Pete Howlett
Well-known member
Hand cut and machine cut inlays are part od the same family but effectively different 'species'. Here are some extracts from a conversation I am having on my Facebook page and in a forum:
I've been working a lot with shell inlayed into brown wood - mgurure to be precise and IR. As anyone doing inlay work will know, if you don't get the tolerances right, the inlay will have a 'defining outline' which often reveals itself as a black line - rather like the work of Jamie Hamley. So for newbies using CNC technology for inlay work this is what I have found out:
1: The tolerance for pearl is 0.025mm/001".
2: To get sharp external corners the pocket must be 'relieved'
3: Precise Bits is the best company for fine cutters - their speeds and feeds recommendations are so helpful to someone like me who cannot do math. Gurian are agent for them but you can buy direct.
4: CNC technology allows you to use sub 1mm thick material which is both cost effective and conservationist - my logos are cut from 0.7mmm thick shell rather than the standard 1.2mm or 1.5mm.
5: Using epoxy to fix inlays is messy and unnecessary if you get 1 and 2 right.
In response to a comparison to hand cutting and my work using 'brown wood', a really hard gig when inlaying:
..... unless you are Larry Robinson, shows the gaps which is why hand inlayers use ebony... My gig is inlaying into brown wood and pushing the CNC to the limit. It requires absolute tolerances and after work with a sharp scalpel. I use cutters that are either 0.4mm or 0.6mm to do all the fine work and am exploring 0.8mm - 1mm for the main clearing of the pockets to speed the process up. Speeds and feeds are all well and good but like any other job, you still have to 'read the wood'!
It requires meticulous surveying and measuring of the drawing and converting all internal radii, often amounting to 100+ to be radiused to that of the final cutter. Tang wide pockets have to be cut where the fret is positioned over a pice of inlay. The hardest thing is getting the sequence of operations right. The way I do it ties the machine up for almost a day per fretboard! This also is as technically demanding as any hand cutting and in my opinion, because of the levels of accuracy, demonstrates an equality though different level/type of skill to hand cutting. Imagine how many more Larson Bros instruments would have been made with the Dyer tree of life if they had access to CNC technologies? Their instruments may have to turned out symmetrical in the first place....
I've been working a lot with shell inlayed into brown wood - mgurure to be precise and IR. As anyone doing inlay work will know, if you don't get the tolerances right, the inlay will have a 'defining outline' which often reveals itself as a black line - rather like the work of Jamie Hamley. So for newbies using CNC technology for inlay work this is what I have found out:
1: The tolerance for pearl is 0.025mm/001".
2: To get sharp external corners the pocket must be 'relieved'
3: Precise Bits is the best company for fine cutters - their speeds and feeds recommendations are so helpful to someone like me who cannot do math. Gurian are agent for them but you can buy direct.
4: CNC technology allows you to use sub 1mm thick material which is both cost effective and conservationist - my logos are cut from 0.7mmm thick shell rather than the standard 1.2mm or 1.5mm.
5: Using epoxy to fix inlays is messy and unnecessary if you get 1 and 2 right.
In response to a comparison to hand cutting and my work using 'brown wood', a really hard gig when inlaying:
..... unless you are Larry Robinson, shows the gaps which is why hand inlayers use ebony... My gig is inlaying into brown wood and pushing the CNC to the limit. It requires absolute tolerances and after work with a sharp scalpel. I use cutters that are either 0.4mm or 0.6mm to do all the fine work and am exploring 0.8mm - 1mm for the main clearing of the pockets to speed the process up. Speeds and feeds are all well and good but like any other job, you still have to 'read the wood'!
It requires meticulous surveying and measuring of the drawing and converting all internal radii, often amounting to 100+ to be radiused to that of the final cutter. Tang wide pockets have to be cut where the fret is positioned over a pice of inlay. The hardest thing is getting the sequence of operations right. The way I do it ties the machine up for almost a day per fretboard! This also is as technically demanding as any hand cutting and in my opinion, because of the levels of accuracy, demonstrates an equality though different level/type of skill to hand cutting. Imagine how many more Larson Bros instruments would have been made with the Dyer tree of life if they had access to CNC technologies? Their instruments may have to turned out symmetrical in the first place....
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