Newest Template Routing Bits. Opinions?

[Bruce Johnson]

Get the biggest ancient old one you can find and the extra mass will dampen the whole shop and your router will work magic foreverafter....

I'm not so sure about that...

My Big Green Pin Router weighs 3000 lbs and has plenty of mass for damping.....But it will tear out wood like a monster, if I don't control the depth of cut on it.....Here's an example, going around the outside of a walnut headstock block......

I refined my process with shallower depth of cut per pass. I can now rout all around the outside of these parts with virtually no tearout. Smooth finish, accurate to size within 0.005". This was done with a straight standard 1/2" Freud router bit.

It can be done with a router bit, if you keep it under good control and don't take too big of a bite.

 

[lbridenstine]

This goes almost without saying, but it's NOT a good idea to try and do anything substantial with a router that is using a 1/4" collet. Friends don't let friends use 1/4" collets for anything beyond roundovers!

Honestly, I used a Ryobi router with a 1/4" collet for 10+ years and it was fine as long as you take shallow passes.

 

[rudy4444]

I used a template and router bit exactly once to shape a body. Never again. Because of the tear out. Since then, I use a band saw (or a jig saw in the old pre-bandsaw days) to cut the wood as close as I can get it, and I sand the rest to the line with my oscillating sander. No tear out, it's fairly quick, and it's actually my favorite part of building, seeing that body take shape. I highly recommend it. Additionally, with any good vac, a lot of the dust is captured.

Re-read this and pay heed!

I don't do that many bodies, but mapleglo's method is superior in every way to using a router, with the possible exception of creating a LOT of saw dust in the process!

I like to trace the actual outline on the body blank, cut to within 1/16" of the outline, and then finish up by sanding the majority of the convex outline with a disc sander and handling anything I can't get to, including all concave areas, with the vertical oscillating spindle sander. Use the largest diameter you have and switch to smaller diameters only when you can't get in tight enough.

I don't mind routers at all, but this is SO much more relaxing, easy to do, predictable, and has very little chance of creating problem spots on the body outline.

Again, do it this way. Unless you have some sort of high volume production situation it's hands down the best way to do it for a small shop.

I offered my router suggestions only because, as Taylor Swift says "Some people just gonna route".

 

[Beej]

Honestly, I used a Ryobi router with a 1/4" collet for 10+ years and it was fine as long as you take shallow passes.

I'm shocked, shocked I tell you!

 

[Gilmourisgod]

I actually could use the Robosander "freehand" by removing the bearing. Sometimes I chuck it in a cordless drill and hold onto the bearing to act as a low-budget spindle-sander for doing stuff like volutes and belly-cuts. With an oscillating sander, how do you avoid inconsistencies in the contour? Practice makes perfect, I guess. Alas, I don't own one, though I've almost talked myself into buying one a the Harbor Freight models a few times.

On another note, am I the only one using a pattern bit to cut tapers on a neck beam, with a suitable straightedge attached to the top acting as a straight template? How are other people cutting tapered blanks on something like a neck-through? I haven't had much luck with using a tablesaw taper jig, a tiny error at one end results in a significant error at the other end. That was actually where I first noticed some "waviness" in the finish using my CMT shear cut bit. if I can't get that bit running true, I guess it's scrap.

 

[BishopJP]

FWIW, I use straight-flute, top-bearing pattern bits. I have several 1/2" diameter bits of varying lengths; 1/4", 1/2", 3/4" and 1". I also like to add bearings to the bit so I have two stacked together. This gives me the most flexibility for getting the depths I need. Yes, I have had tear-out, but almost every time I can recall it was due to operator error. Usually trying to take too big a bite.

I shaped the horns on this bass with a template and hand held router, then added the chamfers with the same router.

...although, admittedly, using a table router might have been safer...

On another note, am I the only one using a pattern bit to cut tapers on a neck beam, with a suitable straightedge attached to the top acting as a straight template? How are other people cutting tapered blanks on something like a neck-through? I haven't had much luck with using a tablesaw taper jig, a tiny error at one end results in a significant error at the other end. That was actually where I first noticed some "waviness" in the finish using my CMT shear cut bit. if I can't get that bit running true, I guess it's scrap.

I have used a pattern bit to route tapers, seemed to work fine. Although, last time I made tapers, I just used a track saw.

 

[mapleglo]

am I the only one using a pattern bit to cut tapers on a neck beam, with a suitable straightedge attached to the top acting as a straight template?

I do use a pattern bit with a straight edge for finishing the tapers on a neck, after cutting as close as I can with my band saw. Anything more than 1/16", I make a few passes with the router. I'm still terrified of tear out.

 

[Bruce Johnson]

About sanding the perimeters of bodies, Yes, I agree with mapleglo that the best way to avoid router tearout is to....not rout the perimeters! I did that for a long time on my Scroll Bass bodies. Bandsawing them to within 1/16" of a pencil line, then cleaning up most of the perimeter on the edge sander. The large concaves on the sides of the body were smoothed out on the end roller of the edge sander. The small concave at the cutaway was on the oscillating spindle sander. The last step was hand sanding the perimeter with hard flat blocks to smooth out any little steps or bumps.

That made the perimeter into a smooth square surface, with no lumps or waviness or tearout. From there, I'd use a hand router with a radius bit, bottom bearing, to radius the top and bottom edges. I'd do that in three steps of depth, with the last one a very small cut. To prevent tearout. And then hand sanding on rubber blocks to blend the radiuses into the straight edge.

That's definitely the most reliable way to finish-shape the perimeter of a bass body. It takes a lot of time, and it's not real accurate to a pattern. But that's fine for one-offs and customs and limited production. That's what I recommend for most small builders.

Cutting the perimeter by routing will be faster and more accurate....but there's an investment in tooling and working out the process. Usually not worth it for a one-off instrument.

Back in the earliest days of building my Scroll Basses, I did work out a process of routing the perimeters with a big hand router, a custom shaped bit, and 3-stage pattern fixtures. I got the process to work pretty well, but I still had some trouble with tearout. Particularly with ash bodies. So I went with the edge sanding process for a long time.

These days, I'm playing around with the big pin routers. With them, I can accurately follow a pattern and control the depth of cut. I can now rout the full perimeter of a walnut or poplar body with no tearout at all. The main advantage of the pin router is that changing the depth of cut takes, like, 2 seconds. So, it's actually very quick to do the whole perimeter of a body in six light passes. And the shallow passes are what prevents the tearout.

I've also messed around with "Robo-Sanding"; that is, power sanding to a template, which is riding on a bearing wheel. Years back, I modified my edge sander to put a bearing wheel down below the end roller. It's the Robo-Sander idea, but with a long sanding belt and a big motor. I made it specifically for doing body perimeters. I mounted Scroll Bass bodies on a 3/4" MDF pattern and ran them along the bearing wheel. The edge sander had plenty of power and belt length to sand away the wood quickly and not clog up.

It kinda sorta worked. But it was still somewhat uneven and lumpy. I'd end up taking the body off the pattern and cleaning it up by hand, on the edge sander and with a block. What I learned is that pattern-following sanding (Robo-Sanding) wasn't really giving me any better results than bandsawing to a pencil line and smoothing it out handheld on the edge sander/spindle sander. And it wasn't saving me any time.

I still have that bearing wheel rig on my edge sander, although I haven't used it in many years. I'll take some pictures of it if you guys are curious.

 

[Lo-E]

But it was still somewhat uneven and lumpy.

Be nice, Bruce. Some of my best friends are somewhat uneven and lumpy.

 

[Big B.]

I've been using router bits to trim highly figured bodies to shape for years but I prefer small top bearing bits, not a big pattern bit that will cut the whole face at once. The key is never going deeper than 1/8" - 3/16" depth per pass. Basically whatever depth allows you to climb cut without the bit fighting you. I clamp the body down securely, slowly climb cut one pass, and then I run the router back in the "proper" direction to clean up the cut then drop the bit and repeat. I start with a short cutter, move to a longer bit when I need to, and then instead of routing all the way down, I'll flip the body over and remove the last pass with a bottom bearing bit so I dont have to cut into my bench.

Trying to cut a guitar body profile in one pass will almost never work. You can get it to work with a large shaper, good cutters, and proper rub collars like I've seen in the Fender custom shop but thats a different thing than using router bits. The obvious problem is that a hand router doesn't have enough weight and torque to remove that much material in one pass without the router bouncing. The less obvious problem is that router bits are small in diameter, and the angle of the blade leaving the wood is nearly perpendicular to the wood grain. Even though you are running down the board with the grain the blade is leaving the cut at an angle closer to a crosscut than a rip cut. It's works with a large 5" diameter shaper head because the angle of the blade leaving the wood is much less perpendicular and closer to parralel. This is why climb cutting works so well. When you use a climb cut that spot where the bit leaves the wood at a perpendicular angle gets cut away before the router has a chance to grab it. I wish I was more internet savvy because a diagram would make so much more sense than describing it. The last problem with a router bit is that there is only so much room for wood chips to escape so if you remove too much material at once the amount of wood chips build up and will make your router chatter if not catch and throw itself because you won't be able to keep it tight to the board. This is another reason that routing the whole face with a large bit rarely works out well.

There are some very good videos of basses being CNC cut on the Warwick youtube page. I'd recommend checking out some of those and watch how they carve away in multiple passes and try to replicate that.

 

[Bruce Johnson]

Be nice, Bruce. Some of my best friends are somewhat uneven and lumpy.

I'm uneven and lumpy. But I try not to let my basses be like that.

 

[ardgedee]

I play how I feel, which is uneven and lumpy.

 

[rudy4444]

I actually could use the Robosander "freehand" by removing the bearing. Sometimes I chuck it in a cordless drill and hold onto the bearing to act as a low-budget spindle-sander for doing stuff like volutes and belly-cuts. With an oscillating sander, how do you avoid inconsistencies in the contour? Practice makes perfect, I guess. Alas, I don't own one, though I've almost talked myself into buying one a the Harbor Freight models a few times.

On another note, am I the only one using a pattern bit to cut tapers on a neck beam, with a suitable straightedge attached to the top acting as a straight template? How are other people cutting tapered blanks on something like a neck-through? I haven't had much luck with using a tablesaw taper jig, a tiny error at one end results in a significant error at the other end. That was actually where I first noticed some "waviness" in the finish using my CMT shear cut bit. if I can't get that bit running true, I guess it's scrap.

I bought my oscillating spindle sander on a fluke several years ago when I saw one of the recommended brands (with a cast iron table) for $100. It almost instantly provided me with one of those forehead slapping "Where has this been all my life?" moments.

As far as avoiding inconsistencies in the contour... a bit of experience, staying at attention, and keeping the work moving.

Your method of cutting neck profile is exactly what I do. I pattern route after the slotted board is attached. The neck width is first trimmed close to the top pattern board and I do light climb cuts so the fragile edges of the fret slots are cut cleanly with no chip out. I use a bottom bearing 1/2 bit with a 1/4" shank (bearing mounts on the 1/4" shank). I've been using this bit for years and it still works well for that purpose. It also gets used for pattern routing pickup cavities occasionally.

I just finished this one up, mapleglo's band saw / sanding technique on the body and the neck / fret board pattern routed to shape. Climb cutting the neck / fret board edge is easy pie and there's no knuckle-biting involved.

 

[Dave Higham]

The necessity (or not) and usefulness of both top and bottom bearing eludes me too.

On the router table, with the template under the body and in contact with the bottom bearing, route only the areas with the grain. Turn the body over, so the template is on top and lower the cutter so the template is in contact with the top bearing. Now route the rest. You'll still be routing with the grain. Small cuts, etc. still apply.

 

[vibroverbus]

I also like to add bearings to the bit so I have two stacked together.

Interesting tip! Have to have a bit with suitable shank length of course, and probably better for 1/2" shanks. I've had a few situations where that would have helped me trying to follow a profile that was recessed.

I haven't tried to make a body in decades, neither would I try to do detail shapes in super brittle woods but I'm following this thread because has loads of great general router tips, but I do have 3 routers and use them a lot for all kinds of things.

I will say its funny that the "cut it as close as possible on bandsaw first" is mostly mentioned here in relation to sanding-shaping, because I would say that would be my #1 technique for ROUTING also if I was worried about tearout. In addition to just the better control and less chance of chatter causing an "event" - super shallow cut routing reduces the exit angle dramatically. So similarly for exit-angle reasons I might try and use the biggest cutter that will achieve the radius I need. Using a tiny diameter bit if it is not needed is just increasing chances of problems.

That's all I got.

 

[TFM94]

Straight off the bandsaw, routing full depth at once will sooner or later result in tearout. Even with a super heavy router setup. Routing the perimeter of a body will have you go in and out of the grain multiple times.

I use a handheld plunge router and very shallow template bits. This allows my to do multiple shallow passes, even with a thin template. 2-3mm at a time. This way I have good conrol over the cut, even when climb cutting. I very rarely have any tearout this way, and if I do have it, it's just a small piece, at most the cutting depth.

When the bit gets old and worn, it can happen that little steps remain between the different passes. This is the only time I'd use a full-depth bit to square up the edge after (!) having already routed the perimeter. I'm removing much less than half a mm, so tearout is very unlikely.

I've tried several full-depth bits, straight, spiral and some other weird patterns, but sooner or later they all took a bite. A shallow template bit is much cheaper, and more versatile, too. So, my favorite template router bit looks like this:

 

[Max Bogosity]

Until recently all I had was a pretty weak old Black & Decker 1/4" router that was pretty much incapable of taking a cut of more than a mm or two at a time. I guess it was accidentally protecting me against tearout.

 

[eddybuzzard]

Until recently all I had was a pretty weak old Black & Decker 1/4" router that was pretty much incapable of taking a cut of more than a mm or two at a time. I guess it was accidentally protecting me against tearout.

Kinda like an old dog, that just wants to lay down, when you take it for walk

 

[Max Bogosity]

Kinda like an old dog, that just wants to lay down, when you take it for walk

Ha, yes, I have one of those too.