Official Luthiers Forum!

Hi All,

I'd like to draw your attention to the posting that was put up on the woodgears.ca site today: http://woodgears.ca/pantograph/inlay2.html

It shows me and Matthias Wandel experimenting with using his pantograph to do guitar inlays. While the video is OK, I don't think it adequately conveys the power or potential of the combination of his pantograph and Big Print software. I was pressing him to go into more detail, especially about Big Print, but to Matthias it is more important that his videos move along at a good clip and be entertaining rather than come across as an infomercial. So I would encourage you to take the time to also read about and understand what his Big Print program can do. Here's the link to that: http://woodgears.ca/bigprint/index.html

In summary, here's what doing inlay with the pantograph/Big Print software can do for you:

1) Most importantly, with a little practice, you can do very accurate inlays. This happens because you get a 3 to 1 advantage with the pantograph and you are tracing an image from Big Print that is much more accurate than you can do by tracing the shell.
2) No tracing of shell. Just position your inlay as you intend it and take a picture. Load the picture into Big Print and get a print out at whatever scale you need. Trace the picture with the pantograph to route your inlay pockets.
3) Like an inlay you've found on the net? Made your own drawing for an inlay? Load the image into Big Print, print it out at the needed scale and trace it with the pantograph to cut your shell, then do the same to route your pockets.
4) Vision is so much improved because you are following a picture, not the actual wood being routed. So you are not trying to see the small area mostly obscured by a router base that has wood debris coming out of it.
5) When you are following an image that is three times the size of your inlay, it feels like you have tons of room and it's easy to stay in the lines.

Some of the comments coming back on the video are saying that making a casting and a 1 to 1 duplicator is a better approach. I might agree with that if you always are using the same inlay. But if you are doing different inlays or a large inlay, think about how much easier it would be to just take a picture than to make molds.

I fear I've done what Matthias wanted to avoid and come across too much as trying to sell something. So I'll stop and end off by saying that my purpose in this message was not for any gain for myself - my motivation is that I wanted to share with you what I think is a really great tool.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

You can always combine both methods too. If you are hand cutting your inlays then why would making a mold be a problem if it's more accurate? You can always re use the plastic mold material by heating it up again if that's an issure. Depending on how smooth and lack of play in the pantograph will also effect the outcome. If you already have a Makenzie style duplicator you can also just connect a pantograph to it if you want to try this method. It will save you making a mount for the pencil grinder. Just someting more to think about.

Very cool. I've always wondered why people don't do inlay with reducing pantographs.

One suggestion: for the tiny inlay used on guitars, I'd think going to metal construction and bronze bearings would be a big improvement. Aluminum isn't much harder to work than say ebony. Seems like the wood construction has a bit too much potential slop, and is more appropriate for signage and things like that.

I'd probably use 1/4" ball bearings over brass if I were to invest the time and cost of alu.

" I've always wondered why people don't do inlay with reducing pantographs."

That is the way I do all my inlays. There are some pics of "The Poorman's CNC" at my website at the bottom of the in the shop link http://goatrockukulele.com

_________________
Michael F Smith
Goat Rock Ukulele
http://goatrockukulele.com

Mike, I did notice your original post showing your "poorman's CNC" and thought it was great. If I was doing original inlays, I'm sure I would have made a pantograph earlier and if I ever have "standard" inlays I do on many guitars, I will be making some templates.

I get most of my inlay from Andy DePaule. The last one was the vine and thorn fret board and head inlay. If I use that as an example, what I did was lay it all out on the fret board, traced it with a white pencil crayon and then routed the pockets with my Dremel and Stew-Mac router base. Turned out OK but it helps a lot that it was in ebony. Now what I would envisage doing is making a print out of my fret board with Fretfinder 2D (to get a white background), positioning the inlay on the Fretfinder printout, taking a picture of it, loading that into Big Print and making a three size print out and routing the pockets out using the print out and pantograph as shown in the video.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Yesterday I tried cutting some letters in ebony and holly to get a feel for how this method would work for cutting the inlay rather than routing the pocket. First, I should apologize for not having done this prior to my original post. Here's a picture showing the first tries:



Please ignore the inlayed letter "D". I was trying an idea that didn't work so it ended up sloppy. In my opinion, the inlayed letter "A" is not too bad and definitely better than I can do freehand without the pantograph. The two cut letter "A"s I don't think make the grade. They have a wobbly look and, of course, I couldn't capture the really fine cuts in the original shell.

So following Mike's advice, I made a template for the letter "D" on my scroll saw and used his method to trace that on the pantograph. The results are shown below:



The big letter is the template and the smaller ones are the results of tracing that template with the pantograph. In the first try I didn't go deep enough with the router bit so the letter didn't release. Also, as you see, I wasn't able to capture the flourish in the top left of the letter because I couldn't get the pantograph follower into that small space (recall that the pantograph follower has to be three times as wide as the router bit). For the second try, I used a slightly thinner follower and got a little of the flourish. Better. but still some wobble. That could be from the fact that I'm not the greatest with a scroll saw so my template has wobbles or that I didn't secure the inlay blank well enough. I only used masking tape around the edges. In reality if I was doing shell, I would glue it.

Overall though, it seems clear to me that for cutting inlays a template is the way to go but it does make me want to get ever smaller router bits so I can get more detail. It looks as though the smallest available that still has a long enough cutting edge for 1.5 mm thick shell is .02" dia. That's pretty small, but not as small as thin jeweler's saws. Perhaps another trick is just to avoid doing inlays that have sharp inside corners.

As I said in my previous message, I get most of my inlay pre-cut from Andy DePaule. In this case, would I now go through the trouble of making templates to route the pockets? I don't think so. That would be a lot of work for big inlays and, at the end of it, I'm not convinced I would gain much accuracy. So for this use, I think tracing a Big Print print out with the pantograph is a fast, viable approach.

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Pat, I've settled in on 1/32" endmills. I'm not exactly sure of the width of my stylus but I can measure it if you want. I do know that I had to try slightly different diameters of the stylus to get the type of fits I was happy with. I also cut out my patterns with jewelers saw blades chucked into my scroll saw to make every thing fit just right in the end product. It seems that the thickness of the jewelers saw blade kerf when reduced by about 3x is just perfect and provides a snap in place cut. The reduction of my unit isn't 3 it's about 2.7x. I wanted to be able to do an entire ukulele headstock and be able to do patterns around a soundhole and found 3x required too large a pattern. You don't want the arms on your unit to have to go to severe angles as they loose accuracy in that position. As you can see by this example, the fits are pretty good. In this example the fits are a little too good in the lava. The lava is divided into several segments, but you can't tell because it fits too good. I should have filed the edges where they meet for the proper effect. It doesn't always work out with such good fits especially in really had material such as MOP because if the endmills aren't really sharp you can get a little play. I constantly get a kick out of guys telling me why this method won't work or that you can't cut small parts. They chicken eye is a pretty small part that I would struggle cutting out with a jewelers saw by hand.

I don't want to leave the impression that this method is all roses. I takes a while to get dialed in. I broke a lot of endmills just being clumsy at first and I do break endmills still, especially in MOP. I now break about 1 per inlay and for me this is the price of doing business and I don't worry about it. It's a lot more fun to cut wood, recon stone and ablam than to cut pearl with endmills.

_________________
Michael F Smith
Goat Rock Ukulele
http://goatrockukulele.com

Thanks for the information Mike. Nice looking inlay - the fits look great. Certainly looks like you are making it work at 1/32" which is encouraging. Thanks for the idea of experimenting with slightly different size followers. If you don't mind measuring yours, that would be great, but I have a feeling trial and error may be the best approach to optimize on this.

I get my end mills here in Mississauga, Ontario: http://deboertool.com/DeboertoolOnline/ ... px?CPage=2 If you check prices, you will see that they start going up fast once you get smaller than 1/32" with the .02" one being close to $16.00. I wouldn't mind that if I didn't think they would break too often.

Much to my surprise, a fellow that reads the woodgears.ca site volunteered to CNC laser cut some templates for me. So I asked him to do my logo since that's the only inlay I currently repeat. It will be interesting to see how that works out.

I think it's likely that Matthias and I will do one more video perhaps titled "Further Experiments Doing Inlay With the Pantograph" where the emphasis will be on cutting out the inlay progressing from freehand, to making a template, to using the laser cut template and cutting some shell. People like to see the development of these things and hopefully we'll be getting some decent results by the end. If you don't mind, I may want to pick your brains further as I work on this. My other challenge is that, ultimately, I'm not particularly artistic, so even if I had the best tools available, I doubt I could come up with inlays as nice as yours.

Cheers,
Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

my stylus is .09, and my reduction is 2.714x so that would mean my stylus is slightly larger that the actual reduction would dictate.

1/32 (the endmill) = .03125 x 2.714 (the reduction in my case) =.0848 and I'm using .09 stylus diameter, so for me just a little larger stylus than math would indicate is what worked best. It could a little runout in even the best dremel, could be the jewelers saw kerf, could be other factors, I have no clue.

_________________
Michael F Smith
Goat Rock Ukulele
http://goatrockukulele.com

That is how Larrivee did all their inlays til the adoption of CBC....

Nice to hear that the CBC now has a home they can rely on....(The Canadian Broadcasting Corporation has suffered a lot of funding cut-backs in recent years).

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

Mike, have to say those are some really impressive inlays. This thread has been really informative, Thanks Pat. I've downloaded the plans for the pantograph, and now have a new jig to work on.

Ha ha ha!
CNC, it's dynamite!

With a tight machine, it's essentially the same as cutting them out on CNC, and I've made an awful lot of dots for our sponsors today: the letters i and j. Some of them were down below 1mm, but you do need to drop down to a 1/64" cutter for the really tiny stuff. I'm sure a pantograph with bearings and pins at every corner would be able to make smooth cuts.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

1/64" cutter!!

The place where I get the end mills has them that dia. but the cutting length is only 1.14 mm. So I'd have to make multiple passes to get through 1.5 mm shell.

Do they break often?

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

You do have to use multiple passes, as they've got to high an aspect ratio to take a plunge cut at any reasonable speed. I have some at 1/100", but those break if an ant sneezes across the street.

The 1/64" ones do break easily, but I have also had them last through cutting up three full sheets of abalam or an equivalent amount of pearl if the stars are aligned. And by the stars aligned I mean the cutters have a good stream of air clearing out the dust, the toolpath has very smooth motion, and the shell is all fixtured so it's dead level across the whole set of parts. I'm looking forward to seeing what I'll be able to do with the linear motors once they're on my new machine, there's no comparison in smoothness between one of those and even a high end motor with a screw. It's smoothness of motion that always kills you with these, same deal with slotting for frets with tiny high-aspect-ratio cutters.

_________________
Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

Was wondering where my post from yesterday was and I found it this morning - forgot to press submit. Totally agree with Bob:

I too use the 1/64" cutter with my CNC and I don't know how you'd be able to hand cut shell with one of those, even with a pantograph. The issue is that it takes a smooth and steady feed to keep it from breaking. I use a constant z-depth feedrate when cutting with these bits and don't break them very much any more. Before then, I was breaking them like mad.

Maybe with really shallow cuts.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Given that a 1/64" bit runs close to $25.00, it seems to me that it wouldn't take many of these breaking before it wouldn't make economic sense to cut your own MOP. Andy DePaule, for example, only charges $12.00 for one of my "Hawley" logos. Am I missing something?

Pat

_________________
There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.