making double sided PCB's

[djh82uk]

Hmm, are Home and Limit switches essentailly the same thing?

I have found a few peoples exampls of them on the taig mill, and they use upto 5 swtiches, 1 for Z and 2 for X and 2 for Y

DJH

[acondit]

DJH,

Originally Posted by djh82uk Thank you I can understand how the home switch helps you to move back the the same point each time, but how does it help you get the spindle 0.25" from the dowel initially? when i first set it up?

By drilling the dowel holes at specified locations in relation to home (i.e., use the cnc to drill the holes for the dowels), you can move under cnc control to the offsets that you want. Lets say that you drill the right most dowel hole at x10.0 y1.0 and you want an offset of 0.25 from the edge of the dowel and you used a 0.250 dowel. You would specify G10 L2 P2 X9.625 Y1.375 Z???? (X is 10" minus 0.250 offset from the edge of the dowel and minus the radius of the dowel 0.125" or 9.625"). Then you drilled the left-most dowel hole at x4.0 y1.0. You would specify G10 L2 P3 X4.375 Y1.375 Z???? (X is 4" plus 0.250 offset from the edge of the dowel and plus the radius of the dowel 0.125" or 4.375").

Also you said that I just have to make sure that the dowels are equidistant from where i want to start cutting, but surely they both need to be 0.25" from the start of the border of the design? Otherwise they won't line up? Ok scrap that, I just figured out how thick I am, obviously when i flip the board it will automatically be in the correct place as the board has been flipped, just so long as the dowels are at the end of the board on both side. Ok so i know how that works now

OK, great.

My only problem is figuring out how to get the spindle exactly 0.25" from the dowel on both axis.

See above.

Im sorry this must be so painful for you, as you can tell this is not my strong point, but I am trying to learn, albeit slowly.

Writing directions is not my strong point either. I just hope this helps.

DJH

Best wishes,
Alan

[djh82uk]

Ahh right ok, so i get the locations of the dowels while im actually drilling them, I then write them down somewhere

I then enter the G55 commands etc into the top of the Gcode, and it goes to the offset and pretends that is a temporary 0,0 home while doing that side of the board. That correct?


Also i have the home switches figured out now, found somewhere that sells them with adapter plates for the taig, just hope he will ship to the Uk.

Thanks

DJH

[acondit]

DJH,

It sounds like you got it.

Alan

[djh82uk]

Thank you for all your help

DJH

[djh82uk]

Hiya

I have my home switches now

What would be the easiest way to do the dowel holes?

The boards I use are 100mm x 160mm, I guess I just draw it in cad?

And grab the co-ordiantes of the dowels from the Gcode to setup the G55/G56 offsets?

DJH

[djh82uk]

Ok. beings as the only place I could mount the Home switches was at the limit of the machines travel, i am still struggling to drill the holes in the right place. I can do it using an offset, but then i do not know the co-ordinates of the dowels then, or perhaps I could use the machine coords in mach2?

DJH

[acondit]

Originally Posted by djh82uk Hiya I have my home switches now What would be the easiest way to do the dowel holes? The boards I use are 100mm x 160mm, I guess I just draw it in cad? And grab the co-ordiantes of the dowels from the Gcode to setup the G55/G56 offsets? DJH

DJH,

You could draw a dxf of the work surface of your machine and the location of the dowels. Then you create gcode to drill the dowel holes at those locations. Use those coordinates (adjusted by the radius of your dowels) for your offsets. This is because you want your offsets to be the edge of the dowels not the center of the dowels.

Alan

[djh82uk]

Hiya

Thanks I think i got it now, Only i flipped the board the wrong way

where do you get your cutting bits from? I have been using the 60 degree bits from max uk, only they are either snapping right at the end, or going blunt very quickly

I may go back to V cutters.

Plus the spindle belt on my Taig has frayed now

DJH

[acondit]

DJH,

Here is a link to cutters that someone else provided.
http://www.thinktink.com

Also take a look at this thread. http://www.cnczone.com/forums/showthread.php?t=2078

Alan