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paulj

Elevator pull cord recommendation

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paulj

I've managed to break the thread from the elevator servo to the elevator on my MadRES (stupidity at it's best...!). Can anyone recommend a replacement? Would cotton sowing thread do?

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Graham Woods

I think Dacron is a good choice as it's not supposed to stretch very much.

This one is 0.55mm thick; I think it is used for sewing leather.

gw

dacron.jpg

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paulj

Thanks Graham! I also saw some kevlar thread on eBay which looks good.

 

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cirrusRC

for my DLG's I use Climax Protec fishing line.    The abrasion resistance is excellent,  it doesn't stretch and thermal properties are good.

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paulj
17 minutes ago, cirrusRC said:

for my DLG's I use Climax Protec fishing line.    The abrasion resistance is excellent,  it doesn't stretch and thermal properties are good.

What size/strength do you select?

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cirrusRC

doh sorry its not fishing line - its for kites.       Think I am using 25daN/50lbs   but will check later.     It can be a pain to get hold of in smaller lengths.

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Steve J

It is worth checking out the model yacht people for things like this.

Steve

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paulj

I actually have a model yacht, and finding a comment elsewhere on the internet reminded me that I had some rigging line in the cupboard. However, I have two sizes - 0.8mm and 1.0mm, both significantly thicker than the 0.25mm thread currently on the model. It is very non elastic and strong mind you! I ordered some of the T80 kevlar thread, which is 0.29mm diameter, so should be similar to what is coming off.

 

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CTR

Chipping in here!

I used to have a company manufacturing competition kites and Dynema was the line of choice. There was a small amount of initial stretch (non elastic from the braiding structure settling in). Also it was very good at low friction sliding between the two lines of the kites when twisted multiple times. Sounds great for gliders then, right?

There is one main drawback. The line has a low melting point (it is made from PE and stretched during manufacture of the filament to give the low stretch characteristics). Not a problem when sliding the twisted lines after doing multiple loops in one direction because there is very little friction. However, when twisted with a nylon or Kevlar line, the Dynema is the first to melt.

Dynema with a polyester outer braid is available, probably the construction of the fishing line. Non stretch due to the Dynema core and friction resistance from the polyester. Most of the diameter is from the polyester. 80lb strain Dynema is less than 0.3mm.

Kevlar’s shortcoming is poor UV resistance.

 

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Kyri
36 minutes ago, CTR said:

Chipping in here!

I used to have a company manufacturing competition kites and Dynema was the line of choice. There was a small amount of initial stretch (non elastic from the braiding structure settling in). Also it was very good at low friction sliding between the two lines of the kites when twisted multiple times. Sounds great for gliders then, right?

There is one main drawback. The line has a low melting point (it is made from PE and stretched during manufacture of the filament to give the low stretch characteristics). Not a problem when sliding the twisted lines after doing multiple loops in one direction because there is very little friction. However, when twisted with a nylon or Kevlar line, the Dynema is the first to melt.

Dynema with a polyester outer braid is available, probably the construction of the fishing line. Non stretch due to the Dynema core and friction resistance from the polyester. Most of the diameter is from the polyester. 80lb strain Dynema is less than 0.3mm.

Kevlar’s shortcoming is poor UV resistance.

 

Great explanation of the different material characteristics!. I have flown kites and the lines are pretty amazing (for the relatively basic polymer they are made from)

 

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martynk

Try sea ranger fishing line. Comes in a variety of BS and diameters. It is very low stretch and doesn't seem to snag or fray

 

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Tony

Hi

If you PM me with your address I'll send you some as I use fishing braid that doesn't stretch and have about 100m so I can give you a few metres if you wish and I'll put some crimps in for you. Never had any problems with it and it lasts forever.

Tony

PS it's the same line I used on my Madres

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Tony

Caught the last post yesterday so hopefully with you Monday. Sorry for the delay.

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