RCU Forums

RCU Forums (http://www.rcuniverse.com/forum/)
-   Beginners (http://www.rcuniverse.com/forum/beginners-85/)
-   -   Pull pull setup ? (http://www.rcuniverse.com/forum/beginners-85/11289371-pull-pull-setup.html)

Popriv 11-07-2012 02:53 AM

Pull pull setup ?
 
Setting up a pull pull rudder on a small electric Yak. AUW will be about 2lbs.
There is no turnbuckle supplied like on my bigger glow pull pull system. Looks like you just pull tight when crimping the ferrel?
Tried it and the crimp doesn't hold... Very light weight wire...

No luck searching for options?

Seems like you would need some adjustment even on such a lightweight setup?

Anyone know of a lightweight pull pull setup that's available ?


Thanks
Steve

goirish 11-07-2012 03:03 AM

RE: Pull pull setup ?
 
Have you looped the line back through the ferrel

john josey 11-07-2012 03:33 AM

RE: Pull pull setup ?
 


Are they any help to you. Sorry about the large pictures.
http://i709.photobucket.com/albums/w.../Image0642.jpg

http://i709.photobucket.com/albums/w.../Image0711.jpg

Cheers
john</p>

goirish 11-07-2012 03:50 AM

RE: Pull pull setup ?
 
1 Attachment(s)
On the 2nd picture, take the tail and loop it back through the ferrel before you crimp it. You will then have 3 strands of cable going through the ferrel. I have never had one slip using this method. just my 2c

sorry for the poor picture but I think you can see what I mean

john josey 11-07-2012 04:04 AM

RE: Pull pull setup ?
 

Quote:

ORIGINAL: goirish

On the 2nd picture, take the tail and loop it back through the ferrel before you crimp it. You will then have 3 strands of cable going through the ferrel. I have never had one slip using this method. just my 2c

sorry for the poor picture but I think you can see what I mean
Yeah, i agree. You could even go one further and keep passing it through, 'bulking up' so to speak before final crimping. I have to say though, i would like some adjustment on one end, even with the small weight penalty.

CGRetired 11-07-2012 04:36 AM

RE: Pull pull setup ?
 
Check this link. They have a setup that looks like it might be much better than crimping the cable. Also, it has info about vinyl coated kevlar, which is what I use rather than metal.

CGr.

http://www.acpsales.com/Kevlar-Tow-and-Cords.html

Rodney 11-07-2012 04:48 AM

RE: Pull pull setup ?
 
On such a small model, you can use monofiliment fishing line with no problems. I do that all the time and never have a temperature or stretching problem, even on some models weighing up to 4 pounds. Using monofiliment you can just tie a knot and put some CA on it which is much easier than a crimp. Yes, use the clevis and adjustments shown in the picture above, they work great. The main thing with pull-pull be sure to have a little positive Ackerman in the setup as it will make the control much nicer and be easy on the servos and hinges. Do not over tighten the lines, just taunt enough to not have any slack at neutral position.

flyinwalenda 11-07-2012 05:52 AM

RE: Pull pull setup ?
 
I have also used fishing tackle swivels and clips on some set-ups. They may look a bit out of place but are cheap and work fine.

jaka 11-07-2012 07:17 AM

RE: Pull pull setup ?
 
1 Attachment(s)
Hi!
Like this!
You tread it in the ferrel once...then true it in again ...and then a third time. No dangling loop outside the ferrel!

Gray Beard 11-07-2012 07:36 AM

RE: Pull pull setup ?
 
The gizmo's John is showing are called rigging couplers and DuBro makes and sells them. I make up my own systems but I go to the sporting goods store and buy braided stainless steel plastic coated fishing leader. It comes in a lot of sizes. You can loop this line and use a match to melt the plastic onto itself and not even need the Ferrel to crimp. On a simple loop and Ferrel I crimp the Ferrel then use a heat source, usually a soldering iron and just heat the Ferrel until the plastic coating melts onto itself. Just running the line through the Ferrel as Gene mentioned with an extra loop then crimping will keep the line from slipping. When I was at Bass Pro a few weeks ago buying more leader I found some really fine light weight wire that is perfect for small electrics. I didn't buy any though, I had tunnel vision while I was looking for the wire for the planes I was setting up. My bad, now I could use some.

Popriv 11-07-2012 10:26 AM

RE: Pull pull setup ?
 
Not enough wire supplied to loop through again.. in this case... But I guess my question is what is the adjustment hardware called as I have not found it in a search.

I like the idea of fishing line... I have some 40 pound line at home..... I need the threaded rod with the hole in the end that the line goes through.

thanks

Steve

Popriv 11-07-2012 10:28 AM

RE: Pull pull setup ?
 
Jaka, I just looked at your photo. I do have enough line to do that...

But still want to be able to adjust it after its locked in...

Steve

flyinwalenda 11-07-2012 10:32 AM

RE: Pull pull setup ?
 
Rigging Couplers and/or  Turnbuckles
<br type="_moz"/>

Gray Beard 11-07-2012 10:39 AM

RE: Pull pull setup ?
 
Rigging couplers have the hole through one end, you use a nut on them and then tighten them into a clevis, when tight just tighten up the nut onto the clevis so it doesn't come loose. Turn Buckles are fantastic to use on the wire rigging of Bipes. Both work great but the rigging coupler is a lighter system . The come in both 2-56 and 4-40.

kwblake 11-07-2012 11:17 AM

RE: Pull pull setup ?
 
Hey folks.  Rodney made a comment that this setup should have "positive Ackerman" .  Could someone please explain this.

Thanks

flyinwalenda 11-07-2012 11:23 AM

RE: Pull pull setup ?
 
www.qmfc.org/school/ackerman.htm

jaka 11-07-2012 11:56 AM

RE: Pull pull setup ?
 
1 Attachment(s)
Hi!
I use thinnest possible 17 lbs wire on my 50cc gas airplane (side rudder)!
All adjustments are done inside the fuselage.
The adjusters are just 2mm steel rods hammered flat at one end and then drilled with 0,75-1,0mm drill bit.

CGRetired 11-07-2012 02:40 PM

RE: Pull pull setup ?
 
You have not looked at Kevlar? Much lighter, easier to work with, and very strong.

CGRetired 11-07-2012 02:42 PM

RE: Pull pull setup ?
 

Quote:

ORIGINAL: kwblake

Hey folks. Rodney made a comment that this setup should have ''positive Ackerman'' . Could someone please explain this.

Thanks

Yeah, I have to agree with this.

This is a beginners forum. Terms like "Positive Ackerman" make absoutely no sense to a beginner. Either explain this or don't use the term in this forum.

CGr.

Popriv 11-07-2012 04:06 PM

RE: Pull pull setup ?
 
1 Attachment(s)
great info! I wouldnt have thought of making my own by hammering a threaded rod flat and drilling a hole... I need to polish the hole a bit but it should work?

add a nut and thread into a cleavis

thanks

I ruined both ferrels on my previous attept.. fuel tubing I have is to big... any other options? so close...

flyinwalenda 11-07-2012 04:10 PM

RE: Pull pull setup ?
 
Not too shabby for the first try !

MTK 11-07-2012 07:00 PM

RE: Pull pull setup ?
 

Quote:

ORIGINAL: CGRetired

You have not looked at Kevlar? Much lighter, easier to work with, and very strong.
Plus kevlar doesn't need any extra looping through a ferule. I simply expose the kevlar, hold it against itself and drip 1 drop of thin ca. Once it kicks, you're done

I still have a stash I made using teflon coating...terrific stuff

To JaKa, very nice and tidy installation...I suggest that you use a short piece of heat shrink on the ferule next time for a pro look

kwblake 11-08-2012 04:46 AM

RE: Pull pull setup ?
 

Quote:

ORIGINAL: CGRetired


Quote:

ORIGINAL: kwblake

Hey folks. Rodney made a comment that this setup should have ''positive Ackerman'' . Could someone please explain this.

Thanks

Yeah, I have to agree with this.

This is a beginners forum. Terms like "Positive Ackerman" make absoutely no sense to a beginner. Either explain this or don't use the term in this forum.

CGr.
Maybe I'm missing something here, but isn't the main reason for these forums to learn? If someone uses a term we don't understand, ASK. That is why I asked what Ackerman was. To LEARN. Thanks very much walenda, very informative. I am going to subscribe to this thread, just to keep the link about Ackerman.

CGRetired 11-08-2012 05:13 AM

RE: Pull pull setup ?
 
You are absolutely right. However, using a term like "Ackerman", which I would imagine not many here know what it is, without a definition or an explanation, especially in a Beginners Forum, does not help the beginner at all. How many trainers use Pull-Pull? How many new pilots in training should be concerned with "Ackerman"? The point here is that if an unusual term is used, please provide a simple explanation or a link to an explanation.

You said it yourself. "to learn". But how is someone to learn without a little assist? The person that used the term, mainly Rodney, should have provided the definition or explanation rather than just leaving it hang like that.

Thanks to flyinwalenda for providing a link to the definition and description. I am sure it helped those that don't know understand the term.

My comment was generalized to anyone that posts such items without providing definitions. It happens all the time and I so note with a reminder.

CGr.

Gray Beard 11-08-2012 08:15 AM

RE: Pull pull setup ?
 
I was setting up pull/pull systems for a couple years before I ever heard the term Ackerman and all my planes flew very well. Even after learning what it was and how it worked I didn't worry much about it until I started getting into precision planes and there set up. As a sport pilot it mattered to me not at all, if I had the slack in the cables I never worried about it. Then I started precision flying with pattern and IMAC planes. Incorrect Ackerman didn't show up on my pattern planes due to the speed flown but I finally started to notice it on IMAC type of planes and flying. That's when I started taking the time to set the Ackerman correctly. Any good 3-D or free style pilot will notice it instantly. When you pull your rudder to the slack side there is a delay in the rudder movement and authority or speed until the slack line starts taking control again. I agree with CG, as beginners it isn't something to worry about but as beginners it is something you can start incorporating in your planes now so you learn how it's done and get in the habit of setting up your pull/pull systems correctly. Due to servo placement and how the lines are run inside the plane you sometimes just can't get all the slack out but you can usually get them close. I got along quite well before I ever heard of Ackerman but I do strive for perfection in my aircraft set up. Don't always get it but I try hard. No reason to ever loose sleep over it though but now is a good time to start learning how to set up your planes as well as you can.
I have friends here on RCU that dwell on the subject, I try but tend to not over think it.


All times are GMT -8. The time now is 01:37 AM.