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Speed,Combat,Scale,Racing => Scale Models => Topic started by: Hemi Steve on October 01, 2019, 07:07:13 AM

Title: Scale Nats question 1
Post by: Hemi Steve on October 01, 2019, 07:07:13 AM
Here is my first question.
In the control Line general rules, paragraph 5.3.1 talks in part about line terminations.  I use the figure 4 method which is the crimped tube style.  However, I use 3 crimps rather than 2  in order to make double damn sure I get a good termination and I use colored heat shrink tubing over the termination to identify up and down lines.  Is the 3 crimp method ok?  is the heat shrink ok in view of the recommendation to regularly inspect the wire for broken strands by the crimped tube?

See attached picture.

Steve
Title: Re: Scale Nats question 1
Post by: Will Hinton on October 01, 2019, 07:59:37 AM
Personal opinion only, I wouldn't be comfortable covering the terminal ares so that I couldn't se the lines for possible broken strands. D>K
Title: Re: Scale Nats question 1
Post by: Hemi Steve on October 01, 2019, 08:33:48 AM
Thanks for the feedback Will.  It's easy enough to remove the heat shrink and use paint for identification.  What about the triple crimp as it is not exactly according to the figure 4 illustration?
Steve
Title: Re: Scale Nats question 1
Post by: john e. holliday on October 01, 2019, 10:15:31 AM
Myself I would use crimped lines only in an emergency.  I have been using swagged lines as it give more contact area between the cable and the tubing/furrel.  For long term use nothing beats wrapped lines.  Look at the crimp and you see a sharp vee cutting into the cable. D>K
Title: Re: Scale Nats question 1
Post by: Hemi Steve on October 01, 2019, 12:14:16 PM
Thanks Doc.
I understand what you are saying.  I don't believe I've ever seen a swaged joint on control lines.  Is there a tool available to do that joint?  In view of the fact that a swaged joint is not described in the rules would you get grief when the control system gets a safety inspection? Do you use the standard copper tube in the swaged joint?

Steve
Title: Re: Scale Nats question 1
Post by: Trostle on October 01, 2019, 04:42:23 PM
The Control Line General rule book shows several methods to make line ends.  The alternate method for stranded lines is to crimp copper or soft brass tubing over the looped end of multi-strand lines.  No matter how carefully you do the crimping, there will be some distortion of the cross section of one or more strands in that multi-strand line which will compromise the integrity/strength of that line.  It is my opinion and the opinion of others that crimping the line ends is to be discouraged.

Keith
Title: Re: Scale Nats question 1
Post by: john e. holliday on October 01, 2019, 05:09:19 PM
Thanks Doc.
I understand what you are saying.  I don't believe I've ever seen a swaged joint on control lines.  Is there a tool available to do that joint?  In view of the fact that a swaged joint is not described in the rules would you get grief when the control system gets a safety inspection? Do you use the standard copper tube in the swaged joint?

Steve

Yes there is a tool to do the swagging with.   The late Carl Shoupe used to make them.  I made mine using needle nose pliers and a drill press.   Takes practice to get it right.  Either here or Stuka stunt is posts on swagging.  So far have had no problems even over doing the pull tests. D>K
Title: Re: Scale Nats question 1
Post by: Tim Wescott on October 02, 2019, 04:55:55 PM
Yes there is a tool to do the swagging with.   The late Carl Shoupe used to make them.  I made mine using needle nose pliers and a drill press.   Takes practice to get it right.  Either here or Stuka stunt is posts on swagging.  So far have had no problems even over doing the pull tests. D>K

MBS Model Supply carries a swaging tool that looks to me like a commercial product.

They also carry sleeves that come in both black and silver (I think he packages them both into the same kit -- you'd have to ask him if you order).

When I swage, I color-code with the sleeves from MBS, and I cover with clear heat-shrink.

Or you can wrap with copper wire -- it's prettier.  You can buy a 1/4 roll of #30 or #32 magnet wire, one each of some light color and some dark color, and your great-grandkids will still have copper wire for winding lines.
Title: Re: Scale Nats question 1
Post by: Hemi Steve on October 03, 2019, 06:10:57 AM
Thanks for the reply Tim.
I don't see the tool or colored sleeves on their web site.  Is that stuff where you have to call  to order??

THenks

Steve