**Next message:**Michael Tsenter: "Re: architectural prototypes"**Previous message:**M. Burns (marshall@ennex.com): "Fabber prices"**In reply to:**Christopher Jelley: "Current RP System Prices"**Next in thread:**Floyd Roberts: "Re: Adaptive slicing problems."**Reply:**Floyd Roberts: "Re: Adaptive slicing problems."**Maybe reply:**C. Brock Rooney: "Re: Adaptive slicing problems."**Maybe reply:**Nkin@aol.com: "Re: Adaptive slicing problems."**Reply:**Peter de Jager: "Re: Adaptive slicing problems."**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ] [ attachment ]

Hi all;

My name is Ray Hope. I've been working on slicing procedures for layered

manufacturing, and am using layers with sloping boundary surfaces to

eliminate the stair case effect. I have recently been working on adaptive

slicing, and have come across some cases that can cause problems. So I

thought I should call on the greater collective knowledge of the group and

see if we can come up with some ideas.

Note I am obtaining the definition of parts from B-spline surfaces. Layer

error is approximated from the radius of curvature and angle of the

surface normal.

Problem 1.

Joins between two or more surfaces, and vertices can cause the error

approximation to give incorrect results. Previously published work (by

others) has tried to solve this problem by slicing the part so that the

surface joins coincide with layer joins. However this can only work if the

surface joins are in the same plane as the layers. In many cases where a

part is defined by two intersecting surfaces, the intersection curve is not

in the layer plane. So what do we do?

Problem 2.

The method mentioned above to predict the error, produces a predicted

error much less than the true value near inflection points. This is

because at an inflection point the curvature becomes zero, and is also very

small nearby. So how should we predict error near inflection points?

I look forward to hearing some interesting suggestion from all of you.

Thanks

Ray Hope

Department of Mechanical Engineering

The University of Queensland

Brisbane QLD 4072

AUSTRALIA

Ph +61 7 3365 4179

Home +61 7 3217 7410

Facsimile +61 7 3365 4799

Email: hope@mech.uq.edu.au

**Next message:**Michael Tsenter: "Re: architectural prototypes"**Previous message:**M. Burns (marshall@ennex.com): "Fabber prices"**In reply to:**Christopher Jelley: "Current RP System Prices"**Next in thread:**Floyd Roberts: "Re: Adaptive slicing problems."**Reply:**Floyd Roberts: "Re: Adaptive slicing problems."**Maybe reply:**C. Brock Rooney: "Re: Adaptive slicing problems."**Maybe reply:**Nkin@aol.com: "Re: Adaptive slicing problems."**Reply:**Peter de Jager: "Re: Adaptive slicing problems."**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ] [ attachment ]

*
This archive was generated by hypermail 2.1.2
: Tue Jun 05 2001 - 22:39:22 EEST
*