HDX300 Build Videos wll be here

[aklauz]

Well since the last crash I have this thing back together, gyro properly configured, switched back to flat bottom wood blades, reduced cyclic so its not as touchy, and I'm back to almost square one. The heli spools up fine. however there is not enough hold with the tail. As soon as I lift off the heli wants to spin left even with full right rudder input. This is actually my third heli I have a trex 450 and a pantera .50 that fly great and I built. This heli however has been a nightmare even setup right I can't get it to work and there are no instruction worth referencing so everything is a shot in the dark and I'm running out of ideas and money for this project so far I spent plenty and hours of tinker time and 0 flight time. Please help!!!!!!!!!!!!! lol

[aristo]

what main tail drive gear are you using.30t 36t or 40t?

[aklauz]

Best I can tell it is a 36T its the blue plastic one that came with the belt cp conversion kit here is a link to it:

http://www.helidirect.com/product_in...oducts_id=4481

Thanks again,
Ant

[aristo]

36 should hold,i use the 40 but i also made a 3mm tail shaft for mine.

[razer t-rex]

this is probally a stupid question but would i be able to use the same servos and 4in1 as my cp or do i have to buy a new control, reciver and motor?

thanks,
nick

[aristo]

the s75's while a poor choice yes.4n1 nope.

[CRJ]

Hey guys,

Does anyone know what size screw is used to clamp the tail boom to the main frame? I tried a 2X12 mm shc but its just a tad too short. I can't find any metrics in 2mm longer than 12mm. Is it maybe a 2.5X14 or 16mm? Thanks

Mike

[pete1979]

Originally Posted by CRJ

Hey guys,

Does anyone know what size screw is used to clamp the tail boom to the main frame? I tried a 2X12 mm shc but its just a tad too short. I can't find any metrics in 2mm longer than 12mm. Is it maybe a 2.5X14 or 16mm? Thanks

Mike

I replaced the screw with a stud, I bought a piece of threaded rod from my LHS cut it to length, screwed it into the hole and then put a nut and washer on. It works perfectly and clamps the boom solid.

[pete1979]

Hello everybody, please can you help by letting me know just how many of you guys have had problems fitting the upgrade 40 tooth belt pulley. I found that using the HDX300 belt with the 40t pulley meant having to shorten the boom or push it ways forwards. Neither of these really works well because the result is the same, you end up with the tail rotor clashing with the main rotor; and a shorter boom makes the tail less efficient: was this your problem and how did you find a fix and are you satisfied with the result. I am asking this because I believe that there is a really good solution and I am talking with Helidirect about this. I am posting this because it would be good to see if there is sufficient interest in fixing this problem. The cost would be under $15 and would leave you with a 40t pulley, a boom sufficient to clear 255mm blades using the latest HDX300 Tail blades. Please could you post and let me know. Thank you

[LAdamo]

On my HDX300, which took a painful amount of trial and error during the build from scratch, I use the 36T tail gear driving the 9T V3 tail shaft on the V3 tail. This gives 4:1 which seems to be plenty fast - after I did the following:

1. Use microheli tail fin for CP-Pro (takes drilling of 2 holes to make fit). MH-CP064VF is the part #.

2. Use K&B 59mm tail blades for TREX450. Only one of the 3 tail blades that helidirect lists actually works, but they are virtually the same size as the K&B and much heavier on the small, "hard to keep from vibrating", "easy to bend" tail shaft.

3. Pay extremely careful attention to the bearings in the tail case. It is easy to screw the side plates on and not have them parallel and in my experience with 2 tails, the bearings that come in tail case were bad out of the box. I believe they are 2 x 5 x 2.5. I put ceramic ones in both sides of a new tail after I had changed only one in the first and ended up blowing apart the other bearing to the point I couldn't get it out of the plate.

Dry fit the tail together without the blade grips and hub on and apply a little pressure to the shaft with a belt while rotating the shaft. Be very critical of bearing roughness that is not there without belt pressure, but is with it. I also had to trim the plastic ridge on the tail shaft gear on the right side only for the best fit.

4. Lastly, the bearings in the tail grips were the wrong size. The inner hole that the 2mm bolt goes though was 2.5mm allowing the grips to fall off center (guess the overseas factory workers don't know what 10k rpm means). I think they needed to be 2 x 5 x 2.

Don't be afraid of headspeed!

BTW - My HDX300 flies great!

[Takis]

Hi Bob and all suffering with this heli.
I have build 10 helis from Gaui 200 to Gaui 550, T-Rex, Belt CP and other. Boob videos was my school and always I ended up with nice flying helis.
With this one (I bought 2 of them) is impossible.
Nice heli, only flown for 10min.
Everything is balanced and I loose my tail due to vibrations.
I use blue pulley and tail shaft. I lost 2 tails and 3 shafts, I did everything possible. Head is vibrations free and gyro is fine.
WHat to do with the tail?
Do I have to buy another brand?
Silver pulley and shaft are better?
Is any trick I can do?
Please help me...
Best
Takis

[nexgen]

I want to see the boob videos too!!

[nexgen]

so what are peoples favorite motor for this heli. I was thinking of getting the Z-Power 5150Kv motor, but am not sure what size pinion to use. Anyone else tried this motor? Is there a "most popular" motor in this thread?

[LAdamo]

I'm running the JGF 400DH - http://www.helidirect.com/product_in...roducts_id=432 - with a 10T pinion. Bought an 11T to try, but haven't yet.

[Buzzkill]

Did anyone ever get this heli to fly consitantly? I was surprised to see this thread wasn't dead a long time ago.

[aristo]

ive got 2 of em buzz and they fly just fine for me

[LAdamo]

Mine flies really nicely as long as it isn't too windy. The small parts are easily bent/warped/worn out of whack, but it is fun.

[nexgen]

So what are people using for pack size? 2s or 3s? I did get the Z power 5150Kv, and have a 10t pinion on it. Running 3s it gets pretty hot, so I have heard that I should try 2s with that motor. For the JGF 400DH, what pack are ppl running theres on?

[LAdamo]

I use the Flight Power v2 1345mAh 3 cell with JGF 400.

[nexgen]

So I have been doing some adjustments on my head, I had to replace a bent main shaft (V3 ), and some servos. I went over everything testing in stages, heres what I came up with:

-The links on the head were a little off (v3 head), the washout arms and the mixer arms were not parallell, so I adjusted the linkage rods. The flybar cage was still a little off, and I need to work that out still.

-Spinning up the heli with no blades, and tail disengaged, the head is spot on with no vibes.

-Reconnecting the tail, with no main or tail blades, there is a small vibe in the tail, need to check the shaft to see if it's bent. no vibes in the head.

-added tail blades, no main blades, still a little vibe in tail, but none in the head.

-Balanced, and added main blades, and setup pitch on my pitch gague, and took her out to fly:

-The blades are off track and the head shakes like crazy!! I adjusted the tracking, and it looks good in my hand, but when I set the heli down and lift off, the whole thing is shaking, and barely has any lift (plenty of headspeed, can 'hear the pitch' in the blades). When I look at the heli from behind while it is in the air I can see the rotor disk, and heres the wierd part the onlu spot that it looks like the blades are out of track are from about 9 to 11 if 12 oclock was at the nose side of the disk, and 6 oclock was at the tail.

It's like that 1/4th of the disk is out of track.


I can only think that this is because either; the head is vibrating like it is, or maybe that the flybar cage is a little off, or the tail has some vibes


I think that the blades seem a little heavy, so I can see how a minute balance problem could add big vibes on the head.

I'm just not sure where to start, I guess I'll go over everything. I also have some smaller tail blades that I got here
that I want to try, thinking that the smaller size/weight may help the tail vibes. The ones I have on there now are about 10mm longer I think.


One thing I am having trouble with is the link lengths. I have seen posts on it, but they are always a little different, what has worked for others for link lengths on the v3 head. Also if anybody knows how high the swash should be from the frame that would give me a great place to start as I have no Idea!