trouble zeroing using plate

[Bob T]

Hi, used my 2007 prs standard the last several days, last night, and first cut this morning with no problems. while zeroing a 60 deg. v bit it bumped it into the plate continuously until i slapped the keyboard. because the size of the bit makes gator clipping difficult, tried again, same. jacked it up, tried to fake a Z several inches up, continued down. once cancelled, continued to go up to its limits. screen popped up, control box issue, restart or try again. restart, same. Ideas?

thanks,

Bob

[Bob T]

moving on x, y, both, and z manually all work,

[srwtlc]

Have you verified that the input 1 circuit is working? Does the input 1 indicator light up when touching the plate to ground/clip?

[cowboy1296]

the only time that happened to me the zero plate connection wires were loose.

[Bob T]

thanks scott and cowboy. Checked light on 1, nothing. wire looked good, but clipped stripped tightened and now passes light test. just took a zero. thanks for the help!

[dmidkiff]

Always use the light test before zeroing the z. Many of us learned this just like you have.

[bobmoore]

cost me a chipped 60 degree and a broken 1/8 inch bit before I got serious about checking every time I zero.

[coryatjohn]

I only use the zero plate when cutting clear plastic. I have a bright light mounted on the wall and use the "shadow" method for bringing the bit down to the table or material. The shadow cast by the gap between the bit and the surface magnifies the gap and I can get just as close with this method than I can using the plate. Plus no chance of forgetting to remove the clip. If I'm using a V bit or a really small bit, I use a piece of paper to get it exactly at the surface. In all the times I've used this method, I've never had a problem.

[cowboy1296]

Chances are i am totally wrong but this has never failed me. But i put the alligator clip on the screw that screws up to the router. (hopefully that made sense). That way i dont have to worry about the router ripping the clip wire in half.

[Bob T]

Thanks everyone. Yes, the light test will now be commonplace here. I have had trouble before with painted bits, this would help knowing the connection is good.
John coryat, please explain how you set your z,, controls settings. Tried doing that before, too jumpy for me.

I know this was kind of basic, but freaked out a little when a control box message popped up yesterday, thanks for the helpful tips everyone.

[coryatjohn]

>> John coryat, please explain how you set your z,, controls settings. Tried doing that before, too jumpy for me.

I lower the bit down using the "K" command and the page down button to the point where it's less than a quarter inch above the surface, then hit the "D" to get it into single step mode with steps set at 0.005". Then I single step it down until the gap is gone. By using a light coming from the side, the gap is actually magnified quite a bit so it's very easy to tell, even from a distance, when the gap goes to zero. For pointy bits or very small ones, I get it close, then put a piece of lightweight paper under the bit and bring the bit down until it catches the paper.

I've had problems doing exact work with the plate since even the slightest bit of chips under the plate would throw it off a lot. I still use it now and then but really, prefer to know for certain zero is where I think it is.

[gundog]

I have a different machine but on occasion my zero switch is not accurate so I have started a routine of checking it after setting zero by sending the tool to 1" above where I just zeroed and using a precision parallel that is 1" wide and checking that the bit is exactly 1". This would be easy to do with your SB as well. The material I cut runs over $200 a sheet and although it does not happen very often 2 times in 2 years the second time a month ago I have adopted the practice above. The last time it failed to accurately set zero it was .085" off and ruined half the sheet of parts that had a dovetail in them.

Mike