I have a lot of time on hands here so I thought that I would burn through some of the scraps that I have sitting in buckets. Time for some more knobs!Tools & Material Needed:
- Drill Press
- Forstner Bits (1/2” & 3/4”)
- 11/32” Twist Bit
- Band Saw
- Sanding equipment of your choosing
- Scrap Hardwood ~ 4” x 4”
- Threaded Inserts (It works just as good with T-Nuts)
1 – Attach the drawing to a piece of scrap or lay it out using a compass. Here I’m using some scrap 4/4 FAS QSWO off cut.
2 – Using a 1/2” Forstner bit, drill a 1/2” x 1/16” Hole in the center of the knob. This will be for the threaded insert so that it sits just below the surface of the knob.
3 – Using a 11/32” twist bit, drill a through hole for the threaded insert.
4 – Insert the Threaded Insert.
- Your recess and through hole sizes may be different sizes depending on your threaded insert.
5 – Using a 3/4” Forstner bit drill the through holes that will become the hand grips.
- I like to use Bostik’s BLADECOTE (Dri-Cote) lubricant to help with drilling the holes.
6 – Off to the band saw to cut the knobs free. You could use a fret saw, jig saw, et. al here if you don’t have a band saw.
7 – Sand and remove the pattern. I knock off the sharp edges at my disc sander. If you used spray adhesive to attach the pattern, putting a little mineral spirits on a rag and wiping it on the pattern will loosen the glue and it will lift off without any fuss.
Drawing: I’ve included a 4” scale mark on the drawing so that you can print it out to scale.
I’ve made all different sizes and shapes of this type of knob. I like this size the best as it seems to fit most jigs and accessories that I use them on. I’ve also made them from a lot of different types of material; plywood, MDF, soft wood and hard wood. Hard wood is by far the best choice for these knobs.
- I’ve also used T-Nuts in place of the threaded insert. The same process is applicable, you just have to size the holes in steps 2 and 3 for a T-Nut.
- You can also add a 1” dowel to the back side of the knob so that it stands off from the jig/fixture/etc. After you cut them free from the blanks, just drill a hole part way through, ~1/2”, on the back side to accommodate the dowel and glue it in place. Just don’t install the threaded insert until AFTER you add the dowel or you will probably drill into the insert.
- These work great with T-Bolts as is. You’ll probably want to make sure that you screw the knob on with the threaded insert to the INSIDE. This way when you tighten up the knob, it will tend to tighten the threaded insert.
- You can epoxy in a a length of all-thread and use them as a Knob with a Threaded Stud. I’ve also just threaded in a bolt from the front side and locked it down that way too.
Here’s a knob on my small router trammel that I’ve threaded in a 1/4×20 stove bolt and used it that way.
-- Chunk's Workshop pictures: http://spadfest.rcspads.com/thumbnails.php?album=135