Making and Centering a Router plate

[Benchwayze]

I have a sheet of 10mm Ally that I want to use for a base.

This is what I want to do:

Take some lengths of screwed rod, (say 30mm long) that will match the thread of the mounting holes in the router base.
Chuck these into a drill-press, and using a file, put points on one end.
Cut a screwdriver slot in the other end. Set them aside.

Cut a blank plate from the aluminium and draw diagonals across it.
Put a centre-point or perhaps a tungsten 'V' cutter in the router.
Put the unplugged router onto the blank and centre it using the centre point or cutter and the diagonals as a guide.
Clamp the router and the plate down.
Put one of the home-made screws into each mounting hole, and tighten them down enough to make a mark that will guide a drill.
Remove the alloy blank, and if necessary, centre-punch the screw marks.
Drill and countersink the mounting holes.
Fit the blank to the router, blind; with no hole in the middle.
Flush the centre-point or cutter down to the plate, and set a plunge depth that will allow me to make just a dimple in the aluminium.
Start up the router, flat on the bench and use the centre-point/cutter to put a dimple in the blank.
Switch off, unplug and remove the blank plate.
Using the dimple as a drilling guide, drill right through the aluminium with a fly-cutter, or a hole –cutter, of the desired diameter.

That should give me a plate that is dead centred to the particular router I use.
Now just mark the plate with the identity of the router it was made for.

This is for a plain, router plate, to suit cutters up to about 50mm in diameter, to obviate the need for reducing rings.

So, that is the plan.

It will work... The aperture would be centered… Yes?

Or have I missed something?

John :?:

PS... To bring a centre-point true with the router, bolt the router to a thick board and clamp it down. Raise the plunge mechanism to full height. Switch on the router at slowest speed. Gently use a file to true up the centre-point.

 

[xy mosian]

Sounds good to me, although it wouldn't work with my Makita as the mounting holes don't go all the way through the base. Presumably you'll mark the orientation of the router just in case the mounting holes are not concentric with the spindle.

Let us know how you get on.
xy

 

[Benchwayze]

Sounds good to me, although it wouldn't work with my Makita as the mounting holes don't go all the way through the base. Presumably you'll mark the orientation of the router just in case the mounting holes are not concentric with the spindle.

Let us know how you get on.
xy

Cheers Moss,

Yes, that 's exactly why, because although the router won't be out by much, if it is, at least the plate will be concentric.

With your model, you could still make your pointed screws, but no need for a slot in the other end. Just thread them into the holes from underneath. Then you could mark the plate once you centred the router. Or, make a dummy plate like that, from 10mm MDF. Then drill through that to put mounting holes in the alloy.

Yes?

Should work.

Regards
John

 

[xy mosian]

That sounds good. Thing is I don't use my router, the big one anyway, very much these days. When I did need a quick upside down job I rather cheeted and slung the machine from the guide bars and used a thin slip sheet for the table.

Interestingly I found that the rebate for the bush on my machine was not centred by about 0.3mm. Now that doesn't sound like much but my work very much improved when I re-worked the rebate to fix the problem.

Sadly that concentricity is a figure which rarely shows up in reviews, I've never seen a check on whether the surface of the base is square to the shaft either.

With a 10mm plate aren't you going to lose a lot of cutter reach? Of course there are always extensions I suppose.

Have fun. xy

 

[No skills]

Not sure I have the right end of the stick here - quite often not, so bear with me..

Cant you use a drill bit in the collet of the router and use that to make the pilot hole in the ally plate - obviously very slowly lowered and using cutting fluid. Thus giving you a perfectly placed hole in the sub base your making?

Just a thought.

 

[Benchwayze]

Unless things have changed, I was always advised that twist drills should not be used in a router. Something to do with the accuracy of the shank if I recall. Maybe there are drills that can be used in a router these days, but then I don't often work metal with the router.

I suppose I could use an end mill, but I am using the cutter only to mark the plate, for drilling. I will take the plate to the drill table to cut out the apertures which will be about 30mm diameter, using a fly cutter.
regards
John

 

[George_N]

The factory baseplate is usually screwed to the router and comes off easily. You can stick that to your mounting plate with double sided tape and simply drill through the screw holes. If you don't want to run a drill through the screw holes, use the factory base plate as a pattern and make another out of MDF that you won't mind drilling through...that way if you want to make multiple mounting plates you have the pattern. Once the screw holes are drilled and countersunk, you mark the centre as you ssaid with a V point bit and cut the aperture by your method of choice.