Well, you could use the too-small ones as spoilboards.
1cm off on opposite eges (esp. left-right) wouldn’t be too bad / might be usable though?
Strange that there would be any argument or discussion other than admission of error and urgent desire to get it right.
Ha how does that make sense, that shop shouldn’t be in business if they can figure out the difference between centimeters and millimeter!
I work with fabrication shops all the time, granted I’ve worked with a couple that don’t even know how to read a drawing, but when it comes down to something as basic as units of mesure, that just blows my mind!
You only say you have enough spoilboard material 'cause you haven’t started cutting. Just wait, you’ll run through it and be scrounging for more before you know it.
The most common mistake I’ve seen is people using millimeters and mils interchangeably. Admittedly it’s an easy mistake to make, but still a pretty big difference.
Looking good!
You realise that’s as good as it will ever look. 
Just wait until you hit it with an over enthusiast router bit…
Marking the spacers is an excellent idea. I spent 10 minutes yesterday trying to adjust Z axis spacers when I couldn’t easily see why the high/low spot was.
This?
Instead of the traditional spoilboard, have you considered T-Track as an option? @DavidWestley has a few posts on his T-Track spoil board.
I did the same but used sail track, a lot cheaper.
For that kind of money get a metal plate, have it ground to a reasonable flatness, then drilled and tapped.
As it was a one off job, I made a simple jig out of 6mm MDF.
Part C goes against the edge of the spoil board and the jig is clamped onto the spoil board (clamp on part A)
The router base then just runs along the dark marked face of part A to make the cut, Part C is placed as a stop at the appropriate distance. You do end up routing though part C so you could make it shorter.
One pass with the larger bit part way though the board and one pass with the smaller bit, all the way through the board.
Never mind, you’ve got your new, super fast internet to play with while you’re waiting.
All your careful work will pay off on the end though. You’ll have it cutting by Christmas.
I rushed the build on mine a bit and it shows in getting the alignment of the Y rails just right. I’ve also found that 9mm MDF is NOT thick enough for a torsion box (something I think you mentioned to me a while back, should have listened)
As long as the flutes are wider than the shank, you can still cut thicker than 3/4" with that bit. The only other issue would be stick out from the router collet.
You didn’t mention if you did this in a single pass to the full depth of the board or in multiple passes. For 3/4", 3 or 4 passes at high speed should make a cleaner cut with no burning.
As you say, Forstner bits don’t follow a pilot hole so use the Forstner bit to drill first using the awl mark. You can then drill a pilot hole using the centre mark that the Forstner bit leaves and drill the final size hole from the back.
How about using one of these?
http://www.sears.com/wolfcraft-4525-drill-guide-attachment-for-1-4-inch/p-SPM2993863801?prdNo=2&blockNo=2&blockType=G2
MarcCohen, be careful with that drill guide. I bought one once and hit a knot when drilling a hole and the whole unit twisted from the torque of the drill and broke. It’s not very sturdy to say the least. Hence it was off to Harbor Freight and drill press time.
Yes, that is precisely what I was referring to.
I have a drill press, but from what I understood Angus was trying to do, a drill press would not be an easy solution. I agree that these drill guides are somewhat flimsy, but again, for what Angus was trying to do, I think it would have been a simple and easy solution.
