bl 4g3 and vp tail

[keirhag]

I've been workin' on this one for about a month and a half now. unfortunately my digital camera bit it and haven't gotten around to get a new one so the pics are off my phone..... basically what you're lookin at is a 4g3 with 4#3b servos, spectrum ar6300 rx, medusa 12x30 5300kv bl motor, castle 6a speed controler, blue arrow micro gyro, mia tuff lg, at the moment the gen 1 airy metal head, and a hand made shaft driven vp tail.
at some point when i actually buy a new camera I'll try to get some video up of it flying.
I'm hoping some others have tried this and curious how you made out. or if anybody has any questions on it I'll be happy to answer them.

[mxrider2637]

Dude that is nice, i might get a 4g3, are they worth it?

[keirhag]

honestly, buying it stock (rtf) I have no idea. I built this one from parts bought individually. I have not gone inverted with it yet, probably won't for a while. but as far as learning to fly these type of heli's, I'd like to say walkera is the way to go. reward verses cost they are the best. good luck!!

[Dusty1000]

They are brilliant helis, though the brushed motors make the 4#3B motors seem reliable. There is a brushless 4G3 about to be released, some are for sale at the moment though have the old 4 in 1: RX2605. The new 4 in 1 will be called RX2605A, should be out in a couple of weeks. Also there is a 'V2' kit out which consists of better servos and a new frame. Hopefully the brushless 4G3s will be fitted with this.

[Tom77]

That looks great!

Where did you get the parts that you used to make the shaft driven VP tail? How many of them did you have to fabricate yourself? How hard did it turn out to be compared to what you thought when you decided to do this?

[keirhag]

oh boy let me see. some of the parts are made from old 4#3b parts some are modified parts from the 4g3 and the rest are either carbon and flat sheet fiberglass.
i purposely cut the blades from 4#3 main blades so that they would have a small amount of positive pitch. the blade holders are cut from old 4#3 tail motor holders so they do have small 3x1mm bearings in them. the center carrier is the flybar holder from the 4g3 and this gets a bit tricky. in order to use two 6x1mm screws to hold the blade holders and at the same time clamp the assembly to the main shaft you have to modify it by square clamping the ends of the holder because its cut for a 1.5mm screw. the slider was the toughest part. it is the base of a 4#3 frame were the bearing for the main shaft presses in, cut and filed with a ball end on one side and flat pin on the other. the inner part is a small peice of aluminum filed down to except two small ball connector cut from 4g3 blade control arms and then mushrooned over on the other side to keep the bearing in place. the gears are 4g3 tail gears. i reamed out the larger gear to fit snuggly over the main shaft and hand filed two small ones so that they would mesh properly at a 90 deg angle. you have to cut alot of the frame out to fit the gear in. so i added some reiforcement to the main shaft support and to the tail shaft holder. added some pictures so that you can see some of the reinforcement and if you look close you can see the drive gear on the main shaft. i use a 4mm outer with 3mm inner dia carbon tube for the tail and a 1mm carbon rod for the shaft ( thought about using piano wire for this but found that the carbon rod has alot of spring to it which has saved me from breaking other parts during flight). the same 3x1mm bearings (4#3 and4g3 tail blade shaft bearings) are used in the tube to hold the shaft. i used 4 total one at each end one close to the middle to support the shaft and one right at the spot where the set screw holds the tube to the frame so that it doesn't crush the tube. a little trick i learned is the bearings don't fit real tight in the tube, but if you dab a small amount of zippy glue on the outside of the tube it swells just enough to tighten down the bearings. another thing is the large gear tends to drop a little after flying causing some play in the gears so i had to put a small spacer between it and the lower bearing to hold it up.
I wasn't really sure what to expect when i started this one. it was fun though and it flies great!!! i think i spent more money on it than i had expected but it was worth it.
If this is something anybody wants to do I'll answer any questions you ask.

[Tom77]

Thanks for all that info. It looks like a fun project. I am going to think about doing something like that one day, but not ready to start quite yet.

Have fun flying it! Let us know how it goes.

[mprasm]

Can you take better macro shots of the VP tail, please? I'm looking for a person/way to make a DD BL VP tail to perfect this thing without the fuss from shaft/belt. The ESC signal for main motor will be done in parallel to the tail motor ESC so that it emulates proportional throttle RPM. The tail rudder servo is done via the now available rudder socket then via conventional gyro pass through. EQMOD did this with his CP2. I hope you/somebody else can pave the way for 4G3 version, since you have successfully worked out the details for VP setup. Thanks!

PS: Did I wrote how cool neat & clean your VP design is? Well, it is!

[keirhag]

I'm in the process of buying a new camera. so as soon as it comes in I will post some higher quality photos.
that sounds like a great project! keep us updated on the progress. would love to see some pics.

[mprasm]

Perhaps may spark some inspiration. Low-cost custom part manufacturing.
http://www.shapeways.com/model/13225/rotor_tail.html

[lesodell]

cool stuff , it would be nice if walkera would make a tail that would hold i would gladly

[keirhag]

ok here are some good photos. will post some video soon. found out the hard way that if you don't round off the ends on the airy cf blades, they don't fold completely if you hit something and you will bend the holder shaft

[keirhag]

its still a bit on the heavy side but once i get everything set to my liking i'm going to work on mothing it. oh and a pick of what to do with the blades and what will happen if you don't.

[mprasm]

Wow! Thank you for the extremely clear photos. Will study them thoroughly. Excellent craftmanship, btw.

[keirhag]

a little video of the heli flying. sorry for the terrible piloting skills. still learning. and don't mind the hung over roommate.

walkera 4g3 bl spektrum variable pitch vp tail and my lousy piloting skills (2 min 0 sec)

[lesodell]

very nice keep up the good work

[keirhag]

if you haven't see this yet, here is a thread worth checking out http://www.rcgroups.com/forums/showt...=871709&page=1 above and beyond impressive!!

[mprasm]

USUL's works are amazing. Though I wished he would produce something that will easily adopt 4G3 mechanics/electronics and combine it with his tail. Sort of like the Neon BD frame or at worst, Freestyle VP tail both for HBCP2/FP. Now it will take him a longer time just to get the Mini Echo into mass production, while 4G3 is already screaming to be perfected with a new frame w/ SD/VP tail.

[tintoy]

This is a fantastic bit of work! (the 4g3 modding, and the mini-echo). The 4g3 is just astounding!

[keirhag]

I was curious.. does anyone have any experience with hh gyros. i just installed a telebee gr201 on my 4g3 and it seems to work, but i was under the impression that it would eliminate tail wonder on idle up. its almost like it takes a second to orient itself just after takeoff. I'm not entirely sure if its just the way it is or i have something setup wrong? any input would be heplful. thanks