wheel hubs
 

OK guys, a question... If I keep it lubricated, is it possible to run the steel shaft directly in the aluminum hub - i.e., without the brass bushings?

Bob

RE: wheel hubs
 

Define "keep it lubricated". Unless you've got something on board feeding it, you are going to grind away something. I know I don't need to tell you about the softer metal bushing. And why they don't last forever.

Go with a smaller axle and put the bushing in there and then if the strut hole is too big, bush it with brass tubing over the axle. If this is even your problem.

It works great, ask me how I know ;)

RE: wheel hubs
 

Point 1 Not all "aluminium" is equal. You can get hard wearing alloys.

Point 2 Give it a go without bushing and add bushing if it wears.

Fast is good but faster is usually better.

RE: wheel hubs
 

The existing axle is so much larger than the one meant for the wheels that I think bushing the axle to fit the hole in the strut would be difficult. It would take at least two brass tube thicknesses, and maybe three.

The hubs seem to be pretty hard aluminum, but what I'm most worried about is the aluminum hub galling and binding on the steel shaft. If they wear some, I think it would be easier to drill out the hubs just a bit more and bush them to the shaft with a brass tube, but I don't want to do that unless it is really necessary.

I think I'll try it this way, keep them well greased up (as opposed to my normal "if it ain't broke, don't take it apart" maintenance scheme :D ), and see what happens...

Bob

RE: wheel hubs
 

Bob, I will bet you will find that it takes two layers of brass tubing.

I have done this with zero issues on three jets. My eurofighter was this way, I built a Boomerang XL for a guy and did it on his, and my latest Isobar is temporarily that way till the wheels and brakes I want show up and I don't know when that will be.

You can cut a small circle in the two shimmed brass tubes and run your set screw straight to the axle.

PS, how cool I figured out your delimma ;)

RE: wheel hubs
 

Depending on your field you may be better to run them dry.

Grease them and the grit will stick and cause more wear. If you have seals and can keep the grit out or are flying from a clean runway, then lubricate.

I believe the sand yacht guys used to run their bearings dry for this very reason, but I may be out of date on this.

RE: wheel hubs
 

Skateboard bearings admittedly used to use graphite as a lubricant, it does not get sticky like J Duncker rightly suggests with grease but still provides a lubricant that does not run out all over the place.

A friend of mine when I was young enough to partake, was really into this, he used to shave HB rated pencils and gently sand the graphite with fine paper and place the sandings in a little tin, and would then sprinkle this on the bearing.

It appeared to work anyhow,

Gazzer

RE: wheel hubs
 

Sean,

You did figure out about 80% of my delimma. The other 20% is that I don't have the smaller axles that fit the wheels and I want to fly this weekend! :D

I think I'll try it this way and if I see a lot of grey gunk comming off indicating a lot of wear in the aluminum hubs, I'll put the bushings back in and break bad and buy the smaller axles...

Bob

RE: wheel hubs
 

Bob, turns out that Mcmaster carr sells 3/16" wheel axles, also piano whire with wheel collars works great

RE: wheel hubs
 

In case anybody was wondering, Sean was right - aluminum hubs on the steel axle didn't work. At least not for more than one flight. On the taxi back after the landing, one of the wheels seized and when I disassembled it, the brake was full of metal shavings.

SO... I used Sean's suggestion of 3/16 ths wire with wheel collars for axles and bushed them with two thicknesses of brass tubing to fit the struts. It took about two hours, but I should have done it in the first place - the easy way out doesn't pay...

The good part is I now have a really nice set of gear, struts, and wheels on my Euro - two years after I finished it - the cheap way doesn't pay either!

:eek:

Bob