Inlay pantograph

[Frank Ford]

A nice machine - simple and solid!

When working with a hand-guided pantograph, I've found it quite difficult to avoid breaking super tiny end mills. Unlike CNC, a manual machine doesn't give precise linear movement, so chip load and the forces on the end mill can vary too much - one small slip or quick move, and there goes the end mill.

If you haven't yet, I suggest you investigate "single lip" cutters, sometimes called "engraving bits." They are far more robust and work for the shallow cutting involved in inlay with less breakage. High speed is necessary, of course, and chip evacuation is an issue without compressed air blowing in the cut.

[tadol]

I can see how these techniques can really help in a production situation where you'd need many copies of the same thing, but is the fret saw dead? Don't take this wrong - I am as big a fan of the custom machine as well as hi-tech goodies, but for the custom inlay or repair, is the time and setup and price on these units cost effective compared to hand sawing and routing an inlay? Just wondering what feelings those using these have about that -

[difalkner]

Originally Posted by Frank Ford

A nice machine - simple and solid!

When working with a hand-guided pantograph, I've found it quite difficult to avoid breaking super tiny end mills. Unlike CNC, a manual machine doesn't give precise linear movement, so chip load and the forces on the end mill can vary too much - one small slip or quick move, and there goes the end mill.

If you haven't yet, I suggest you investigate "single lip" cutters, sometimes called "engraving bits." They are far more robust and work for the shallow cutting involved in inlay with less breakage. High speed is necessary, of course, and chip evacuation is an issue without compressed air blowing in the cut.

Thanks, Frank! I really am pleased with how smooth it is and tight at the same time, no slack in movement. It works great for cutting the pocket for the Abalone inlay but I don't know that it will do an acceptable job on the shell. I plan to try a small piece and if it works then I'll post it here (if it doesn't then you'll never hear about it... ).

Originally Posted by tadol

I can see how these techniques can really help in a production situation where you'd need many copies of the same thing, but is the fret saw dead? Don't take this wrong - I am as big a fan of the custom machine as well as hi-tech goodies, but for the custom inlay or repair, is the time and setup and price on these units cost effective compared to hand sawing and routing an inlay? Just wondering what feelings those using these have about that -

I agree with you but I built this pantograph because I want a high degree of repeatability on my headstock logo (that I designed and realize it is not that easy to cut - I could have made it easier but alas, I'm past that point now). It's eye/neck/back straining to route the small cavities for the shell and by using the pantograph I can now concentrate on the 4 times larger template that I cut on my scroll saw. My fret saw isn't gathering dust, though. It's got a sharp blade and I use it often.

But I guess the other reason for the pantograph is that I enjoy designing and building things like this about as much as I do the guitar work. It's probably a sickness of some sort - fixtureitis or something

[Aubade Acoustics]

I stand corrected. In my earlier post I stated that the Shell was .020 but after checking it was .040. Here is a photo of one inlayed and the one on the right ready to pop in. The "a" above the shell blank need about 3 minutes of clean up before it is ready to install. The photo quality is not very good with the iPad but I can assure you that it looks great cut on the laser.

[LouieAtienza]

Originally Posted by difalkner

Thanks, Frank! I really am pleased with how smooth it is and tight at the same time, no slack in movement. It works great for cutting the pocket for the Abalone inlay but I don't know that it will do an acceptable job on the shell. I plan to try a small piece and if it works then I'll post it here (if it doesn't then you'll never hear about it... ).

I agree with you but I built this pantograph because I want a high degree of repeatability on my headstock logo (that I designed and realize it is not that easy to cut - I could have made it easier but alas, I'm past that point now). It's eye/neck/back straining to route the small cavities for the shell and by using the pantograph I can now concentrate on the 4 times larger template that I cut on my scroll saw. My fret saw isn't gathering dust, though. It's got a sharp blade and I use it often.

But I guess the other reason for the pantograph is that I enjoy designing and building things like this about as much as I do the guitar work. It's probably a sickness of some sort - fixtureitis or something

I hear you on the jigs. I have as much fun dreaming them up and making them. Even devoted a thread to them recently. Fun to come up with mechanical means to do a task.

[mirwa]

Originally Posted by Aubade Acoustics

I stand corrected. In my earlier post I stated that the Shell was .020 but after checking it was .040. Here is a photo of one inlayed and the one on the right ready to pop in. The "a" above the shell blank need about 3 minutes of clean up before it is ready to install. The photo quality is not very good with the iPad but I can assure you that it looks great cut on the laser.

Very clean, I will have to start experimenting with ours again.

Steve

[mirwa]

Originally Posted by difalkner

Nice work! I assume you cut the 0.060" shell in multiple passes - correct?

I would be super careful if using this to do inlay work, I totally love the idea, but it is so easy to break these small end mills when you cannot feel them doing the work.

Dont think I am trying to take away from this, I reckon you did a brilliant job and think it would be great if you shared the build process with others.

I bought a commercial duplicator for achieving what your doing, but its still so easy to break tools as you cannot feel the wood under your hands.

Steve

[LouieAtienza]

Originally Posted by mirwa

I would be super careful if using this to do inlay work, I totally love the idea, but it is so easy to break these small end mills when you cannot feel them doing the work.

Dont think I am trying to take away from this, I reckon you did a brilliant job and think it would be great if you shared the build process with others.

I bought a commercial duplicator for achieving what your doing, but its still so easy to break tools as you cannot feel the wood under your hands.

Steve

Well the nice thing is your speed is also decreased by the same ratio as well. But it is just as important to not go too slow, and to keep the "swarf" out of the kerf, as recutting chips and cutter "rubbing" will also cause the tool to heat up, which is the main cause of failure. Ebony is no problem, but rosewoods are more a problem for me because the oils gum up the endmills. I thought of using a cheap airbrush to mist vegetable oil onto the cutter to prevent this, but never tried. I think a shroud behind hooked to a vacuum or dust extractor would be a great idea as well.

Do you have air assist on your lasers? That may help. I operated two 20W lasers when I was still in the sign industry, but they were not powerful enough to cut shell, or at least I couldn't find any parameters that worked well...

[mirwa]

Yes both lasers have pressure assisted air.

Using the cnc - controlled feeds and speeds, the .5mm end mills work a dream even on our big cnc 12ft by 6ft, no need to air assist, or lubricate and so forth, just getting the parameters right, hence why its so difficult to do it by hand let alone remotely by hand

[difalkner]

Originally Posted by mirwa

Yes both lasers have pressure assisted air.

Using the cnc - controlled feeds and speeds, the .5mm end mills work a dream even on our big cnc 12ft by 6ft, no need to air assist, or lubricate and so forth, just getting the parameters right, hence why its so difficult to do it by hand let alone remotely by hand

Steve, how do you secure the pieces of shell for cutting on your CNC?

[mirwa]

Hide glue, and then under hot water to dissolve it

[mirwa]

Originally Posted by Aubade Acoustics

I stand corrected. In my earlier post I stated that the Shell was .020 but after checking it was .040. H

Clearly I am doing something wrong then, heres one I did after reading your reply, I found a piece less than 40 thou and it did exactly a we have always experienced, it powders the edge and only penetrates down 20 thou max

This is using a 100 watt laser at max settings and slow speed, I have also tried all other variable powers and speeds. 100 watt laser I can cut through 3/4 inch mdf with these settings

My manufacturer informed me the reason it would not work when we enquired is because of the calcium levels in the shell, it makes the shell powder up

Super intrigued now..

[LouieAtienza]

Originally Posted by mirwa

Clearly I am doing something wrong then, heres one I did after reading your reply, I found a piece less than 40 thou and it did exactly a we have always experienced, it powders the edge and only penetrates down 20 thou max

This is using a 100 watt laser at max settings and slow speed, I have also tried all other variable powers and speeds. 100 watt laser I can cut through 3/4 inch mdf with these settings

My manufacturer informed me the reason it would not work when we enquired is because of the calcium levels in the shell, it makes the shell powder up

Super intrigued now..

Possible the lens is a different focal length on Aubade Acoustic's machine? Or possibly you can run the job as it "cuts" down to .020", then raise the table .020" and re-run the job?

[mirwa]

In focus is in focus, so I don't see that as the issue. Most machines have a 2 inch focal length, but so long as it's calibrated to the top surface this negates any issues further down the chain, you will note out machine can cut 3/4 mdf, so it's got some serious power in it

Even raising or lowering the table won't do it for us, the issue is after the first cut, the area is impregnated with the calcium buildup from the laser trying to cut the shell, to get the calcium buildup out, you have to drag a razor blade through the area and dig it out.

We have even previously tried this with compressed air over the job while it was cutting, but no luck, hence my earlier reply you cannot cut shell greater than 20", however it appears that it is possible from someone's earlier posts.

The other issue we see when attempting to do it with the laser, is instead of a super thin laser cut line of .2mm width we get a cut line of almost 1mm and that's because the laser beam is reflecting sideways as well whilst it's trying to cut the shell, so you get not only lack of depth but you get unwanted width.

For this reason I am very intrigued.

I love the laser of doing templates and work, and if I could get it to accurately cut shell, I will be doing it everyday without fail
Steve

[Aubade Acoustics]

Originally Posted by mirwa

Clearly I am doing something wrong then, heres one I did after reading your reply, I found a piece less than 40 thou and it did exactly a we have always experienced, it powders the edge and only penetrates down 20 thou max

This is using a 100 watt laser at max settings and slow speed, I have also tried all other variable powers and speeds. 100 watt laser I can cut through 3/4 inch mdf with these settings

My manufacturer informed me the reason it would not work when we enquired is because of the calcium levels in the shell, it makes the shell powder up

Super intrigued now..

Hey Steve,
The shell blank is a laminated blank and not solid shell. I started out bringing him the blanks with tape on one side. He would laser the 'a' in the tape and it gave me a pattern to cut by with the hand saw. At the time his laser was a universal 25 watt with an updated 40 watt tube. Would not cut through it. He recently purchased a new 60 watt universal so we tried it again and after trial and error he was able to do the .040 sheet but not the thicker solid shell. Maybe the laminations make the difference? I am certainly no expert at lasers or anything else for that matter except paying bills and taxes.
Mike