Tue Jul 9 02:49:56 EDT 2019

```I use 1/128 because it is a round number in floating point. 0.01 is a
recurring fraction. It probably doesn't make any difference in most cases,
but seems like a good idea.

an exact union, and then you rotated it and they came apart.

They would only possibly come apart if you rotate them individually before
the union. Rotating a unioned object should not break it, but it can
perturb the vertices and make flat plans no longer exactly flat.

On Tue, 9 Jul 2019 at 02:50, A. Craig West <acraigwest at gmail.com> wrote:

> I usually use a 0.01 unit overlap, it really doesn't need to be much
>
> On Mon, 8 Jul 2019, 21:38 Dan Shriver, <tabbydan at gmail.com> wrote:
>
>> Nate: it's not a pyramid, its a series of arched hallways.  The form of
>> the arch morphs between ogee and roman arch styles.   The o.  verall path
>> of 1/3 of the hallways is in the shape of an ogee arch.
>>
>> Once I finish with that I'll put in domes and decorative buttress works.
>>
>> an exact union, and then you rotated it and they came apart.  I am
>> wondering if I need to rethink how to make 1/3 of the archway.  Since I
>> intend to do it where I rotate it (and right now I'm using a box to exactly
>> saw off what is in the next octant), I am thinking that for the ones I
>> rotate I need to shift the bounding box so there is more overlap.  But how
>> much do I need?  1 unit, 0.5 units????  Any ideas?
>>
>> On Mon, Jul 8, 2019 at 4:22 PM NateTG <nate-openscadforum at pedantic.org>
>> wrote:
>>
>>> DanS wrote
>>> > Nate: what I was asking in the original post was how to take 1/6th of
>>> the
>>> > hallway design my head and make 1/3.  So yes it is a mirror operation.
>>> > The
>>> > best way to eliminate the stuff that overlapped the next octant turned
>>> out
>>> > to be using a box.
>>> >
>>> > After that I take that whole shape and need to displace it and rotate
>>> it
>>> > by
>>> > 120 (I need to do that twice).
>>>
>>> So you're trying to make something like a triangular pyramid but with
>>> ogee
>>> profiles?
>>>
>>>
>>>
>>>
>>>
>>> --
>>>
>>> _______________________________________________
>>>
>> _______________________________________________