Mountain Biking - Custom brake caliper machining

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View Full Version : Custom brake caliper machining


elf 232
05-13-08, 09:28 PM
My brother works in the machine shop at his college and has access to one of the computer controlled machining tools and iv been thinking about making some brake calipers, i have seen this done before and it looks rather simple, especially with the shop tools at hand and could be done for very cheap if it worked would be some pretty beastly calipers and using aluminum, they should be somewhat light.

Heres my thought on a design:


http://i220.photobucket.com/albums/dd223/justinm231/caliper-1.jpg


Im particularly looking for someone who has done machining.


ed
05-13-08, 09:30 PM
Won't work...and you will fail...and you will be a failure living in a van down by the river!!:roflmao2:



JK dude...keep us posted. This could be a REALLY interesting thread and a fun project, dude:thumb:

elf 232
05-13-08, 09:47 PM
Won't work...and you will fail...and you will be a failure living in a van down by the river!!:roflmao2:



JK dude...keep us posted. This could be a REALLY interesting thread and a fun project, dude:thumb:

TRUST ME, my track record for mad scientist projects like this isnt good, im currently about 75% failure rate.

250' zip line: fail, reason: Thought i had enough clearance between a tree that the cable passed by and didnt and cant find a suitable replacement takeoff and landing trees.

Chainsaw powered RC car: Fail, Reason: I must say i thought this one out pretty well but when it came down to it, i didnt have the money, also chainsaw engine shaft was bent. I REALLY WANT TO REVISIT THIS ONE IF ANYONE HAS ANY OLD CHAINSAW MOTOR THAT THEY WILL GIVE ME OR I CAN BUY OFF THEM FOR A FEW BUCKS, IT WOULD GREATLY APPRECIATED AND GO TO GOOD USE!

Downhill racing go-cart: Fail, Reason: This was similar to one of those box car road races but it was for off road. I didnt put any design into it, and just put it together as i went and it turned out to be just too heavy for practical use. This was mainly because i used a frame (with wheels already attached) from a kids pedal cart "thing" and it was made from heavy steel tubes.

Rocket fuel: BIG success: I was pretty down for a while because (as you said!) every project i had done as of yet was a complete failure. This one got my hopes up again for success.


Since im using a $20,000 machine this time to see my dream through, i cant see where i can go wrong!:)


BenLi
05-13-08, 09:48 PM
I've never done it myself, but two things:

1) Decide on whose pads you want to use. Which will figure into your design

2) I wouldn't start out with scratch. I would suggest maybe using an existing caliper as a starting point.

elf 232
05-13-08, 09:50 PM
I know the pistons probably look a little sketchy but i plan to look at other hydraulic disc brake pistons before i start on anything.

elf 232
05-13-08, 09:51 PM
2) I wouldn't start out with scratch. I would suggest maybe using an existing caliper as a starting point.

Not quite sure what you mean by this, do u mean use an existing design?

Svr
05-13-08, 09:52 PM
A hydraulic single sided twin piston setup?

Are you serious? You could go to a motorcycle junkyard and find a better performing caliper than that.

My advice: Find the best performing hydraulic opposed piston MTB disc brake caliper and copy it. Test the prototype for many years, doccument its flaws, and hire an engineer to design something better.

elf 232
05-13-08, 09:55 PM
A hydraulic single sided twin piston setup?

Are you serious? You could go to a motorcycle junkyard and find a better performing caliper than that.

My advice: Find the best performing hydraulic opposed piston MTB disc brake caliper and copy it. Test the prototype for many years, doccument its flaws, and hire an engineer to design something better.

I prefer a single sided design, it allows for simple change in distance of the brake pad from the rotor without messing with hydraulic adjustment. The main prob I have with my LX hydros is that the pad on the far side rubs, and theres really not much way to stop it, this completely negates that problem and will also, allow for better fluid flow.

My entire family is a bunch of engineers...

BenLi
05-13-08, 10:01 PM
What master cylinder are you planning to connect this to? That is also a part of the equation. If terms of mechanical advantage, I think you would want a greater radius piston for more force.

Svr
05-13-08, 10:03 PM
My entire family is a bunch of engineers...



Mine too.

Several of them have spent their entire career correcting the mistakes of other engineers.

elf 232
05-13-08, 10:05 PM
What master cylinder are you planning to connect this to? That is also a part of the equation. If terms of mechanical advantage, I think you would want a greater radius piston for more force.

LX hydro levers..... but i dont think thats what your asking, my hydros never used a master cylinder, please explain.

BenLi
05-13-08, 10:08 PM
LX hydro levers..... but i dont think thats what your asking, my hydros never used a master cylinder, please explain.

The master cylinder is where you apply the pressure (essentially the levers), and the slave cylinder is there the pressure is transferred to (the caliper pistons).

So, you should probably get some technical specs on how much liquid the lever displaces, etc.

elf 232
05-13-08, 10:16 PM
Mine too.

Several of them have spent their entire career correcting the mistakes of other engineers.

That fits my dad's job description perfectly, he is the one that goes to all of his companies jobs and tells the contractors what they did wrong... and make sure it is worked out.

With the housing market down right now its pretty rough, to have to deal with any grumpy nearly out of work contractors, many of them arent though.

elf 232
05-13-08, 10:21 PM
The master cylinder is where you apply the pressure (essentially the levers), and the slave cylinder is there the pressure is transferred to (the caliper pistons).

So, you should probably get some technical specs on how much liquid the lever displaces, etc.

Definetly a good thought, the LX calipers have two pistons, one on each side, and have plenty of pull room left, but if i substantially increase the piston size that could definetly be a big deal.

The drawing is a primitive overall idea, i have no doubt dimensions and specs will greatly changed before any work begins, especially on the pistons, i might try to just pop some pistons from another type of hyrdo caliper in there, hopefully making it easier on myself.

Dannihilator
05-13-08, 10:54 PM
Best of luck with this.

ed
05-14-08, 10:33 AM
250' zip line:
Chainsaw powered RC car:
Downhill racing go-cart:
Rocket fuel: BIG success:

I wanna hang out with you!!:welcome