When To Zero

[Jerome]

We are beginning to do some routing and the PRS Alpha is fantastic. I am a bit confused about when to Zero the Z. I hope I'm using the right term, this is when to use the Z Zero Plate.

Will the machine remember the Z location when it is turned off or should I Zero each morning when I turn it on?

Thanks in Advance
Jerome

[dana_swift]

STRONG WARNING! Zero before cutting new thicknesses of material if the top is zero. Or using material from a different batch, thicknesses change.

Never count on the zero holding if the Bot is off. Watch your router when the power goes off and often it "drifts" a bit. The drift on my system seems to depend on how much of the weight of the dust collector hose is leaning on the Z car. If a lot of the hose is pushing down on the Z, when the power is off it drifts down.

Zero after every bit change.

Sometimes I zero more than once just because I am not sure I found the high spot in a piece of stock to zero on.

If you quit the SB3 program, and re-start it but the Bot has maintained power, it MAY maintain Z, but don't count on it. Usually I re-zero after that also.

Hope that helps-

D

[blackhawk]

I second everything that Dana said.

[curtiss]

Always touch the plate to the bit before you zero to make sure the contact light goes on.

This only takes an extra second and can prevent a "WTH is going on" situation, as your bit smashes into the plate. Some of those routers are so quiet you may have fogot to turn it off...

Typing C3 when you mean to type C2 is sort of a pain....

[jerry_stanek]

I will zero to my table top most of the time at the start of a file. I just fell saver to do it that way. If I am cutting more than one sheet with the same bit I will only zero once at the start of the job.

[tracys]

After I zero, I have a machinist 1-2-3 block and slide it up to the bit to check that it did return to 1" after it was done. I have mine set to return to 1". I've had it a few times stay too low.

[Gary Campbell]

Jerome...
You didn't mention, but I assume you are using the ATC. Depending on what version of the SB ATC files you are using, the Z position and any offsets you applied by rezeroing to a material top are stored. These offsets will be reapplied when you home the tool in 3 axes. (C3)

Or, if you home the tool and then zero the z to material top, any bit you change to should be zeroed to that same height.

If you are zeroing to the bed, and assuming you have used the calibration routines properly, you never have to use the plate.

That said, and to answer your question, you should never have to use the zero plate unless you need to introduce a new zero height into the system. This is one of the best features of a fixed zero block and a prox on the Z.

Because there is such a great difference between the way the ATC works vs most others out there, make sure you note that in future questions.

[Jerome]

I want to thank everybody who responded to my Z Zero question.

My spindle does sink to the table top overnight so it is not in the same place the next morning. If I understand Gary correctly since I have the ATC, the spindle will zero itself when I do a C3.

That said we had some problems getting the original setup program to work. Because of the ATC Shopbot decided I needed longer rails on my machine. When they arrive I intend to start all over again and make sure I set it up right.

Thank You again
Jerome

[Gary Campbell]

I think they should send me longer rails for mine too!

[frank134]

Hi Gary…
With that statement you made about the rails you make me think. I know you had a PRS Alpha before you got you ATC. I have the PRS Alpha with a 5 x 10 table. What I want to ask is what all would I have to change to make mine and ATC. Are the rails longer on an ATC? Is the Y and the Z any difference?
What would I be adding or changing? I thought only the spindle and spindle controller and the tool changing bar would be it or is there more to it? I ask because I like to know what I could sell to offset the cost to change to a ATC.
Thank

[Gary Campbell]

Frank...
As far as I have noticed, all is the same as my last machine.

You would remove your spindle and VFD, then add the ATC spindle, ATC interfeace board, toolbar and pneumatic controls. Pop in the Custom\ATC folder of files and you should be running.

[frank134]

Thank Gary that help alot.