Grounding tools

[david allen]

I'm trying to setup a zeroing program using a brass corner plate as a contact plate. ie the corner plate is put on a corner of the material with a spring clamp and the tool contacts it on 3 sides to find the zero. the plate has a wire attached and the wire clips to a limit switch contact on the carriage.

problem is, the bit isn't grounded. the router only has 2 wires on the plug. manually touching the plate to the carriage actuates the limit function. same with touching the outside of the router. touching the tool bit though, doesn't. right now, I'm clipping a jumper wire from the bit to the frame.

anyone know a better way?

da

[birdsofplay]

Run a ground wire FROM your SB board to the SB Frame.
There's a convenient screw terminal available on the t-37 I/O board for your internal connection.
Check the books/manual.

Carefull, my frame has no paint, ya know !

I Had the same problem, but not any more !!! :-)

I installed micro switches for the X-Y zero and
just use a plate of knowen thickness for the Z

[david allen]

I'm getting ground on the frame OK. I'm even getting a good ground on the _outside_ of the router. the problem is getting a ground at the bit. I'm running a jumper wire now, but that doesn't help if I want to re-zero during a program.

da

[seaside@esva.net]

David,

What kind of router are you using?

Bill

[birdsofplay]

Now wait a minute ...

If you are going to be zeroing during the program
THEN you will be touching this plate with a "RUNNING" bit ! right ?
Do I need to say more ?

OK, you could be controlling router on/off, in program, otherwise, forget it.

The microswitches, that I mentioned above solve the running bit issue.
I'll even send ya some if ya want.

Z very rarely misses steps and needs rezero during program operation.

[garbob]

I have only set up the z zero function so far. But I don't see why this method wouldn't work as well for zeroing the x and y axis(s). The input switch wire from the controller would be split to provide 2 more wires (x and y). These wires would be mounted (isolated from ground) on the x and y stops attached to a pointy thing so that they would contact the same exact place on the carriage(s) every time. When the routine from Shopbot is run for the zeroing of the x and y axis (you could also insert the zero routine in here too) you would insert the offset from zero to the appropriate axis and you have set the zero point for the table. I also think this type of thing could be used for temporarily setting x,y,z zero on a workpiece anywhere on the table but I'm not sure about how to do this, yet.

[david allen]

I'm using a B&D model 7615 (I think)it's a plunge model with the base removed and the motor strapped to the carriage.

yes, I would be turning off the router during the re-zero and only re-zeroing the Z-axis within the program. if it's not a problem, I guess I don't need to worry about it. past experience with other machines though have taught me to be cautious.

I have limit switches set up (actually, spring loaded bolts as carriage contacts) to get a machine zero. however, I'd like to actually measure the material location and reference from it so that I can have some slop in fixturing.

da