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Nov 20, 2012, 10:59 PM
Just fly
evltoy's Avatar
ahh... sorry. I just did a quick read and looked at the links.

Have to excuse me as I'm in the middle for writing code and me head is fried from doing it for the last 3hrs.
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Nov 21, 2012, 02:47 PM
Registered User
Atomic Skull's Avatar
Helidirect has the RJX 500 FBL head for less than Hobbyking now, and they carry the silver version as well.

http://helidirect.com/t-rex-500-flyb...de-p-18628.hdx

http://helidirect.com/t-rex-500-flyb...er-p-24229.hdx
Nov 21, 2012, 02:52 PM
Need More PURPLE !!
Dejavu*Xion's Avatar
Ya know what im looking for and just cant seem to find. Is the Limited Edition silver "align" 450 fb head. Or did align even come out with this in the 450 size ? Sure would like to find one.
Nov 21, 2012, 02:52 PM
Registered User
Atomic Skull's Avatar
Quote:
Originally Posted by eagle777
Anyone getting tired of hearing about Hostess? I didn't know it was such a deal. Do a lot of people eat Hostess snacks? I haven't for quite a while, and really don't know anyone that admits to it. Probably the nostalgia, but I did see people buying like a $100-200 worth of Twinkes and HoHos and whatever else at the local Hostess store on the news. Heh, we can be so manipulated
I find it ridiculous that they are shutting down a profitable company just to make a stand on ideology. There's no way that "we can't afford to stay in business if were pay our employees decently" can be true with how profitable that company is.
Nov 21, 2012, 05:34 PM
Registered User
mhills51's Avatar
Sometimes you can take the color off with oven cleaner.
Nov 21, 2012, 05:58 PM
Mallcopterist
2Doggs's Avatar
Quote:
Originally Posted by Atomic Skull
Helidirect has the RJX 500 FBL head for less than Hobbyking now, and they carry the silver version as well.

http://helidirect.com/t-rex-500-flyb...de-p-18628.hdx

http://helidirect.com/t-rex-500-flyb...er-p-24229.hdx
I really like the HK RJX head on my 450, and the 500 head looks to have three Jesus bolt hole options, which is handy for setting it as low as it can go.

Like the 450 head, though, it looks like it has really long grip arms. That results to the need to use longer servo arms, which will result in the servo to swash links being even more out of vertical.

Any idea what the distance is from the grip arm linkage ball to the centre of the feathering spindle?
Nov 21, 2012, 08:00 PM
Closed Account
Quote:
Originally Posted by 2Doggs
I really like the HK RJX head on my 450, and the 500 head looks to have three Jesus bolt hole options, which is handy for setting it as low as it can go.

Like the 450 head, though, it looks like it has really long grip arms. That results to the need to use longer servo arms, which will result in the servo to swash links being even more out of vertical.

Any idea what the distance is from the grip arm linkage ball to the centre of the feathering spindle?
I measured about 29mm.
Nov 21, 2012, 09:07 PM
Mallcopterist
2Doggs's Avatar
Quote:
Originally Posted by eagle777
I measured about 29mm.
Thanks!
Nov 22, 2012, 07:53 PM
Registered User
Atomic Skull's Avatar
Quote:
Originally Posted by 2Doggs
I really like the HK RJX head on my 450, and the 500 head looks to have three Jesus bolt hole options, which is handy for setting it as low as it can go.

Like the 450 head, though, it looks like it has really long grip arms. That results to the need to use longer servo arms, which will result in the servo to swash links being even more out of vertical.

I have an RJX head on my 500 now and it works perfectly fine with the links set to 19mm out on the servo horns as specified in the manual. In the Robird setup I didn't even have to adjust the collective pitch min/max sliders. +/- 12 degrees was the default 100% on the sliders.

EDIT: Actually this is wrong, the manual specifies 16-16.5 and I have them set to 17.5 which is the closest hole on the servo horns.
Last edited by Atomic Skull; Nov 23, 2012 at 01:17 AM.
Nov 22, 2012, 08:30 PM
Mallcopterist
2Doggs's Avatar
Quote:
Originally Posted by Atomic Skull
I have an RJX head on my 500 now and it works perfectly fine with the links set to 19mm out on the servo horns as specified in the manual. In the Robird setup I didn't even have to adjust the collective pitch min/max sliders. +/- 12 degrees was the default 100% on the sliders.
That's good to know. On my 450, if I set up -12 to +12 and 8 of cyclic, I ran out of servo travel with 13mm arms, and ended up using 15mm arms. So the grip arm/servo arm ratio on the 450 ended up as 22/15 = 1.47, fairly comparable to 29/19 = 1.53.

As a matter of interest, how vertical are the servo to swash links at 50% collective? I gather Align moved the servos slightly further away from the mainshaft on the 500E Pro.
Nov 22, 2012, 11:06 PM
Closed Account
Here's what I have at ~50% collective at more or less straight on. I understand it is non-optimal, but the head works well for me. I just bought a couple nut drivers for 450 & 500 to stop chewing up the grip nuts with needle nose pliers
Nov 22, 2012, 11:17 PM
Mallcopterist
2Doggs's Avatar

Serendipitous?


Quote:
Originally Posted by eagle777
Here's what I have at ~50% collective at more or less straight on. I understand it is non-optimal, but the head works well for me. I just bought a couple nut drivers for 450 & 500 to stop chewing up the grip nuts with needle nose pliers
Thanks for posting the pic. The links look to be 2 or 3mm out of vertical, but at least all three are at more or less the same angle - so you'll get a differential pitch of only 3% or so. You get about that much differential from the angled links from the inner swash to the grip arms, but it's in the opposite sense, so everything cancels out, almost as if it was meant to be that way....
Nov 22, 2012, 11:28 PM
Closed Account
Quote:
Originally Posted by 2Doggs
Thanks for posting the pic. The links look to be 2 or 3mm out of vertical, but at least all three are at more or less the same angle - so you'll get a differential pitch of only 3% or so. You get about that much differential from the angled links from the inner swash to the grip arms, but it's in the opposite sense, so everything cancels out, almost as if it was meant to be that way....
Sorry, I thought you wanted swash to head. I'll attempt to make a measurement or two.
Last edited by eagle777; Nov 22, 2012 at 11:34 PM.
Nov 23, 2012, 12:20 AM
Closed Account
The main shaft would bisect the horizontal lines, the end of the lines represent the ~center of the ball links. Hope this helps, I've learned a bit from your posts from the past day here. And elsewhere of course.
Last edited by eagle777; Nov 23, 2012 at 12:31 AM. Reason: I wish I had a CAD program to make this to scale.
Nov 23, 2012, 12:40 AM
Registered User
Atomic Skull's Avatar
Quote:
Originally Posted by 2Doggs
That's good to know. On my 450, if I set up -12 to +12 and 8 of cyclic, I ran out of servo travel with 13mm arms, and ended up using 15mm arms. So the grip arm/servo arm ratio on the 450 ended up as 22/15 = 1.47, fairly comparable to 29/19 = 1.53.

As a matter of interest, how vertical are the servo to swash links at 50% collective? I gather Align moved the servos slightly further away from the mainshaft on the 500E Pro.
As far as I know they didn't, the angled links on the Trex 500 were designed that way intentionally. One of Finless Bob's videos explains the reasons why the link geometry is the way it is.

http://video.helifreak.com/?subpath=...ame=geo101.wmv

Quote:
Originally Posted by Atomic Skull
I have an RJX head on my 500 now and it works perfectly fine with the links set to 19mm out on the servo horns as specified in the manual. In the Robird setup I didn't even have to adjust the collective pitch min/max sliders. +/- 12 degrees was the default 100% on the sliders.
I was wrong about this, the manual specifies 16-16.5mm and I have the balls on the servo horns at 17.5mm (the closest hole to 16.5mm on the horns that come with the 28013's) I guess I misremembered.



Only thing I don't like about the RJX head is that the swashdriver arms use an oddball sized bearing that's very difficult to find. The only place I've been able to find the 3x7x2.5 flange bearings it uses are from China based sellers on ebay. Replacement arms cost $22 from Helidirect or $10 from Hobbyking. Interestingly the replacement pitch arms are actually cheaper from Helidirect than from Hobbyking.
Last edited by Atomic Skull; Nov 23, 2012 at 01:52 AM.


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