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OSG has another sale on and I'm wondering how surfacing woods like alder, swamp ash, figured maple etc with an insert face mill would compare to thickness sanding @ 150 grit.

The goal would be to automate the process of getting accurately thicknesses parts with a secondary goal of reducing hand sanding or at the very least not increasing the hand sanding necessary for finish prep.

Anyone have experience with this?

Seems like overkill to me. Inserts are for hard stuff like stainless, Inconel, Waspaloy, and the like. Find a large diameter 2 flute endmill, and drive on.

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"Act your age, not your shoe size" - Prince

Not a bad idea Chris. I'd like something in the 2"-3" diameter range. Too large for a router bit but maybe a spoilboard surfacer.

A spoil board cutter isn't designed for any significant depth of cut plus any decent one with inserts will cost close to an OSG 80mm PRC. As for insert cutters only being used for hard materials I would have to disagree, we use indexable tools for cutting Aluminium every day - glance around YouTube or any of the tool manufacturers catalogues and you'll see we're not alone.

The OSG would give you far more flexibility and durability for not much more than a decent spoil board cutter..

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www.morganguitarworks.com
www.morgancustomguitars.com

Neil are you suggesting a round cutter PRC as opposed to a 90 degree version (PSE I think)?

We have a 38 mm PRC that we use for carving and it's brilliant. Beyond brilliant actually. I just won't do profiles.

Spoilboard cutters will leave a much cleaner surface than endmills because the inserts are on the bottom plane of the cutter instead of the side. But the cut is nowhere near clean enough to replace sanding or even planing for that matter. It would take way too much hand sanding to clean up the face of a guitar that has been surfaced with anything on a cnc.

We use insert cutters for everything we can and we take off 1/8"+ at a time with our spoilboard surfacers.

Neil's got me thinking about a larger PRC tool. I've been tweaking the headstock face plane and transition to nut edge blend using the PRC. Running a fairly low feed rate leaves the face plane shiny smooth and the end grain on the transition sheared beautifully clean.

Absolutely, I've tried the 45deg and the 90deg indexable face mills and now do all my surfacing with a PRC style indexable cutter - works especially well on highly figured woods.

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www.morganguitarworks.com
www.morgancustomguitars.com

Face mills work great...we used them to surface all the electric guitar backs at PRS. Hardly any sanding at all after running one of those across a back..! They used them on the fingerboard glue up surface as well on necks. I believe we used them to flatten the glue up surface on fingerboards as well.

It's been a few years so I can't recall the exact style, but we had great results & that was standard practice.

Trev

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http://www.PeakeGuitars.com

Thumbs up on the insert surfacing bit. I went with the smaller Amana, 1 1/4" diameter, because it works in my tool changer, and it is pretty incredible. I'm going to start using it for precision thicknessing sawn veneers as well as all parts that take a surfacing cut...which is practically everything.

Thanks Rick. While looking up that Amana bit, I stumbled across their stagger tooth insert bit. I've been looking for one of these for profiling.

I use a 63mm face mill with indexable cutters designed for Aluminium in my turret mill to surface and thickness some of my hardwood stock for fret boards and bridges. It leaves a glass like finish that would only be spoiled by hitting it with a piece of 600 grit sandpaper.

On softer woods like Spanish Cedar it's not near as good a finish, but you wouldn't expect it to be either.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

Yep, face mill is where it's at. General purpose inserts will give a good finish at the sort of edge speeds you're dealing with at a 3" diameter and 5-10K RPM. Shiny. If you get the inserts made especially for aluminum, then it'll be even better. Last I was in production at SL, I was also using the 3" face mill for roughing necks and bodies

Like Allen said, sanding only ruins the finish from a good face mill.

I'd recommend looking at the stuff from Glacern. They sell nice stuff at a good price, and they stock spiffy sharp aluminum inserts for them.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

At the opposite end of the spectrum, I'm looking for a bit for my Hitachi router based hobby cnc machine to surface my spoilboard. I see people mention spoilboard cutters, but I don't know what would be appropriate for a 2-1/5 hp router. I am also catastrophically cheap. Any suggestions?

Probably want to stick with a simple router bit. We ran a 1-1/2" bit at about 10K RPM with our router.