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V

Vigardo

Sat, Jan 23, 2021 11:17 AM

fouroh-llc wrote

...the dimensions are going to differ from the CAD data one particular
way.. when I print them horizontal the dimensions and the deviation from
CAD data going
to differ another way.
[...]
the dovetail should be printed according to deployment - surface, wall and
ceiling mount - so the dovetail
angle changes.

I think you would try to use and customize different tolerances for x/y axis
and for z-axis.

You already may have figured it out but in 3D printing z-axis errors differ
from those in x/y axis. The issue may be a bit complex since despite z-axis
positioning precision is typically higher, the surface of the dovetail would
be quite rough. To minimize this latter effect, you can reduce layer height
and/or use surface ironing:
https://blog.prusaprinters.org/make-top-surfaces-super-smooth-ironing-prusaslicer-2-3-beta_41506/

--
Sent from: http://forum.openscad.org/

fouroh-llc wrote > ...the dimensions are going to differ from the CAD data one particular > way.. when I print them horizontal the dimensions and the deviation from > CAD data going > to differ another way. > [...] > the dovetail should be printed according to deployment - surface, wall and > ceiling mount - so the dovetail > angle changes. I think you would try to use and customize different tolerances for x/y axis and for z-axis. You already may have figured it out but in 3D printing z-axis errors differ from those in x/y axis. The issue may be a bit complex since despite z-axis positioning precision is typically higher, the surface of the dovetail would be quite rough. To minimize this latter effect, you can reduce layer height and/or use surface ironing: https://blog.prusaprinters.org/make-top-surfaces-super-smooth-ironing-prusaslicer-2-3-beta_41506/ -- Sent from: http://forum.openscad.org/

RW

Ray West

Sat, Jan 23, 2021 1:51 PM

On 23/01/2021 01:22, fouroh-llc wrote:

2.) Print: to allow the dovetail to work, the layers must be aligned -
mating surfaces with creases from the layers are sticking and noisy, but
after sanding them smooth the dimension also changes.

That's why dovetails have adjustable gibs. \ ///

Maybe you need to tune the printer/slicer to match the filament, and
keep to those settings, and the same filament of course. Petg is easier
to machine cf pla, but is usually more flexible. For lightweight
mechanisms filled petg is available, and the ender 5 can handle that,
but best with a hardened nozzle. If the idea is that others can
replicate the plastic parts, then as well as the stl file, you will need
to supply the source/type of the filament, and all the slicer/printer
settings, and mention the details of the finishing, and even then they
may not get it to work. Of course, an item designed for plastic often
needs to be different than one designed for metal, something to be aware
of if trying to prototype a working metal apparatus in plastic.

Best wishes,

Ray

On 23/01/2021 01:22, fouroh-llc wrote: > 2.) Print: to allow the dovetail to work, the layers must be aligned - > mating surfaces with creases from the layers are sticking and noisy, but > after sanding them smooth the dimension also changes. That's why dovetails have adjustable gibs. \\ /// Maybe you need to tune the printer/slicer to match the filament, and keep to those settings, and the same filament of course. Petg is easier to machine cf pla, but is usually more flexible. For lightweight mechanisms filled petg is available, and the ender 5 can handle that, but best with a hardened nozzle. If the idea is that others can replicate the plastic parts, then as well as the stl file, you will need to supply the source/type of the filament, and all the slicer/printer settings, and mention the details of the finishing, and even then they may not get it to work. Of course, an item designed for plastic often needs to be different than one designed for metal, something to be aware of if trying to prototype a working metal apparatus in plastic. Best wishes, Ray

T

Troberg

Sat, Jan 23, 2021 7:24 PM

adrianv wrote

You can manage this particular complexity by having your part modules
accept
a "slop" argument or arguments that specify how to vary the part size.

Yep, that's how I do it, but for another purpose. I design the parts as I
want them to come out, then I have a slim argument, which makes them
slightly smaller if true, so I can see where one part ends and another
begins on screen.

--
Sent from: http://forum.openscad.org/

adrianv wrote > You can manage this particular complexity by having your part modules > accept > a "slop" argument or arguments that specify how to vary the part size. Yep, that's how I do it, but for another purpose. I design the parts as I want them to come out, then I have a slim argument, which makes them slightly smaller if true, so I can see where one part ends and another begins on screen. -- Sent from: http://forum.openscad.org/

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