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#1 rickyblaze Jan 19, 2005 06:46 AM

Xrb Fast Forward Flight Mod
 
1 Attachment(s)
I don't know if anybody else has tried this. But last night after going for a late night flight I got to thinking,there had to be a way to improve the forward flight speed on the XRB's as they are awful slow. Then after looking the setup over a light bulb turned on (a very dim one) I thought about how you could increase the cyclic pitch to the lower rotors and thought about how on an airplane you lower the control rod on the control horn. Well guess what there is a control horn on the control arm.

Anyway I drilled a hole of the same diameter as the stock hole the control fits about .18" above the stock location. I don't know if it's my imagination but when I tested it the forward speed was faster. You'll have to be sure and re-track your blades when your done. As soon as somebody else tries it then I'll know for sure but my battery was went dead before I could complete the flying test and it was after midnight so I went to bed.

Somebody else give it a shot and see if it was my imagination :D

#2 humveeflyer Jan 19, 2005 07:06 AM

Thanks Rick! I will give this a try on my HF. Great idea!

#3 Swilson50 Jan 19, 2005 09:12 AM

Rick, you're the "king of XRB"
 
Thanks, Rick.
From the beginning, you've led the pack in XRB mods and tricks. I don't have any trouble with FF inside (the slower the better to avoid walls and ivy).
However, I've noticed that when flying outdoors, it requires almost complete forward control of the joystick (even when using your extreme tape lamination).
By the way, the XRB is wonderful in winds under 3 mph. I have really learned a lot about helicopter control this way. I don't have a gym to practice in. Outdoors gives "time for errors".
ALSO NOTE: Your mod will also improve the "aileron" cyclic as well.

Thanks again.
Stan in Dodge City

#4 Terry Rigden Jan 19, 2005 10:09 AM

Nice one Rick, once again you are at the forefront of XRB development.

I'll give this one a go next time I fly in a big space.

Regards

Terry

#5 edwardp Jan 19, 2005 10:11 AM

A bloody good idea!! No, make that a blazing good idea! :D

#6 rickyblaze Jan 19, 2005 02:56 PM

You guys might want to try it before you pat my back :o It seemed to work but now I'm back home and only have the livingroom or my cluttered garage to try it. Like I said above it seemed as if I had alot more forward speed but my battery was about dead when I thought of it and that was at midnight so I flew it for a very short time. It needs to be verified as a workable mod by more people but please be careful. I don't know what size bit I used but it fit the stock holes tight.

I've got another idea but I gotta try it first and I'll be glad to share as soon as I test it. :D

Have fun,Rick

#7 wiltok Jan 19, 2005 03:09 PM

Has anyone else noticed the XRB flies much faster backwards? It took me a while to learn nose in flight - and it seemed like I could zip around backwards very quickly. Maybe it's my imagination...??

#8 rickyblaze Jan 19, 2005 03:16 PM

It seemed to me that it did,but it's kinda like it does in forward it starts out fast then peters out

Rick

#9 OPP_HELI Jan 19, 2005 08:18 PM

RICKY u rock!!!!!

Your little scored me big time tonite..... :D :D WON SET OF CF BLADES :D :D !!!!!!

Wow u ppl r rite Rick is TRULY THE KING OF THE XRB.......Tell u wat if you want i'll sent you a pair of my HEATSINK if you want it.

:cool: DEREK IN UR SERVICE!!!!!!! :cool:

#10 edwardp Jan 19, 2005 09:58 PM

No problems if it doesn't. But the mod made a lot of sense and I'm pretty sure it would work. Though I haven't tried it yet. I going to take the whole head assembly off, so that I can be be more precise in the job. I'm just a little concerned on the extra torque required from the servo or wether the head assembly and blades can handle the extra travel or wether the flying behaviour will leave much to be desired, but heck, if you don't try, you'll never know.

Wiltok
It has long buggered me that it does indeed fly backwards faster. It also rolls faster too. On my XRB at least, the fore-aft servo horn are not centered(parallel) out of the factory. It's probably because the tail is heavier than the front. Even if you move the battery to balance, there'll always be all the extra mass to slow down the fore-aft motion. If the horns are not centered then the servo travel for forward flight will always be lesser than the travel for backwards or left, right cyclic. That's why even though I like the Lama body, I've been doing all my flying without it.

Rick's suggestion also solves the limited servo travel problem. On a computer radio I can now dial in mebbe 70% EPA for all cyclic controls except forward where I leave at 100%. And if I want to retain the docile hovering manners I'll use negative expos.

All in all, extra travel is definitely a very good thing! :D

#11 coaxial-gyro Jan 20, 2005 03:37 AM

Quote:

Originally Posted by wiltok
Has anyone else noticed the XRB flies much faster backwards? It took me a while to learn nose in flight - and it seemed like I could zip around backwards very quickly. Maybe it's my imagination...??


I took the whole canopy inc' tail ,straight off my eskyXRB that provides me full forward backward tilt for FF travel , the tail inhibits the forward tilt !. :mad: as so was metioned you fly better backwards becuase the tail tilts you better that way . Now I use no body at all , the dam thing is twichy as hell as there's nothing to counter act it , my friend thought it was ment to yaw at 1000 rpm !

#12 edwardp Jan 20, 2005 02:31 PM

FFF mod first impression
 
Drilled the holes 4.5mm above the stock position. A tad more than Rick's. Figured if it becomes too squirelly, I'll still have space to drill another pair in between. Fitted all new blades(unlaminated) to eliminate at least one variable and we're set to go...

And how it goes! The sticks are definitely much more sensitive. But there's also a very nasty and consistent wobble. No problem, I'll just adjust the tracking and improve the balancing. Took her up again soon after. But what? It's wobbling even worst than before and then it happened! A spectacular blade strike! No damage luckily. My first crash in quite a while. Never mind, let's take a breather and figure out what's wrong. Ok, unlaminated blades are definitely a no-no, also mebbe I'm so used to the stock controls that I'm overcontrolling? Well nothing that expos can't fix! -30 exponential on all cyclic controls ought to do it for the time being...Promptly tried it. No good. Not much of a difference. The wobbles still there, controls are all over the place. Ok, mebbe I overdid it on that pushrod throw. So I drilled another pair of holes in between the new holes and the stock ones. They are now only 2mm away from the stock location. Again I took her up.... :(

To make a long story short, nothing really worked for me! I got more servo travel but that's about it. I did minimise the wobbling towards the end but the lower blade tracking had to be way off to do that. It's not so much the controls, as it pretty much goes where you tell it to go, but what comes after that, that leaves much to be desired. Where on the stock setup, it will settle into a nice predictable hover everytime you 'brake' a forward motion, on this it'll just drift in one direction or another. At this point I'm really starting to appreciate the precision of the factory setup and the ammount of testing, the engineers must have put thru, to give us the XRB.

Oh well, no harm done. Just a quad of measly blades. Don't try, won't find out. But don't take my word for it...Two wrongs don't make a right... :o

For what it's worth, I still think it's a pretty good idea, Ricky. ;)

#13 ELGEE525 Jan 20, 2005 08:08 PM

I think that when you change the angle of the control lever, you need to adjust the control link(it screws in/out) to insure the lower blades are at the same angle of pitch that they were at before the mod. By raising the pitch lever angle to the higher hole, you are shortning the link and decreasing the pitch of the lower blades, throwing the system out of balance. The higher up you drill the holes, the more angle , the longer the link needs to be. Just a thought, I'm on the road on a business trip and the heli is at home so I couldn't test it before I posted this. It's just mechanics-- and may not be the solution to the wobble. The larger change in cyclic definitely calls for laminated blades to prevent blade strikes. By the way, I've now got three weeks or more on the same set of strapping tape/carbon rod leading edge blades- including some pretty substantile blade strikes on various cars, furniture and pets- and they are still in great shape.
My XRB probably has close to 150 flights on it with NO electrical or motor problems- I opened up the entire case for cooling and keep the motors,gears,and rotor shaft well lubed -light oil on the motors, lithium grease on the main gears, and graphite on the mainshaft. Less friction = more horsepower and more airtime, and a lot less stress on the motors. I can't believe this thing has lasted this long !!Four months of continous flying. I wish I had this learn on before I crashed a bunch of Piccollos and Hummingbirds !! It was having a heli so stable that I was able to get my visual orentation in order,and my control inputs to become natural instead of panic reactions. Now it's time to finish my T-REX !!

Larry G.

#14 OPP_HELI Jan 20, 2005 08:37 PM

I drilled at a 2mm about the stock hole and it worked real well!!!!! :D

#15 rickyblaze Jan 20, 2005 08:43 PM

I have observed that it flys better forward but has a slower reverse now


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