Router Forums banner

'Newb' To Routing - Need Some Guidance

2K views 8 replies 5 participants last post by  Stardust 
#1 ·
Hi Folks,

I'm relatively new to woodworking in general (never done any routing before), but I'm slowly preparing to begin, so I recently purchased a Porter Cable 690LR Plunge Router with bits, but I've got a few entry-level questions that I simply cannot seem to get answered at my local hardware store.

The bulk of my routing needs involve routing-out 3/4" deep cavities of various shapes for the installation of pickups and other electronics in electric guitar bodies, using 3/16" thick fre-fab acrylic templates.

Now, keep in mind that I have not yet tried any routing even on practice pieces of wood (which I most definitely will do beforehand to be safe), but as I understand it, I could accomplish such routing with either a fixed base (by repeated/deeper passes of the bit adjusted to different positions or eights in the collet), or by simply using the proper setting of my plunge base.

But my question is this . . . either way (using either approach), how does one keep the bearing (that apparently needs to ride on the shaft of the cutting bit) in constant contact with the edge of the template, when the cutting bit and collet are moving up and down? Do I add more bearings to the shaft? Before I go seriously screwing-up the wood, the bit, the bearing or the router), what do I need to do? What am I missing here?
 
See less See more
#2 ·
Welcome to the forum, Joe.

I would be looking for a bearing guided template bit with a 1/2" cutting depth. After the first pass against the template, the bearing can ride against the cut side to increase the depth.

....when the cutting bit and collet are moving up and down?
The depth has to be set, you cannot use the plunge for this method.
 
#3 ·
James,

Thank you for the warm greeting, and the insights, but I'm afraid I still don't quite understand. Without the 'plunge' base, how would I achieve a depth of 3/4" with a 1/2" bit?

My templates are indeed 'bearing guided' but they're 3/16" deep. I suppose if I use a bit with 1" cutting depth and a 3/16" thick template (adding another 1/16" from the double-sided tape used to adhere the template), it would yield a net 3/4" (12/16") deep cavity, which is probably close enough, but that's kind of a backwards way of doing it, isn't it?
 
#4 ·
Hi Joe and welcome

If you are doing it with a plunge router then your first cut, on a cutter like the Amana 45462 template trimmer (5/8in diameter x 1/2in deep bit) would take you to 1/2in depth. Removing the template and using the sides of the already routed 1/2in deep pocket would then allow you to go down to about 1-1/4 to 1-1/2in on subsequent passes

The other possibility; have you considered the use of a guide bush and template for this sort of task instead? You could make your template 1/4in oversize all round (so 1/2in wider than the required cut-out) then use a cutter 1/2in diameter less than the guide bush to do the cut-out. e.g. a 1in guide bush with a 1/2in cutter. A series of progressively deeper passes could be made quite easily.

Regards

Phil
 
#5 ·
Thanks Phil, you explained it better than I did.......
 
#6 ·
Joe, if you are using a 1/2" shank bit you could go the full depth in one cut. If you are using 1/4" shank you should do it in 2 passes at least. If your template is exact size so that you need a bearing guided bit and can't use a template guide bushing and you don't have a short flush trim bit as Phil suggested, then rout out the depth close to the template. On the final pass go the full depth and run the bearing against your template.

Doing it as Phil's second suggestion allows you to use straight bits, which are cheaper, and allows you to make as many passes as necessary to get to the depth you want without straining your router bit or your router.
 
#7 ·
This tutorial basically illustrates what Phil. has explaind. To calculate the size of opening in the template, the simple formula is: guide diameter minus bit dia. plus the size of finished opening. For instance, if an opening 2.5" square is required and we choose a 1" guide and 1/2" bit, we get: 1"-.5"+2.5" = 3" opening in the template.
 

Attachments

#8 ·
Many thanks guys!

I've looked over these various suggestions and tips, as well as the tutorial, and I've done some more practicing. Basically, here's what's going-on:

A. My cutting bits are 3/8" and 1/2" bearing-guided with 1/4" shafts, and they're both working fine.

B. My router has a graduated 'depth of cut' adjustment dial on it that seems to work quite well (i.e., its fairly accurate).

C. When I use the 1/2" cutting bit with top bearing and make two separate passes at differing depths of (say) 1/2" then 3/4", there are two issues that develop:

1. FIRST PASS (1/2" DEEP): The cutting bit has a slight (rounded) shoulder on it just above its top-most cutting edge where it meets the 1/4" shaft (i.e., the area between the cutting edge and the bearing), which prohibits the bearing from sitting perfectly flush with the bit by about 1/32" or so (see diagram below). This is proving to be a bit problematic because on the first pass (1/2" depth), with the bearing riding perfectly aligned and flush with the 3/16" thick template, it is under-cutting the wood slightly, leaving a razor thin lip of wood at the very surface (i.e., the space between the bearing and cutting bit caused by the shoulder).

| | | | Bearing
/ \ Shoulder (causing a razor-thin lip of wood to remain at the very surface)
| | Cutting Edge
| | Cutting Edge


2. SECOND PASS (3/4" DEEP): On the second pass at the deeper and final (3/4") depth, using the same (1/2") bit, the earlier cut is not deep enough to allow for removal of the template to use the walls of the first cut, and yet, the bearing ends-up riding slightly below grade of the template. So, I'm thinking about using the trick whereby you insert a short sleeve (spacer) of hollow (1/4" ID) teflon tubing over the cutting bit shaft (between the top of the bits cutting edge and the bearing), forcing the bearing to ride slightly higher on the shaft. This would allow me to cut deeper and still have the bearing riding on the edge of the template. Is this a good idea or is it taboo?
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top