News:



  • March 29, 2024, 09:46:35 AM

Login with username, password and session length

Author Topic: Line termination for button bellcranks (stranded lines)  (Read 1663 times)

Offline Gary James

  • Trade Count: (0)
  • Lieutenant
  • ***
  • Posts: 54
  • Shredding streamers since 1971
    • Mini-IMP Aircraft Co.
Line termination for button bellcranks (stranded lines)
« on: August 09, 2019, 06:10:56 PM »
I've just finished up a new Sportsman Goodyear (DMAA rules) and need to make up a set of lines.  The model has buttons on the bellcrank, as per standard practice.  Reading the general CL rules on line terminations, it looks to me that for stranded lines, it is not required to make the double loop connection.  According to the text, the double loop is required for solid lines but not for stranded lines.  Is this correct?
Gary James
Weatherford, TX
AMA 68845

Tom Vieira

  • Guest
  • Trade Count: (0)
Re: Line termination for button bellcranks (stranded lines)
« Reply #1 on: August 09, 2019, 09:24:44 PM »
Correct.  Tie it off just like normal.

Sent from my SM-G960U using Tapatalk


Offline bill bischoff

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1698
Re: Line termination for button bellcranks (stranded lines)
« Reply #2 on: August 09, 2019, 10:47:45 PM »
Double loops are required when the wire rotates and rubs around the button. The double loop doubles the bearing area. In this case, the eyelets are built onto the lines in the standard manner. There is no movement between the wire and the eyelet. The eyelet moves freely around the button. The line attaches by screwing the button down over it. The short screw that holds the button to the bellcrank is threaded into the bellcrank and secured with Loctite. (Don't Loctite the button onto the screw). Hope that clears it up.

BB

Tom Vieira

  • Guest
  • Trade Count: (0)
Re: Line termination for button bellcranks (stranded lines)
« Reply #3 on: August 10, 2019, 07:08:31 AM »
Ahhhh....  so that's the origin of the rule...  nice!

Sent from my SM-G960U using Tapatalk


Offline BillLee

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1292
Re: Line termination for button bellcranks (stranded lines)
« Reply #4 on: August 10, 2019, 01:33:17 PM »
The rules governing this question are almost unintelligible and are prime fodder for the language lawyers.  >:(
Bill Lee
AMA 20018

Offline Paul Smith

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 5793
Re: Line termination for button bellcranks (stranded lines)
« Reply #5 on: August 11, 2019, 09:23:46 PM »
I didn't think of this before but, the solid wire forms a spring that holds the line on the button but if the stranded wire goes slack it can fall right off.

You could deal with this via a solid loop bound & soldered to the stranded line.

For example, .015" 7-strand lines with .018" solid loops around the buttons.  The terminal loops would have roughly twice the steel as the flying lines.  I believe that many of European lines & planes are done that way.
Paul Smith

Offline bill bischoff

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1698
Re: Line termination for button bellcranks (stranded lines)
« Reply #6 on: August 12, 2019, 06:35:02 AM »
I know this happens, especially in F2D, but doesn't this constitute a splice? Splices are verboten, CL General 5.3.5.

Offline Paul Smith

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 5793
Re: Line termination for button bellcranks (stranded lines)
« Reply #7 on: August 12, 2019, 10:14:05 PM »
I know this happens, especially in F2D, but doesn't this constitute a splice? Splices are verboten, CL General 5.3.5.

It's not a splice, just a method of termination.

Actually buttons ELIMINATE the "splice" where the lines splice to the leadouts. 
Paul Smith

Offline bill bischoff

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1698
Re: Line termination for button bellcranks (stranded lines)
« Reply #8 on: August 13, 2019, 06:42:51 AM »
If the actual flying line itself does not go around the button, eyelet, etc but stops short, and a different piece of wire it attached, how would that not be a SPLICE in the line? Granted, this is a discussion of semantics rather than functionality.

Offline BillLee

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1292
Re: Line termination for button bellcranks (stranded lines)
« Reply #9 on: August 13, 2019, 09:26:50 AM »
If the actual flying line itself does not go around the button, eyelet, etc but stops short, and a different piece of wire it attached, how would that not be a SPLICE in the line? Granted, this is a discussion of semantics rather than functionality.

Ah! More fodder to feed the language lawyers!  ::)

Solution: lines continuous around the button with an extra piece of solid included in the loop/solder.
Bill Lee
AMA 20018

Offline bill bischoff

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1698
Re: Line termination for button bellcranks (stranded lines)
« Reply #10 on: August 13, 2019, 09:52:53 AM »
Sure. That should satisfy everyone  ~>


Advertise Here
Tags:
 


Advertise Here