flexible plastic
You are right of course Michael. My apologies.
Cheers, Gene Heskett
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page http://geneslinuxbox.net:6309/gene
Isn't TPU another name for that?
No TPU is like rubber. Polypropylene is what some food container lids are
made from, e.g. Tupperware. Unlike TPU it is quite slippery, like
polyethylene, and it can't be glued easily.
To print it I used a sticky back PP sheet stuck to a sheet of glass as it
only really sticks to itself. This is a cap I made for a triangular tube
that held my glasses on my belt.
[image: IMG_20210630_141207417.jpg]
I have a chopping board made from PP that I will try printing on next time
as the sheet got welded to the part and ripped up. The trick is to do the
first layer a bit high to reduce adhesion.
On Wed, 30 Jun 2021 at 13:46, Gene Heskett gheskett@shentel.net wrote:
You are right of course Michael. My apologies.
Cheers, Gene Heskett
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page http://geneslinuxbox.net:6309/gene
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Gene:
Printing with TPU and its variants is challenging, but not impossible.
Having the right printer configuration (direct drive with no gaps in the
filament path after the drive gears) helps, but it can be printed using
a Bowden tube. One important issue is keeping the extruder stepper
motor (and the drive gear that is attached to that motor) cool enough
that the filament does not soften and fail to be extruded properly. My
frustration with soft filaments ended once I pointed a pedestal fan at
the printer from about 4 feet away during the print.
There are a lot of different choices out there (see NinjaTek's NinjaFlex
and Cheetah, or MatterHacker's SoftPLA, for example), with different
printing difficulties (SoftPLA is dead easy) and levels of flexibility.
PLA is very flexible when printed in two layers, so scale is important.
NinjaFlex and Cheetah are very flexible if printed with small infill and
minimal external shells, but if printed more densely or for larger parts
can become very close to rigid. The material you choose depends on the
details of the part you are trying to create.
I have found Cheetah to be both flexible and indestructible: a printed
two layer sheet is essentially impossible to tear apart, although it can
be made to deform slightly.
I hope this helps.
Jon
On 6/30/2021 8:45 AM, Gene Heskett wrote:
You are right of course Michael. My apologies.
Cheers, Gene Heskett
nophead:
Can you reduce post-printing part adhesion through use of hair spray or
glue stick? Sometimes the parts pop off after the bed cools; if not,
then a quick rinse under water can dissolve the hair spray or glue
between the part and the bed.
Jon
On 6/30/2021 9:19 AM, nop head wrote:
Isn't TPU another name for that?
No TPU is like rubber. Polypropylene is what some food container lids
are made from, e.g. Tupperware. Unlike TPU it is quite slippery, like
polyethylene, and it can't be glued easily.
To print it I used a sticky back PP sheet stuck to a sheet of glass as
it only really sticks to itself. This is a cap I made for a triangular
tube that held my glasses on my belt.
IMG_20210630_141207417.jpg
I have a chopping board made from PP that I will try printing on next
time as the sheet got welded to the part and ripped up. The trick is
to do the first layer a bit high to reduce adhesion.
Not sure if PP would stick to glue stick because it is one of those plastic
that you can't glue. However, the sticky back film must use a glue that
sticks to it.
TPU is totally unsuitable for a spline because it is an elastomer, so it
stretches and squashes. I saw a video from Jame Bruton where he made a
harmonic drive from it but it was very lossy and easily slipped. You want
something hard that will bend like spring steel.
Most hard plastics will bend when thin but they will break if you flex them
backwards and forwards hundreds of times. PP will flex forever I think and
doesn't stretch or squash like TPU. It isn't particularly hard though, so
might wear away at the teeth. It should be low friction though, which will
mitigate that.
On Wed, 30 Jun 2021 at 14:32, jon jon@jonbondy.com wrote:
nophead:
Can you reduce post-printing part adhesion through use of hair spray or
glue stick? Sometimes the parts pop off after the bed cools; if not, then
a quick rinse under water can dissolve the hair spray or glue between the
part and the bed.
Jon
On 6/30/2021 9:19 AM, nop head wrote:
Isn't TPU another name for that?
No TPU is like rubber. Polypropylene is what some food container lids are
made from, e.g. Tupperware. Unlike TPU it is quite slippery, like
polyethylene, and it can't be glued easily.
To print it I used a sticky back PP sheet stuck to a sheet of glass as it
only really sticks to itself. This is a cap I made for a triangular tube
that held my glasses on my belt.
[image: IMG_20210630_141207417.jpg]
I have a chopping board made from PP that I will try printing on next time
as the sheet got welded to the part and ripped up. The trick is to do the
first layer a bit high to reduce adhesion.
Hi Gene,
I would try Petg, - If you can print pla, petg is not too difficult. You
need to print some tests to set retraction, etc, but depending on what
slicer you have, there will be temperature towers, stringing tests, etc.
built in, or easily added. There are various grades of tpu, but as Nop
head mentions, that is not you want. wrt fora, I have found the various
discords (found via octoprint) to have some very knowledgable and
helpful/patient folk. I've not used the 3d printing one, per se., (not
sure if this link will work for you
https://discord.com/channels/167661427862142976/339862027789008898 )
Nylon absorbs water, and you really need a heated chamber to print it
and generally higher temperatures all round. If you want springiness,
then you could embed a few circles of piano wire into the print.
On Wednesday 30 June 2021 09:19:58 nop head wrote:
Isn't TPU another name for that?
No TPU is like rubber. Polypropylene is what some food container lids
are made from, e.g. Tupperware. Unlike TPU it is quite slippery, like
polyethylene, and it can't be glued easily.
Sounds like it might be worth looking into so I ordered a roll and its
matching glue stick from MatterHackers.
To print it I used a sticky back PP sheet stuck to a sheet of glass as
it only really sticks to itself. This is a cap I made for a triangular
tube that held my glasses on my belt.
I wasn't able to find one of those, this CR-10S Pro V2 has the dark grey
textured, sorta like polycarbonate cover on a heavy alu sheet. BLT scans
it in 25 places before every print. And that part works really well.
[image: IMG_20210630_141207417.jpg]
Thanks nop head.
Cheers, Gene Heskett
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page http://geneslinuxbox.net:6309/gene