Zero Z and changing bits?

[WillyInBris]

Ok time to get serious.

Guys got a bit of a question I may have the answer tell me what you think.

When I carved the Green man face I used one bit it was a 6mm roundnose bit for both the rough cut and the finish cut anyway I wasn't very happy with the finish cut due to lost detail what I want to do is use the 6mm for the rough cut and a 3mm for the finish cut but how do I keep the Zero on my Z.

I was thinking maybe a collar on both bits, could that work I am sure I have seen them used on drill bits but I ain't to sure if this would work?

Whats your thoughts or do we have an easier way of doing it?

[Greolt]

Sean

What you want to do is set the zero to the top of the material in your 3D model.

Then with the first tool, zero the Z at a point like the cross in the pic.

With the second tool fitted, that cross is still there so re zero the Z to the same point.

Alternatively you can do the same three steps to the table or bottom of material.

Greg

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[WillyInBris]

Thanks Greg silly me :doh: some times you just go brain dead :U.

If only Rod could invent a Perth made 1/4 Die Grinder auto tool changer :U I would even pay for the R&D costs and the trip south to install it.


Sean

[rodm]

Sean,
Have you made one of Greg's Z axis touchplates yet? If not then this is the first thing I would do seeing you have to make tool changes.

I'll go with the alternative and zero to the table then allow for material thickness. The reason I say this is because the table is always there and there is a chance you could loose your top of material reference when cutting the job.

Another alternative is to place a piece of MDF over the job and and zero to that allowing for the thichness of the MDF. This will then bridge the material hollows for your tool change.

[simso]

Go gregs zero device, until I saw it in action on rods setup, I gave it a cursory thought, now I dont know how I ever lived without it. One touch perfectly setup every time.

Come on rod when is the laser locator setup going to be finished,Now that my cnc is housed under the bench Im thinking of doing that and doing the other usb camera mod with it, saves crawling underneath all the time, but awesome for dust control

Steve

[rodm]

Hi Steve,
I have canned the laser pointers after a couple of tests with them. I am concerned about laser ricochet damaging my eyes. Your setup might be better being encolsed but if you are cutting a reflective surface then there is a risk. Probably a bit of paranoia by me and you are welcome to grab one to trial it and form your own opinion.
I have found an alternative and are waiting for the camera to be shipped. It is a USB tube camera and Mach3 has a video window with crosshairs so hopefully I wil get the same result and I am told higher accuracy. More to come on this and I'll send you an email with camera details as the photo is from ebay and copywite. I will still use Greg's code as it will work the same to position the axes.

[WillyInBris]

Yep I made one remember the really fast black and silver one :D