Making hardwood dominos???

[Scott Larson]

Hey folks,  I was wondering if anyone has a tip for me.

I'm working on building a crib and part of the justification of buying a domino was to use it to build all of the rails (so they would have an interesting shape, an argument my wife actually agreed to) sort of like some of the louver projects I've seen guys doing.  While I have found that I can make good fitting rails to fit the 8mm cutter holes using a 3/16 round over bit, I've not found a good bit that produces a proper radius using the 10mm cutter (my intended size).  Since I'm having to make 2 cribs (twins) I have to make a heck of a lot of rails so I'm looking for something that fits nice enough that I need a minimal amount of hand sanding afterwords.  I've been unable to find any metric round over bits that might make quick work of this but perhaps I'm looking in the wrong place.  My 1/8 round over bit is not quite producing the precise fit I'm after.  I'm wondering if anyone has any ideas or could direct me to resources to help me out?

Thanks again for any info
-Scott

 

[greg mann]

The 3/16 roundover you feel works for 8mm slots should work even better for 10mm. An 8mm mortice has 4mm radii, of course, and this is .1575". This is almost a perfect match for 5/32". In the woodworking world it IS perfect, only .0012" different. Your 3/16 roundover is a full 1/32 (.0313") different than a perfect fit (5/32). Not that you will easily find a 5/32 roundover to achieve woodworking perfection on the 8mm fit; but you are already happy there, right? The difference in radius value between a 3/16 roundover and a 5mm, for the 100mm mortise, is only .010". If you aim to take a scosh less than a perfect tangent blend to the flats of your stock you can easily cut this in half. You can then hand sand a few swipes to blend the tangent line fair, something you probably expected to do anyway to get rid of the router cusps.

 

[Scott Larson]

Thanks Greg for the quick reply.  It looks like I have the tools, just "knot" always the knowledge 
I'll head back out to the router table and see if I can squeeze a bit more out of the 3/16 to satisfy my quest.  I was surprised as well that the 3/16th seemed pretty darn good using the 8mm cutter knowing it was a bit oversize.  I'll let you know how it ends up.
Thanks again

 

[JJ Wavra]

I baught the 3mm radius festool bit to make 6mm dominos.  The dominos were in hard maple and the finish quality and actual geometry of the radius was excellent.  You could always get a 5 mm radius bit and put that in your router table.  If you don't have an 8mm collet then you can get a reducer for a 1/2" collet, this is what I did and had a lot of success with it.

JJ

 

[Warrior]

I make my own sipo dominoes by the 100's at a time.

Unless you are doing thru mortises, matching radii for tenon and mortise is not necessary. I either just put a chamfer on the tenon stock on the jointer or leave them square.

I make my domino tenons to fit in either the middle or wide settings with just a bit of wiggle room to the sides to make assembly a bit less stressful.

Making a precise fit for positive placement is also easily accomplished with a chamfered tenon. I think easier than trying to match up imperical roundover bits to metric radii.

Eiji

 

[greg mann]

I make my own sipo dominoes by the 100's at a time.

Unless you are doing thru mortises, matching radii for tenon and mortise is not necessary. I either just put a chamfer on the tenon stock on the jointer or leave them square.

I make my domino tenons to fit in either the middle or wide settings with just a bit of wiggle room to the sides to make assembly a bit less stressful.

Making a precise fit for positive placement is also easily accomplished with a chamfered tenon. I think easier than trying to match up imperical roundover bits to metric radii.

Eiji

Eiji,

You are just too darn practical.  ;D You have a knack for not seeing a problem where one doesn't exist. :