alright!! did a little mod today. As most people know, RJX stock head dampers are VEERY stiff and if you drop the headspeed, then you get this wobble or shake.
I grabbed orange material that i had, it's a rubber tube that i had in my garage forever, so i cut it down to size and fitted into the head instead of regular dampers. I actually had to cut a little linger length, cos it was a little small on diameter and would play in the head, but once it was longer and i squished it with feathering shaft bolts, it was all good. Actually fairly rigid compared to what i thought it would be.
They feel like a sausage in the fingers if you squeeze, compared to regular dampers the stock RJX head has, which are like rubber tires in comparison
anyways, here's the specs and vid i did.
800kv motor running 6s regularly(3s for the low headspeed test this time)
10t pinion | 100t maingear helical
5000mah 6s 25Cbatt regularly (3s 4000mah 30C for this headspeed test in vids)
Headspeed ~1700 regularly (870 this time)
Decided to add a coat of automotive paint to my blades. I usually crash 'em shortly afterwards though
anyways, I paint blades so they look kewl when rotating. effect especially visible when on camera. I painted them opposite angles and slightly offset to maximize flicker when flying. maybe will do vid of what it looks like. they need to dry for some time, but to be honest, i've flown next day without probs but tomorrow work, so meh..
Well, it's a long story(i'll make it short) and started off when I was getting ready to build a 600 size helicopter. RJX 600.
I was going to do "economy" servos on the sticks, but was convinced by some people here that it's not worth it to have cheap servos, because if they fail, the heli to repair will cost much more than money saved on servos, so I was recommended to use promodeler servos instead from audacitymodels.com They've been excellent! They center well and survive crashes well as well. Ask me how i know.
But the main reason I feel that I need to write this thread is because of the recent experience I had with customer service.
I started having little twitching on tail from the servo, so before "trying things", I decided to contact audacity, because their servos are warranted for 1 year, which is awesome! you usually buy stuff and then you have to go through 50 million videos to prove it's broken or have to bug the seller 'til death to have issue fixed! many times, you're often left with nothing else to do, but buy new because seller would not respond. seen that? i have.
Anyways, this is not the case with Audacity! I sent them e-mail and received a reply less than 1 hour later. 50 minutes to be exact!! it was Friday, 26-th, I didn't expect anyone to reply to me because I thought everyone was still in the "after Christmas rest" Get this, fellas, I actually got a reply from the owner himself. here's the quote:
sorting out tailwag. stock settings were fine for swash, but tail was wagging and it was increasing to a point of "wag of death". it would increasingly oscillate to a point where it's uncontrollable. that means you have to land
EDIT: i think wag is here to stay. one of the members decided to experiment and put a cyclic servo on his tail to see what happens. Same thing, wagging! K-bar probably doesn't like cyclic servo on the tail. wants something faster. I got the wag to a minimum now...well, compared to what it was, but it's still there.
well, got myself a new motor. Turnigy SK3 800kv. it is rated for 6-10 cell batteries and I will be running it on my 6s setup. Did a couple test hovers and i was pretty happy. Got 8minutes 55 seconds of hovering in the backyard. Full 100% throttle.
tried 90%, but doesn't switch...probably because governor needs some headroom.
here i tried 80, 85, but couldn't switch to 90%, so landed, took off again, thought idle switch went bad, set curves to different position, still won't switch into 90, not even 88%...so o well, i decided
anyways, my preference is flying 65% throttle. I know that if i go higher, then difference between amp draw is minimal between switches and ESC is more efficient, but all those amps still add up and take away flight time. I do soft sport flying, nothing 3d, so it suits me oh...if windy i go into 70%...
right frame: fixed
right landing skid: fixed/straightened
right landing struts: like $1 (lexan from home depot)
2plastic linkages: had spares with kit
servo arm: turned over as it has 4 arms
5 bearings: $5
CF blades: $25
1 tailbrace: $3.50
1 mainshaft: $7.50
1 feather shaft: $3.25
1 tailboom: $6.50
1 swash: $47.80
still a healthy bill, even though i "salvaged" quite a few parts, such as canopy and frame. some spares come on pairs, such as mainshaft, boom, braces, so since i used only one, i posted half the price.
realistically, i spent little over $200 on everything, but because i ordered a new canopy just in case, which is now sitting in reserve and another set of CF blades, also linkages and some other stuff.
It's one of those hobbies where you "accumulate" stuff over time, but trying to keep it to a minimum. i have about 4 booms left and i believe 5 braces and some other things.
Stupid me...lost orientation in flight today. I was doing a slow pass 2 o'clock high and started to turn her around, but looked like tail went the other way, so i gave it rudder to wiggle, but couldn't tell!! I panicked as I couldn't figure out which way to correct. It looked like rudder was going the other way!! Heli started to tilt and i was losing altitude and not level. I dumped throttle hold in place and she went down on her right side from a height of pine trees...30-50feet?
I thought my receiver glitched, so i grabbed little heli...450 and went to recreate the scenario...stupid me...same thing, it's hard to tell, but when you just have silhouette against grey cloud and no sun shining on the heli from your side, i totally can lose orientation...heli looks like it's the opposite direction when it's JUST at the right angle!!! I made the same slow high 2 o'clock pass and started to do a turnaround and there!! i almost lost it again, but I saved it with a high G pullout. I feel bummed right now here are pix:
well, this was bound to happen sooner or later i guess. i went out for a flight today with my little one and a big one. flew the little one flawlessly and first battery with a big one. Last flight i was flying with higher RPM and was doing some aggressive accelerations. During a turn-around i noticed RPM's starting to drop and realized it's going down...
it was over large pile of empty crates and some garage nearby. Knowing that i have to make it back to the grassy land, i dropped collective and dove forward towards me trying to get it over the fence and to the grass. By that time, RPM's were too low for a forward flight and i started transition into autorotation and was going down with low rpm's. right before impact, i gave hard collective and she went in almost flat on the skids and impact happened....
I ran to the crash site looking frantically for survivors... here are the pics...