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I'm unhappy with my flush trim bit. Straight edge, no shear angle. Need a recommendation for a good bit, 1/4" shank. Bearing guided (of course), bottom, what about the shear angled bits? I'm leaning towards spiral down cut, but they are expensive. So I'm asking for advice.

Thanks!

Why are you unhappy with it?

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EddieLee

For what task?

Oops. Title said it. Before binding, after the top and back are on? We use our binding bit and cut a recess all around, smaller in both height and depth than the bindings. Makes so you don't have to sand endgrain when flatsanding the sides...

Thanks Ed, that's a good tip. Hadn't thought of it.

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Jim Watts
http://jameswattsguitars.com

Perhaps my trim bit is getting dull, but I'm getting pulls on certain directions for the soft wood. Works fine for the hard wood. Maybe switch to a shear blade? Or maybe just get a new straight blade bit? I get it. My binding bit (like your's I'm sure) is a straight edge rabbit. And I don't currently have issues with it.

As for over cutting before flattening, that makes sense. I may have to think about that some

Mike

I can't find it on their website, but I've always used an Amana bit with good results. 1/4" shank, 1/2" diameter, with sheer.

Don't cut the actual channels at first. You want a small rabbet smaller than your bindings. Then flatten your sides and cut your actual binding channels...

Ed, that is brilliant!

Heh! You heard it here first...just like me:)

Using your binding ledge bit to take the plates just a tad less than flush was a Mario P. idea that he wrote about on the OLF in the past.

Works great and takes the plates out of play when leveling the sides.

I do the same. 5/8 bit with 1/2 bearing

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Pat

Yep, that's what I do as well .. but I have two routers specifically setup for the task .. one, a cheap Skil plunge with a flush trim 1/2 inch bit, that's all that router does, so its always setup and ready to go .. then I have a binding ledge setup on another lam trimmer, that's set shallow and not as tall as the real binding, go around with that, then sand/scrape the sides flat.

And I always do both routes as climb cuts .... no tear out.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Seems like I remember Mario P.(grumpy) used a rotozip to trim tops and backs once upon a time. One of the few things he did that didn't seem like a good idea to me.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

That is correct! Grumpy uses or did use a 1/8" Rotozip flush cut bit.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

In practice, I've found it unnecessary to do an initial flush pass with a second lesser rabbet pass. Just starting with the lesser rabbet pass is enough. Always following the climb cut patterns of course...

Speaking of Grumpy and his rotozip reminded me of my rosette cutters..............cut off rotozip bit resharpened on the ends.
Tom

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A person who has never made a mistake has never made anything!!!

I got my binding router bit and bearings from Stewart-MacDonald, and I use the 0.925 bearing to flush cut my sides. In the directions I received from them, they referred to the 0.925" bearing as "Flush cut bearing: For trimming glued bindings and newly assembled guitar tops and backs." I have not used it for trimming glued bindings; I prefer to simply use my scraper and sandpaper.

If you need a spiral flush cut bit, this is where I get most of my router bits. Price is decent, quality is good and shipping is free. Never used the spiral/flush combo, but I've used their solid carbide spriral bits and they generally last me a long while. They also have some shear cut bits that are probably more attractively priced than the spiral bits.

http://www.mlcswoodworking.com/shopsite ... solid.html

That being said, I'm always so surprised at how few people use Dave White's modification to the Williams' binding jig, that makes the need for different bearings and bits unnecessary. One spiral down cut bit takes care of everything, including flush trim, the initial rabbet before leveling the sides and then the actual binding ledge. Just sayin'.

http://www.defaoiteguitars.com/page33.htm

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sweat the small stuff.

I appreciate all this info. But the question I am asking is which type of bit is best (in your opinion) for this type work? Is a straight best? Spiral (up or down)? Shear cut? Or just the old rabbet with bearing?

In my limited experience, I've had really great results with the spiral down cut bit. That is, no tear out, no fuzz, etc. Just a nice clean channel.

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sweat the small stuff.

I'd agree with Heath, but it has to be a bit that works with whatever binding system you currently are using...

Lots of different systems will let you use a spiral downshear which will most likely always give the cleanest cut.

The problem with Dave White's system is that you'd need to adjust the rinky dink makita depth stop for every cut. A lot of time wasted on test cuts and a lot of potential for error. I think Doolin's and the Larrivee inspired one would be better suited to a spiral bit...

It is a good idea to learn to sharpen the shear bits. Spirals are impossible in the shop without special equipment.

I use a shear 1/4 inch flush trim bit. My too and back are on and rectangle shaped and overhang the side rim. I use a router table with a doughnut surrounding the bit. I route into the overhang until the bearing hits the rib. Then follow the rim without regard changing direction. I just rout off the overhang as the bit plows through it.
I have a video somewhere if anyone is interested.







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Ken

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Ken

I'm not particularly interested in the binding aspect of all of this. I'm talking about basic cleanup work after top and back are attached. I want a super reliable flush bit that minimizes tearout, and can take on excess overhang without risk. It just seems to me that something other than a straight edge bit is called for. As for medlings ideas, I'm considering that. But only after I've done the trim