Swissing a NCFM Moth - after hearing from Matin that a goal of a sub 12oz Moth was easily obtainable, I decided to set our sights on a sub 10oz Swiss Moth (maybe ~8oz). Couple of decisions to make, include or exclude a CF longeron, use std CF Wing Spar system or small CF rod system, bagged Depron fin & elevons or balsa?

Initial plan: 8gr HS-45HB servos in the fuse (ahead of CG) with micro pushrods to elevon, cut holes out of the wing, New Stuff laminating film, minimize the CF spars, balsa sheet elevons & build up balsa fin and run a 1S1P LiPo with my Micro Boost Regulator.

Should be interesting to see how it comes out

watching and waiting, sounds cool.
I remember a Red Herring I built, 6.5 oz, what a blast
a larger moth at 8oz, whew, fun times to come

Chip
I am in for this ...

Watching

Rubio

Consider a depron fin. You could make a bunch and slot mount them lighter and easier than balsa build ups. Will be interested in how she goes!
Andy

Cool idea Chip, looking forward to the build.
Jimbo.

Are we talking about a four foot Moth here?

Thanks Guys,

I don't want to make this a "how-low-can-you-go" build, since it may be possible to build too light for the current airfoil, but there are a few trade-offs to be made between durability and lightness.

Starting off with the weight of my NCFM bits, here's the wing and fuselage on the scale at a nice 2.5oz. A quick add up of 2 servos @ 8gr, 600mAH LiPo @ 20gr, 3mil NS ~ 25gr, balsa elevons @ 14gr and some CF spar (tbd) gives a roughed in weight of ~6oz, which leaves a 2oz contingency for Goop, CF and fin. Nice!

Originally Posted by chip.greely

Thanks Guys,

I don't want to make this a "how-low-can-you-go" build, since it may be possible to build too light for the current airfoil, but there are a few trade-offs to be made between durability and lightness.

Starting off with the weight of my NCFM bits, here's the wing and fuselage on the scale at a nice 2.5oz. A quick add up of 2 servos @ 8gr, 600mAH LiPo @ 20gr, 3mil NS ~ 25gr, balsa elevons @ 14gr and some CF spar (tbd) gives a roughed in weight of ~6oz, which leaves a 2oz contingency for Goop, CF and fin. Nice!

And you are going to carve off some weight shaping the fuse, so then you can put in a cardboard ballast tube sized for mini-marshmallows and load it up on those epic Dave's Beach days!

Mike

Originally Posted by SrWade

And you are going to carve off some weight shaping the fuse, so then you can put in a cardboard ballast tube sized for mini-marshmallows and load it up on those epic Dave's Beach days!

Mike

Yeah! The mini-marshmallow slugs would have holes in 'em!!!

Holes in 'em,

.....now we're talking about Lifesavers, not mini-marshmallows

Well I'll be paying attention... Have a 24oz Moth that's tons of fun, but barely gets used... There have been many debates during lulls in the wind at our slope on the merits of an ultralight Moth...

I'd stick with the marshmallows, myself. If you have a lipo fire, they're pretoasted for ya!

Hey goldguy! Now this is something we should be doing!

Got the cores. I'll get started as soon as I get my repairs caught up and that might mean not flying with you dorks anymore. I'm also waiting to see if Chip's diet works.

Dave is too. His latest Moth turned out to be a huge slug, heavier than yours. It's pretty though and good for cutting down trees on Hornby.

They should at least stay repaired for a while, there hasn't been any wind in weeks!

Sorry to clutter up your thread, chip! I'm ordering one in the morning, so hopefully I'll soon have something ON topic to add hahaha!

Now this thread is giving me ideas of a swissed m60. There could be a lot of weight saving if you swiss those 60inch wings

Originally Posted by chip.greely

Initial plan: 8gr HS-45HB servos in the fuse (ahead of CG) with micro pushrods to elevon, cut holes out of the wing, New Stuff laminating film, minimize the CF spars, balsa sheet elevons & build up balsa fin and run a 1S1P LiPo with my Micro Boost Regulator.

I like the idea of a lightweight moth, but I am not sure about that control setup. Light or not this thing is still going to shift, and with centring accuracy hugely important on planks I'm not sure long, lightweight pushrods and an 8g analog servo (even one as good as an HS-45) would be my choice. My guess is you may get some hunting in pitch (I've seen this on Alulas when they're launched really hard).