square wood into a round hole

[Mahogany_Rush]

I need to take a 3 inch square board and cut it to where I don't need to sand so much to make it round. I don't have a lathe and can't convince SWMBO that this is only the beginning and I really need a lathe. I can only think of 4 cuts at 45 deg. Is there another cut I could make to shave even more sanding off. I could even use my jointer if you have a better idea than the BT3K. I think I have over thought this one out and now nothing makes sense. Thanks
Jim

[LCHIEN]

I need to take a 3 inch square board and cut it to where I don't need to sand so much to make it round. I don't have a lathe and can't convince SWMBO that this is only the beginning and I really need a lathe. I can only think of 4 cuts at 45 deg. Is there another cut I could make to shave even more sanding off. I could even use my jointer if you have a better idea than the BT3K. I think I have over thought this one out and now nothing makes sense. Thanks
Jim

everything has tolerances. You don't say how close you want to get it to round, without using a lathe. How close do you want it or need it to be?

If you rip off four 45° corners to make it an octagon, the remaining sides will probably be flat enouh to bevel it one more time (tilt the blade 22.5&#176 and do it on the original 8 sides so that one side rests against the table and the other side rests against the rip fence (and the blade tilted away from the fence). I'd mark the original 8 sides (number them 1-8) because by the time I reached the 7th or 8th side to rip the board will now have 15 sides to choose from.

With 16 sides it will be pretty close to being round, again this depends upon your requirements.

When you bevel rip the first time to make it an octagon, you will need to set the right rip width to make it a perfect octagon. Later, when you make the next 8 rips to make a hexadecigon (16 sides) you'll need to set the proper width again. Do you know how to do this or did you forget your high school trigonometry? If you don't do this right then you will end up with a square board that looks like you just beveled the corners.

[venkatbo]

If you have a router, you may be able to do circular cuts using a jig. Cut deeper and deeper each traversal..

Also, I've seen some vendor provide a sanding sheet mounted as a blade in a TS, then you basically have a circular sander... After you get it close to a circle as Loring suggests, you can sand off the protrusions - can draw an internal reference circle first, with a pencil.

Better yet, you may be ble to convince zMrs to get you 'more tools' just so you can 'preserve' your digits.... using a TS on a 3" square is too close for comfort, I think

/venkat

[DaveW]

If you have a router, you may be able to do circular cuts using a jig. Cut deeper and deeper each traversal..

Another alternative is to make the rough cut using a jig saw (as close to the line as possible, and one pass with the router/jig.

[Mahogany_Rush]

Thanks everyone, I did briefly think about 45 deg and then 22.5 deg cuts but like I said I over thought it. It is going to be the top rail to a sleigh bed for my daughter and perfectly round is not needed. I think I'll TS 45's then 22.5's and make a jig to roll it across the router. That was something I never thought of but have seen some reference to it on this site for pen turning. You guys are the best. I just wish I could get a new tool out of this some how. LOL. Thanks again
Jim

[jhart]

You might think about using a 3" or 3 1/4" hole saw to cut the basic shape. Not too expensive if you have to buy it

[Tom Miller]

I don't have a lathe and can't convince SWMBO that this is only the beginning and I really need a lathe.

You definitely do not need a lathe to do this.





A nice new bandsaw would do fine.

Regards,
Tom

[guycox]

If this were larger you "could" use the table saw

I need to take a 3 inch square board and cut it to where I don't need to sand so much to make it round. I don't have a lathe and can't convince SWMBO that this is only the beginning and I really need a lathe. I can only think of 4 cuts at 45 deg. Is there another cut I could make to shave even more sanding off. I could even use my jointer if you have a better idea than the BT3K. I think I have over thought this one out and now nothing makes sense. Thanks
Jim

My table saw book shows a jig for actually making a circle on a table saw.. I don't think I'd try it on a 3" diameter circle.

It's too small for a router.

Drum sander on a drill press and pivot pin might be the best bet.. A wolfcraft portable drill holder would work.

[LCHIEN]

My table saw book shows a jig for actually making a circle on a table saw.. I don't think I'd try it on a 3" diameter circle.

It's too small for a router.

Drum sander on a drill press and pivot pin might be the best bet.. A wolfcraft portable drill holder would work.

Guy, he's not making a "disk", he's making a "pole".

[Mahogany_Rush]

I cut the board at 45 deg and then again with 22.5 deg. It worked great. and actually I didn't sand it down as round as I could. The shape and feel of the rail looked great with some of the flat spots left in. Very subtle but it added an old world or primitive look to it that is really cool. It looks perfectly round till you get really close or touch it. And the grain of the maple is fantastic on that piece. The small flat spots add some different patterns that I think I would have lost if ot had been perfectly round. Thanks for all the help.
Jim