Router Usage

[sapwood]

OK, I have a Hitachi M12V router and a few 1/2 collar bits and I've read several books about routers and jigs. However, the books focus mostly on router tables, jigs, and bit definitions with very little info on actual usage.

Are there speed setting charts, references, or suggestions? Common sense dicates that bigger bits should have lower speed setttings than small ones (as with DP).

How much material can I safely remove per pass when using chamfer, cove, rabbet, etc.? Obviously wood type/density and router power are factors.

What's the difference/advantage using straight bits (1/4, 1/2) versus using spiral upcut bits?

Am I asking too much 8-O
Sapwood

 

[Ray Martin]

Roger,

You're right, much of the router stuff really is covered by common sense... I'll offer a couple of thoughts (and I only have a couple) and general principles:

- 1/4" versus 1/2" shaft; the heavier shaft will most likely cut with less vibration and therefore give you a cleaner cut.
- the bigger the bit, the less you should try to remove in a single pass
- wider bits do require slower speeds, so a varriable speed feature is a really nice thing on a router
- the denser the wood, the less you should try to remove with each pass
- larger motors will strain less, particularly with bigger bits and or denser woods and therefore be safer and offer a cleaner cut
- there are more router jigs available than you would ever be able to use or even fit into your shop.
- if I were buynig a router for mounting in a table, I'd go for the biggest motor I could afford
- if you're new to router use, I'd smooth off some 2X4s, pretend they were expensive wood and practice loads
- spiral up bits clear the debris out of the cut channel / dado / etc. and that lets you see what you're doing and prevents clog / burn / loosing the line you might be cutting
- if you want to cut dadoes in plywood, remember that plywood sizes are always a lie... it's not really 3/4", it's 23/32s. There are bits sized for specifically for plywood
- never seat the bit all the way into the collet
- keep the collet really clean so the bits fit / seat properly... you'll get less vibration and a much cleaner cut

I'll shut up and sit down now... and let the guys who know what they are doing offer some real advice. (Getting advice from me is like asking a friend to help with your golf swing instead of going to a pro.)

Ray

 

[Steve D]

I'd have to say that Ray hit the majority of the high points. The only thing I would differ with him on is practicing on 2x4's. 1) They are pine - soft and not prone to tearout. 2) They are pine - full of sap which will screw up your bits. 3) They are pine :mrgreen: (this one's for you Woodguy).

Spiral bits also come in downcut. Upcut is excellent for mortise & tennon (chip clearing) downcut is excellent for veneer ply (downward shearing cut, less prone to chip out.

Speed - big = slow, small = fast. Many bits will show a recommended speed on the packaging. This is helpful except 1) most people throw away the packaging 2) most routers don't have rpm's on the dial, just numbers. My general rule of thumb is: really big bits, table only, 10,000 RPM, medium bits handheld or table, 15,000 RPM, small bits handheld or table, 20,000 RPM. I also use 1/2" whenever possible.

Much comes down to feel but several light passes are better than heavy cuts. A small profile like a bead or roundover can often be done in a single pass but larger profiles or wood prone to tearout generally requires multiple passes. I usuall try and leave a very light cut for the last pass.

 

[erasmussen]

They about got it covered.
Except watch the rotation climb cutting can be dangress (sp)

 

[BBF]

Sapwood, Amana Tool Catolog has a great discription of each bit, What its for, What rpm for each plus a actual view of each cut. I got mine by calling them and asking them for a Catolog.

 

[sapwood]

Thanks for the great suggestions folks. :icon_thum
I made some holes and disks in plywood (cheap) yesterday using the small Jasper Circle Jig. The info/suggestions on speed settings were very helpful. None of the bits I've purchase contained speed specs. I'm also begining to understand the importance of proper support for the router. As the M12 is pretty heavy it's destined for the router table. But until I purchase a smaller one, it will serve as an all-purpose router.

Nothing like the fun of learning a new tool, powered or hand :mrgreen:

Gratefully,
Sapwood

 

[Canuck]

So here is a question or two for you Roger regarding the Jasper jig.

I bought one myself to cut some 6 inch holes in pine. I also did spring for a 1/4" spiral upcut bit hoping that it would clear the dust from cut. Well, it didn't do a very good job. Had to stop a couple of times to clear the "slot" before completing the cut. Now my question. 1) Would I have been better off just using a 1/4" straight bit? and 2) I ran the router in a counter clockwise direction with the jig. Did I just head in the wrong direction causing the bit not to clear the dust?:-?

I do really like the jig and its ability to cut so many different diameter of holes!

(I have to admit that I stole the idea from Anna-Catherine's(SharpBlade) dog feeder.)

Wayne

 

[McRabbet]

Counter-clockwide is recommended to avoid climb cutting and to reduce chip-out. The 1/4" spiral upcut bit is a good choice, but even it won't self-clean. Patience and a vacuum hose nearby. I'd take three passes thru 3/4" stock, and if feasible, I'd turn the stock over and use the extended centerpoint hole for the final pass on the reverse side.

Rob

 

[Canuck]

Thanks Rob!

I did the cut in four passes, but I didn't vacuum. Next time I'll know better. At least "I am headed in the right direction" with the cut! (It was the 1st time that I actually used my DW618 plunge base and totally forgot to hook it up to my small shopvac!:BangHead: )

Thanks again!

Wayne

 

[sapwood]

Wayne, I used what I had--a straight cut double flute. However the plywood was only 3/8! Tried clockwise and counter, and counter did better. I also stole the idea from Ann Catherine :-D It was tricky figuring out the settings for cutting "disks" instead of holes. The limited instructions weren't that helpful. After a little trial and error and limited math skills I determined that you need to add 1/2" to pivot value to achieve desired disk size. Since width of bit is 1/4" and it's a circle, you need to accommodate both sides of circle 8-O However, I was not successful in cutting a hole that disk that would fit in hole snugly (inlay?). Calipher readings indicate they are both same size, but the disc was a smidgen too large and I wasn't able to sand it down evenly. Next I try the forstner bit/circle jig combo to achieve fit. Other sugggestions appreciated :mrgreen:

Sapwood

 

[junquecol]

Triangle Woodworker's library has Gary Rogouski"s tape on the router. As a member you are allowed to check out tapes and books. Sorry to hear that some spent good money buying Jasper when you could make your own. When cutting a circle, route about 1/3 the way through, then using bandsaw remove waste just outside desired circle. Take flush trim bit, resting against routed area and finish circle. Remind me some time to show you my adjustable circle cutter.

 

[sapwood]

Thanks Bruce, I'll definitely check out the tape. I've used the library several times already and it's great. And I wondered if flush trim bit might be used.

Sapwood

 

[michaelgarner]

one thing I tend to stay away from is trying to stop the bit with my hands,,it just simply hurts,,lol

 

[Tarhead]

Some of you are probably saying...that Mark guy must read alot of magazines....well I sit in airports a whole bunch and USA Today gets consumed before my coffee gets cold....so here I am again quoting something from a magazine.
This time it's the bonus "Router Shop Guide" from American Woodworker, March, 2006:
They (whoever they are:eusa_thin ) say and my experience agrees:
It's not the rate (RPM) but the speed the cutter head is moving that's critical. The bigger the cutter head and the higher the RPM, the faster the outer edges are moving.
If your bit has a cutter diameter of up to 1 inch you're ok to 24,000rpm.
Up to 2 in...18,000 rpm
Up to 2.5 in...16,000 rpm
Up to 3.5 in...12,000 rpm (that's a bigun for a router!)

Feed Rate:
The slower the feedrate (like in mortise routing), the slower the RPM, gives you more control

Chatter:
If the bit chatters or leaves scallop marks the RPM is too slow or you're pushing the router to fast.

Mark