Router Tips for Template Use

[bgavin]

I'm starting this thread to get solid tips for how to use following bits, etc, with templates.

My need:
Example is the OT12 top box. The need is a template to quickly cut the port cutouts that double as handles in the sides.

I want to make a template that attaches to the wood panel. I do a plunge into the center with the router, and use the template to quickly make the cutout.

My question:
What is the right router bit? Top following, or ??
The up-spiral cutting bit is ideal for making rapid cuts, but I don't know how it would be used with a follower bearing, or whatever is required to follow the template.

[DJPhatman]

Make your template out of 1/4" or 3/16" metal, and 1/8" larger than the actual opening you are cutting. Install a 1/4" Brass template guide bushing seen here. Attach your template to your work piece, put the guide tip against the template edge, plunge the router bit and go. I have the HF bushings, and they really work well.

[DaveK]

The need is a template to quickly cut the port cutouts that double as handles in the sides.

I did pretty much the same thing for the handle cutouts in the top corner of a T39. I made the template out of 1/2 ply. I used a hole saw to cut out the circular ends, then a saber saw for the straight cuts to remove the wood between the two circles. To use it, attach to the panel and route with a top-bearing pattern bit.

Here's some tips I figured out in the process. First, make the template from a bigger blank. I wish I had left more room outside the pattern to clamp the template to the work and allow room for the router base to travel. Second, if you are always making holes at the same offset from the edge of the panel, screw a guide strip to the underside of the template to make positioning easier. Third, mark the centerlines of the pattern BEFORE cutting the holes and extend the lines all the way to the edge of the template. Fourth, it's hard to properly clamp the template close to the edge of a panel. Use a couple brads to secure it or pre-drill recessed screw holes to attach the template to the work. This probably is not a problem with OT12 handles because they are far enough from the edge to give you more clamping room. Fifth, pre-cut most of the hole in the work using a saw, spade bit, or whatever. Just leave 1/4 to 1/8 inch of material for the router to remove to reduce wear on the bit.

[Tim A]

Fourth, it's hard to properly clamp the template close to the edge of a panel. Use a couple brads to secure it or pre-drill recessed screw holes to attach the template to the work.

That's HUGE. It is much easier and quicker to allign the template and pop 4 brads into it than to fumble around with clamps. They won't slip and there's nothing in the way of the router. Brads are extremely useful when your template and workpiece are small.

I use both top bearing bits and template collars, depending on the application. Up-cut spiral bits work very well, and are especially helpful in small diameters when routing an interior corner. For the template you're referring to, I use a 1/2" X 1" top bearing straight bit. The template is made of 1/2" baltic. The bearing glides around the curved ends more smoothly than a collar and you don't have to worry about side-loading the bit.

[bgavin]

Thanks for the tips. I bought two Freud up-spiral bits because I read they cut BB like butter. I'll muck about to see if I understand what is needed to use these bits with a top bearing, collar, etc. I find a straight 1/4" carbide bit is VERY slow when cutting BB, which is why I bought the up-spiral. I want to quickly cut these holes, not nurse-maid them with multiple plunge cuts.

Understood on the large template to allow mounting. I don't have a brad nailer, but a hammer will do.

I figure these templates would rapidly let me cut the OT12 baffle also. I cut a rectangular cutout in the baffle of the correct area, that matches the width of the horn throat. When I do the next set of OT212, I will skip the flange-thing altogether and use a single piece baffle and spacer. I fit the grill material on the inside baffle surface where it is serviceable.

[bgavin]

I need some more clarification please:

I have Freud up-spiral bits. #75-102. They are 1/4" shank and 1/4" cutting diameter.

Do I understand correctly, to use a #62-103 bearing (1/4" ID, 1/2" OD) along with a collar, on the up-spiral bit? I'm unsure how to use this bit with a bearing.

[Tim A]

I need some more clarification please:

I have Freud up-spiral bits. #75-102. They are 1/4" shank and 1/4" cutting diameter.

Do I understand correctly, to use a #62-103 bearing (1/4" ID, 1/2" OD) along with a collar, on the up-spiral bit? I'm unsure how to use this bit with a bearing.

The bearing will be too large for your template. The only way a bearing works is if it's the same diameter as the bit, or if you adjust your template to take into account the larger bearing. That's where a collar comes in, it's either/or, not both.

Collars are a pain to change, so bearing bits make life much easier if you're working with a single router. If you really need to go with the spiral bit then you'll need a collar. The collar will be larger diameter, so you'll still have to take that into account when making the template. A collar for a 1/4" bit will have a 5/16" opening for the bit, then the thickness of the collar wall itself.

[wallywally]

I need some more clarification please:

I have Freud up-spiral bits. #75-102. They are 1/4" shank and 1/4" cutting diameter.

Do I understand correctly, to use a #62-103 bearing (1/4" ID, 1/2" OD) along with a collar, on the up-spiral bit? I'm unsure how to use this bit with a bearing.

You use either a collar or a bearing not both. IME most bits that are to be used with bearings come with the bearing installed. If you install a bearing make sure it is a press fit so it doesn't wander up or down the bit. With the bit you have chosen I'd just use a collar.

[bgavin]

The Freud site shows collars, but doesn't make it all that clear. Thanks for the clarification. I chose the up-spiral bits because I understand they cut much faster than a straight edge bit. When I use the Jasper jig, I make 3 passes per baffle hole in 1/2" BB to avoid stressing the bit. I go VERY slowly. This is highly inefficient, so I opted for the up-spiral bit instead.

I'm willing to make the templates larger and use a collar. This seems like it will rub hell out of the template after awhile.

I'm also willing to buy a top-bearing straight edge bit for the template tasks, but it seems like that will put me right back into the ultra-slow process again. Tim, what am I missing here, for rapidly cutting OT12 handle holes in 1/2" BB with a template?

[wallywally]

I'm also willing to buy a top-bearing straight edge bit for the template tasks, but it seems like that will put me right back into the ultra-slow process again. Tim, what am I missing here, for rapidly cutting OT12 handle holes in 1/2" BB with a template?

If your using a template and a straight cut bit and want speed you must rough cut and then finish with the router.

[Tim A]

what am I missing here, for rapidly cutting OT12 handle holes in 1/2" BB with a template?

Nothing. The fact is that with homeowner grade tools and bits, it's a process. However, you can speed it up by using a larger bit. Mine is a 1/2" diameter with a 1" cutting length. For this use, the larger bit is fine and you won't have to worry about it snapping as readily. Still, you're going to have to make a couple of passes. I can make the cut in a single pass when using SPF or Auraco. BB requires a couple of passes.

The spiral bit will work fine with your jasper jig, but I doubt it will cut the BB as quickly as you hope. A sharp edge is a sharp edge. The spiral bit has an advantage in that the cutting edge is in constant contact with the workpiece resulting in a smooth cut without chattering or kickback. The other nice thing about spiral bits is the cutting length, which is long enough to allow templates made of 3/4" if you like.

The fastest way to do this (in my experience, someone else may have a better process) is to use a plunge router with preset depth stops. Make the first pass, plunge to the next stop and do it again. That at least eliminates having to reset the router each time. With a 1/2" diameter bit it can be done in two passes. The first pass is less than half due to the added drag from the bottom of the bit being in contact, the second pass is thicker with the end of the bit free.

[LelandCrooks]

The fastest way to do this (in my experience, someone else may have a better process) is to use a plunge router with preset depth stops. Make the first pass, plunge to the next stop and do it again. That at least eliminates having to reset the router each time. With a 1/2" diameter bit it can be done in two passes. The first pass is less than half due to the added drag from the bottom of the bit being in contact, the second pass is thicker with the end of the bit free.

+1 on the money. The bigger arbor of the 1/2 bit takes away all the worries about cutting hard. I snapped a 1/4 pretty quickly, went to the 1/2 and you can go like hell with it. 2 passes are required, a single pass even with a big router chatters very badly.

[gdougherty]

Mine was a Porter cable from HD, not a Freud, but I found it pretty easy to overheat and snap a 1/4" up-cut spiral bit in 1/2" Arauco when cutting driver holes on a TLAH. I took it in 3-4 passes and I could spin it around reasonably quick. If I tried it in two I had to take it slow and easy. I like the idea of rough cutting the majority and trimming afterward using the template. A 1/2" top bearing like Tim mentioned would be great there. Drop your template on, quick bust through with a forstner bit or something large, run the jig saw quickly across the inside of the connecting line. With a good drill, bit and a rough cut blade on the jigsaw, that's probably less than a minute. Run the router around the template in one pass to make everything clean. Build the template with blocks so it fits over the side panel and lines up from all edges and you'd have an easy port hole production line.
Plunge router as recommended was a major brain saver. Gotta love those Jasper Jigs too.

[bgavin]

My router is an industrial strength Sears with 1/2" collet. I have 1/2" straight bits already. No good with Jasper, as it is calibrated to 1/4", but that is OK. I'm hoping the up-spiral will go faster than 1/4" straight on the Jasper. I have to do 4 passes, and terribly slow, to avoid snapping a bit.

I was hoping there was a smart method to avoid all the tedious pre-cutting. For two OT212, that means 8 ports have to be cut. I can figure something out with a jig saw for the rough cut, then template it for the final. I do the OT baffle rectangular cuts with my new Bosch jig saw and a straight edge. I get nice clean cuts, but again the setup is somewhat time consuming. But not as bad as the vents are going to be.

[Tim A]

My router is an industrial strength Sears with 1/2" collet. I have 1/2" straight bits already. No good with Jasper, as it is calibrated to 1/4", but that is OK. I'm hoping the up-spiral will go faster than 1/4" straight on the Jasper. I have to do 4 passes, and terribly slow, to avoid snapping a bit.

The 1/2" bearing guided bit refers specifically to the OTop port question. The Spiral bit will work fine in the Jasper.

To use a different size bit in the Jasper just add or subtract half the difference of the bit size from the 1/4" calibration. 1/2" bit -1/4" bit = 1/4"/2=1/8". So in that case use the pin hole 1/8" larger than the circle you want to cut. (I think that's right, I'd prefer to be looking at it! )