Balsa Wood - Cutting Shapes

[maxv]

Does anyone have experience cutting curved shapes out of balsa? I am trying to cut some circular shapes out of 1 x 2 planks, and when cutting across the end grain, the balsa gets very 'chewed up'. I have tried making a rough cut pass and then coming back to trim off the final 1/32 inch. This helps, but it is still rough. I am using a 1/4 plunge bit (2 flute) from Amana, running about 15,000 RPM. The direction of the cut doesn't seem to matter.


Is there another technique, or router bit type that would work better for very soft wood like this?

[gus]

Try a down cut bit if you have one and see what happens. I have had luck with that in other problem woods.

[rick_woodward]

Page 109 in Woodcraft catalog shows double cut carbide burrs set. I have bought these individually from welding supply stores. In power carving, bits similar to these are called stump cutters. They are aggresive yet give a smooth finish. I was looking for 1/4" shank coarse diamond bits for you but cannot remember where i seen them. Balsa is so soft and fragile i think the key is a continous cutting surface. Test for optimal rpm, feed speed and stepdown.

[trakwebster]

This may be a real dumb idea ... but would it be possible to 'sandwich' the balsa between sheets of some other (expendable) material?

(I'm imagining that if the balsa was stabilized by a bit of pressure above and below, perhaps it wouldn't move so wiggly with the bit. Just an idea. Maybe a silly one.)

[gwilson]

Arthur
I also do fret work with a scrollsaw and to help support the main wood I work on layering is how I do it. Even with hardwoods when they get really thin, the inside can break when cutting. But if you layer the wood for support you get less breakage and nicer edges when main wood in the middle layer.
Hope it helps.
Gerald W.

[rg_engravers]

I have done 1000s of fret patterns and have used hairspray to hold 1/8 to 1/4 material in place, Try using hot glue too.
just apply it to some scrap material so you do not dammage your table.

Ron

[knight_toolworks]

the wood is pretty soft of course it likes sharp tools. I would go for a higher rpm and maybe a 4 flute bit if you have it.