Indicating existing features on a water jet

[RJT]

Easiest example, if you have a flat wide ring (disk) where the ID is finished, and you want to waterjet features concentric to the ID, how do you pick up the finished bore ? A fixture isn't practical, bores are different sizes, 3 jaw chuck would gum up in a hurry. Different example, you want to produce holes at a certain dimension from a finished edge? Is there some kind of electronic edge finder available for waterjet? I'm sure an applications engineer from the waterjet manufacturer could answer these questions,but don't want to go there yet.

 

[TeachMePlease]

I'd have to imagine that a clever machinist could build a bracket for one of those electronic edge finders that don't need to be spun, but light up on contact with anything conductive. A couple test cuts, some math, and even if it's not centered 100% perfectly, you've got your offsets stored. Right?

Or am I underthinking it? (I have no experience with waterjets, just spitballing here)

 

[Doug]

Doo you want your answer to be here ?
or over at PM ?

Let's not get into "saturation bombing" of questions please.

 

[RJT]

Is posting in both places frowned upon? FWIW I got 2 responses here in 10 minutes. Nothing there in 3 hours.

 

[Herding Cats]

How big is the bore? Could have a "bushing" to locate the part off of the nozzle. If the part is not symmetrical a cheap probe not on XY zero would still let you set G68

 

[Kustomizer]

I welded some brackets to the underside of a larger square piece of steel, bolted it to the grid in the waterjet then cut a spline looking piece that fit snug in my existing ring from the larger square. Then I can drop the parts on the spline and cut my profile

 

[Vancbiker]

On the rare occasion we had to something similar with our waterjet, we just used the nozzle like a poor man’s edge finder. Bring it up to a piece of shim till it drags then offset by half the diameter plus the thickness of the shim. Accurate enough for the process.

 

[Doug]

Is posting in both places frowned upon? FWIW I got 2 responses here in 10 minutes. Nothing there in 3 hours.

i I see it leads to problems.
we've had some doo multiple in the same website (PM) under different sub forums, and you've got people
providing "help" and allot of nashing of teeth.
"I already got that over at xyz" and the like.

 

[Doug]

On the rare occasion we had to something similar with our waterjet, we just used the nozzle like a poor man’s edge finder. Bring it up to a piece of shim till it drags then offset by half the diameter plus the thickness of the shim. Accurate enough for the process.

"Laser beams".....the Plasma torch people male a clip on device that goes over the barrel of the torch, gives cross hairs.

 

[CNC_Chip_Thin]

I love tough questions!

Here's my first thought...

1. Secure the part on the machine
2. Get a 3d indicator like a Haimer of something similar you can mount centered on the nozzle
3. Eye ball the ID as best as possible
3. Write a program that interpolates the ID of bore (compensating for the OD of the indicator of course)
4. Run program and adjust center as needed until indicator reads as close to Zero as necessary

Next question...

 

[Herding Cats]

Is posting in both places frowned upon? FWIW I got 2 responses here in 10 minutes. Nothing there in 3 hours.

I'm fine with it provided it's not to incite a pissing match or some other nonsense. (which I don't believe it is)

 

[Mike1974]

Is posting in both places frowned upon? FWIW I got 2 responses here in 10 minutes. Nothing there in 3 hours.

Not here sir. We prefer everything just stays civil as much as possible. I've seen cross posts and I think that's fine....

 

[RJT]

Understood. I'm all for keeping things civil.

 

[vmipacman]

I have watched some waterjet work at several shops and always supprised there isn’t some sort of indicator for the head?!
They typically rely heavily on the WJ itself to make its own fixturing. Like screw a pc of plywood down and wj a right angle for stop to nest in.

In this case, how about peircing a set of ortonanal holes at 0, 90, 180, 270 in increments that match your different hole sizes. Concentric holes patterns. Then set the disk down and eyeball to land the hole edge on the correct hole pattern