Need A Quote- RFQ - 50mm Optical Trigger disk/wheel (Laser CNC?)

[mtnickel]

This wheel is 50mm in diameter. It will be a spinning disk for an optical sensor and needs to maintain flatness.

I don't know much about materials, but the original was probably .003-.004" thick. Is flexible but returns to near perfect flatness. It could go as big as .015" but .005 - .01" would be ideal (as long as it maintains it's strong flat property). I take it some sort of spring steel would be required.

I've only included the solidworks files (part/drawing) (dimensions in mm, but i can convert to other units/file formats if need be...i'm just new at this so bare with me). Also included DWG files, but not sure if I saved them correctly (one with mm one in inches).

I only need one of these things, and I'm in no huge hurry. I take it a CNC laser would be best.

Any takers? Please note I'm a just a poor boy fixing up a datsun 260z.

Thanks,
Mark Nickel

[mtnickel]

anyone? does my description look okay or can i make any of the files more clear? easier units? anything?
Thanks

Mark

[Matt@RFR]

The thickness plus the flatness callout is what's killing you. Any material that thin cut by something that inputs heat will warp the hell out of it, including lasers. You could bypass the heat input by having a custom die made and have it punched out, but that would cost a few thousand dollars and still not be anywhere near flat. Milling something that thin even on a custom vacuum plate would be tricky, and would STILL warp, more than likely. The part could be flattend by a very experienced person over several hours, but I doubt you want to pay for that.

Can you not find another in a junk yard, or even buy a new one from a dealer?

Does this thing bolt to the dampner or crank pulley? If that's the case, I doubt it needs to be as flat as you're saying. Be carefull using the word "perfect" around machinists! Those seven letters tend to add 1000% to part costs.

As a side note, I get a kick out of the fact that out of all the parts I've made, my wife is so far the only one to come up with something I couldn't make. And she started with, "Sweetie, can you make me a simple part?".

[mtnickel]

Ok, perhaps i didn't quite realize my exact wording and the implications it made.

The wheel sits in a 1/16" gap (but is offset from the center). So theoretical maximum thickness is just under 1/32".

Sensor
========
(1/32" - wheel thickness).
--------------|||||||-------------- < wheel
1/32"
========

So the wheel spins through the sensor checking when there are holes.

Flatness does not need to be "perfect" by any means...just flat enough so it does not hit the upper or lower edge. The thicker the wheel, the greater the flatness tolerance.

As for finding another stock one, it won't work since i'm using a custom Fuel injeciton system and the 360 ticks in the stock wheel is too much for the cpu to handle.

It sits inside the distributor housing...not on the crank pulley.

Maybe this will help. if not i might just go to a system that does use the crank pulley and a VR sensor.

Mark

Originally Posted by Matt@RFR The thickness plus the flatness callout is what's killing you. Any material that thin cut by something that inputs heat will warp the hell out of it, including lasers. You could bypass the heat input by having a custom die made and have it punched out, but that would cost a few thousand dollars and still not be anywhere near flat. Milling something that thin even on a custom vacuum plate would be tricky, and would STILL warp, more than likely. The part could be flattend by a very experienced person over several hours, but I doubt you want to pay for that. Can you not find another in a junk yard, or even buy a new one from a dealer? Does this thing bolt to the dampner or crank pulley? If that's the case, I doubt it needs to be as flat as you're saying. Be carefull using the word "perfect" around machinists! Those seven letters tend to add 1000% to part costs. As a side note, I get a kick out of the fact that out of all the parts I've made, my wife is so far the only one to come up with something I couldn't make. And she started with, "Sweetie, can you make me a simple part?".

[mtnickel]

Ok, well based on a few responses i got, i think i'll just abort the project and get my spark signal elsewhere.

Thanks for the responses guys.

[Matt@RFR]

Originally Posted by mtnickel As for finding another stock one, it won't work since i'm using a custom Fuel injeciton system and the 360 ticks in the stock wheel is too much for the cpu to handle. Mark

Mark, can you simply grind off however many teeth on the stock part to make it work? I know nothing about EFI and vehicle computers, but thought I'd throw that thought out there.

[mtnickel]

That was my original idea. I would need to fill in 1/2 of the slots (possibly with an epoxy or even some sort of paint as the slits are tiny enough to suspend the substance). As for cutting out the other slots. I attempted it by hand with some magnifying glasses and a dremel with a tiny tip, but it was very tedious, and i worried about possibly taking a touch off the leading edge.

I suppose had i filled every slot up, then perhaps just the slots could be machined out if someone had a small enough bit.

But in the end i think it's looking easier to just use the other system. It will require lathing down the crank pulley, but that's about it for machining. No custom work really.

Thanks again for the idea's and help.

mark

[WOLOG]

How about getting it water jetted?

[mtnickel]

Thanks again guys for the ideas...but this new system i'm looking into really will be less work.