Thread: How to make a wooden pentagon knob?

Originally Posted by Dengue

Hello, I would like to make a wooden pentagon knob as shown, about 40mm OD, with a 5/16" threaded insert in the centre, but not right through, unlike the one in the picture.
pentagon.jpg
Can anyone please advise on the best way to design and cut one of these?

Dengue,

One way that I've seen done by a local Woodie was to use a bandsaw with a 1/4 inch wide blade (or narrower) or with a scrollsaw. Pretty straight forward as demo'ed in this Youtube vid ..... https://www.youtube.com/watch?v=EGqNF6O1ugU

My personal way of doing it (from before I had a bandsaw) was to use a forstner bit and some power sanding, as per this Youtube video ...... https://www.youtube.com/watch?v=18PP0XY8X2s

One thing that I've learnt is that plywood seems to make the strongest knobs. I laminate a few scraps of ply to get the thickness I need. Knobs made from hoop pine (my first attempts) all broke, or the threaded inserts tore out, relatively easily. I also made one using forest red gum - it was hard as blazes to drill and sand, but it also seemed to be fairly strong.

Hope those ideas help.

Regards,

RoyG

if you're worried about areas of short grain breaking off in use, I suggest you look at laminating the blank with alternating grain

given the tools I have access to I'd be inclined to rough out the shape on a bandsaw with a narrow blade and then finish with rasps.

Does it have to be 5 pronged?

A3 spoke Mercedes star would give plenty of grip with a strong centre.

If it has to be 5 then band/jig saw a circle and mark the indentations. Then set up a coarse small sanding drum in a drill press a sand away what is not required.

Just a thought.

Thanks Bob, these arthritic thumbs would probably cope better with the 3 spoke handle, so will do a rough drawing to get an idea of the required circle diameters