Metric Router Bits with 1/4 inch Shank

SSDiver2112

SSDiver2112

Escott Cues
I do not have CNC. I was wanting to use the router and indexed headstock to make holes for abalone inlay dots. The router takes 1/4 inch shank bits but the inlay dots come in millimeters. I have not been able to find bits with a 1/4 inch shank that can make a metric hole.
 
Do a metric to inches conversion and find a bit that's a little bigger. You will have to compensate for clearance anyway.

Ie. A 3 mm dot doesn't require a 3mm hole.

3mm = 0.118"

A 0.0200" router bit would work just fine providing 2 thou clearance for glue.

Sent from my Pixel 8 Pro using Tapatalk
 
SSDiver2112 said:
I do not have CNC. I was wanting to use the router and indexed headstock to make holes for abalone inlay dots. The router takes 1/4 inch shank bits but the inlay dots come in millimeters. I have not been able to find bits with a 1/4 inch shank that can make a metric hole.
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What size dots are the shell?
 
triley41395 said:
What size dots are the shell?
Click to expand...
4mm dots.
I got a 5/32” bit to experiment with. It is a tiny bit bigger than the dot so it isn’t a perfect seamless fit.

I just used CA. Maybe sawdust or dye in epoxy will be better.

This it purpleheart but I plan on them going into rosewood.

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I am not a cue maker but I am a machinist. Typically plunge cutting with a end mill will cut slightly oversized. If you can get a centercutting 5/32 end mill with a 1/4 inch shank that should do the trick for you. If you can't find one that's 5/32 or 4mm end mill with a 1/4 inch shank shoot me a message, I'll grind one up for you.
Lee
 
triley41395 said:
I am not a cue maker but I am a machinist. Typically plunge cutting with a end mill will cut slightly oversized. If you can get a centercutting 5/32 end mill with a 1/4 inch shank that should do the trick for you. If you can't find one that's 5/32 or 4mm end mill with a 1/4 inch shank shoot me a message, I'll grind one up for you.
Lee
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Thanks I will see what I can find.

Looks like I need to make a riser or something for the router. I got a mount from deco cues but it sits too low in the rest.

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triley41395 said:
I am not a cue maker but I am a machinist. Typically plunge cutting with a end mill will cut slightly oversized. If you can get a centercutting 5/32 end mill with a 1/4 inch shank that should do the trick for you. If you can't find one that's 5/32 or 4mm end mill with a 1/4 inch shank shoot me a message, I'll grind one up for you.
Lee
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Even drill bits cut a bit oversized. The effect varies inversely with stiffness and alignment (if the machine isn't very stiff or well aligned, the hole will be bigger than the same cutter used in stiff and well aligned machine.

I would expect that the results seen are about as good as can be expected with the setup used.
 
Mr. Diver -
You seem to be an inquisitive guy interested in a lot of things, so this is thrown out there from that perspective.
It probably won't help you directly unless you do get a pin router. :)

In the old daze before cnc , production woodworking included making a lot of parts to templates on pin routers.
In order to fine-tune the cutting circle dia to the pattern, or to "re-size" a sharpened up cutter so it continued to make the same size parts off the template, there are eccentric chucks. Many with balance features.

(Google whine/gripe/bash here..... I can no longer find images or articles on the net. Ever since Google started to use AI it has really dumbed down what search engines find - they only respond to the newest stuff out there, or the most successfully common popularly requested, and usually within the first couple hits go completely off on their own direction instead of searching the terms you actually entered. gripe, gripe, gripe.....)

Anyway, the cutters were single flute, and the chucks could be (were intended to be able to be) easily loosened, and rotated, to give + or - dia. There is usually a scale, and the manual describes the amount of dia change in a given range. I have a couple pin routers and STR one of the eccentric chucks somewhere but have not actually used it myself.

This might suggest a workable bodge for the obsessive, though: for a 1/2" collet, make/bore a reducer sleeve just slightly off center, and scribe a few witness marks on the end to align the flute of a single lip cutter. You need to add some relief to the cut angle and back of the bit to make it cut undersize. OTOH it could be made to bore a few .001's" over size, maybe even up to .010" or so. IOW, grind it undersize a little, then adjust through the eccentric feature.

However, what i do is same as Lee mentions above - just grind a common 2 fluter to the dia i need.
If it's only a couple - 5 thousandths , you can carefully hone on a good flat honing stone or diamond plate to reduce that much.

If all you are doing is drilling flat bottom holes, you could buy screw machine length/stubby drills and (freehand) re-grind the point. Such as letter D or near metric size. When re-grinding, i'd add slight spurs for a cleaner perimeter cut. Anything +/- maybe .005 shank will still grip ok in an ER 1/4" collet or similar DA collet.

smt
 
Ssonerai said:
Mr. Diver -
You seem to be an inquisitive guy interested in a lot of things, so this is thrown out there from that perspective.
It probably won't help you directly unless you do get a pin router. :)

In the old daze before cnc , production woodworking included making a lot of parts to templates on pin routers.
In order to fine-tune the cutting circle dia to the pattern, or to "re-size" a sharpened up cutter so it continued to make the same size parts off the template, there are eccentric chucks. Many with balance features.

(Google whine/gripe/bash here..... I can no longer find images or articles on the net. Ever since Google started to use AI it has really dumbed down what search engines find - they only respond to the newest stuff out there, or the most successfully common popularly requested, and usually within the first couple hits go completely off on their own direction instead of searching the terms you actually entered. gripe, gripe, gripe.....)

Anyway, the cutters were single flute, and the chucks could be (were intended to be able to be) easily loosened, and rotated, to give + or - dia. There is usually a scale, and the manual describes the amount of dia change in a given range. I have a couple pin routers and STR one of the eccentric chucks somewhere but have not actually used it myself.

This might suggest a workable bodge for the obsessive, though: for a 1/2" collet, make/bore a reducer sleeve just slightly off center, and scribe a few witness marks on the end to align the flute of a single lip cutter. You need to add some relief to the cut angle and back of the bit to make it cut undersize. OTOH it could be made to bore a few .001's" over size, maybe even up to .010" or so. IOW, grind it undersize a little, then adjust through the eccentric feature.

However, what i do is same as Lee mentions above - just grind a common 2 fluter to the dia i need.
If it's only a couple - 5 thousandths , you can carefully hone on a good flat honing stone or diamond plate to reduce that much.

If all you are doing is drilling flat bottom holes, you could buy screw machine length/stubby drills and (freehand) re-grind the point. Such as letter D or near metric size. When re-grinding, i'd add slight spurs for a cleaner perimeter cut. Anything +/- maybe .005 shank will still grip ok in an ER 1/4" collet or similar DA collet.

smt
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Thanks for the tips. The pin router is very interesting but as you said, it won’t help in this situation.
 
Special thanks to Tom Hassos of Deco Cue. He has been very helpful. I was having trouble getting the router tip centered. I want the router horizontal and oriented perpendicular to the cue. No matter which way I turned the mount, the router was too high or too low and couldn’t be adjusted on the tool post enough.

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Maybe I’m the first to try using his mount this way, or others fixed it themselves. I don’t have the tools to cut a recess in the mount to get around the cross slide crank so I thought I could add a plate to extend the mount a little.

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Tom was very responsive to my questions and he is making the adapter for me. It is already on the way so I should be back in business this weekend.

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You can use a Dremel tool with chuck, or get a pin chuck for your router with a 1/4 shank. You can drill a very slightly undersized hole and then push a mm reamer into the hole by hand and rotate it and your fit will be near perfect.
 
The pin router is very interesting but as you said, it won’t help in this situation.
Click to expand...

You might have missed my point, though?
With one (cheap/or easy to make) slightly eccentric bushing & an undersize bit, within a given range you can dial in any size you want within very fine limits in any router.

OTOH once into production, having a purpose ground tool makes sense.

smt
 
So far so good!

Did some practice runs this morning using a center cut bit. Much cleaner hole and makes a flat bottom. So the 5/32 works for the 4mm dots.

I sidelined this cue a while ago because I thought it was missing something. Then I recently got the idea for the abalone dots which led me to new tools as usual.

Glued the dots in and waiting to dry now. They are at least 3/4 in so I will file them about flush and then sand everything together before finishing it. Still have to do the joint and pin.


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Glad that the 5/32 worked out for you. Can't wait to see the completed cue. Looks like it will turn out nice.
 
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