Bit to make countersink holes with CNC?

[rmwarren]

I hear you.

The bearing blocks are in the corners of the plate and I think button head screws are are low enough that I don’t even need to counterbore.

The flipside is those small counterbores are so easy with Origin. Set F&S really slow and helix the thru hole, then add an offset and you can helix the counterbores without moving Origin. A disposable 1/8" O-flute off Amazon works great in 6061.

Looking forward to seeing the results. I've been wanting to make a sled because why not? Just don't really need one, but what fun is it being practical?

RMW

 

[Cheese]

Ya, my Crafted Elements sled just uses cheeseheads to mount both the blocks and standard rounds for the router.  There's a little play in the mounting to the blocks so you can tram.  You'd have issues if you wanted to countersink the bottom of the sled for all hardware.

Nothing wrong with cheeseheads... [smile] ....that's what the 1010 uses along with over sized through holes and counterbores to center the copying ring. You just need to make sure that there is enough material thickness to ensure that the cheeseheads can be firmly snugged down.

I really like flathead screws for precision alignment, but I usually reserve that technique for when I can absolutely control the machining. There is no room for adjustment...the flathead screw will always center itself no matter what degree countersink it's put into, from 60º to 140º...it's the same.

 

[Mini Me]

On some bearing blocks the mounting hole pattern is offset to the centre line of the block. I found out the hard way and now I use counter bores to attach to the bearing blocks. Using spacers is the easiest way to get the rails perfectly parallel as mentioned above. I have done a few projects similar to this and in the end for accuracy I made a digital xy table for my drill press which made things a lot easier.

 

[Packard]

I must be missing some point here.  If the shaper drills the holes, wouldn’t it be simpler to take the plate to the drill press and simply use a counter sink bit or a oversized drill bit to make the chamfer.  There are a lot more angles available with oversized drill bits. But you do have to be careful not to over drill. 

Ive made router plates in acrylic.  I don’t have a cnc shaper, so I used transfer punches to locate the holes and a drill press.

 

[Cheese]

I must be missing some point here.  If the shaper drills the holes, wouldn’t it be simpler to take the plate to the drill press and simply use a counter sink bit or a oversized drill bit to make the chamfer.  There are a lot more angles available with oversized drill bits. But you do have to be careful not to over drill. 

The Shaper Origin already "knows" the exact coordinates of the drilled holes, what Michael want's to do is to use that information to place the countersink at the exact same coordinate. That way the vertical axis of the countersink and the vertical axis of the hole are within .001" or less of each other.

He's dealing with the parallel alignment of linear bearings and their concomitant rails so thousandths of an inch are important to prevent any binding.

 

[Michael Kellough]

I must be missing some point here.  If the shaper drills the holes, wouldn’t it be simpler to take the plate to the drill press and simply use a counter sink bit or a oversized drill bit to make the chamfer.  There are a lot more angles available with oversized drill bits. But you do have to be careful not to over drill. 

Ive made router plates in acrylic.  I don’t have a cnc shaper, so I used transfer punches to locate the holes and a drill press.

[member=74278]Packard[/member]  I’ve made a few rigs using linear rails in the past (decades ago) and I did use transfer punches to mark where the holes for mounting blocks needed to be drilled. I’d use the same old methods again if I didn’t own the Shaper Origin.

I feel I don’t use it enough so lately I’ve been trying to use it whenever I can rather than only when I need it. Each time it’s used provides more familiarity and I learn something that hopefully I won’t have to figure out under the stress of a deadline, when the tool is needed.

As has been pointed out by others the best method is to make oversized holes and then use spacers to set the linear rails (while installed in the bearing blocks) parallel to one another and then tighten the screws. It could all be done with a Sharpie and hand drill and maybe a punch if you wanted to avoid needing to further enlarge a few holes later.

 

[Packard]

OK.  A reasonable explanation. Thanks for the reply.