MTK

I agree with Chris...no need for expensive epoxy. There are several good, inexpensive epoxies that are reasonably thin and are made thixotropic with fumed silica. PolyEpoxy from AS$S, CJ Composites epoxy and US Composites epoxy are all suitable.So are West Systems, Pro Set and MGS, but much more pricy

I use laminating types because I can control how thick I make the stuff and control the set-up time. I also add glass and carbon for strength. BTW, when cutting glass and carbon cloth scraps, cut on bias. I use kevlar shears and make a pile of 1/8" long reinforcing filler very quickly.The only thing I do different (big hands just don't fit) is to use a simple fillet shaping tool made from popsickle sticks, and then back the joint up with a layer of 1 oz cloth to keep things tidy. Strong enough fora DLE55 so it's possibly overkill for motors. But it weighs next to nothing.....

Neko

Making good progress on this beautiful plane, except for making the firewall. I have tried three times now to laminate some 1/4" ply with carbon fiber (which I've never done before), but each time the results are inconsistent. That is, there are places where the CF sticks extremely well, and others where it does not. If I pull on the part of the fabric that overhangs the edge of the ply, a swath of it will lift off the ply, peeling back until it reaches a place where it has stuck very well. At that point the CF tears. I have to pull pretty hard, but I was under the impression I should not be able to pull it off at all. In the latest try, there is a layer of glue that has stuck to the ply, which holds a nice impression of the weave. So it seems to be the CF that is not sticking properly to the glue. But sometimes it seems like the glue separates from the ply instead, leaving it smooth.

I've tried two different resins (Zap's Z-poxy and a generic automotive fiberglass resin). And two different weights of CF (2 oz and 4 oz). After putting everything in place, I place the ply between two very flat stiff plastic plates (1/2" thick), and put a lot of weight on top (probably 20 pounds or more). Am I not putting enough resin? Or is it too much weight and I'm squeezing the resin layer too thin? The ply is a 6"x12" sheet from the local hobby shop, which I sand and vacuum before use. I use about 1.5 oz of resin on each side, but a lot of that ends up squeezed out around the edges of the ply.

One other thing I notice is that I am not able to set up the z-bend push-rods correctly. With the ball joints screwed on by 4 or 5 turns and the control horns set so that they are nicely perpendicular to the push rods, the control surfaces end up deflected fairly far from neutral (in the direction of the servo). I don't want to unscrew the ball joints more so that they are hanging by one or 2 threads. I was thinking of using threaded rod (strengthened with CF tube) and ball joints on both ends, but is there a way to get the z-bends to work better?

David

f3a05

Decent quality 5-ply 1/4 ply is more than adequate on its own, for a firewall for your size of electric motor.
If you feel you must have a carbon fibre laminate, flowing a little thin cyano onto any small failed epoxied areas should rescue the situation.
Not many F3A flyers use z-bends on their pushrods; your very own Mr Hyde, amongst other notables, has popularised the simple method of cyanoing carbon fibre rods directly into ball joints at both servo, and flying surface, horns.

john agnew

David

I have just finished my Nuance 120 and did not like the Z bends, I replaced mine with all thread rod (2mm) and a carbon tube, leave about 12mm rod protruding from both ends of the tube for adjustment of the ball link or clevis if you prefer, use medium cyano to glue the rod into the carbon tube, light,stiff and safe. I agree with f3a05, you don't need to laminate carbon cloth to your firewall if you are using 1/4" birch ply.

John

Jason Arnold

1/8" Aircraft Ply with carbon both sides is more than adequate for F3A electrics.

Your adhesion problems are more than likely caused by inadequate wetting with epoxy. Use laminating resin and coat the ply and stipple it into the carbon ensuring it's fully wetted out with epoxy. If you have the facilities, vacuum bagging helps.

Cheers,
Jason.

MTK

Neko,

I wrote about this a long time ago and some use my technique with great success. Here's how I do it for medium sized gas engines, up to60cc (overkill for an electric motor BTW, but very lightweight):

1/4" cross grained balsa...various sources; I think you can get as small as 1 square foot from ACP and from Aircraft Spruce, It is usually presealed, cut slightly oversized to allow final trim to perfection
3K carbon cloth, 2x2 twill (2 starnds over and 2 under, stronger), but I have also done laminates with plain weave (1 strand over and one under, weaker) with good results.
A good laminating epoxy, many sources (west systems, Pro Set, US Composites, CJ Composites, Poly Epoxy, etc etc)
Plastic food wrap film and roller
A pair of mylar sheets shaped like your firewall. Thickness around 010 is fine
Carbon tubing with ID large enough to fit your mounting boltsand 1/2" diameter 1/8"thick birchplywood rings for 6-32 blind nuts
A food preserver vacuum system or regular vacuum set-up for wing bagging

Mix epoxy and spread it over the CF cloth inside a pocket made with the plastic film. Fold the plastic film over and roll with the roller until saturated. Let it rest 10 minutes to allow full epoxy penetration. When ready to install, you can cut the plastic film with scisors or razor blade to the firewall shape. When ready, peel the plastic and lightly blot CF with asswipes

Apply a thin layer of epoxy over the presealed wood and install the front and back CF cloth saturated pieces, making sure they cover everything. Trim with scissors if necessary to minimize overlap. Then place mylar sheets front and back and tape in place

Install assembly inside a vacuum bag and draw vacuum. Let cure on a flat surface with a small amount of weight on top to keep it flat.

Next day, remove, do the final trim and do a temporary installation with motor, to find the mounting locations. Also mark areas on the firewall that you will remove. For example, on my gasoline firewalls I remove the center section of the firewall that matches the center section of my soft mount. It reduces weight by as much as 25-30%. Firewalls weigh around 35 grams when I'm done

Drill the holeslocated earlier for the motor or mount .Install the carbon tubes and ply rings with 6-32 blind nuts attached. Install motor or mount and secure firewall to the fuse with epoxy and microballoons, with some glass chop for strength. I only do small sections at this time to just hold, then I final glue the FW after the motor is removed.

For electric, firewalls can be lighter than for my gasoline counterparts. There's planty of strength with the carbon cloth on both sides of the balsa. As far as shape and lightening holes,think of a 5 spoke car wheel rim. Leave 1/2" to 5/8" spokes and remove the sections in between. Leave the perimeter of the firewall to mount properly in the fuse

Good luck!!

Neko

Almost done with my Nuance. I finally got a good lamination on the firewall.

I am making the stabs removable by running carbon-fiber tubing inside the fuse between the holes that hold the mounting screws. I'll run 4-40 threaded rod through that and through the mounting tabs. Then plastic nuts on the threaded rod will hold the stabs in place. By making the stabs removable, I might actually be able to fit the plane in my sedan.

A couple of questions on setup.

patternflyer1

My Feedback: (11)

Your stabs should have been removable with the two mounting tabs if its like mine. Unless that has changed. Either way, I like the idea of doing it with the tubes anyway. Makes for a tight fit. Good choice.

As for control throws, well, that depends on how you like to set up your planes. I will check mine tomorrow and post. I use dual rates for my snaps and spins, other than that, i use the bare minimum throws to fly. When I set up a program for Chip to fly it, I was shocked by how much throw he uses in regular flight compared to me.

I have taken and added a touch of right thrust and some down thrust to mine. Have to go back up a small amount but i really like how it is flying compared to when I flew it at the nats. After i checked when i got home, i had too much positive incidence in the wing. By a lot. Seems to be locking in really good now. I have also moved the cg forward a little. But that's with the dtfs wings and episode stabs. I am going to try some other things to it also. Just for fun. I want to see the differences i can make to it. Its pretty good regardless, just want to try some stuff. I also may switch to a 20x15 as per BJs setup.

Chris

Neko

Here's another question. A few people mention replacing the provided hinges with Great Planes CA hinges, and one of the local guys here suggests using Robarts plastic hinges. What is the problem with the hinges that come with the plane?

On the removable stabs, the tubes are inside the fuse and act as a guide for the threaded rod, which protrudes out through the mounting tabs. All this does is replace the wood screws that normally hold the stabs.

patternflyer1

My Feedback: (11)

I don't see any issue with the stock hinges. I would have used them but I wanted to install more than what come stock. Not because i thought the standard amount was inadequate, but i have a certain amount i always use. Some of us get used to using the same ca hinges and just use those in all our planes. Ca hinges will generally have a small amount of binding compared to the robarts. So some prefer robarts. I always bend my ca hinges in half back and forth several times before i install them.

Chris

Neko

All built and flying! As I said, this is my first 2M, and it's awesome. My latest crisis is that the tips of all the color patches on the wing are lifting up. Should I take an iron to them? CA?

patternflyer1

My Feedback: (11)

Yes, just take an iron to it. Dont use high heat, the covering shrinks really easily. I have had some lift on mine also. Just keep an eye on it.

pippy

When film trim has points in the direction of travel they lift very easily so what I do is put a tiny drop of quick drying varnish on the point and then It just cannot lift. Ironing is only a temporary solution I found.

AmericanSpectre505

You can also put a drip of thin CA on a Q-tip and outline the edge(s) that will not stay down with repeated heating with the iron.

BH

pippy

That sound like a good idea. Thanks

patternflyer1

My Feedback: (11)

Trying the stab addition that Chip did to Matts Episode. So far so good. I like how it tracks more on the lines. I may need to change the right thrust a little. Not sure yet. Was kinda windy.

Chris

TonyF

My Feedback: (92)

Stab fences do the same thing, maybe even better. The one you have on it is really small. Try a larger one for a better effect.

patternflyer1

My Feedback: (11)

I agree, I did use a smaller stab fence. I really noticed a difference with the increased vertical fin area though. I could use some episode stab fences seeing as my nuance has episode stabs. It's essentially a episode minus the can.. I am just playing around with it to see what effects what.

C

papaone

Hello

Yesterday I received the box from Bondaero. Thanks to Chris Bond a very nice guy.
http://www.bondaero.co.uk/
Plane is for a friend I'm going to assembly.

Jeff Worsham

My Feedback: (28)

Nice! Your wheels look a little different than what I've seen come with BJ models in the US. Are they plastic hub wheels?

Dave Harmon

Looks like it comes with a motor mount now as well.

pippy

I got those wheels with my episode and they are plastic hubs. They are very light and perfect for a smooth surface.

Dave Harmon

Yep....those wheels came with my Nuance too....but the hub axle hole wears quickly because it is just plastic.
I put some tubing in the hole but that didnt last long either.
Then I changed to MAXX (MPI) 2.25" wheels and the problem is solved.
These are really nice wheels and you can get replacement tires for them too.

bondtasha

The motor mount is not standard this is a Bondaero manufactured part

STEVE HOSNER

I need some of the Purple or wine colored covering. Does anyone have any idea of what brand and color the covering is on the Nuance?

Thanks for your help Guys!

Steve