PDA

View Full Version : 500 ESP, DS-510 linkage ball on 13 mm? --- and Step L ---


Pages : 1 [2] 3

labmaster
09-24-2011, 01:24 AM
The original T-Rex500 is not very optimal at the overall geometry of the swashplate control.

The problem is that the swashplate inner ring to outer ring ratio is not too good.
As this ratio defines the collective to cyclic ratio you will have problems maxing out the pitch ranges and not violating the cyclic resolution restrictions of a flybarless system.

You have to modify the swashplate ratio to get more collective and less cyclic deflection on the same servo travel, as this would allow you to move the ball on the servo outside a little bit and still achive blue at 6 (means, no lost cyclic resolution) . With the ball out a little bit on the servo you then are able to get a higher collective range on the bladegrips with less servo travel and this on the other hand will save you some servo travel for getting more cyclics before running into any binding.

To modify the swashplate ratio you have to make the outer ring of the swashplate wider or the inner ring of the swashplate smaller. At the original Align FBL conversions you get shorter inner ball to make the inner ring smaller, this helps but could not fix the problem completely (depending on the collective and cyclic values you want to go)

Another problem on this heli is the limited room for the servo horns, as especially on the elevator servo the servo is not able to do its full range without touching parts of the frame.
For this i modified a servodisk so that it looks like a servohorn with a curve in it where it is going around the binding place a bit, every millimeter could be of help here.

best regards,
Walter

helidude71
09-24-2011, 04:13 AM
... across the pond from you.

Scott

:rotf

helidude71
09-24-2011, 04:19 AM
I'm not quite sure what you mean by how I made out with step L, I didn't have any issues. I basically went to the extents like it said and set everything for just under max throws where there is no binding. There actually didnt appear to be any difference in the amount of throw on the swash. At least I didnt see any. I'm new to the whole FBL setup, so I wont know until I do a test flight, which wont be untill Sunday cause I'm working tomorrow. Using 510M's btw.

OK, the reason I asked is because you had the servo balls one hole further out (16mm) I guess?
This is not recommended by the Align FBL manual but will give you more servo throw.
I wonder if you can get a blue LED with this setup for Step J and L?

Do you remember if it was without binding?

helidude71
09-24-2011, 04:29 AM
...

On the aileron and pitch servos, I can see where the ball has rubbed on the label of the servo. No biggie to me as long as the servo still moves through and the arm doesn't flex. The link barely touches the plastic surrounding the servo's post. No singing. The light is blue.

Frankly, I can't ever see myself using these extremes. I mean full negative collective with full climb? Full positive collective with full dive? I can't see it. Somebody may, but I don't fly at those extremes right now.

I know it doesn't help you much, but there you go.

Scott

Interesting, you see the label is damaged on the servos and don't see yourself flying like this.
My flying skills will also not allow, but it looks like the Beast is using the space you give it!

Are you really hitting a blue LED at Step L?
That is great, maybe I messed up somewhere, I can't get it better than red. :confused:

helidude71
09-24-2011, 04:46 AM
The original T-Rex500 is not very optimal at the overall geometry of the swashplate control.

The problem is that the swashplate inner ring to outer ring ratio is not too good.
As this ratio defines the collective to cyclic ratio you will have problems maxing out the pitch ranges and not violating the cyclic resolution restrictions of a flybarless system.

You have to modify the swashplate ratio to get more collective and less cyclic deflection on the same servo travel, as this would allow you to move the ball on the servo outside a little bit and still achive blue at 6 (means, no lost cyclic resolution) . With the ball out a little bit on the servo you then are able to get a higher collective range on the bladegrips with less servo travel and this on the other hand will save you some servo travel for getting more cyclics before running into any binding.

To modify the swashplate ratio you have to make the outer ring of the swashplate wider or the inner ring of the swashplate smaller. At the original Align FBL conversions you get shorter inner ball to make the inner ring smaller, this helps but could not fix the problem completely (depending on the collective and cyclic values you want to go)

Another problem on this heli is the limited room for the servo horns, as especially on the elevator servo the servo is not able to do its full range without touching parts of the frame.
For this i modified a servodisk so that it looks like a servohorn with a curve in it where it is going around the binding place a bit, every millimeter could be of help here.

best regards,
Walter

Thx, after reading this twice I think you are spot on. :thumbup:
With the servo balls at 13mm I need all the cyclic throw I can get.
For that I stick with the stock (longer) balls at the inner swash ring.

I asked myself why the hell Align gives me the shorter balls for the inner swash ring?
But if I understand you correct, when I move the servo balls one hole out I need to reduce cyclic throw with them?
If this is, why would Align stick in the FBL manual with 13mm?
Not to argue you but trying to understand why.

Probably because you hit other frame parts you where seeing but then there is no need for the shorter balls on the inner swash ring. :thinking

You solved binding at the frame, do the servos handle well with the extra force because of the longer arm?
Do you run a blue LED at step J and L with NO binding?

Sorry for all the questions. :oops:
(FBL n00b here.)

dunkonu23
09-24-2011, 09:32 AM
Interesting, you see the label is damaged on the servos and don't see yourself flying like this.
My flying skills will also not allow, but it looks like the Beast is using the space you give it!

Are you really hitting a blue LED at Step L?
That is great, maybe I messed up somewhere, I can't get it better than red. :confused:

I don't see it at all. I'm pretty sure the rubbing was from all the setup I've done on them in the past and my last two crashes where on the first crash at IRCHA both aileron and pitch servos were completely stripped and one had a broken arm (the one intact arm would spin completely around) and on the last crash at Dayton where links were broken and popped off.

In the setup last night, I swear I have a blue light. I deliberately backed off to see what the minimums I could get are and it was right in line with what you wrote earlier -- +-8 degrees cyclic at the point where the light went red. There was some wiggle room between 8 and 12 degrees cyclic where the light stayed blue, though. From what you've written, I don't think you'd be comfortable within the 4 degree "wiggle range".

Another solution, and it was one Finless alluded to in his T-Rex 500 build video was to simply use another servo type. He saw the rubbing on the servo case, too. Mine barely rub, though. They don't rub enough to make the servo sing so I just don't worry about it. Metal gears may have something to do with the lack of singing too as they may transfer more torque to the arm--but that might be a stretch.

Scott

DVUSHELI
09-24-2011, 09:41 AM
I was using the long horns with the balls in the stock locations. Like this, I was getting 10* of cyclic @ blue light with no binding. I moved them in one hole and got something like 7.5* @blue. So, I put the shorter balls onto the inner swash ring, while still using the second hole in on the horns and bingo, 6* @blue. I still have +-12* full pitch and no binding. I'm at work, refresh me on what step L is please.

OK, the reason I asked is because you had the servo balls one hole further out (16mm) I guess?
This is not recommended by the Align FBL manual but will give you more servo throw.
I wonder if you can get a blue LED with this setup for Step J and L?

Do you remember if it was without binding?

helidude71
09-24-2011, 02:56 PM
J= Swashplate - cyclic pitch geometry (6*)
L= Swashplate - cyclic limit

I'm afraid "long horns with the balls in the stock locations" differs on which manual you grab.
That can be 16 or 19.5 mm. :face
Never mind, you came from 16 mm because you moved one in and that is the second hole.

So, do I understand it correct that you could NOT get 6* and a blue LED at step J with your previous ball setup?
(16 mm, 3th hole.)

dunkonu23
09-24-2011, 07:51 PM
I couldn't get blue until I moved to 13 mm, either.

Scott

helidude71
09-25-2011, 12:42 PM
I couldn't get blue until I moved to 13 mm, either.

Scott

For Step J I assume.
Interesting, how do you go with Step L with balls on 13 mm?
(Which color, just before binding at full negative collective pitch?)

dunkonu23
09-25-2011, 02:10 PM
Yep, at step J on my 500, blue wasn't possible until I moved the balls to 13mm on all cyclic horns.

I've never had binding. I judge binding by the servos singing and whether or not motion is impeded. If the servos are quiet -- and mine are -- I don't consider the ball lightly rubbing on the label of the servo to be binding or impeding movement. Maybe if I had plastic gears in the servo, they'd sing, but as I stated, I do think part of the lack of singing is due to the metal gears in my DS510's. If I adjusted so the balls didn't lightly rub on the aileron and pitch servo, I'd JUST get blue--meaning if I backed of just tad, it'd go red.

Scott

helidude71
09-25-2011, 03:27 PM
Yep, at step J on my 500, blue wasn't possible until I moved the balls to 13mm on all cyclic horns.

I've never had binding. I judge binding by the servos singing and whether or not motion is impeded. If the servos are quiet -- and mine are -- I don't consider the ball lightly rubbing on the label of the servo to be binding or impeding movement. Maybe if I had plastic gears in the servo, they'd sing, but as I stated, I do think part of the lack of singing is due to the metal gears in my DS510's. If I adjusted so the balls didn't lightly rub on the aileron and pitch servo, I'd JUST get blue--meaning if I backed of just tad, it'd go red.

Scott

Yeah, seems the same here.
I use plastic gears so maybe mine are singing a tad earlier.

I don't accept the servo balls rub the label, it really starts singing.
Because of this I get only a red LED.

Like you said before, different servos solves it but that means spending a few bucks.
(In fact euros across the pond.) :lol:

dunkonu23
09-25-2011, 04:29 PM
I have to pull the tail assembly off tomorrow (I broke two RCScrewz tightening the gear box to the frame), so that means I have to pull the microbeast, if I have time I'll take a couple of pictures to show you where mine are and just how little the balls are rubbing on the label. I don't know if it will help you, but since I have to work on the helicopter (did I say I hate breaking screws?), it's worth a go.

Scott

DVUSHELI
09-25-2011, 05:55 PM
Well boys, I hate to say it, but I maidened my 500 w/ the BX and KDE head. Needless to say.........I - AM - NEVER - BUYING - ANOTHER - FLYBARRED - HELI!!!!!
This thing freakin ROCKSSSS!!!!!!!!! Rolls are tight, flips are right on center. Hapy would be an understatement:bacon:bacon:bacon

helidude71
09-26-2011, 03:11 PM
I have to pull the tail assembly off tomorrow (I broke two RCScrewz tightening the gear box to the frame), so that means I have to pull the microbeast, if I have time I'll take a couple of pictures to show you where mine are and just how little the balls are rubbing on the label. I don't know if it will help you, but since I have to work on the helicopter (did I say I hate breaking screws?), it's worth a go.

Scott

These are mine from post #6.

http://www.helifreak.com/attachment.php?attachmentid=254999&d=1316551653

http://www.helifreak.com/attachment.php?attachmentid=255000&d=1316551653

And congrets DVUSHELI with your bird! :thumbup:

dunkonu23
09-26-2011, 06:45 PM
I didn't get pictures today... tomorrow. I forgot the new tail gear box won't be here until then. On another note, the only original parts (not counting electronics) on my 500 now are the battery tray, motor mount/pinion/motor, and the tail fin.

Scott

dunkonu23
09-27-2011, 04:03 PM
Here's the pictures of mine...

http://www.helifreak.com/attachment.php?attachmentid=256574&stc=1&d=1317157257

http://www.helifreak.com/attachment.php?attachmentid=256575&stc=1&d=1317157257


http://www.helifreak.com/attachment.php?attachmentid=256576&stc=1&d=1317157257

Scott

helidude71
09-28-2011, 03:11 AM
Here's the pictures of mine...

...

http://www.helifreak.com/attachment.php?attachmentid=256575&stc=1&d=1317157257


...

Scott

http://www.helifreak.com/attachment.php?attachmentid=255000&d=1316551653

Nice!
It really shows why you hit BLUE and I hit RED.
My servos are making some freaking noise when I do that. :face (Plastic gears.)

I leave it as it is for now. :thumbup:

dunkonu23
09-28-2011, 04:13 AM
Good deal! As long as you're happy, bro. I think this thread has been very useful for all of us with 500's using microbeasts. It has really made us look closely at our setups. For example, since I never got singing servos, I never really looked at the elevator to see that it was lightly touching both the tail drive gear box at the lower extreme and lightly touching my antirotation bracket at the upper extreme. Each is easily addressed with a dremel and a couple of minutes, but interesting to me, nonetheless.

I think it's odd that one servo rubs just enough to take off the plastic from the label and the other doesn't even do that, but you can see on the plastic where it does touch just enough to leave a mark. Fun stuff.

Scott

helidude71
09-28-2011, 04:41 AM
Yep, I've seen as well if you want the most of it, the elevator starts hitting the tail drive gear box.
The antirotation bracket will flex a bit I guess, but the tail drive gear box sure doesn't. :D

Thx for the discussion, it cleared up my understanding as well. :hug:

dunkonu23
09-28-2011, 05:12 AM
LOL! After breaking two ARB's in consecutive crashes, I decided to go with the KDE ARB. I do have a plastic one as a spare in the event I decide I don't want to break frames anymore. :)

Scott

helidude71
09-28-2011, 05:25 AM
The original T-Rex500 is not very optimal at the overall geometry of the swashplate control.

The problem is that the swashplate inner ring to outer ring ratio is not too good.
As this ratio defines the collective to cyclic ratio you will have problems maxing out the pitch ranges and not violating the cyclic resolution restrictions of a flybarless system.

You have to modify the swashplate ratio to get more collective and less cyclic deflection on the same servo travel, as this would allow you to move the ball on the servo outside a little bit and still achive blue at 6 (means, no lost cyclic resolution) . With the ball out a little bit on the servo you then are able to get a higher collective range on the bladegrips with less servo travel and this on the other hand will save you some servo travel for getting more cyclics before running into any binding.

To modify the swashplate ratio you have to make the outer ring of the swashplate wider or the inner ring of the swashplate smaller. At the original Align FBL conversions you get shorter inner ball to make the inner ring smaller, this helps but could not fix the problem completely (depending on the collective and cyclic values you want to go)

Another problem on this heli is the limited room for the servo horns, as especially on the elevator servo the servo is not able to do its full range without touching parts of the frame.
For this i modified a servodisk so that it looks like a servohorn with a curve in it where it is going around the binding place a bit, every millimeter could be of help here.

best regards,
Walter

After re-reading this post it looks I can give it a try to put the balls on the servo arms one more out (16 mm hole) and use the shorter balls on the inner swash ring.
All this with the stock swashplate and Align FBL head.

Anyone with this exact same setup care to comment?
Will Step J and L be BLUE with +/-12* at step K?

sutty
09-28-2011, 02:13 PM
I don't, but I had wondered why someone hadn't given Walter's suggestions a go until now. If anyone will know, he will. If going from 13mm to 16mm on the arm is too much to make back up by going shorter on the inner swash, you can always go longer on the outer swash as well, which I think Walter also mentions. I think I mentioned before that I would have like to stay at the recommmended 13mm, but I guess what you lose there by going to 16mm, you simply get back by changing the other ratios.

Interested to hear how you get on in the end, even though I don't have a 500. I imagine those that do will be even more keen to find out exactly what can be achieved with the right choice of balls, and perhaps a little work on the AR bracket. Interesting that Walter explained that the 500 has poor geometry wtih the standard swash, this must be why I have a completely different experience with my 250, 450, and 550.

Good luck.

Cheers

Sutty

DVUSHELI
09-28-2011, 06:56 PM
Helidude, use the 2nd hole from the outside of the arm

helidude71
09-29-2011, 04:02 AM
Helidude, use the 2nd hole from the outside of the arm

OK, to make sure we talk about at the same thing a picture.
You mean the hole with the arrow?

http://www.helifreak.com/attachment.php?attachmentid=256856&d=1317286920