Wood breakout during turning

[mountain4don]

I am in the process of turning stair spindles out of oak. And at the ends of the turned sections there is a sharp reduction in diameter from the 1.5" square stock. It has a very slight taper down to the rounded section. When turning these the wood has a tendancy to tear out along this line right at the surface of the square. Is there anything I can do to prevent this? My stock is 1.5" square and I need this full dimension in the finished spindle.

[terrydowning]

Oak is notorious for tear out due to it's open grain. SHARP Tools are a must. I recommend honing the edge before you start on these critical areas. Bumping the lathe speed up may help as well.

Also if you are talking about the transition from square to round.

A tip I have seen is to use a back saw and cut a kerf to the depth of your transition on the angles, and then tape the square areas with masking tape. I think I saw this on a sawdust session but I'm not certain. Disclaimer, I have not tried this personally.

Best of luck Don.

[RobertTaylor]

the only tool that will make that cut is a sharp skew

[fjimp]

I would never questions Bob's expertise on turning. I am certain he has far more experience than I have. Still I recently acquired a set of lathe chisels I like very much from Woodcraft. May I respectfully suggest taking a look at this video's found at this link.

http://www.woodcraft.com/product/2080216/30200/fullsize-detailer.aspx#ProdInformationTab

Jim

[SDSSmith]

I believe mountaindon is using the duplicator with the carbide inserts to make duplicate spindles. If he has not tried it already, I would try the diamond shaped carbide.

[RobertTaylor]

Jim, Rob, You guys are correct. I forgot about Mountain Don's earlier thread. I based my post on my experience turning childs tops and the handles go from square on the end to round. i use a skew to make that transition very quickly with no tearout. if i use a spindle gouge it does not go smoothly.

[mountain4don]

I believe mountaindon is using the duplicator with the carbide inserts to make duplicate spindles. If he has not tried it already, I would try the diamond shaped carbide.

You guys are not correct. I am not making stair spindles as in my prior questions. My wife is. I set her up with the Shopsmith with the lathe duplicator and gave her a big pile of spindle blanks all ready to clamp into the lathe with both ends all set up. But she is having some trouble at the ends of the transition from the rounded spindle out to the original square dimension. I will mount the diamond shaped cutter and have her try that. I also wondered about mounting the round cutter and using that to gouge out the larger areas of wood in the centers before changing to the diamond cutter for detailing?

[pennview]

Take a look at this you-tube video -- http://www.youtube.com/watch?v=LpBTx_1r4fQ on how to handle the transition. While the demonstrator is using hand-held tools and you are not, it may help with the understanding of what's happening and lead you to a different approach on working that transition point than using the duplicator exclusively.

Others have suggested using a saw or skew, and after watching that three minute clip you might want to give that a try. You can always lay out the transition points and then use the saw or skew to start the transition, and then switch to using the duplicating cutters. It may add an extra step or two, but you'll end up with less tear out.

You can always test the saw cut with the lathe off on some portion of the spindle where the turning is at it's narrowest diameter. If it doesn't work for you, nothing is lost since you'll simply carve that part of the spindle away anyhow.

[beeg]

Is she cutting WITH the grain or against it?

[mountain4don]

Is she cutting WITH the grain or against it?

The grain runs straight down the length of the spindle blank, and of course she is rotating the spindle blank with the cutter against it, so I guess she is cutting perpendicular to the grain. So not with the grain or against the grain. I am trying to figure out a jig to use a fine tooth saw to cut the square down to the diameter of the round section.