HDX300 head on a blade CP

[Mr.Mike]

I just got my new rotor head from Heli Direct. I got their new HDX300, heres a pic. http://i55.photobucket.com/albums/g1...X300-HSTXB.jpg

Here are their directions for adapting it to use with stock servos and a stock transmitter:

Option 1: Using Stock Transmitter and Servos. Take the upper mixing arm assembly off the head and turn it upside down, or flip it. Remove both upper mixing arms and turn them back right side up so the slant or “V” in the mixing arm is pointed down. Add washers to shim the arm out to clear the mixing arm assembly pivot screw - this will provide the clearance required for the fly bar control balls. Next, remove both balls from each upper mixing arm and reinstall them on the inside of the mixing arms. Next, remove the lower mixing arm and turn it upside down, or flip it. Remove small c-clip (be careful not to loose the c-clip) on both the support arms and swap them. Pay attention to the ball holes on the support arms, making sure they are properly positioned to reinstall on the swash plate. Reinstall the c-clips and swash plate.

So a couple problems... The pivot screws for the upper mixing arm assy were glued or locktited in place, I wrecked 3 allen keys and nearly wrecked the screws taking them out, I thought I was going to strip some thing out.

The other problem I had is when you flip the arms up right they require extra washers which seem to not be supplied with the the stuff they send, not only that but to ship it out enough you need nearly 1/8" of shims. I sent a message to the company to help me solve the problem. In dealing with the issues this evening I wonder if any one there has tried to do this them selves with a pre-assembled part....

either way, if any one has any advice it would be of great help, this head unit is stunning and I really want to put it good use.

Thanks guys
Sincerely,
Frustrated beyond control

ha ha J/K

mike

[Daz(DJLFlapper)]

Hello Mike,

Sorry to here that your project is not going as smooth as listening to the instructions lead you to think. The link that you posted does not work either, but that is nothing important.
Their is always a risk when you take on any part that requires adaptations to fit. Especialy if you don't have any one to ask if it works before you order your parts. I wish you all the best with the rebuild and hope that it works out ok. If you do get it sorted how about a pic to show off you work.

Good luck,

[Mr.Mike]

Well what is, is this...

stock, the blade cp servos pull down the swash to add pitch to the blades, this head wants the servos to push up. so by swaping the links you change the geometry in a way that the blades add pitch with downward swash movement. So all well there.

I still need some tiny washers with a 1mm hole in them and longer bolts to attach the arms. Once I find the proper spacing and the right length screws I can make measurements to send to heli direct. They were all about useing what ever info I come up with. If they supplied a coller and longer screws this swap would be a snap. They seem more then willing to let me help them sort the problem, which is cool.

I maybe a noob pilot, but I build custom cars for a living, this is the same thing just on a smaller scale

I'll let you all know how it is going and try to post pics too, if i can figure out how ha ha!!

Mike

[MichaelDZH]

Hi. I find forum about work and travel. Where can I to see it?
Best Regards, Michael.

[Mr.Mike]

OK, one problem solved. my blades will now get positive pitch... well maybe with some link adjustments ha ha.. I have some binding issues though but I am going to wait till I get my main gear and the shaft firmly bolted down before I go too far. Its funny too because heli direct said they were having problems with bent shafts, even at spool up.

Their fix was to make stronger shafts but I think its the fly bar ring hitting the blade grips and my binding issue that causeing the bent shafts. when I work the ele. and arl stick it torques the main shaft pretty good in the housing. I dont know if its a link issue or not. being new its tuff. but I did watch some of the posted vids here which will help me with set up.

well I'll keep you posted.

mike

[ArrowNaughtic]

Hi Mike,
I too bought the hdx300 head and shaft from an online vendor. I ended up switching to a futaba radio (6EXHP) and did my adjusting in the swash menu to reverse the pitch.
Binding issues.............. For a machined part to come with so many binding issues has forced me to remove the CNC head and go back to stock. Also stock TX as I didn't want to mess with the programming nitemare i had setting up this "upgrade". I have completely disassembled the head, lubed all metal parts, smoothed out the feathering shaft and blade grips, and still have a sticky collective issue and also the dreaded tail bob pointing at blade grips. When you recieved yours....was it as stiff and sticky as mine was? I am going to have to tear it all apart again, and sand smooth all parts and lube again, until I can breathe on any part of the head and move it. Then will reinstall and adjust as necessary.
The guru at my LHS told me that setting up your servos first is the key, then set your swash and finally adjust all your other mixing arms and blade pitch. there is a good hdx head setup video on this site for the HDX300 head, the older style but still a good base point to go off of. http://helifreak.com/viewtopic.php?t=17482
See if that head setup video clicks for you. Towards the end he added a little stuff as in the video his setup was causing binding issues so he corrected it.
Hope some of that helped, and when you find the perfect setup.......tell me too!!!


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Of all the things I ever lost.............................. I miss my mind the most!

[Mr.Mike]

Well Arrow.

This is the run down so far.

With the newer style head I have there are a few issues, mostly because I am running stock electrics. When you order the head (newer model) you also need a new mainshaft gear.

The first issue is dealing with pitch. The stock blade CP creates pitch by pulling the swash down. This new head is designed to create pitch by pushing the swash up... so right off the bat some thing needs to change. I had to take the upper mixing arm assy off and flip it, then take the two arms off and flip them over, then add spacers and longer bolts so they clear the pivot. Then the blade grips have to be reversed so that the ball joint is on the leading edge insted of the trailing edge. So far so good.

But at this point the links that run from the swash to upper mixing arm bind on the lower mixing arm bolts. To fix that I had to flip the lower mixing arm assy up side down. On heli direct's site they now suggest that you swap the two arms, but the arms are identicle so that dosnt work so well, they are made to attach to the ball from only one direction. With a little effort they can be switched, it just dosnt seem right.

I started leveling things up beginning with the swash, then moving up from there. I tried to make the arms close to level at dead stick. Every thing works smoothly and is rather nice, even under power. but.....

The all mighty but.... under full elevator or alaron(sp) the swash binds the main shaft, actually slows it down. What I need is for the servo arms to throw less. I dont know how to do that though

I was wondering if I could move the servo link closer to the center of the arm to limit travel... I'm concerned that in doing that it might make the bird a bit twitchy...

sorry for the long post. check out my other post "The head is on!" in this seciton, I have pics posted too.

[Draiter]

Hey there,
What you need to do to shorten the travel using the stock TX is to move the links on the servo horn in a hole or two, BUT, make sure you move all the links in the same amout.
Hope this helps... I got a HDX300 Head as well and have the Century main gear with auto hub... Should be easy to transfer the head to the other shaft after a bit of grinding..
Did you read the thread on pulling the shafts from old computer cd-roms... those things are STRONG....

Cheers