Question for you airplane wrenches...

[Justin B.]

I have a set of "K-Bike" rotors that are in excellent shape, but unfortunately the "hat" has a different offset than my R100.  The discs themselves are the correct size so I would like to remove my old discs (look OK but their ailment is hard to describe) and bolt these "new" ones in place.  When I was in the service my Platoon Sgt. had a '49 Panhead that crap fell off from all the time and one item that seemed to loosen up regularly was the sprocket ring on the rear wheel.  It was attached to a hub by small high grade bolts. Being in an aviation company we wandered by the hanger and one of the crew chiefs turned us on to some very nice high-grade bolts (drilled for safety wire) and lock-nuts.  We installed these and never had to re-tighten his sprocket again!

I need recommendations on what spec hardware I should use (in lieu of rivets) to reattach the discs.  Don't have access to aviation bolts anymore but I'll think of something!    I'm thinking at least a grade 5, fine thread, with an unthreaded portion a little shorter than the two pieces are thick.  Stainless would be nice but I don't know about the strength, or maybe my thinking is way overkill...

[nhmaf]

I am not an airplane mechanic, nor do I play one on TV, but...

A common bolt failure on some KAwasaki bikes (which I have one) can be the bolts that hold the engine to the
trellis frame (engine is a stressed chassis member).  For these uses, a grade 8 bolt is the minimum one should use.
You will have a number of bolts on the disk, and they will be smaller, but I'd think of using grade 8 there as well if I could.

[goomicoo]

You'll need AN bolts drilled for safety wire. Give me the measurements and I''ll try to find the part numbers for you.
Size bolt
Grip length (shoulder and threaded section) measured from under bolt head to the end of the threaded section.
Shoulder length
This hardware will be subject to shear loads in it's application
Grade 8 may work as well.

[montmil]

You'll need AN bolts drilled for safety wire. Give me the measurements and I''ll try to find the part numbers for you.
Size bolt
Grip length (shoulder and threaded section) measured from under bolt head to the end of the threaded section.
Shoulder length
This hardware will be subject to shear loads in it's application
Grade 8 may work as well.

goomicoo almost got it right... Spec your grip length -which is the length of the unthreaded portion of the bolt shank. Nominal length is the bolt's overall length from underside of head to end of threaded portion. The link goes to Aircraft Spruce, you know these guys, Justin. They have all the data you'll need for specs.

You may wish to consider matching nylok nuts rather than the drilled bolt shank which would require a cotter pin and a castellated nut. Perhaps not the best anchor choice for your application.  

http://www.aircraftspruce.com/catalog/hapages/anbolts.php

Let me know what you end up needing and I'll probably have it in my shop. Have hundreds of pounds of AN-MS hardware -some stainless bolts but limited nuts- stashed about. My lawnmower is almost all AN hardware!

Monte

[Justin B.]

I'll try to grind or mill off one of the rivets tomorrow and do some measuring...

Monte, my old 450 Honda contained almost all airplane hardware.  Plus the hanger hydraulic shop made my front brake lines after I extended the forks.  I sorta miss those days...

[donbmw]

The link below is East Coast Aviation. The company I work for buys all our hardware from them. They have all type of fasteners. I used some HiLok fastener to attach my final drive spline that goes on the wheel hub. There are many fasteners that could be use for this just make sure you have the room for what you use.

Don

http://www.ecasinc.com/

[montmil]

I'll try to grind or mill off one of the rivets tomorrow and do some measuring...

Monte, my old 450 Honda contained almost all airplane hardware.  Plus the hanger hydraulic shop made my front brake lines after I extended the forks.  I sorta miss those days...

You can make a quick 'n dirty grip length measurement tool from a paperclip.

Straighten out the clip and bend a sharp 90 degree angle on one end. Clip the bent portion to a length that will pass through the component/s you need to measure. using a knife or suitable tool, scratch a mark to gauge the grip length and measure the hi-tech paperclip grip length gauge.

There are also low profile nylok nuts, if clearance is an issue. A snug fit -bolt through component- is vital to reduce the possibility of movement during operation. Don't want any fretting action...

Monte