Probably starting a religious war, but I've actually had better luck with engraving bits that actual mills for traces. I change over to a real mill for milling operations.

What I really need to do is master gcode well enough to have a routine that re-zero's the height after changing a bit.

Bob


On Thu, Mar 21, 2019 at 4:26 PM John Ferguson via Groups.Io <jferg977=[email protected]> wrote:

I suppose swarf isn't the best word, but I'm curious about how you guys get rid of the chips which lodge in cuts.?? I've been chasing them out with a needle, buy it's tedious.

I've got 90 psi air in the shop. Maybe I should try that.

I've got my production system running very smoothly. Design In Eagle, generate Gcode in pcpcode, sometimes include autocad millwork with gcode generated in SheetCAM, set up work piece, set height on cutter and go.

I make all of my boards from 2.5x4.0 workpieces. I made an aluminum fixture with a depression which fist these workpieces and has a lid which locates 4 holes one in each corner.?? I drill the holes and then screw the board down to an HDPE fixture bolted to the table on my 6040 router.?? The HDPE has 4 holes which take 6-32 nylon socket head caps screws.?? I face off the surface the board sits on every 4th or 5th board to maintain level.??

I adjust the bit height by rolling a piece of .250 drill rod back and forth until the bit just clears and then dropping it one click on the servo so it doesn't quite clear.?? I have vertical "home" set at Z=1.000 on the machine so I have to raise the spindle .750 before I start.?? I suppose I could lower the home to .250 and eliminate the "raise" but having it at one inch gives me enough time to catch some kinds of screw-ups.

I've been delighted with this bit. I buy them from Precise Bits and they seem to last pretty well.??

EM3E8-0100-15V 0.0100in. (0.254mm) tip dia., 3-flute 15?° tapered stub trace-isolation bit, 0.020 in. DOC, 1.42 in. (36mm) OAL 2 $16.95 $33.90

The size of the bur on the edge of cuts seems to increase as they wear out, but only downside of this seems to be more dressing of the finished board. I use 400 grit paper and final clean up with 800 crocus cloth.

I've been tinning the finished boards with MG Chemical 421.?? I'm a bit mystified why I get better tinning if i rough up the board with 400 grit before plating it.?? I wash board with acetone before tinning.

After I've soldered everything (all through hole - no smds yet), I go over the board with a loupe and remove any shorts with braid and clean out any suspicious cuts with a needle.

and they always work, at least the ones I haven't messed up the circuits on.

If you read this and see anything stupid, let me know.?? Also I'm still like a better way to get rid of chips.

regards,

John ferguson?? delray beach

Bob,
Been there and done that!? I use a probing function on a fixed tool pad that has +5V on it and a ground clip on the tool to make sure we have a good contact.? The touch pad is on G53 and I have managed to make tool offsets work in Turbocnc.? I believe others have done it in Mach and other controllers.? Another way to do it is to have a dedicated area on your blank pcb and use the electrical method to touch off and not worry about fixture offsets.?

In this case, use a probe function and call a G92 Z0 at the probe.? Raise the tool to clear everything and forge on.

Country


?At 3/21/2019 04:52 PM, bownes wrote:

Probably starting a religious war, but I've actually had better luck with engraving bits that actual mills for traces. I change over to a real mill for milling operations.

What I really need to do is master gcode well enough to have a routine that re-zero's the height after changing a bit.

Bob


On Thu, Mar 21, 2019 at 4:26 PM John Ferguson via Groups.Io <jferg977=[email protected]> wrote:

I suppose swarf isn't the best word, but I'm curious about how you guys get rid of the chips which lodge in cuts.?? I've been chasing them out with a needle, buy it's tedious.

I've got 90 psi air in the shop. Maybe I should try that.

I've got my production system running very smoothly. Design In Eagle, generate Gcode in pcpcode, sometimes include autocad millwork with gcode generated in SheetCAM, set up work piece, set height on cutter and go.

I make all of my boards from 2.5x4.0 workpieces. I made an aluminum fixture with a depression which fist these workpieces and has a lid which locates 4 holes one in each corner.?? I drill the holes and then screw the board down to an HDPE fixture bolted to the table on my 6040 router.?? The HDPE has 4 holes which take 6-32 nylon socket head caps screws.?? I face off the surface the board sits on every 4th or 5th board to maintain level.??

I adjust the bit height by rolling a piece of .250 drill rod back and forth until the bit just clears and then dropping it one click on the servo so it doesn't quite clear.?? I have vertical "home" set at Z=1.000 on the machine so I have to raise the spindle .750 before I start.?? I suppose I could lower the home to .250 and eliminate the "raise" but having it at one inch gives me enough time to catch some kinds of screw-ups.

I've been delighted with this bit. I buy them from Precise Bits and they seem to last pretty well.??

EM3E8-0100-15V 0.0100in. (0.254mm) tip dia., 3-flute 15?° tapered stub trace-isolation bit, 0.020 in. DOC, 1.42 in. (36mm) OAL 2 $16.95 $33.90

The size of the bur on the edge of cuts seems to increase as they wear out, but only downside of this seems to be more dressing of the finished board. I use 400 grit paper and final clean up with 800 crocus cloth.

I've been tinning the finished boards with MG Chemical 421.?? I'm a bit mystified why I get better tinning if i rough up the board with 400 grit before plating it.?? I wash board with acetone before tinning.

After I've soldered everything (all through hole - no smds yet), I go over the board with a loupe and remove any shorts with braid and clean out any suspicious cuts with a needle.

and they always work, at least the ones I haven't messed up the circuits on.

If you read this and see anything stupid, let me know.?? Also I'm still like a better way to get rid of chips.

regards,

John ferguson?? delray beach

I thought I was asking about swarf.?

On 3/21/19 5:30 PM, Art Eckstein wrote:

Bob,
Been there and done that!? I use a probing function on a fixed tool pad that has +5V on it and a ground clip on the tool to make sure we have a good contact.? The touch pad is on G53 and I have managed to make tool offsets work in Turbocnc.? I believe others have done it in Mach and other controllers.? Another way to do it is to have a dedicated area on your blank pcb and use the electrical method to touch off and not worry about fixture offsets.?

In this case, use a probe function and call a G92 Z0 at the probe.? Raise the tool to clear everything and forge on.

Country


?At 3/21/2019 04:52 PM, bownes wrote:

Probably starting a religious war, but I've actually had better luck with engraving bits that actual mills for traces. I change over to a real mill for milling operations.

What I really need to do is master gcode well enough to have a routine that re-zero's the height after changing a bit.

Bob


On Thu, Mar 21, 2019 at 4:26 PM John Ferguson via Groups.Io <jferg977=[email protected]> wrote:

I suppose swarf isn't the best word, but I'm curious about how you guys get rid of the chips which lodge in cuts.?? I've been chasing them out with a needle, buy it's tedious.

I've got 90 psi air in the shop. Maybe I should try that.

I've got my production system running very smoothly. Design In Eagle, generate Gcode in pcpcode, sometimes include autocad millwork with gcode generated in SheetCAM, set up work piece, set height on cutter and go.

I make all of my boards from 2.5x4.0 workpieces. I made an aluminum fixture with a depression which fist these workpieces and has a lid which locates 4 holes one in each corner.?? I drill the holes and then screw the board down to an HDPE fixture bolted to the table on my 6040 router.?? The HDPE has 4 holes which take 6-32 nylon socket head caps screws.?? I face off the surface the board sits on every 4th or 5th board to maintain level.??

I adjust the bit height by rolling a piece of .250 drill rod back and forth until the bit just clears and then dropping it one click on the servo so it doesn't quite clear.?? I have vertical "home" set at Z=1.000 on the machine so I have to raise the spindle .750 before I start.?? I suppose I could lower the home to .250 and eliminate the "raise" but having it at one inch gives me enough time to catch some kinds of screw-ups.

I've been delighted with this bit. I buy them from Precise Bits and they seem to last pretty well.??

EM3E8-0100-15V 0.0100in. (0.254mm) tip dia., 3-flute 15?° tapered stub trace-isolation bit, 0.020 in. DOC, 1.42 in. (36mm) OAL 2 $16.95 $33.90

The size of the bur on the edge of cuts seems to increase as they wear out, but only downside of this seems to be more dressing of the finished board. I use 400 grit paper and final clean up with 800 crocus cloth.

I've been tinning the finished boards with MG Chemical 421.?? I'm a bit mystified why I get better tinning if i rough up the board with 400 grit before plating it.?? I wash board with acetone before tinning.

After I've soldered everything (all through hole - no smds yet), I go over the board with a loupe and remove any shorts with braid and clean out any suspicious cuts with a needle.

and they always work, at least the ones I haven't messed up the circuits on.

If you read this and see anything stupid, let me know.?? Also I'm still like a better way to get rid of chips.

regards,

John ferguson?? delray beach

What step size do you use and what cutter diameter?

I’ve found if I use a step of >=50% the cutter foam, I get these “leftovers”, but, if I set a step of 30-40%, it tends to be clean. Takes longer, of course.

Dan Staver

Tave Tech Corp.

3130 Hollycrest Dr.

Colorado Springs, CO 80920

+1-719-359-5352 - office

+1-719-502-1675 - cell

tavetech - Skype

dan.staver@...

W3QDO

I had the idea of repeating the cuts assuming that the next pass would throw the swarf out of the groove.

Yes, that’s the idea. I got tired of cleaning the grooves myself.

John T. Johnson
PhD Candidate - Cognitive Motor Control Laboratory
Lab TA NEURO 2001 Principles
School of Biological Sciences
Georgia Institute of Technology

678-575-2093
john.johnson@...

On 22 Mar 2019, at 8:26, John Ferguson via Groups.Io wrote:

HI Dan,

I've been cutting my "grooves" in a single pass. I'm assuming "steps" means offsets, maybe cutting a groove and then making another pass .001 nearer the trace to clean it up. Is that it?

I had the idea of repeating the cuts assuming that the next pass would throw the swarf out of the groove.

If I want to do steps, I assume I would need to increase trace separation in Eagle and then set the step in pcbgcode.? If this is approximately right, I'll go back to the manual and try it.

my boards, except for one, are single sided with no vias.? they have a number pf dip sockets and traces must pass between pins and there isn't a lot of space there - .010 pin separation and I like to use the long pads; tight.

what do you think?


john

On 3/21/19 9:35 PM, Dan.Staver wrote:

What step size do you use and what cutter diameter?
I’ve found if I use a step of >=50% the cutter foam, I get these “leftovers”, but, if I set a step of 30-40%, it tends to be clean. Takes longer, of course.

Dan Staver
Tave Tech Corp.
3130 Hollycrest Dr.
Colorado Springs, CO 80920
+1-719-359-5352 - office
+1-719-502-1675 - cell
tavetech - Skype
dan.staver@... <mailto:dan.staver@...>
<>
W3QDO

sounds like the old shampoo ad. Cut, repeat.

While I'm at it i want to again thank you for your wonderful code.? As I wrote when I first surfaced the swarf problem, I've gotten my design and cut routine down cold - everything works.

best regards,

john ferguson

On 3/22/19 1:21 PM, John Johnson wrote:

I had the idea of repeating the cuts assuming that the next pass
would throw the swarf out of the groove.

Yes, that’s the idea. I got tired of cleaning the grooves myself.

John T. Johnson
PhD Candidate - Cognitive Motor Control Laboratory
Lab TA NEURO 2001 Principles
School of Biological Sciences
Georgia Institute of Technology

678-575-2093
john.johnson@...

On 22 Mar 2019, at 8:26, John Ferguson via Groups.Io wrote:

HI Dan,

I've been cutting my "grooves" in a single pass. I'm assuming
"steps" means offsets, maybe cutting a groove and then making
another pass .001 nearer the trace to clean it up. Is that it?

I had the idea of repeating the cuts assuming that the next pass
would throw the swarf out of the groove.

If I want to do steps, I assume I would need to increase trace
separation in Eagle and then set the step in pcbgcode.? If this is
approximately right, I'll go back to the manual and try it.

my boards, except for one, are single sided with no vias. they
have a number pf dip sockets and traces must pass between pins and
there isn't a lot of space there - .010 pin separation and I like
to use the long pads; tight.

what do you think?


john

On 3/21/19 9:35 PM, Dan.Staver wrote:

What step size do you use and what cutter diameter?
I’ve found if I use a step of >=50% the cutter foam, I get
these “leftovers”, but, if I set a step of 30-40%, it tends to
be clean. Takes longer, of course.

Dan Staver
Tave Tech Corp.
3130 Hollycrest Dr.
Colorado Springs, CO 80920
+1-719-359-5352 - office
+1-719-502-1675 - cell
tavetech - Skype
dan.staver@... <mailto:dan.staver@...>
www.tavetech.com <>
W3QDO

sorry if I return with the same theme: it is useful to use your software to generate the trace layout with a bit of 0.10mm and then increase the separation between tracks with a bit of 0.7mm.

Can you generate the residual areas where the bit of 0.70 does not arrive (angles, sectors where should bit 0.7 be cut because it invades another track) that should be done by pocket operation for copper cleaning? I have managed to solve it with bcnc, but it is not a practical solution,