On 10/10/22 19:51, Robin Szemeti via Emc-users wrote:
Assuming you want to machine it rather than 3D print it, consider Tufnol.
https://www.theplasticshop.co.uk/tufnol-whale-brand-sheet-rod-tube.html
That looks interesting, until the amount of machining required to match
the weight of the printed version is figured in,
which is 50% or more air once the skin is removed, This piece is flying
weight, where every gram impacts
how fast it can be accelerated by a given amount of motor power. OOTB
this printer has a default max speed
of 60mm/second. Carefull application of both accel and jerk and its
working well at 350mm, but that is top speed
and takes over 200mm in a straight line to get up to that speed. And
another 200mm to get stopped again.
That time to accel/decel is apparently not figured in by any of the
slicers, and a 15 hour print turns into 2 or 3
days depending on the complexity of the part.
Two main factors limit the top speed, 1st being how fast the hot end can
melt the plastic so its available to the nozzle.
Exceed that and you don't get enough plastic. The other is the loss of
torque of a stepper as its sped up, the lack
of enough current due to the inductance when its being driven at the
higher speeds. A 3NM motor at 50 rpm
becomes a ,1NM motor at 1500 to 2000 rpms, My printed part is about half
the weight of the steel part I took out.
And it appears the warpage might be a one time re-adjust. I didn't have
to readjust after a 3 day job that wiped out a $30
spool of PETG+CF. I did have to reset the zero offset, about .2mm.
I've now made an improved version that shouldn't warp as easily but
changing that is a half day job and my round
tuit is in the dishwasher, ;o)>
Take care and stay well Robin.
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, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
