D holes

[Mike OMelia]

I want to make some knobs for my stove top out of walnut and ebony. The plastic ones mount to the shaft via a "D hole". Is there a technique/tool for making such a hole?

The plastic knobs are junk, expensive, and not heat resistant.

[craig greene]

I don't know if this will work but right off the bat I would probably get a dowel (or you may have to turn one) the size of the hole. In your new knob, drill the hole the same size. Make a jig to hold the dowel and on a band saw or similar, cut the dowel off to make the "D" portion. Glue this into the hole in the new knob and that should form the "D" hole you are looking for. Just a thought.....

It seems also that some of the knobs I have seen have a metal insert that forms the "D". You may be able to purchase some or remove the ones from some old knobs and use them. Then you would only have to drill the prober size hole.

[Josiah Bartlett]

I've made a few knobs for guitars- I just use a round hole with a set screw on the flat part of the D. You can use a brass insert with a set screw if you are concerned about the wood breaking or stripping out.

[Mike OMelia]

Not fond of the set screw idea... these knobs are maybe 2.5" in diameter. The dowel idea has merit. I could not find inserts on McMaster. Maybe I don't know what they are really called. I think if such a thing could be found, might be the best idea. Maybe a collar? (keyed)

Mike

[Mike OMelia]

http://www.mcmaster.com/#about-shaft-collars/=9udut1

Maybe these? but how do I get the wood/metal interface to not slip?

Epoxy? I think I want to be able to take these on and off from time to time for cleaning.

Mike

[Gene Howe]

If you use the collars, you could drill a hole in the knob for a small screw driver access, position the collar so the screw head meets the hole, then epoxy the collar into the knob.
Or, find an appliance repair guy and ask him what those clips are called. He may even give you enough.

[John Coloccia]

Before you make a wooden knob, check these guys out. Maybe you can find a nice knob that will work for you. I think of the pain in the butt when things spill on your knobs, and how nasty they can get over time.

http://www.surplussales.com/ShaftHardware/Knobs-9.html

[Chris Fournier]

Carefully remove the "D-core" from the plastic knobs by whatever means you can - I'd likely saw and/or use my metal lathe. Make your wooden knob blanks and glue the plastic "D-core" into bored hole in the wooden knob. Make up a custom mandrel for the lathe and then carefully turn your new wooden knobs.

A lot of work and I doubt that the wooden knobs will hold up well to the radiant heat of your stove better than the plastic knobs but it's doable from a fabrication standpoint.

[Mike OMelia]

Chris, thats a good idea... and you are right, the heat will get them too most likely. I do like John's idea...

[Josiah Bartlett]

Knurl the outside of the inserts with a triangle file and press fit them, and secure with epoxy.