HDX300 Build Videos wll be here

[ptremb]

Ok guys here is a strange one.
I finaly got my pinoin in and installed,wound it up to check the direction(wrong of course)flip 2 wires and wind it up again.The tail belt popped off the leading(left side) guide roller and proceded to run on the outside.Oh well it's not tight enough.Snug up the belt a little more and try again.I saw the belt ride down the guide roller and I shut it off before it popped.
I pulled the servos and proceded to move the guide rollers to the rear mount holes closer to the tail boom thinking the belt twist was pushing the belt down on the roller faster from the close relation to the drive sprocket angle of attack.Put it all together wound it up,same thing but faster on the ride off the guide roller.
Ok what have I messed up.I pulled the rollers off,and spun the main gear by hand to watch the tracking.Smack dab in the middle of the drive sprocket.Install the trailing roller and spin the main gear,still in the middle.Install the leading roller and spin,the belt walked off.Try swapping rollers, the belt still walked off.I thought the rollers looked like they were to high causing the belt to go up than down, so I put a washer under the stand off to lower the guide into a more straight alignment with the main drive sprocket.this causes the belt to ride down the guide roller so fast that 1 full revolution of the main gear and the belt is off the leading guide roller.
Take both rollers back off and spin up by hand and the belt stays right in the center of the drive sprocket.
So what do you think?
This is with the plastic tail box by the way.

[cbdane]

Ok guys here is a strange one.

This has been an interesting project. Unfortunately, since I got together all of the parts I've had business travel and lot's of work so I just haven't pushed it to completion. Everything has been a little bit of a struggle making things fit, work, etc. I have not read anything very positive about this heli except from those who are just reacting to the pretty pictures on the web.

I was looking forward to Finless flying experience but, obviously, no success there or we would have heard. I have searched for one tiny bit of video evidence that the heli flies well (other than the 2 clips on HeliDirect) and I can't find any. I've shelved all my bits 'n pieces for now until I have more time.

On your pulley problem, the tail and pulleys are completely assembled on mine and at least spinning it by hand doesn't roll the belt off. I haven't installed the motor and tried to power it up, yet, though.

I'd love to hear what issues Bob is having with his to prevent further reports.

[Finless]

Hopefully I will have my tail issue resolved and be flying it this weekend.

Bob

[ptremb]

I have been doing the same cbdane.I started this in july.getting parts every few weeks.I had the frame assy together for over a month,than I finaly got the pinion,everyone was out once I had a few extra $$(just waiting on the head now,hopefully tomorrow).Everything went together fairly easy and in good alignment,I thought,but once I put real power to it I got this belt issue.hopefully I can figure this out before monday as it's back to work than.

[greenh0rn]

Ok guys here is a strange one.
I finaly got my pinoin in and installed,wound it up to check the direction(wrong of course)flip 2 wires and wind it up again.The tail belt popped off the leading(left side) guide roller and proceded to run on the outside.Oh well it's not tight enough.Snug up the belt a little more and try again.I saw the belt ride down the guide roller and I shut it off before it popped.
I pulled the servos and proceded to move the guide rollers to the rear mount holes closer to the tail boom thinking the belt twist was pushing the belt down on the roller faster from the close relation to the drive sprocket angle of attack.Put it all together wound it up,same thing but faster on the ride off the guide roller.
Ok what have I messed up.I pulled the rollers off,and spun the main gear by hand to watch the tracking.Smack dab in the middle of the drive sprocket.Install the trailing roller and spin the main gear,still in the middle.Install the leading roller and spin,the belt walked off.Try swapping rollers, the belt still walked off.I thought the rollers looked like they were to high causing the belt to go up than down, so I put a washer under the stand off to lower the guide into a more straight alignment with the main drive sprocket.this causes the belt to ride down the guide roller so fast that 1 full revolution of the main gear and the belt is off the leading guide roller.
Take both rollers back off and spin up by hand and the belt stays right in the center of the drive sprocket.
So what do you think?
This is with the plastic tail box by the way.

Hi,

is the belt on the tail gear and tail pulley centered? could that be the problem?

[ptremb]

I don't know what it's problem was, but now it won't throw the belt no mater how hard I try.still rides very low though so I don't know how long the belt will last.

Got my head today and decided I'd give it a chance.Put everything back together,setup the servos/links/etc.

To give some info,I'm doing mine slightly different than all the others in that I am going to use a 2 cell as opposed to the 3 cell since I have them already.I purchased the 400dh to use on this based on the Kv rating of 4400 at JGF.Couple this with a 9 tooth pinion should net near 1900 head speed.The short time that I had this thing wound up with blades on it,it sounded sick :twisted: .I can only imagine what a 3 cell would do.I'm going to tach it later today to set my throttle curve.I'm going to have to bring my current clamp home next week to make sure I'm not going to kill the batts or the motor as max power is 170w (15A@11.3V) so this would be about 22A@7.4V,a little high for my batts,but I figure that for the week end I won't do much more than hovering and light circuts till I get it trimmed out.

I still need to finish making my batt tray and get the gyro mounted/wires secured.Hopefully late friday I'll get to see how it flies.
Thanks much guys.

[hdx300hope]

I was just wondering if anyone can help with my problem. I have the hdx300 with the cnc head & tail and the problem that i have is that when i start this thing up my tail holds on the ground but once i leave the ground it starts spinning in circles. I check to make sure that my heading hold is going the right way and it is. I am using the G90 Eflight Heading hold that i used on my Blade CP Pro. Any Help would eb great?

[greenh0rn]

I was just wondering if anyone can help with my problem. I have the hdx300 with the cnc head & tail and the problem that i have is that when i start this thing up my tail holds on the ground but once i leave the ground it starts spinning in circles. I check to make sure that my heading hold is going the right way and it is. I am using the G90 Eflight Heading hold that i used on my Blade CP Pro. Any Help would eb great?

umm.. your tail rotor going counter clockwise?

[ptremb]

A few things are needed before an answer can be given.
what direction is it spinning in,cw/ccw?How fast is it spinning?can you stop the spin with control input from the sticks?Have you tried to reverse the gyro switch on the gyro(not the radio)?does this make it better or worse?Is the tail rotor turning in the correct direction?ie ccw when looking at the tail rotor(rotating up into the main blades),tail blades installed correctly.Do you have the tail pitch slider centered?any binding in the linkage to the tail?If you can answer correct to all these questions,see below.If any answer is not correct, repair or ask how before seeing below


*********************
the following relates to the latest tail design only,see here for a pic.
http://www.helidirect.com/product_info.php?cPath=30_65&products_id=1487
If you don't have this assy DO NOT FOLLOW.


there have been some reports that the latest version(narrow case w/ no set screw on the tail shaft sprocket) of the cnc tail won't allow enough pitch to counter the torque so a "rebuild of the tail" is required.Possible assy/design flaw
the first fix is here.
http://www.rcgroups.com/forums/showpost.php?p=6049088&postcount=947
a better rebuild that allows things to have correct alignment
http://www.rcgroups.com/forums/showpost.php?p=6092787&postcount=1085
Hope this helps.

[ptremb]

one other thing to check is that your tail drive sprocket isn't spinning on the mainshaft.I just got back from my maiden flight and was having a hard time keeping the tail straight at the end,turns out the tail drive sprocket was slipping on the mainshaft preventing correction of much more than a hover.

[hdx300hope]

Ya i looked again and every thing is right on mine my helli is turning ccw even when i have the tail turnrd full to try and hold it stright. It seems to spim fairly fast so i think that i have to rebuild the tail i guess?, Did you have the same problem with yours? Would it help if i used the 40T instead of the 32T?

[head]

If your belt tension is not tight enough your the tail will spin.

[hdx300hope]

But my belt tension is very tight and my tail is not slipping. Thats why i thought maybe going to a bigger tooth on the main tail gear that might give me some more tail spped to hold the helli staight?

[carlo_the_wonder_frog]

While trying to seat my bearings in the belt pulley, I covered the bearing in cloth and used small pieces of ply on each side. Somehow I inadvertantly got the whole assembly canted at an angle. Ended up mushrooming one end of the pulley, its a really bad bend. Anyone know where to get just a pulley? I may have to buy a whole new frame kit :( aaargh I'm such a moron!!

[greenh0rn]

While trying to seat my bearings in the belt pulley, I covered the bearing in cloth and used small pieces of ply on each side. Somehow I inadvertantly got the whole assembly canted at an angle. Ended up mushrooming one end of the pulley, its a really bad bend. Anyone know where to get just a pulley? I may have to buy a whole new frame kit :( aaargh I'm such a moron!!

I messed up my idle pulleys too. Emailed Helidirect about 2 weeks ago.. still waiting.........

[cbdane]

While trying to seat my bearings in the belt pulley, I covered the bearing in cloth and used small pieces of ply on each side. Somehow I inadvertantly got the whole assembly canted at an angle. Ended up mushrooming one end of the pulley, its a really bad bend. Anyone know where to get just a pulley? I may have to buy a whole new frame kit :( aaargh I'm such a moron!!

Try this one:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLBJ8&P=ML

or here:

http://www.grandrc.com/inc/sdetail/12433

Seems like to me, either of these would work and the bearing is already pressed in. They are slightly larger in diameter so the only concern would be whether they force the belt halves to close together at the inlet to the tail boom.

[johnnychimpo]

In your pic, the pullys are off from the boom like mine. Is this correct alignment or do we need to file down the pully spacers to make the align with the tail boom???

OK new frame build is up... Basically what changes was what screws to use where. No biggy.

However I do want to share this. The manufacturer shows the 2 main pulley idlers being under the screws for the rear servo plate. I did not like that approach personally.
1) I felt it was to close to the main drive pulley and might stress the belt more
2) It left longer run of the belt with no support.

So below is a picture showing how the manufacturer built it but in my videos you will see I prefered to mount them in the rear holes.

Just sharing for the benefit of all so you can decide.

Bob

[greenh0rn]

While trying to seat my bearings in the belt pulley, I covered the bearing in cloth and used small pieces of ply on each side. Somehow I inadvertantly got the whole assembly canted at an angle. Ended up mushrooming one end of the pulley, its a really bad bend. Anyone know where to get just a pulley? I may have to buy a whole new frame kit :( aaargh I'm such a moron!!

Try this one:

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXLBJ8&P=ML

or here:

http://www.grandrc.com/inc/sdetail/12433

Seems like to me, either of these would work and the bearing is already pressed in. They are slightly larger in diameter so the only concern would be whether they force the belt halves to close together at the inlet to the tail boom.

if larger dia pulleys are used. wonder if its better to mount the left one on the lower hole and the right one on the upper hole :mrgreen:

[chrisg]

I have the original kit with the first aluminum tail assembly. No matter what i do my heli just spins. The gyro is setup correctly and the ruder is operating properly and I have ample head speed. Can you help me?

[bluemooone]

Spinning around and around and around ect. ................. even tryed a 401 . I think It broke its little 401 brain . I am thinking the front pully is too small.............

[rdlohr]

You don't have the direction switch on the gyro set wrong do you?

[chrisg]

You don't have the direction switch on the gyro set wrong do you?

The gyro switch is correct. When its in the wrong position the heli spins even faster.

I have tried locking the rudder in the left and the right positions and then moving the heli's tail left and right while at full throttle and I feel no resistance at all. When I do that with my TREX I can feel the resistance from the rudder. I don't think there is enoug speed on the tail rudder.

[bluemooone]

Nope set right . right direction ect . Will spin either way now , just will not hold ,and a 401 wags the tail at all settings. Could someone who has this working tell me there head speed ,say at lift off? this might be key here.

[ptremb]

I have the original kit with the first aluminum tail assembly. No matter what i do my heli just spins. The gyro is setup correctly and the ruder is operating properly and I have ample head speed. Can you help me?

when you assy. the tail, did you use the blue cnc tail sprocket that came w/ the frame kit? if not check that your tail has an 8 tooth sprocket and not a 10 tooth sprocket. The reason I'm asking is the first few original cnc tails that were shipped are actualy for a shogun v1 that run a 10 tooth sprocket on the tail w/ a 40 tooth main sprocket to give a 4:1 ratio, and the hdx needs the 8 tooth sprocket on the tail to match the 32 tooth drive sprocket to give a 4:1 ratio

[dr5liter]

BOB, I have a Blade Cp pro with all the hop ups, I also bought all the goodies for the HDX300, My question is could I use the eflight 20amp ESC and 370 brushless motor? Are the servos any good on the eflight? I have so far bought everything but the last 3 control hs55 servos, I did buy the hsd-877 tail servo. Im almost done but need advice on the motor and esc. And what gear to use, I dont understand what a 11t or 9t differance will be. A 101 on gears would be great. I wont be doing any 3d for a while. Im already about $400 into it and im trying to save a few bucks.