Router Bit Depth - Need Advice

[MescaBug]

Hello,

I did my first router job yesterday, on a blank piece of wood. I made a few mistakes but overall, I think I did a good job. However, I need advice about the cut:

Is it better to route a little at first and dig deeper each pass? Or is it better to drop the bit to the desire depth, use a very high speed setting and do one pass only? That would apply to all routing jobs; neck pocket, pickup, control cavity..

I did 3-4 pass, cutting deeper each time. It's hard to do a clean job with this method.

Thanks,

David

Edited April 18, 2007 by MescaBug

[Inisheer]

Always do it in passes, and don't go much more than 1/8" each time. If you do it all at once there is a greater chance of tearout, and the bit will not be as easy to control.

[ryanb]

I agree with doing it in passes --- it's much safer that way. But 1/8" at a time is ridiculous. If you have to take passes that small, either your router is woefully underpowered or you are using some cheap-ass bits.

Use a speed tht is appropriate for the size and type of bit you are using (and the material). If you are having trouble doing a "clean job" in multiple passes, it is probably something wrong with the template you are using (or your technique). You should be able to make perfectly repeatable routes in multiple passes (at least good enough to not need any more than a touch of sandpaper).

[Inisheer]

The instructions that came with my router said to go in 1/8" passes....so that's why I do that. That worked well, so it may be possible to go even deeper than that. But if he is new to using a router, I wouldn't recommend doing very deep passes at first.

I admit that I am new and still learning though, so thank you for correcting me. Happy routing.

[Jon]

David, are you using a router template so the ball bearing can follow it? All you need to do is take each pass at about 1/4" very carefully (don't go too slow!) and you'll have top notch results.

[thegarehanman]

My rule of thumb has always been about 1/8" minimum, unless I'm routing for inlays, but other than that, I make passes equal to one half the diameter of the bit I'm using. Also, David, setting your router to it's highest speed is not always a good thing. Typically you want a lower speed for wider bits. Your router probably came with some guidelines and recomendations regarding speed.

peace,

russ

[Jaden]

RPM is indicated on the bit - unless the bits are "cheap ass" as someone has said.

Im sure that there is a 'rule of thumb' for much of this but.... it depends on a lot of factors.

wood type

bit length

dit diameter

bit shaprness

jig accuracy

router power

I always cut in passes but I wouldnt use the same depth for Ash as I would for Basswood or MDF or chipboard.

then there is the balance of RPM and feed rate to prevent burning etc etc etc......

[WezV]

personally i would recommend starting by going in 1/8" passes - as you get more familiar with the tool and the wood its ok to increase that but i would never attempt to do it all in one pass, thats just asking for trouble

[erikbojerik]

I go in 1/8" passes as well. Make sure your template is rock-steady. And don't press too heavily against the edges of the template when you rout, you can impart a very slight amount of tilt to the bit shaft and get some uneven passes that way.

[Kammo1]

The golden rule to routing is this which I have performed for over 20+ years and that is "Never Ever" cut more than 1/2 the diameter of the cutter, so in lay mans term if you have a 1/2 cutter never cut more than a 1/4 in one pass hope this helps

[Mattia]

What all the wise folks said. 3 to 5mm, max.

[MiKro]

As far as bit speed, look at my reply in this topic.

MK

link

[MescaBug]

Thanks for the advice. Really appreciated.

I'm using Stewmac plexiglass humbucker template. When you start the first routing run, it's impossible to use a bearing guided bit. Is there any tricks to help me follow the template without damaging it? Which is exactly what I did, unfortunetaly

Edited April 22, 2007 by MescaBug

[Mattia]

Drill out the excess with a forstner, and then clean up and finish the routing with a single pass. That's more than 1/8" in depth, but if you do it right, a lot less in width. Alternately, which is my preferred approach, use the StewMac template to make a plywood template (1/2" or better stock, I usually use 3/4"), which you won't be able to burn through. Sure, it's not as fancy (and seethrough) but with good centrellines, transparency is a luxury you don't really need, per se.

[Woodenspoke]

Drill out the excess with a forstner, and then clean up and finish the routing with a single pass. That's more than 1/8" in depth, but if you do it right, a lot less in width. Alternately, which is my preferred approach, use the StewMac template to make a plywood template (1/2" or better stock, I usually use 3/4"), which you won't be able to burn through. Sure, it's not as fancy (and seethrough) but with good centrellines, transparency is a luxury you don't really need, per se.

I agree with Mattia, hog out the wood with a fostner bit then pattern route using the template (a new template). What people here have not said is you can take shallow cuts using the whole lenght of as router bit moved in a circular motion (CW direction internal pattern only). No you dont want to just plow through a thick piece of wood in one pass without open space around the bit, a fostner bit provides this space. This technique is not hard to master and fostner bits are dirt cheap. the fostner bit will not leave a perfect surface but the router bit will slowly remove all the pointy edges left by the bit.

Sorry I dont think it came out exactly they way I wanted to describe it but I'm tired of rewriting it. Hope it make sense.

Whiteside makes the best bits I have ever used, they are worth every penny. I wish I knew that when I first started buying bits.

Woodenspoke

[aidlook]

Drill out the excess with a forstner, and then clean up and finish the routing with a single pass. That's more than 1/8" in depth, but if you do it right, a lot less in width. Alternately, which is my preferred approach, use the StewMac template to make a plywood template (1/2" or better stock, I usually use 3/4"), which you won't be able to burn through. Sure, it's not as fancy (and seethrough) but with good centrellines, transparency is a luxury you don't really need, per se.

I use the stewmac as a maste template to make templates out of MDF or Plywood as well(learned not to use the plexi one the hard way...).

But a tip is to use the transparent template to mark out the positions of the routs, and then use the wooden ones for the actual routing

[tim_ado]

the faster the bit the cleaner the cut

with that said if it snaps or theres a tear out there goes your guitar and or you

personal i dont have the balls to rev. it fully I just take my time

[Woodenspoke]

the faster the bit the cleaner the cut

with that said if it snaps or theres a tear out there goes your guitar and or you

personal i dont have the balls to rev. it fully I just take my time

I assume everyone is using 1/2 " shank 3/4" width pattern bit, to break one you need to be a monster. But I am one for always assuming. Even with a 1/4" shank bit your bit diameter should be a minimum of 1/2" and they are hard to break. I would only worry about breakage on bits 1/4" in width or less. I have broken my share of bits and most of them were in the 1/8" range but never have I busted a 1/2 " width bit or larger. I have destroyed edges but that was on particle board and is not guitar related story.

We are talking here about internal pickup routing, a mistake will not be a disaster unless you make a huge one. If you cut out an area which needs a screw glue in another piece of wood it will all be covered by hardware or a pickguard.

Pattern routing depends on two factors the guide plate height and the depth of the bit, and we are talking about a shank mounted bearing, pattern bit. To route a 2" hole for example you need to remove enough wood to get the guide flush with the pattern, use a fostner bit use the technique Mattia and I already mentioned. The next pass is the same only you dont need the pattern you are using the perfect hole you just routed as the guide. 1" deep pattern bit, 2 passes, 2" deep. people who are mentioning 1/8" depth of cuts are doing the same thing. they cant hit the pattern until they remove enough wood so the guide is flush. Its easier and faster to use a drill press or hand drill and the fostner bit just dont try and get too close to the pattern its to remove wood only.

Another pattern routing example on the outside edge of the body. You bandsaw out the shape and leave a 1/16th of an inch overlap. You double stick tape the pattern to the body. You buy a big honking top mounted pattern bit and take a 1/6" deep 1 3/4" high pass all around the body. Its a one pass job and unless you bought a cheapo bit or your router is a piece of garbage the router will move through the cut like butter. Its the same principle but internal routing requires you to make the 1/16" passes using your eyes and brain

Dont take this the wrong way but speed does not equal a better cut. Just use the right bit for the job the better the quality of the bit the better the cut, most mid size routers are not variable speed so the speed part confuses me.

Woodenspoke

Edited May 26, 2007 by Woodenspoke

[tim_ado]

We are talking here about internal pickup routing, a mistake will not be a disaster unless you make a huge one. If you cut out an area which needs a screw glue in another piece of wood it will all be covered by hardware or a pickguard.

yeah i admit i havnt read the whole post ........and for external routing its always good to get practice

plus why do a crap job if its going to be covered up

Dont take this the wrong way but speed does not equal a better cut.

i didnt mean exactly that but dus to the speed of the bit, it allows for a cleaner cut

like you couldnt do a clean job by sticking a router bit into a drill

[WezV]

I must admit that i am a bit lazy at making templates - so if i have a thin template i dont useually bother making a thicker one. I used to start of with a forstner bit but i think i need to replace them now because they are all getting a bit too dull.

Recently i brought a milling router bit from axminster and i love it because it allows me to start routing straight away even with 1/4" templates. It also has a lot less play than longer bits so feels easier to control. I get maybe 3/4" deep with this then switch to a longer bit.

milling bit with bearing

I also like this one:

Bull nose bit with bearings

bull nose bits dont grab onto the wood so again feel easier to control, i find it nice to start my control cavity routes with this bit when i am free handing them (not that i ever do that )

i do have two routers which makes life easier when doing a lot of stuff - i wouldnt mind having a dedicated router for each bit i use regularly

[DrummerDude]

I just want to share my method - it's nothing new but is something that works.

At first, let me say that I am using a cheap-o-router and it does not become more powerful at low speeds. It does not use mechanical reduction but rather it is the power that goes into its motor that controls its speed.

This means that if you set the knob at lower speeds, the router not only reduces its RPM but it also becomes weaker and underpowered. So I am forced to use it at maximum speed no matter what size or diameter bit I am using and no matter what job I am trying to do.

But I guess that a good brand name router will behave otherwise.

Once I tried to use a forstner bit with my router and I set it at low speed of course.

It simply stopped - it was too underpowered to spin the forstner. Then I set the RPM at maximum speed to increase the router's power but it burned the wood because forstner bits are not suitable for work at high speeds.

So it all depens on your router.

If you have a cheap no-name router like mine, it is best to use your drilling mill and make multiple holes with a regular drill bit or a frostner bit. Then just "clean" with the router.

I never had any problems cleaning at full depth and never had to do multiple passes with the router - I simply do not leave too much material in the pre-routing stage.

More sweat in pre-routing, less tears in routing.

And by "tears" I mean both its meanings.

[Woodenspoke]

I just want to share my method - it's nothing new but is something that works.

At first, let me say that I am using a cheap-o-router and it does not become more powerful at low speeds. It does not use mechanical reduction but rather it is the power that goes into its motor that controls its speed.

This means that if you set the knob at lower speeds, the router not only reduces its RPM but it also becomes weaker and underpowered. So I am forced to use it at maximum speed no matter what size or diameter bit I am using and no matter what job I am trying to do.

But I guess that a good brand name router will behave otherwise.

Once I tried to use a forstner bit with my router and I set it at low speed of course.

It simply stopped - it was too underpowered to spin the forstner. Then I set the RPM at maximum speed to increase the router's power but it burned the wood because forstner bits are not suitable for work at high speeds.

So it all depens on your router.

If you have a cheap no-name router like mine, it is best to use your drilling mill and make multiple holes with a regular drill bit or a frostner bit. Then just "clean" with the router.

I never had any problems cleaning at full depth and never had to do multiple passes with the router - I simply do not leave too much material in the pre-routing stage.

More sweat in pre-routing, less tears in routing.

And by "tears" I mean both its meanings.

Drummerdude you have more balls than I do to put a fostner bit in a router. My hats off to you.

With regard to router speed, using a large bit in the router requires you to reduce the speed for your own safety. I have never heard if anyone needing to change speeds on a straight bit, only door panel raising bits that are 2+ inches wide and similar over sized bits. Plus with a bit this size you need 2 1/2-3hp or more and the router is usually equipped with a speed dial.

Yes they sell router speed controller's juts like Drummerdudes setup

Woodenspoke

Edited May 27, 2007 by Woodenspoke