Drilling the accessory kit router plate

[wreckwriter]

I need to drill my router plate to accept my PC 694 router. I have some concerns about screwing it up so please forgive if these questions seems basic...

I have no drill press, only a 1/2" drill and basic bits. Should I be using a specific type of bit for either the hole or, most particularly, the contersink?

I guess my biggest concern is ending up with the router centered. Should I start with one of the pre-drilled holes and just try to center it and drill the other 2?

Should I just take it to a machine shop???

[LarryG]

Don't overthink it.

Machine shop? Nah. You need three holes. It ain't that hard.

Remove your router's plastic subbase and use it as a template to mark your holes. Center the bit opening of the subbase on the opening in the aluminum mounting plate, using your eyeballs and a 6" rule. Or calipers. Whatever you have. The router needs to be FAIRLY closely centered on the mounting plate, so the bit will be nominally centered in the accessory table inserts, but since the bit is round a small amount of off-centeredness is meaningless.

Drill your countersinks first, using an 82deg countersink (standard for flathead machine screws). Then switch to the smaller bit needed for the thru-holes and drill those. Aluminum is soft so any halfway decent twist drill bit will work. Be SURE to clamp the plate down securely, as the bit will have a tendency to grab the soft aluminum.

De-burr with a rattail file, bolt everything together, and away you go.

[LCHIEN]

I need to drill my router plate to accept my PC 694 router. I have some concerns about screwing it up so please forgive if these questions seems basic...

I have no drill press, only a 1/2" drill and basic bits. Should I be using a specific type of bit for either the hole or, most particularly, the contersink?

I guess my biggest concern is ending up with the router centered. Should I start with one of the pre-drilled holes and just try to center it and drill the other 2?

Should I just take it to a machine shop???

Aluminum is easy to drill but there are a few precautions.
If you have a VIX style self-centering bit that would work.
If not, then you need to use a center puch to mark a dimple dead center in each of the 3 hole locations using the router's removable base plate as a template.

Now the hard part is that normal twist bits tend to wander/walk which is bad.
If you got a good dimple I'd start with a 1/16th bit which will sit in the dimple and make a good centering hole. Then use two more bits enlarging the hole each time up to the final size, the bevel-grind of the bit will help it keep centered over your original hole.

Make sure you have good sharp drill bit and use the recommended speeds for aluminum.
Drilling aluminum should be almost like cutting butter and yield nice curly strips - if you get a bunch of chips then you bit is probably dull.

Also clamp your metal work securely because sometimes the bit will grab on exit and spin the workpiece which will cut you or otherwise be unsafe.

Good luck.

[wreckwriter]

The main things I'm worried about are getting the router centered on the hole and getting the countersink right. Don't mean to be a PITA, just want to get it right in one try...

So I need to drill 3 new holes, not use one of the existing holes as a starting point? It seems that its going to be hard to get 3 new holes without getting into an existing hole. I don't have it in front of me so I'm just going by memory from looking at it last night.

82 degree? I guess I need a special bit for that? All I have are cheapie "high speed steel" bits. Also don't know what a VIX bit is. Maybe I need to go look for some bits before I try this.

Thanks guys.

[vaking]

May I make a suggestion on centering the template on aluminum plate. Trace on a piece of paper the router template. Trace on another piece of paper the aluminum plate. Find centers of a main router hole on both pieces of paper using drafting tools (Inexpensive set of drafting tools is good to have in woodworking, if you don't have it - consider it a tool). Allign those centers on 2 pieces of paper using a needle. Transfer positions of mounting holes from the paper with router template trace to the other piece of paper. Lay the paper with the trace of aluminum plate on top of aluminum plate and punch locations of holes right through the paper. This will give good precision where to drill.
Another option is to use centering pin in your router if you have centering pin.
About the specialized bits:
Check these links:
http://www.leevalley.com/hardware/pa...=3,41306,41328
http://www.leevalley.com/hardware/pa...=3,41306,41330
These are just examples, the bits are available everywhere.

[LarryG]

The main things I'm worried about are getting the router centered on the hole and getting the countersink right.

There he goes again ... overthinking it.

As I said, PRECISE centering is not necessary. You do want it close but it you're off a sixteenth, no biggie. You can use one of the methods Alex describes, but if you just plop your router's subbase down on the aluminum plate and keep sliding it around by small amounts, spot-checking the offset measurements around the two holes until they're equal with a 6" rule, that's plenty good. Mark the holes with a pencil and centerpunch them by eye.

You can certainly use one of the existing holes IF one will work. But they probably won't; most routers use three screws to mount the plastic subbase, but the hole-center diameter varies from one manufacturer to another. This means that you will probably not be able to center the big center holes in the subbase and mounting plate unless you drill all three holes anew.

An 82deg countersink is the most usual angle. This is the angle formed by the sloping underside of a flathead machine screw. Available at Lowe's, HD, or a good hardware store. That angle applies to the countersink only ... just use a regular twist drill bit (NOT a brad point!) to drill the thru-holes. You should drill these about 1/32" oversize, so that you'll have the necessary free play for easy attachment of the router's base to the mounting plate.

Again, drill the countersinks FIRST since that will give you the best results using a hand drill. (Even with a drill press, drilling the countersinks second will sometimes cause the countersinking bit to chatter and give you a star-shaped countersink.) You'll have to estimate the required depth but that's not too tough; it's better to be a little too deep than too shallow.

[wreckwriter]

I'm famous for overthinking things. Most likely I'll worry a hole through the plate before I drill one

Do you know the required hole size by any chance? If I had that I could stop on my way home and get a good bit. PC's parts list only shows "screw".

[LarryG]

I'm famous for overthinking things. Most likely I'll worry a hole through the plate before I drill one

I can relate. And there's nothing wrong with being cautious. But you'll find, by the time you're through, that this job was NBD.

The screws are almost certainly going to be a #8 or #10, which take a 5/32" or 3/16" hole respectively. I'm pretty sure the ones for my Makita are #8 x 24 but this can/will vary by manufacturer. As I said, you'll want to drill the holes slightly oversize to give you some working room.

If you don't have any twist drill bits, I suggest buying a small starter set with sizes ranging from 1/16" up to 1/4" ... or even larger if you can afford it. HD and Lowe's will have lots of choices of brands, set sizes, etc. A set will cost more than you need to spend to drill these three holes but if you buy your bits one or two at a time, you'll soon spend enough to have paid for a set a couple times over.

EDIT: Almost forgot something ... the screws that hold your router's subbase on will likely be round heads. To mount the base to the mounting plate, you'll need flatheads of the same diameter and thread pitch, but most likely in a slightly longer length. This is because the aluminum mounting plate is generally thicker than a router's subbase. Take one of your router base screws with you when you go shopping. If you have, say, a #8 x 24 x 1/2" long round head screw, you might need a #8 x 24 x 3/4" long flathead.

[scorrpio]

Some ideas:
1. Use a compass with sharp pencil to draw several concentric circles on a piece of paper, changing the radius by about 1/16" for each circle.

2. Put the aluminum plate on top of paper, near table edge, match it to one of the drawn circles.

3. Put the router subbase on top, also match it to one of the circles. Now clamp the whole thing to the table.

4. Don't bother with punching, etc - just find a drill bit that snugly fits into subbase holes and use subbase itself as the guide to drill the holes. Or at least to start the holes.

[wreckwriter]

Thanks for the tips guys! With one or more of these ideas, I'll get her done

[wreckwriter]

Measured and marked. All of my good clamps are busy holding my wife's glued drawer and windchimes together overnight so I'll drill tomorrow.

When the router is attached to the plate, does it go on with or without the black plastic sub-base plate? I'm thinking without.....

[Black wallnut]

Without! Unless PC has drastically changed thier way of doing things the current screws that come with your router will be flat head machine screws.

IIRC they are 10-24 threads.

[jdschulteis]

There he goes again ... overthinking it.

As I said, PRECISE centering is not necessary. You do want it close but it you're off a sixteenth, no biggie. You can use one of the methods Alex describes, but if you just plop your router's subbase down on the aluminum plate and keep sliding it around by small amounts, spot-checking the offset measurements around the two holes until they're equal with a 6" rule, that's plenty good. Mark the holes with a pencil and centerpunch them by eye.
[. . .]

This is pretty much what I did. I eyeballed the centering of the subbase and centerpunching the holes. I also just used a larger diameter twist bit as a crude countersink. It still works fine.

[LarryG]

+1 on what Mark said ... remove the plastic subbase.

I didn't know that P-C uses flat-head screws but 10-24 is very likely the correct screw size. Yesterday I wrote that I thought my Makita, which is essentially a teal-blue P-C 694 clone, used 8-24 but last night I checked, and sure enough they're 10-24s. (They are round heads, though; an example of what I said about having to check because these things vary by mfr. You guess, you're likely to guess wrong. )

[LCHIEN]

+1 on what Mark said ... remove the plastic subbase.

I didn't know that P-C uses flat-head screws but 10-24 is very likely the correct screw size. Yesterday I wrote that I thought my Makita, which is essentially a teal-blue P-C 694 clone, used 8-24 but last night I checked, and sure enough they're 10-24s. (They are round heads, though; an example of what I said about having to check because these things vary by mfr. You guess, you're likely to guess wrong. )

The Bosch 1617 baseplate has two sets of holes. One set is countersunk for flat head screws and as such is supposed to be perfectly centered as you cannot reposition it due to the centereing effect of the bevel on the screw heads.
But the other set of holes has a counterdrilled hole for round head screws and a little wiggle room. So if you prefer or otherwise need to, you can use round head screws and the second set of holes and a centering tool/bit to precisely center the bit in the baseplate or template guide as needed.
Another cool engineering feature of the Bosch - does the makita, Dewalt or PC x9x have this?