carved round box

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mdred68
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Joined: Tue Oct 30, 2018 5:51 am
Model of CNC Machine: axiom

carved round box

Post by mdred68 »

Hello everyone my name is Mark and I just bought aspire. I want to get started right away on some personalized Christmas gifts. I want to make some round boxes like the crab carved ones Andrew Pitts made. I was wondering what kind of clearances you need between the bottom and the rabbit on the lid. And does wood species make a difference. I was thinking black walnut, cherry, mahogany, or maple. Thanks for any help in advanced.

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adze_cnc
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Re: carved round box

Post by adze_cnc »

The problem with "rabbits" is that they never sit still long enough to measure the tolerances around them. They just hop away going about their bunny business.

The size of rebate, or rabbet as some say, is mostly determined by how tightly or loosely you want the lid to fit. And the wood might make a difference---pine is more forgiving than rock maple for example.

Perhaps you might want to look at various videos/articles (such as https://www.canadianwoodworking.com/pla ... rned-boxes) related to turning wooden boxes on a lathe in relation to lid tightness?

Steven

LittleGreyMan
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Re: carved round box

Post by LittleGreyMan »

Mark,

I'm not sure you'll get all the answers you'd like, but you will probably find valuable informations in "Box-making basics" by David M. Freedman, Taunton Press.

Steven, still chasing rabbits? :D
Best regards

Didier

W7 - Aspire 8.517

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TReischl
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Re: carved round box

Post by TReischl »

If you want to make lids that fit (a very subjective term in box making) the easiest way to go about it is to cut some samples and see what happens.

Cut the mortise in a scrap piece and then cut the tenon in a second scrap piece. See how they fit together.

A lot of factors determine "fit". The first is what you consider a good fit. Some folks want a fit that produces a sucking sound when the lid is removed. Others, not so much. Then there is the issue that the wood may distort or move a bit after or during cutting. What I am trying to say is that the test pieces will get you close, but if you are carving fairly deeply into a piece of wood and removing a lot of outer material things can move. So test pieces get you in the ball park. Another thing is that cutters do not always cut to their stated size or even their measured size due to things like spindle runout, flex, etc.

That is my two cents. Oh, and one more penny: Changes in humidity can make a tight fitting lid impossible to remove without brute force.
"If you see a good fight, get in it." Dr. Vernon Johns

wb9tpg
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Model of CNC Machine: Shapeoko 3 XL

Re: carved round box

Post by wb9tpg »

Having gone though this just recently I'll tell my experience.

I first test cut the lid and case the same size and measured it. On my Shapeoko the bottom measured bigger than the top even though they are the same size in Vcarve.

I then added a negative allowance to the top and experimented with various values. I found and allowance value of -0.015" on both the lid pocket and case lip gave me enough room for:

1) roundness - sometimes they are off a little.
2) finish - it adds thickness so don't forget about it.

I first bought it was too loose but it tightens up when you apply finish to both parts.
Gary Mitchell
Kentucky, USA

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