making wood guitar knobs

[Jedi Clampett]

for those of you who make your own knobs, just wondering what you do if you don't use a lathe?
to my mind using a hole saw or a plug cutter would be my first choices, but if you have used either of these, wonder if you would share your experience?

[Peter Wilcox]

I use a lathe, but if I didn't have one here's what I would try:

Make a block of wood slightly larger than the finished knob size. Drill a hole 1/64" smaller than the pot shaft diameter in the center about 3/4 way through the wood. Chuck up a bit the shaft diameter backwards in the drill and press/hammer the block of wood onto it, hoping it doesn't split. Maybe round off the corners to an octagonal shape, then with rasp/file/sandpaper shape the knob as the drill turns. If you can't get it off afterwards by grabbing it (gloved of course) and turning the drill, drill a hole in a piece of wood and chuck it between the drill and the knob, and hammer on it against the knob.

Just a suggestion off the top of my head.

[John Sonksen]

you could use a hole saw but it'd necessitate making a jig first, which is as easy as anything. You just need to run your hole saw through a piece of wood or plywood, with the pilot attached to the mandrel. Once you have that hole you can clamp that onto the piece of wood you intend to make your knob from. At this point you'd take the pilot bit out of the hole saw and use the jig to guide the hole saw through this next piece. Do not though try and run a hole saw on its own without the pilot drill in place, and without a jig. It will run all over the place and you might hurt yourself. This doesn't really help set a hole to go onto the shaft of your pot, but a drill press vice with a pair of v-blocks should do the trick for that operation.

[Jason Rodgers]

My suggestion (if you have these tools) would be lathe, then hole saw, then plug.

John's suggestion for a hole saw would work, but you could do it with the pilot bit in, if you filled the pilot hole with a contrasting wood or shell or something. A drill press would make this easier (and more safe).

A plug cutter would require a two-step operation in a drill press: clamp the wood securely (in a vice or to the table with backer) and drill the pot shaft hole to the required depth. Then, without moving the wood, replace the bit with a plug cutter and cut out the knob. This keeps the pot hole centered, as long as the bit doesn't wander (which, in my experience, it usually does).

[John Sonksen]

at the cabinet shop we've used the jig trick to drill out grommet holes when a customer requests a larger grommet than what was already in a countertop. In that situation the wood your are drilling through does not have any material with which to engage the pilot bit, so the jig effectively does the same thing. I've done it by hand and it's not risky at all, but I would recommend using say a 3/4" jig plate to for your guide. You could also use a drill press in this operation but make sure your material is clamped down to the press table, otherwise you risk the wood climbing up into the hole saw, (I think this may only be a risk with the pilot bit installed, but it would still be wise to clamp everything down before cutting).

Jason is right of course that you could fill the hole left by the pilot bit with an alternate color wood or material, but that's a way you can do it while maintaining a solid color.

If you go with a plug cutter keep in mind that you'll have a height limitation for the knob as plug cutters are designed to round off the surface being plunged into, so that the resulting plug will more easily fit into the hole that it's meant to plug. This operation is done through compression of the wood on that face and doesn't result in a nice surface finish generally, though using a very hard wood would probably limit this, (but you would still bottom out at a certain height limit with a plug cutter, and off-hand I don't know what this depth would be for a larger dia. plug cutter) Also, this operation must be done on a drill press and your material must be clamped down. This is essentially the same situation as running a pilotless hole saw and if the wood is not secured it can skate around underneath the cutter. I would also add that generally when using a plug cutter, you'd want to start with a thicker piece of wood than how deep you'd plunge the cutter. Typically, the cut plug is broken out later using something as a pry bar to break the plug column away from the bottom of the cut out. This of course results in an unfinished and usually jagged surface which if you followed the pre-drilling procedure for the shaft hole, would be the surface you'd want to finish for the top of the knob. This would require another step to level the surface and you'd likely have some wasting of wood as they aren't all guaranteed to break off at the same height. If it were me I'd skip the plug cutter.

One thing you could do though is use a jig to guide the outside of the hole saw, and modify the pilot drill for both length and diameter, (something you could have done at a saw shop), so that the pilot bit does not go all the way through the opposite face and gives you your ideal inner hole diameter for engaging on the pot. The downside of this would be that the pilot hole which usually extends beyond the plane of the hole saw teeth would have to be shorter and would not engage the wood first, (which is why you'd need to use the jig instead of the pilot bit).

Now with all of that being said, this doesn't really touch on what you'd expect for a surface finish coming out of this operation, and I'd expect it to be fairly rough. Plus, you wouldn't have a great way to sand it later, though you could use a shaft in the pot hole to put it in a chuck and sand it that way, I'd like to figure out a way to make sure your abrasive stays flat and parallel to the axis of the knob otherwise you could get mixed results. Also, you'd possibly deal with the occasional fly away part if you weren't careful.

You could certainly do it this way, but I'm not sure you'd always get the most consistent results. If it were me trying this, I'd probably get fed up with this fairly quick and start looking for a lathe of some sort. (you could also figure out a way to use a live center opposite the chuck on your drill press to make a turning operation possible, but this would be dependent on your press, what kind of center you could scrounge up and there'd be some things to think about that I didn't want to go into as I feel like my answer was already long enough!)

[Dave Stewart]

I've made a number of them .... discussed in past threads
http://www.mimf.com/phpbb/viewtopic.php ... 644#p14925

FWIW, here's my post from that thread
....I do much the same, in a drillpress, mainly because most knobs are way oversized for my tastes. Clamp stock securely, then I'll first just kiss the surface with a forstner bit of just the OD I'm after. Replace that with one to counterbore a pocket so the knob will fit down over the pot nut. Finally, drill for the press-fit mandrel. Rough saw/sand to shape, then fit the mandrel, & finish shaping/sanding in the drillpress. I drill up to 15/64" & have never needed to use a set screw......

[David Robinson]

these are handy too.

http://www.ebay.com/itm/400586671309?_t ... EBIDX%3AIT

[David King]

Those bushings from bezdez are way too tight on the pot shaft and require a 10mm drill to fit their OD. I got a gross of them to try and can't use them.

Dave Stewart's got it . That's the only way to go. The plug cutters are available in straight sided and tapered. You can get really nice ones that can do a 2" long plug. It's nice to start longer to have more room to pry your knob out of there. You can also resharpen the tips many times before you loose height.

[John Sonksen]

Nice David, I have never seen plug cutters that long, I suppose it makes sense though, for other applications than cabinetry, lol...

[David Robinson]

David K - It took a bit (sic) but I got 10mm bit and everything was cool. BTW, I seldom make wood knobs. I use the inserts for other materials.

[Art Davila]

I have a circle cutting jig for use on a band saw, but I have used it on my bench sander with good results. It was not fast or clean but it worked well for the wheels I made fore a toy car.

I was not thrilled about trying to cut something that small on the bandsaw to the belt sander seemed much safer.
I saw a guy make a tiny giraffe on a band saw but I did not see my self putting my fingers that close to the blade. with my luck ppl would start calling me lefty. By default.

[Johnny Rowland]

I have made a lot of them with a 3/4" hole saw.Back the pilot bit off until it barley touches the knob,that give you a mark for center to drill for fitting on to pot.Mount them in a lathe if you want to shape them more.