Shelled Mini-Mendel

My printer is working again and I´m currently trying out the
Hollowed Mini-Mendel I designed.
[www.thingiverse.com]

I plan on filling the printed parts with Epoxy.
If all goes well it should be possible to print a Mini-Mendel in one day and then fill it with epoxy in a matter of minutes to get strong, good parts.
The idea is to save a lot of time, material and warping with using the epoxy as a trivial post-production step. Thus it could be possible to supply the enourmous
demand for mendel-parts by producing mini-mendels not one at a time but in actual
batches and thus enabling people to print the parts for their full mendels themself.

Edited 2 time(s). Last edit at 04/25/2010 10:45AM by MarcusWolschon.

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First print:

frame-vertex_6off 1x with raft
* single shelled object
* The total build time is 860 s = 14min.
* The total distance extruded is 15668.4 mm.
* The total distance traveled is 20595.5 mm.
* The volume extruded is 3.1 cc.

frame-vertex_6off 6x without raft
* single-shelled object
* The total build time is 3213s = 53min for 6 frame-vertex.
* The total distance extruded is 72765.3 mm.
* The total distance traveled is 102804.9 mm.
* The version is 2010-02-12
* The volume extruded is 14.3 cc.

frame-vertex_6off 6x with raft
* layer-height=0.30mm
* movement-rate: 32mm/s (feeding the RepMan with 105RPM=58.8mm/s of filament at 228°C)
* The total build time is 4517s = 1h 15min for 6 frame-vertex.
* The total distance extruded is 86640.6 mm.
* The total distance traveled is 118304.3 mm.
* The version is 2010-02-12
* The volume extruded is 17.0 cc.

(I´ll update this posting once the print is done.)

Result:
* prints super-fast
* despite being single-shelled this object is incredibly strong.
* I´ll do the next print without raft
* a small raft is still required on my printer with ABS and 238°C

Edited 6 time(s). Last edit at 04/25/2010 10:48AM by MarcusWolschon.

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Skeinforge-results for:
* layer-height=0.40mm
* 5mm/2% raft-size
* movement-rate: 32mm/s
* feeding the RepMan with 105RPM=58.8mm/s of filament at 228°C


base-reinforcement-clamp_2 (x1 with raft)
* The total build time is 150 s.
* The total distance extruded is 2463.0 mm.
* The total distance traveled is 3667.2 mm.
* The version is 2010-02-12
* The volume extruded is 0.48 cc.

bowden-extruder-base-clamp (x1 with raft)
* The total build time is 224 s.
* The total distance extruded is 4211.2 mm.
* The total distance traveled is 5568.2 mm.
* The version is 2010-02-12
* The volume extruded is 0.83 cc.

extruder-bracket-bowden_1off (x1 with raft)
* The total build time is 687 s.
* The total distance extruded is 14051.6 mm.
* The total distance traveled is 17399.4 mm.
* The version is 2010-02-12
* The volume extruded is 2.8 cc.

frame-vertex_6off 6x with raft
* The total build time is 4517s = 1h 15min for 6 frame-vertex.
* The total distance extruded is 86640.6 mm.
* The total distance traveled is 118304.3 mm.
* The version is 2010-02-12
* The volume extruded is 17.0 cc.

pinch-wheel-bracket-603-nema17-bowden (x1 with raft)
* The total build time is 1396 s.
* The total distance extruded is 30657.1 mm.
* The total distance traveled is 39398.7 mm.
* The version is 2010-02-12
* The volume extruded is 6.0 cc.

x-180-bearing-clamp_2off (x2 with raft)
* The total build time is 1146s = 19min for all 2 copies
* The total distance extruded is 23932.8 mm.
* The total distance traveled is 31265.2 mm.
* The version is 2010-02-12
* The volume extruded is 4.7 cc.

x-axis-clamp_4off (x4 with raft)
* The total build time is 2491s = 41min for all 4 copies
* The total distance extruded is 50645.9 mm.
* The total distance traveled is 68159.0 mm.
* The version is 2010-02-12
* The volume extruded is 9.9 cc.

x-bar-clamp_1off (x1 with raft)
* The total build time is 365 s.
* The total distance extruded is 6642.9 mm.
* The total distance traveled is 8904.0 mm.
* The version is 2010-02-12
* The volume extruded is 1.3 cc.

x-bearing-clamp_2off (x2 with raft)
* The total build time is 1683s = 28min for all 4 copies
* The total distance extruded is 33755.2 mm.
* The total distance traveled is 47510.8 mm.
* The version is 2010-02-12
* The volume extruded is 6.6 cc.

x-carriage-lower-left_1off (x1 with raft)
* The total build time is 551 s.
* The total distance extruded is 11418.9 mm.
* The total distance traveled is 15074.5 mm.
* The version is 2010-02-12
* The volume extruded is 2.2 cc.

x-carriage-upper_1off (x1 with raft)
* The total build time is 1453 s.
* The total distance extruded is 28966.4 mm.
* The total distance traveled is 39353.2 mm.
* The version is 2010-02-12
* The volume extruded is 5.7 cc.

x-motor-end-clamp_1off (x1 with raft)
* The total build time is 1000 s.
The total distance extruded is 19570.9 mm.
The total distance traveled is 25194.9 mm.
The version is 2010-02-12
The volume extruded is 3.8 cc.

y-bar-clamp-4off (x4 with raft)
* The total build time is 860s =14minfor all 4 copies.
* The total distance extruded is 16763.3 mm.
* The total distance traveled is 23432.1 mm.
* The version is 2010-02-12
* The volume extruded is 3.3 cc.

y-bearing-180 (x1 with raft)
* The total build time is 545 s.
* The total distance extruded is 12551.1 mm.
* The total distance traveled is 14921.8 mm.
* The version is 2010-02-12
* The volume extruded is 2.5 cc.

y-bearing-360-bracket1 (x1 with raft)
* The total build time is 454 s.
* The total distance extruded is 8771.5 mm.
* The total distance traveled is 11712.0 mm.
* The version is 2010-02-12
* The volume extruded is 1.7 cc.

y-belt-nut-trap (x1 with raft)
* The total build time is 209 s.
* The total distance extruded is 3892.9 mm.
* The total distance traveled is 5044.8 mm.
* The version is 2010-02-12
* The volume extruded is 0.76 cc.

y-chassis2_2 (x1 with raft)
* The total build time is 2629 s.
* The total distance extruded is 53305.7 mm.
* The total distance traveled is 63750.3 mm.
* The version is 2010-02-12
* The volume extruded is 10.5 cc.


y-motor-bracket (x1 with raft)
* The total build time is 1014 s.
* The total distance extruded is 20928.6 mm.
* The total distance traveled is 26416.4 mm.
* The version is 2010-02-12
* The volume extruded is 4.1 cc.


z-bar-top-clamp_2 (x1 with raft)
* The total build time is 371 s.
* The total distance extruded is 7196.6 mm.
* The total distance traveled is 9214.2 mm.
* The version is 2010-02-12
* The volume extruded is 1.4 cc.


z-leadscrew-base-tensioner_2 (x1 with raft)
* The total build time is 3256 s.
* The total distance extruded is 83453.3 mm.
* The total distance traveled is 94879.6 mm.
* The version is 2010-02-12
* The volume extruded is 16.4 cc.


Total
* 35977 seconds = 9h 59min 37 seconds for a complete Mini-Mendel
* 101.97 cubic centimeter of material = 110 gramm ob ABS
Can anyone compare this to the regular MiniMendel and the regular Mendel please?

Edited 5 time(s). Last edit at 04/25/2010 12:54PM by MarcusWolschon.

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If you are feeding at 58.8 mm/s, why are you only moving at 32mm/s. Surely you should be able to do the moves at least as fast as the feeds. That might get the time down so you can print 3 a day ;-)

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[www.hydraraptor.blogspot.com]

nophead Wrote:
-------------------------------------------------------
> If you are feeding at 58.8 mm/s, why are you only
> moving at 32mm/s. Surely you should be able to do
> the moves at least as fast as the feeds. That
> might get the time down so you can print 3 a day
> ;-)

[sourceforge.net]

I tried 55mm/s but the extrusion-width was getting irregular with 350RPM really pushing it.
55mm/s is also the fastest known print on a RepMan at the moment.

I will try >32mm/s again but at the moment the ratio of print-quality vs. speed
is fine.

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I am confused. At the top of your print it says 105RPM = 58.8 mm/s so I assume the timings are based on that. But you say you can only extrude up to 55mms and that is 350RPM?

What I was trying to point out is that the numbers at the top imply that you move faster while extruding than you do when moving in between. Normally moves are at least as fast as extrusion and normally a lot faster.

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[www.hydraraptor.blogspot.com]

nophead Wrote:
-------------------------------------------------------
> I am confused. At the top of your print it says
> 105RPM = 58.8 mm/s

I am running the extruder at 115RPM=64,7mm/s of raw 3mm+-0.1mm diameter filament
while the head moves with 32mm/s laying an 0.4mm high and
0.7mm wide stream of extruded filament. (sorry, I just had a look
at the display and it´s 115, not 105.)

Update: Now it´s down to the regular 105RPM=58,8m/s . It was extruding faster during the interface-layer.

> so I assume the timings are
> based on that. But you say you can only extrude up
> to 55mms and that is 350RPM?

350RPM is the RPM for the extruder that I ended up with
in calibrating a movement-rate of 55mm/s to still get the 0.7mm
extruded width at 0.4mm layer-height.

> What I was trying to point out is that the numbers
> at the top imply that you move faster while
> extruding than you do when moving in between.

movement-rate and filament-feed rate do not form a
linear relationship (think space of a circle vs. space of an elypsis to get the actual relationship).
It´s 2 very different things being moved there.

> Normally moves are at least as fast as extrusion
> and normally a lot faster.
Well, these are the numbers that the display tells me.
I guess the mm/s being calculated from the RPM are not in any way
accurate. (firmware 1.0.9)

Edited 2 time(s). Last edit at 04/25/2010 02:19PM by MarcusWolschon.

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The print is done.

The actual parts including rafts weight just 152g (white ABS).
That´s half of the MiniMendel and 1/7th of the Mendel.
All printed in a single afternoon and a single morning.

The printed parts are on sale here:
[forums.reprap.org]

Edited 1 time(s). Last edit at 04/26/2010 05:05AM by MarcusWolschon.

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Hi Marcus,

... have you already tried with infilling the parts with some 2K-epoxy for getting higher stability?

I think with your shelled parts and solidifiyng critical objects after printing with epoxy the building time and the overall costs per set can go down dramatically

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
-------------------------------------------------------
> Hi Marcus,
>
> ... have you already tried with infilling the
> parts with some 2K-epoxy for getting higher
> stability?

Not yet but they look water-tight enough to cause no problems there.
Someone from my local Chaos Computer Club -group is interested in
the parts. I hope to get feedback about how well the epoxy worked
from him. Else I´ll fill some parts myself later.

If epoxy is too thin, you can always use cheap hotglue instead.
It´s less messy to work with and the volume required is not THAT much.


> I think with your shelled parts and solidifiyng
> critical objects after printing with epoxy the
> building time and the overall costs per set can go
> down dramatically

I sure hope so.
That´s why I published all the comparative numbers.

I also just printed my similarly constructed Mendel frame-vertex. Came out perfect and without warping due to some v-shaped cuts I made.
[www.thingiverse.com]
It has much thicker walls and like the frame-vertex of the shelled MiniMendel
is PROBABLY already strong enough without epoxy. Other parts, especially the very
flat ones require the epoxy or just more supports against bending.

Update: For the Mendel Frame-Vertex: I was unable to break it with the full force of my hands despite it being hollow. And I did not even add that one, additional support across the length of it, that I wanted it to have.

Edited 1 time(s). Last edit at 04/26/2010 05:24AM by MarcusWolschon.

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Hi Marcus,

... hotglue (mostly EVA) is really elastic, so a harder filling material would be better ... and/or you embedd some rods or fibres for the needed rigidity.

But anyway - excellent work

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
> ... hotglue (mostly EVA) is really elastic, so a
> harder filling material would be better ...

agreed

> and/or
> you embedd some rods or fibres for the needed
> rigidity.

Way ahead of you.
The parts already have added support-structures.
For some flat parts I´ll add additional ones as they flex too much for my linking
(unfilled).

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Hi Marcus,

> > and/or
> > you embedd some rods or fibres for the needed
> > rigidity.
>
> Way ahead of you.
> The parts already have added support-structures.
>
> For some flat parts I´ll add additional ones as
> they flex too much for my linking
> (unfilled).

... have you constructed/fabbed the support-structures or embedded aditional insets from metal, carbon or other rigid materials?

I think with embedding glass/carbon- or steel-rods in strategic positions while fabbing you can achieve much higher mechanical properties, so no need for final epoxy-filling.

I think we had some threads discussing implementing aditional harder/stiffer parts in the fabbing process for maximum rigidity and contra warping ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
-------------------------------------------------------
> Hi Marcus,
>
> > > and/or
> > > you embedd some rods or fibres for the needed
> > > rigidity.
> >
> > Way ahead of you.
> > The parts already have added
> support-structures.
> >
> > For some flat parts I´ll add additional ones
> as
> > they flex too much for my linking
> > (unfilled).
>
> ... have you constructed/fabbed the
> support-structures or embedded aditional insets
> from metal, carbon or other rigid materials?

No, it´s all part of the model and all ABS.
There is an actual photo of the printed parts.


> I think with embedding glass/carbon- or steel-rods
> in strategic positions while fabbing you can
> achieve much higher mechanical properties, so no
> need for final epoxy-filling.

You can but I don´t think it´s practical as it requires
manual intervention during the print instead of just listening
if the printer starts to make unusual sounds while wou do something
else.


> I think we had some threads discussing
> implementing aditional harder/stiffer parts in the
> fabbing process for maximum rigidity and contra
> warping ...

Do you have a link?
It´s not a road I would go but could be interesting to read up on.
(These parts must be easy to print, else noone will print them.)

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... here is an old post about embedding prefabbed structures and such ... or try the search with "embedding" and "All Dates" set ...