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Cable Tension

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bob1393

Active Member
What tool/instrument have most of you used to set the tension on your control cables? The tool kit we got for our RV12 from Aircraft Tool Supply gave us a digital fish scale. Can we use this? Tensiometers are not cheap.

Thanks for your replies.
Bob
 
I used a tensiometer. It's also important to install the floor pans as per the plans before testing the cables, as it makes a considerable difference to the measured tension.
 
Use a tensionometer. See if a local EAA member or FBO will let you borrow one. Not worth buying one due to your infrequent use.
 
We engineers have a term: good engineering judgement. Naval aviators have a similar term: TLAR (That Looks About Right). --- Let the S#* storm begin!😁
 
RFSchaller said:
We engineers have a term: good engineering judgement. Naval aviators have a similar term: TLAR (That Looks About Right). --- Let the S#* storm begin!😁
Click to expand...

Enough so there is no cable slap on plane parts when control is moved stop to stop aggressively....
 
bob1393 said:
What tool/instrument have most of you used to set the tension on your control cables? The tool kit we got for our RV12 from Aircraft Tool Supply gave us a digital fish scale. Can we use this? Tensiometers are not cheap.

Thanks for your replies.
Bob
Click to expand...


I borrowed one off an A/P friend - ask around - someone will have one. A case of beer is cheaper than $200+.

Also, Van's modified the tension in a later revision....keep in mind that there is a temp/tension scale in the official A/P.

I did mine per the original plans in one extreme temp and when it hit the other extreme, the tension was off....way too sloppy.

See page 2-53 and 2-54:

http://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/amt_airframe_handbook/media/amt_airframe_vol1.pdf
 
Just Curious

Just curious, since there aren't cables in my RV-6 that need tensioning: Which cables in an RV-12 need to be properly tensioned?

Thanks
 
Careful

FYI if you barrow one don't drop it! There are some very brittle parts that will likely break! Be careful and the device, pictured in the prior post, is what you would need.
 
Stabilator Cable tension

I would imagine that the cable tension on stabilator cables would be fairly critical. Using a proper cable tensiometer would be my first choice. And cables tend to stretch a bit after initial tensioning when new, and should be checked a few times after installation, and obviously, on each annual Condition Inspection.

I also think that there must be a method of using a "fish scale" to deflect a control cable a known distance and mathematically come up with the cable tension. Surely there must be a formula, but I have no idea what that formula might be. :eek:

If you know the distance between the two end points, and the force required to deflect the cable a certain distance, you might have the answer.

Probably easier to beg, borrow, steal, or even (GASP) buy a tensiometer!! :rolleyes:
 
PCHunt said:
I would imagine that the cable tension on stabilator cables would be fairly critical. Using a proper cable tensiometer would be my first choice. And cables tend to stretch a bit after initial tensioning when new, and should be checked a few times after installation, and obviously, on each annual Condition Inspection.

I also think that there must be a method of using a "fish scale" to deflect a control cable a known distance and mathematically come up with the cable tension. Surely there must be a formula, but I have no idea what that formula might be. :eek:

If you know the distance between the two end points, and the force required to deflect the cable a certain distance, you might have the answer.
Click to expand...

That's exactly what a cable tensionmeter does, it deflects the cable and measures the amount of deflection but it uses about 6" of cable to do it. If you have a 10' long cable for example you just won't have enough room to deflect it without the cable contacting some part of the structure.
 
Yes Rich

I actually got help for aircraft spruce who put me in touch with the current manufacturer and I was able to have it repaired better than new.
The maintanance facility who let me borrow the tension gauge is a big supporter of all the experimental guys on the field and I was going to fix it or buy him a new one. Greg, the owner was very understanding and gave me an open invitation to use it anytime it's needed in the future.
 
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