Topic: Caliper animation

[SohRon]

anyone notice during a cleaning that the o-ring groove is not square    cross section clearly shows it.
how about a nice closeup gif of the piston to piston o-ring interface, so all can see how it 'rolls up on edge' because of the off-square groove it sits in. 

+1...........you beat me to it....I thought I was not able to get the corners completely cleaned out!

Yes. at rest, piston-facing side of the seal sits flush with the piston, with enough pressure to prevent leaks(good condition piston assumed), but when fluid pressure increases behind the piston and it moves, only the posterior edge of the seal rides/rolls up on the edge on the piston, increasing the pressure in the groove and tightening the seal.
good stuff.

Thanks. Here's a close-up of the seal groove.



This is why the seal doesn't sit flat when you install it. The angle and the little "V" shaped groove at the bottom create a two-tier pressure gradient across the seal so there's more pressure at the rear than the front, and when the brake is applied the seal kind of rolls into itself, transferring the compression from the rear to the front.  When the lever is released, the seal decompresses and returns to its original shape and position.

Great comments, guys!

[Gman]

SohRon,

Bummer to hear about your foot  - best wishes for a speedy recovery! 

The animation is perfect - it's what I imagined happened from reading about calipers ad nauseum + rebuilding mine, but seeing it in action to confirm my suspicions is gratifying.  Thanks!  I've gotta get a bandsaw...   

Cheers,
G

[Black 750K8]

Shifter foot or brake foot?

[dave500]

bourbon/fire and a rock?sounds like the the old drunken aussie rock foot and bourbon game?we dont play that anymore here.

[PeWe]

I searched for a CB750 animation, but found this: http://www.turbosquid.com/3d-models/3d-model-honda-cb750-k0-1969/604833

Plenty of details wrong such as rear hub... brake disc??? but look like  a Honda

[Deltarider]

Sohron, you are hereby appointed chief of the graphics department. Your excellent photographs should also make it to the FAQ.

anyone notice during a cleaning that the o-ring groove is not square    cross section clearly shows it.

In a post years ago I pointed at it that when you remove the seal, you will see that one side is wider, probably out of reaction. Make sure when you use the same seal, the wider side is orientated towards the disk.

[Stev-o]

What can we cut next?

[SohRon]

Thanks for the great comments, guys!

Gman, good to hear from you... yeah, it helps a lot to see the thing in action . Really doesn't leave much to the imagination, does it?

Black 750B... Shifter foot!   

Dave500.... You just freakin' crack me up, dude! Love the commentary! Next time you have your bottom end exposed be sure to get a shot of it. The bike, that is. Tranny?

PeWe... Now, if only he'd done the walk-around as an animation, we'd be set!

Delta... I appreciate your kind words and your insite into the seal. Thanks! I try...   

and, Stev-o... Whatcha got???   

Glad the animation is helpful. Again, thanks for the comments

[HondaMan]

Excellent! 
Sorry about your foot! Heckuva way to end a mountain trip. 

But then, if you hadn't done that, we wouldn't have THIS! 

[754]

Too bad you dont live closeby. I like grinding sectioned parts on my surface grinder.

[brandEn]

what a cool animation. Thanks!

[SohRon]

Excellent! 
Sorry about your foot! Heckuva way to end a mountain trip. 

But then, if you hadn't done that, we wouldn't have THIS! 

Thanks, HM. Actually, I was planning to get to it eventually... it just happened sooner than I anticipated!

Too bad you dont live closeby. I like grinding sectioned parts on my surface grinder.

That would be sweet! I have a belt sander available that does an adequate job, but I'm sure I'd get much smoother results from your setup!

what a cool animation. Thanks!

Thanks, branDen! Much appreciated!

I'm back to work on crutches and a boot. Fun, fun, fun! Hopefully things will heal quickly and I'll be back at my build and the band saw soon! Can't wait!

Thanks to all who have commented.

[Stev-o]

Anybody have a coil we cut cut in half?!

[Gman]

Anybody have a coil we cut cut in half?!

Note to self - unplug first.   

[SohRon]

Anybody have a coil we cut cut in half?!

As a matter of fact, I do (insert maniacal laughter here)!  My question is, do I cut it down the middle or across the wires? Always happy to get outside input before commencing destruction...

[Stev-o]

Anybody have a coil we cut cut in half?!

As a matter of fact, I do (insert maniacal laughter here)!  My question is, do I cut it down the middle or across the wires? Always happy to get outside input before commencing destruction...

Was thinkin down the middle.....hahahahahaha

[754]

Belt sander will do a pretty nice job, a lot of sectioned pieces are very hard to hold in a surface grinder.