Hello guys,

i have a Katana 36% by Aeroworks (World Models) and powered by an Evolution 116CC twin.
Let me first say that me and my friends are not beginners, and that i pre-blanaced my prop and aluminum spinner on a Dubro high point balancer.

since i bought the first Evolution in Israel, and one of the first ever, there were no other mufflers available besides Jtec, so i ordered a set of 2 cans for 140$ + shipping.

after a few flights (i have balanced the propeller and spinner) - both cans broke at the welding joint between the neck and the mounting flange, and Jtec has agreed to immidiately send me a new set (at my shipping cost) - and i agreed (since they recognized it had a bad weld), and the owner also noted to me that i can easily re-weld the broken ones and keep them as spare, so i did.

2 flights later (after the re-weld) both cans broke around the neck (the can this time, not the weld!) (see pics) so i knew a bigger fix was in order. i had a friend who is a machinist mill me 2 thick mounting flanges from solid t^ aluminum blocks, and weld them onto the can, and also weld in 2 aluminum tubes for the bolts to go through (kinda like DA mufflers) and this seems to work good so far. see pics for the new flange we made.

after 2 more flights with the new mount, the rear can caps both broke, one flew off and the other one is cracked at the joint. Jtec knows about everything at this point.
in the meanwhile, i got the new mufflers they sent me (thanks guys) but they have 2" cans rather then 2.5" cans (they say theyre fine for the Evo116cc though theyre smaller), and im not so sure about using these, since i feel they will break in their mounting like set #1 (look at the pics of them when they were new, the mouting flange is weak).

anyway, i made a new design on my own and Jtec told me its around 200$ for a set, and if i send the #2 set back (new) at my cost, add 70$ + pay for the shipping back to me, they could make me a set like that.

The reason im not using the #2 set is that i know theyre going to break just like set #1 since the design is very weak around the mounting joints, causing it to break (see pics)

I ask you guys is it fair that in order to get a decent set of 200$ worth i need to pay:
A. shipping to me of set #1 (35$).
B. shipping to me of set #2 (35$).
C. shipping back to them of set #2 (15$).
D. shipping to me of set #3 (35$).

Thats 120$ just in shipping charges, not to mention the weeks down time.

How do you guys feel about this ? who needs to do what ? Please help me decide what to do here.