BOSL - make threaded_rod and threaded_nut fit
I print this BEFORE I print the model with slicer setting and all that.. I
adjust the radius until they are snug, and I press-fit, then I just grab the
script (without the bounding plane). I am not a programmer, I do not create
fancy "reusable script". When I move to a different printer (I have Ender 3s
and 5s) I test print again, and adjust. Then I save the entire model script.
Inefficient I know, but this is the best I can do.
Cheers!
Mr. Sandor Kunyik
Founder, Technology Evangelist
Factory 4.0 Open Initiative, LLC.
https://hubzilla.factoryfouroh.net/channel/fouroh-llc
Sent from: http://forum.openscad.org/
On 25/02/2021 21:48, adrianv wrote:
How do you print a go/no-go gauge when your printer might be
overextruding and printing inaccurately? It seems like you need to
get such a gauge from another source with guaranteed precision, and
then you can use it to test printed parts.
Hi,
It depends. For example, I have often not bothered with printing
threads, I use taps and dies, as for metal parts - you have be sure that
you have thick enough walls to cut the threads. If you calibrate your
printer to your material, then for coarse threads of, say, half inch and
greater diameter, then you will, with experience learn the tolerances to
apply, there are plenty of test pieces on thingiverse, for example, to
get an idea for the values for you printer. Generally a hole will print
'small' and a shaft will print 'big'. Different materials behave
differently, so chose the plastic that will do the job, and if it is
critical, stick to that for future jobs, else you will have to work it
out again. I'm not sure where 3d printed threads would be desirable, I
use self-tapping screws to fasten the plastic parts together. I suppose
if the filament was being used as a pattern for metal casting, then it
may be beneficial to get a representation of a thread, but the metal
would most likely be machined afterwards. I'm guessing you're using a
diy/home fdm printer - Prussa, Creality, whatever. If the print is to
show a prototype design, then provided the nut does not fall off the
'threaded bolt, then that will most likely do. The thing is, you need to
spend a fair amount of time tuning your printer to match the filament to
get optimum results, and even then the results will be pretty useless
for 'serious fasteners', but good enough for light duties I suppose -
and then the next reel of filament will most likely behave differently.
Best wishes,
Ray
https://www.youtube.com/watch?v=iR6OBlSzp7I&vl=ru
has tests of different ways to screw printed parts together.
He uses destructive tests to measure the strength required to pull the
parts apart as well as the torque required to strip the threads by
over-torquing the bolts.
He has other videos of tests in this area using other methods and
different plastics.
You also have to consider how often you will screw and unscrew the
parts. Plastic by itself will eventually wear away the threads
regardless of how you make the threads. Metal inserts do not have this
problem.
Ron
On 2021-02-26 7:17 a.m., Ray West wrote:
On 25/02/2021 21:48, adrianv wrote:
How do you print a go/no-go gauge when your printer might be
overextruding and printing inaccurately? It seems like you need to
get such a gauge from another source with guaranteed precision, and
then you can use it to test printed parts.
Hi,
It depends. For example, I have often not bothered with printing
threads, I use taps and dies, as for metal parts - you have be sure
that you have thick enough walls to cut the threads. If you calibrate
your printer to your material, then for coarse threads of, say, half
inch and greater diameter, then you will, with experience learn the
tolerances to apply, there are plenty of test pieces on thingiverse,
for example, to get an idea for the values for you printer. Generally
a hole will print 'small' and a shaft will print 'big'. Different
materials behave differently, so chose the plastic that will do the
job, and if it is critical, stick to that for future jobs, else you
will have to work it out again. I'm not sure where 3d printed threads
would be desirable, I use self-tapping screws to fasten the plastic
parts together. I suppose if the filament was being used as a pattern
for metal casting, then it may be beneficial to get a representation
of a thread, but the metal would most likely be machined afterwards.
I'm guessing you're using a diy/home fdm printer - Prussa, Creality,
whatever. If the print is to show a prototype design, then provided
the nut does not fall off the 'threaded bolt, then that will most
likely do. The thing is, you need to spend a fair amount of time
tuning your printer to match the filament to get optimum results, and
even then the results will be pretty useless for 'serious fasteners',
but good enough for light duties I suppose - and then the next reel of
filament will most likely behave differently.
Best wishes,
Ray
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
--
Ron Wheeler
Artifact Software
438-345-3369
rwheeler@artifact-software.com
You start with "it depends" but never said anything about the idea of
printing go/no-go gauges. Printing threads that work is different (and much
easier) than printing a go/no-go gauge.
If you want to suspend a 100 kg weight then plastic printed parts are
obviously the wrong solution. But I did not find it at all difficult to get
reasonable behaving threads from my Prusa. I did not find that it took a
large amount of time to figure out working designs. I printed female pipe
threads so I could mount a light weight object to the ceiling and it seems
quite sturdy. And in this case due to the taper, every tolerance adjustment
I tested worked---they just wedged at different engagement depths. It's
also evidently possible to make the threads substantially stronger on an FDM
printer by orienting the threads sideways (e.g. print threaded rod lying
down). I figured if my thing fell off the ceiling I'd figure out a more
robust mounting approach, but I think failure is unlikely.
mondo wrote
On 25/02/2021 21:48, adrianv wrote:
How do you print a go/no-go gauge when your printer might be
overextruding and printing inaccurately? It seems like you need to
get such a gauge from another source with guaranteed precision, and
then you can use it to test printed parts.
Hi,
It depends. For example, I have often not bothered with printing
threads, I use taps and dies, as for metal parts - you have be sure that
you have thick enough walls to cut the threads. If you calibrate your
printer to your material, then for coarse threads of, say, half inch and
greater diameter, then you will, with experience learn the tolerances to
apply, there are plenty of test pieces on thingiverse, for example, to
get an idea for the values for you printer. Generally a hole will print
'small' and a shaft will print 'big'. Different materials behave
differently, so chose the plastic that will do the job, and if it is
critical, stick to that for future jobs, else you will have to work it
out again. I'm not sure where 3d printed threads would be desirable, I
use self-tapping screws to fasten the plastic parts together. I suppose
if the filament was being used as a pattern for metal casting, then it
may be beneficial to get a representation of a thread, but the metal
would most likely be machined afterwards. I'm guessing you're using a
diy/home fdm printer - Prussa, Creality, whatever. If the print is to
show a prototype design, then provided the nut does not fall off the
'threaded bolt, then that will most likely do. The thing is, you need to
spend a fair amount of time tuning your printer to match the filament to
get optimum results, and even then the results will be pretty useless
for 'serious fasteners', but good enough for light duties I suppose -
and then the next reel of filament will most likely behave differently.
Best wishes,
Ray
OpenSCAD mailing list
Discuss@.openscad
--
Sent from: http://forum.openscad.org/
https://www.youtube.com/watch?v=G-UF4tv3Hvc
This shows some very impressive results with M3 bolts in Prusa PLA that
was not very thick.
Suspending a 100Kg load would not seem to be a problem with or without
inserts.
Screwing directly into plastic is a problem if you have to repeatedly
reattach the parts and you have to be careful about over-torquing the bolt.
With inserts, some are better than others but in the torque tests, the
head snapped off the bolt before the insert started to spin in its mount.
It stands to reason that the larger bolt sizes would be capable of
holding larger weights and the bolts should be capable of withstanding
more torque.
He also comments on infill percentage since that also makes a difference.
The video starts with a short discussion about how to test your PLA and
printer to determine how to size holes in your designs that match what
you want.
He also did some videos testing with materials other than PLA and tests
with washers and nuts.
https://www.youtube.com/watch?v=2wRc1KbEAU8 discusses other ways to
attach bolts to PLA.
On 2021-02-26 4:19 p.m., adrianv wrote:
You start with "it depends" but never said anything about the idea of
printing go/no-go gauges. Printing threads that work is different
(and much easier) than printing a go/no-go gauge.
If you want to suspend a 100 kg weight then plastic printed parts are
obviously the wrong solution. But I did not find it at all difficult
to get reasonable behaving threads from my Prusa. I did not find
that it took a large amount of time to figure out working designs. I
printed female pipe threads so I could mount a light weight object to
the ceiling and it seems quite sturdy. And in this case due to the
taper, every tolerance adjustment I tested worked---they just wedged
at different engagement depths. It's also evidently possible to make
the threads substantially stronger on an FDM printer by orienting the
threads sideways (e.g. print threaded rod lying down). I figured if
my thing fell off the ceiling I'd figure out a more robust mounting
approach, but I think failure is unlikely.
mondo wrote
On 25/02/2021 21:48, adrianv wrote:
How do you print a go/no-go gauge when your printer might be
overextruding and printing inaccurately? It seems like you need to
get such a gauge from another source with guaranteed precision, and
then you can use it to test printed parts.
Hi,
It depends. For example, I have often not bothered with printing
threads, I use taps and dies, as for metal parts - you have be
sure that
you have thick enough walls to cut the threads. If you calibrate your
printer to your material, then for coarse threads of, say, half
inch and
greater diameter, then you will, with experience learn the
tolerances to
apply, there are plenty of test pieces on thingiverse, for
example, to
get an idea for the values for you printer. Generally a hole will
print
'small' and a shaft will print 'big'. Different materials behave
differently, so chose the plastic that will do the job, and if it is
critical, stick to that for future jobs, else you will have to
work it
out again. I'm not sure where 3d printed threads would be
desirable, I
use self-tapping screws to fasten the plastic parts together. I
suppose
if the filament was being used as a pattern for metal casting,
then it
may be beneficial to get a representation of a thread, but the metal
would most likely be machined afterwards. I'm guessing you're using a
diy/home fdm printer - Prussa, Creality, whatever. If the print is to
show a prototype design, then provided the nut does not fall off the
'threaded bolt, then that will most likely do. The thing is, you
need to
spend a fair amount of time tuning your printer to match the
filament to
get optimum results, and even then the results will be pretty useless
for 'serious fasteners', but good enough for light duties I suppose -
and then the next reel of filament will most likely behave
differently.
Best wishes,
Ray
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Artifact Software
438-345-3369
rwheeler@artifact-software.com