Design dilema in toolpathing help needed

[myxpykalix]

Ok since a picture is worth a thousand words heres two. I have this "dished" part loaded up in MW. it is a chair seat with the deminsions listed in pic i got from someone as a stl( see mw1)

Now to show toolpaths i had to hold mouse down and couldn't screencap thus the pic of the monitor (mw2)
If you will notice the Z height is way too high and when i save the toolpaths and take them out to start a cut my Z raises up till it "tops out" and looses coordinates and just falls back down.

My safe Z height in the control software is set at .25". The material is 1.5" thick and the Z zero is set to the top of the material.

I can't figure out how to reset that Z height within the file so it doesn't top out . Any ideas?

8580

8581

[jhicks]

Jack, are you sure you have decimel points in front of that 25 and 1.5?

[myxpykalix]

yes decimal points. I think it's default is 1 inch above material but i was thinking the combination of the height of the bit/the height of material was the problem but thats not it.

This file had to be converted to inches from mm and thats where the problem started giving it a 35 inch thick material. It was changed to 1.5 inches but the problem stayed. I wonder if its any type of locked or embedded toolpath?

[hespj]

Is that object a dished 2D surface or an enclosed 3D object? I have a feeling that stl files have to be enclosed 3D objects.

You might try switching the SB to mm and cutting it in the original mm.

John

[myxpykalix]

That was one question i was going to ask. If the file looks ok when in mm and i know, for example, the file is 16"x 16" and i use a 1/4" endmill by changing the units of measurements on the bot, but using the "imperial" (1/4" bit) i would wind up with the same results correct?

[hespj]

Yes, you "should". I do this all the time; I genearlally work in mm and sometimes the router bitsI use are inch.

Can you select inch size bits when working in mm in Millwizard? You should be able to. Otherwise 1/4" = 6.25mm. 16" is about 400mm - as a rough check.

Be careful not to run a mm file whilst the SB is switched to inches, the SB isn't 400" long!! I speak from experience.

John