth. Keep building. Great project.

Frank

octagon · December 02, 2018, 06:20:09 PM

Michael, I think Frank is right, and his logic makes perfect sense. I constructed the sheeted ailerons today and will do the flaps tomorrow and I think I will use 3 hinges on each. Thought I was going to be able to build all afternoon, but Grandaughter, a trip to Stouffville and Christmas lights got in the way. Only got about an hour and a half in.