ORIGINAL: jfetter
ORIGINAL: brownj
Jack, et. al;
I also have an Impact with the AXI 5330-F / Jeti 90 setup. Everything your reading in these posts is absolutely correct.
I didn't use a soft mount; simply the CF firewall and rubber gromets - no vibration (prop balanced very carefully).
I opted to use a balsa crutch along with the foam one supplied. Paranoid about a fuse failure I guess.
IMHO, the rudder set up was the most agonizing. I opted to install the fin post in the fuse first, then the previously hinged rudder. So far so good. BUT, make sure you have enough rudder travel BEFORE you glue it all together.
The plane flies like a dream and am looking forward to flying it in competition this year.
Now the bad news, with 2-TP5300's, a battery tray and rudder servo tray that are admittedly over-kill, my plane weighs 11lbs 14 oz. Hope it never gets weighed! But the extra weight does not seem to adversely affect the flight quality no matter what speed the wind is blowing.
Best of luck, Jim
Jim,
How does the AXI pull, powerful? What prop are you using (beleive it or not, MotoCalc shows an 18 x 8 as the ideal prop for my setup, logic says not big enough but MotoCalc has served me very well to date with predictions)? Also, I assume you are flying 10S, do you find you have as much power as you need/want? I did the math on your setup and (assuming you are running 10S), you'd have to shave 7 oz per pack from your setup (hard to do). You can accomplish this with 2 x EVO 5S 2500 packs but then your capacity is now half, not sure you can complete the pattern.
I am not a good enough pilot to compete now, I am building this one to learn to fly better and what the heck, it's an awesome looking plane! I expect mine to come in around 11.5 lbs, I should have the final weights by Monday after I install the electronics. I guess I'm lucky in that I get an awesome plane and I don't have to struggle with the weight.
If you had to do it again, would you still install the fin post the same way you did the first time? I can't help but think it is easier to do (your way) because you can absolutely get a solid glue joint this way (versus having to assume the joint is properly glued and worrying about getting epoxy on the hinges, etc)...
Jack
Jack,
The AXI Pulls my overweight (LOL) Impact like a tractor, unlimited vertical. Are you aware the weight limit for competition pattern planes (2 meter planes) is 11 lbs? The good news is no one weighs them.
At least not at local contests.
Yes, I'm using the TP 5300 packs in series (10S). I'm on the look out for lighter batteries, but my 5300's only give me 10-12 mins. of flight time now, not really enough to get a good practice session in.
Prop is an APC 21x12. But I'm going to try a smaller diameter with more pitch as soon as I can, say a 20 (or 19) x 13-15. Just to compare, and see if the plane will penetrate better without increasing the speed too much.
Yes, I would install the rudder / fin post in exactly the same way. Like you say, it's a much better glue joint. After gluing the hinges into the fin post, I also hung the plane from the nose when the glue was drying. My theory was that the glue would puttle around the end of the hinges (inside the fin post) providing a little extra adhesion. And whatever you do, MAKE SURE YOU HAVE ENOUGH RUDDER TRAVEL BEFORE YOU GLUE THE RUDDER ON! Measuring from the tip of the fin (front) to the tip of the rudder counter-balance, I've got 1-5/8 in. travel (each way). This is BARELY enough travel to get in a reliable stall-turn. You should try to get 1-3/4 to 2 in. of travel if you can.
You do know about putting a little light-weight oil on the pivot point of the hinges, right? Just enough to keep any errant epoxy out of the hinge joint, and be careful you don't get any oil on the hinge posts as the epoxy won't stick.
Don't be afraid to try a pattern contest. The Sportsman class would be the starting point, and you'll get lots of help at a contest if needed. But you'll need to practice the sequence until your sick of it before going. Just jump in!!!
If I can help further, send a post or PM.
Jim