School me on the best machine for big hardwood

**bluesking** · 18-04-2019

Originally Posted by Washout

Hi bluesking

I can see why you want to go for larger cutters and for roughing I would agree, however there is another factor to maybe consider dependant on the guitar design/type you are looking to machine. I'm sure you're aware that most routed pockets on say a Les Paul or Telecaster are a. imperial, but b. also are designed for a set of cutters that have certain corner radii e.g. 1/8 inch which means using a 1/4 inch cutter for most humbuckers. So you may be able to rough out the pockets with an 8-12mm cutter, but will have to do a tool change and a clean up operation with a smaller cutter to clear out the corners.

Also I am using 70v nema 23 steppers on my machine and it easily goes to 15mm depth per pass and I could make that 20mm without too much if any additional tool wear - see here: https://youtu.be/WVf5J8XytSA

BTW if you want the CAD for a "normal" Tele I have that linked in video #9 of the series above. There's a thread on here somewhere as well, as it was a kind of community project.

Chris

Hi Chris,
In my experience, traditional LP and tele style guitars are designed to be cut using 1/2" diameter cutters - you can cut pickup cavities, neck pockets and control cavities all using a 1/2". This is also true for a basic Strat design too. It is certainly true for my own designs, which are my focus.

Good to know what sort of cutting performance you are achieving, the results look good. My biggest focus is on top carving - in fact I only went down the CNC path after deciding that I would build a duplicarver for this job alone - and realised that it would be crazy not to look into CNC. Do you have any example of top carves you've produced on your machine?

Thanks for the CAD link, can never have too much source material.

**Washout** · 18-04-2019

I don't have any drop/carve tops yet, but do have the design run up for an RG/Super Strat custom design with a carve which I'll be cutting, once I have finally finished my AS Tele project. The strategy I'll be using for that will be similar to the video you linked, but will use Fusion 360's Adaptive (trochoidal) clearing rather than a traditional slot/side milled waterline strategy. The reasons for that are that it vastly reduces tool and machine wear and you can run at very high speeds (with careful tuning) - you can see the strategy at work on that Tele video when its roughing out the front side cavities where I'm running at approx 3,500mm/min on a single flute cutter, but could increase that dramatically using 2, 3 or 4 flute cutters.

The carve will then be "smoothed" out on a finishing pass using a ballnose cutter of 8+mm, which should then only leave light sanding. You can see some of that in the neck cutting videos on my channel.

The "problem child" cuts for guitars are the final cut outs I've found, where unless you have the room for "adaptive clearing" in a gutter around the body shape, you'll be using slot milling, which means reducing the depth of cut, as it tends to brutalise the machine and cutter otherwise. Doesn't mean it won't do it, but it just takes a lot longer than adaptive clearing. Again you can see the slot milling cut near the end of that video to compare feeds and speeds.

Hope that helps.

**bluesking** · 18-04-2019

Originally Posted by Washout

I don't have any drop/carve tops yet, but do have the design run up for an RG/Super Strat custom design with a carve which I'll be cutting, once I have finally finished my AS Tele project. The strategy I'll be using for that will be similar to the video you linked, but will use Fusion 360's Adaptive (trochoidal) clearing rather than a traditional slot/side milled waterline strategy. The reasons for that are that it vastly reduces tool and machine wear and you can run at very high speeds (with careful tuning) - you can see the strategy at work on that Tele video when its roughing out the front side cavities where I'm running at approx 3,500mm/min on a single flute cutter, but could increase that dramatically using 2, 3 or 4 flute cutters.

The carve will then be "smoothed" out on a finishing pass using a ballnose cutter of 8+mm, which should then only leave light sanding. You can see some of that in the neck cutting videos on my channel.

The "problem child" cuts for guitars are the final cut outs I've found, where unless you have the room for "adaptive clearing" in a gutter around the body shape, you'll be using slot milling, which means reducing the depth of cut, as it tends to brutalise the machine and cutter otherwise. Doesn't mean it won't do it, but it just takes a lot longer than adaptive clearing. Again you can see the slot milling cut near the end of that video to compare feeds and speeds.

Hope that helps.

Thanks Chris,
A little over my head! I'm certainly no CNC expert, my work to date has stopped at the CAD point (using CAM only for inlays and fret slots). I know I'm probably putting the cart before the horse but I need a machine that will be capable of working in a way I understand - I've clearly got a lot of learning ahead of me.

Worst case scenario, if I can at least automate template production I will already be way ahead. My latest design takes me a couple of weeks to manufacture by hand - I'm not expecting it to jump off the CNC ready for finishing: