biggles71

Guys,

As posted in the engine section before I'm experiencing random engine failures in my OS 46AX powered Kyosho Calmato since about the last 6 to 8 flights.
All deadstick landings went undamaged untill today's one....


This morning I experienced an engine failure at the end of the runway after a simulated landing when adding power. The engine quit and after avoiding some obstacles I slightly turned left and made a good landing. Unfortunately it hit a big pole of a fence, directly head on. It broke the spinnner and pushed the firewall completely out. Nosegear is slightly bent and there is some damage to the needle valve. Its support is bent and the plastic tube on the needle valve, where one connects the fuel line is broken off. Replacing it wii solve this one, I guess. The rest of the aircraft is undamaged.

Please have a look at the picture.

Now to the firewall....

A few guys at the flying club said that putting in a new firewall should be no problem... then I went to my RC shop to buy some wood, and the guy told me that the aircraft was a write-off. This because putting another firewall in an ARTF is not possible since the thrustline will never be the same and it will not fly straight anymore...

What do you guys think about the above...? Have you been putting in entire new firewalls in ARTF's ?

I bought the replacement wood parts to do the job. Are there any need to knows on this job ? All advice more than welcome.


Best regards,

Biggles[>:]

MerlinL14

Your LHS is trying to rip you off, I have replaced numerious firewall rip outs without any dire effects to the planes handling. Fit the new firewall and find a new LHS.

CGRetired

My Feedback: (1)

Sounds like a bit of a hype to me. If you put the replacement firewall in the same place after repairing the cheeks, it should track straight as it had before. Put it back together and get that plane back in the air!!

drunkenbushman

Man sorry to hear bout your crash, at least it sounds very fixable, also sounds like your Local store is trying to rip you off, i have heard of much worse crash's that have been repaired and still flown.

How do you find the green Calmato, i bought the red one cause i thoguht it would be easier to see in the sky.

RC MANIAC119

My Feedback: (14)

This is a real quick fix.........don't let that bonehead at the hobby store tell you any different!

Remove your engine, and the blindnuts from the broken firewall.............install the broken firewall back to where it came from, and try to match the rough edges.......DON'T SAND IT TO MAKE IT PRETTY!....when the piece is in place....CLAMP IT TOGETHER...use some thin CA and soak the entire break...............Now cut a new piece of 1/4 ply that will go from the bottom of your fuse, to the top of the old firewall, and install it BEHIND the old firewall. Use some 15 minute Epoxy TO SANDWICH the peices together, once again CLAMP IT!!! When the Epoxy has cured...about 30 minutes........redrill the mounting holes....install your old blind nuts and engine...........monocote where you have to.AND GO FLY!!!! Even if you work slow this should take about and hour, and a couple bucks for the new ply..................

I'll bet that your hobby store guy......dosent even fly!!!!!

Throttle

Sounds like he just wants to sell you another kit.

Deadeye

CA on a firewall? I wouldn't do that. Better to stick with 30 min epoxy, or better yet, polyurethane glue.

StallN

I think the CA is mainly just for two things: First to hold the firewall in place until the ply is glued in, Second, to fuelproof the break area.

Just my thoughts..


S

Deadeye

If you CA the break, the epoxy won't have anything to adhere too, except for weak and brittle CA. Second, CA is NOT fuelproof by a long shot. A CAed firewall is a good way to lose a finger or a hand. Epoxy works great for flush, tight fitting joints. Polyurethane works great for splintered wood and breaks, and for parts that don't have the tightest joints.

conradj87

My Feedback: (1)

I have replaced firewalls before, no biggie, i did almost exactally what lyle did, only with all epoxy and i did it all at once. I also added those triangle stock to the back of teh wall.
I also have the 46AX. Had same problems []. It has been cutting off, but only after it has warmed up a bit. It never dies completely, but it will go back to idle.
Good luck with the fix, it will fly again.

hookedonrc

I've done pretty much the same as everyone else has suggested. I, like jomamma have used epoxy rather than CA and also added traingle stock to the back side so that it strengthens the joints. Don't buy a replacement when fixing the original will be just as good. And it will give you a head start on learning how to make the type of repair that is not that uncommon.

Hegasis

I agree It is totally fixable, and it's an easy fix at that. That guy who told you to write it off is a poo poo head!!! From the looks of it you had bad glue joint and thats why it broke off so cleanly.
Epoxy that baby back on and go fly.

RC-Captain

Look again 1/3 of the fire wall is still in tack holding the wheel. and on one side , the glu joint held.

This pck isn't showing the entire extent of the damage , there is more than meets the eye.

biggles71

Thanks for all the info guys. It confirmed my thoughts before.

I'll epoxy hte baby on, as someone said...


I'm going skiing for a week today. Willl do the repairs when back.


Thanks,

Biggles

StallN

Sorry Deadeye, I was just repeating something I had heard of before. I was told that CA would fuelproof. Personally I have never tried it. I have always used epoxy, especially on a firewall. Since I went to SPAD's I don't do much wood work.

Later

S

RC MANIAC119

My Feedback: (14)

[/quote]
Second, CA is NOT fuelproof by a long shot. A CAed firewall is a good way to lose a finger or a hand. [/quote]


I certainly don't recommend using CA as a Fuelproofer.....but I guarentee that any wood soaked and cured in CA..is definetly fuelproof. CA plugs the pores in wood better than zits on a 13 year olds face!!!![:'(]

airbatic

Listen not to limited folks. Invent your capabilities and effect repairs.

Next time, build your own!

Kraus

Deadeye

Second, CA is NOT fuelproof by a long shot. A CAed firewall is a good way to lose a finger or a hand. [/quote]


I certainly don't recommend using CA as a Fuelproofer.....but I guarentee that any wood soaked and cured in CA..is definetly fuelproof. CA plugs the pores in wood better than zits on a 13 year olds face!!!![:'(]
[/quote]

That may be somewhat true with balsa, but soak some plywood in CA, let it cure, rub some glow fuel on it and let it sit. It will peel and bubble.