Nylon is brittle

[aramsdell]

Nylon is brittle. Does anyone remember boiling the old white nylon props? Unboiled they had the nastiest habit of shattering . When boiled you could bend them almost 180 degrees. Nylon seems to absorb water I guess. I have tried boiling the landing gear for my Swifts and my TREX's. I got really P'd.Off the other day. I needed to change the front landing gear strut on a TREX. The new one shattered while installing it.

To test my theory, I boiled 2 broken Swift gear and 2 TREX gear piecesabout 2 to 3 minutes at full boil.
Yep. Very pliable hot and when finally cooled they would bend a LOT more before finally breaking. They are a little softer now. The TREX gear doesn't sag at all after boiling. The Swift, at over 5.5 pounds will because the stock gear does already. I did a mod on the rear gear to eliminate the shakes and that keeps it from sagging too.




Add salt and pepper to taste. BAM !

[Chris DeSain]

I do not know if this material is nylon but it definitly is notable that the material does become more flexible with heat application. I do not know about the H2O retention you mention as heating with a heat gun produces the same results. It becomes very flexible and when cooled still retains flexibility .

Interesting stuff.

[Coolice]

Hey,

The boiling technique basically removes the moudling stresses introduced into the plastic during manufacturer. I boil my Hummer U/C to make them a little less prone to breaking, but I still manage to.

In the point of the Swift though I do not see the need to boil the under cart, as if it does break it will be through a crash and so is liable to break due to it being long and thin. Best thing you could do if you really want to try protecting it is to reinforce it using carbon tows and resin on the inside of the strut.
Through normal use they will not and have not broken, a crash is likely to break something though :arggg:

The down side to boiling is that the skids then allow the model to sag and will still most likely break due to their slim design.

You mentioned the Trex and they were very prone to breaking, I have seen though there is a very nice and flexible U/C for that model which gives in a crash and so you'd be best to fit one of those.
.

[aramsdell]

Coolice, Flew the redesigned gear today. See my other post about Swift shakes from Friday or Sat. I did a mod to the rear landing gear strut that has stopped all the shakes and stiffens up the bird enormously.
As a bonus it keeps the rear strut from spreading out so the bird sits taller. Most weight is over the rear gear but now it's stiffened so that the front gear is what will spread over time making the tail sit HIGHER.
I flew today from snow, Ice and Pavement as heli-pads. The Swifts have always had exagerated shaking on these types of surfaces. There were virtually no shakes even on melting ICE.
Cheers. :)

[Coolice]

Hey,

Yeah, I did have a good read of your other post. Good idea to brace the U/C and it works on your model so thats what counts.
.