Fairlead Mount Blocks

[BobDz]

I've been experimenting...

Got tired of waiting for parts so I ordered 3/4" phenolic on my own. HDPE came up as an alternative. For fun, I ordered a piece of that as well.

The mounting block is a pretty "inert" piece. In a simpler world it would probably be a block of wood. Not much force or stress applied to this piece. It's sole purpose is to provide a stable hole for the nylon cable fairleads. Pretty simple.

So I made both. Here are the results of my "experiment ".
HDPE is much lighter in weight.
HDPE is quite a bit cheaper.
HDPE machines VERY easily.
Phenolic is a bit more difficult to machine.

Can't think of a reason not to use HDPE.

[Bryan Cotton]

I was going to say wear, but then I remembered the nylon insert.


How much weight does it save?

[BobDz]

Bryan

1.1 ounce each

[Area 51%]

That must be extremely light stuff you're working with. Each of my blocks is just barely over an ounce to start with.

[peter anson]

When I built my Sonex I made nearly all the phenolic parts from nylon; fairleads, rudder pedal bearings and flap tube bearings. On the bearing blocks I added an aluminium plate to spread the bolt load which I don't think was called in the original drawings. I wasn't trying to experiment; it was just a matter of using material that was available. In fact the only place I used phenolic material was for the the canopy latch striker plates because I happened to have some 1/4" sheet. After 12 years and 500 hours all the nylon parts are still working fine and have presented no problems.

Peter

[BobDz]

That must be extremely light stuff you're working with. Each of my blocks is just barely over an ounce to start with.

I have to say that I wasn't impressed with the phenolic I received. It was heavy, and very hard to drill. Not like any phenolic I had used before.

[BobDz]

Peter

I'm actually wondering why Derlin is called out in the plans for thr Flap Tube mounting blocks. Derlin is typically used for machined parts like gears and splined shafts - things that require high strength. I would have thought UHMW plastic would have been used. In the woodworking world UHMW is called "slippery plastic". It's a great bearing material, especially in a situation like the Flap Tube which isn't high stress, or high use.

I'm pretty sure I'm using UHMW.