28 cm SKL/40 (E) Eisenbahngeschütz Bruno 3D printed

[Andrzej Ditrich]

Hello,

the results are about the closest to injection mold quality

Wow that looks realy fine detailed pieces! It might be used as master for further copies made in polyurethane resin and silicone form.
Do You consider barrel as being turned in metal instead of resin?

Regards
AD

[EPOCH3]

Hi - basic Bruno Kanone (E) carriage starting to come together - put a quick primer coat of paint on just so I could see better.
Parts were essentially removed from supports and glued together but no sanding or detailed clean up done yet.
Regards

[EPOCH3]

Hi - I had to redo the pivot assembly anyway since I omitted the ball bearings somehow.
For these parts I used a mixture of Formlabs resins and the results ere far better than using
the 3rd party (cheaper) resin.
Regards

[EPOCH3]

Here are a few pictures of the tail end of the carriage that I printed last night.
The part houses the translation mechanism that permits the carriage to slew a couple of degrees
either side of center. You can see that the small oil lines that I added to the part actually
printed. The part is just tacked on to see what it would look like.

Nothing is cleaned up yet other than the majority of supports removed. The light color
primer will help me see the blemishes and areas that need to be touched up.

I also included one other picture showing the pivot and rotation wheels for fixed emplacement added.

Regards

[EPOCH3]

Hi -

In WWI the 28cm Bruno K (E) could fire from track or be used in a prepared platform configuration and was classified therefore as an Eisenbahn und Bettungsgerüst - E. u. B. equipment. A key design element of the E.u.B. configuration was the use of the Hebebock (or Jack Stand) which allowed the weapon system to be lifted up in order for the railway trucks/bogies to be removed when installing into fixed Bettungsgerüst emplacements.

I was going to use Shapeways service to print the Hebeock just because I didn't think the Form2 printer would print such a weird and intricate part
properly. I went ahead and ran a test print last night and here is the results. Picture shows the part just after snapping off supports with no further cleanup done. I was amazed it printed as well as it did. The test print hi-lited that I actually had made a few design mistakes which I had not caught earlier so I have fixed those and thickened up a few pieces and will reprint a set this next week.

For anyone interested - the part cost about $2.70 in materials to produce.

Regards

[Andrzej Ditrich]

Thanks Greg for very usefull step by step informations
Project looks better and better

[EPOCH3]

Load deck cover as-built and just off the printer - had to split it into two parts
in order to fit.

The picture shows the I-beam used to transition ammo up to the breech area from the ammo
wagon was too thin and it became loose during printing. It has a bend in it which is
supposed to be there but is severely wrapped beyond the bend. I think I can remove
that gently and reprint it separately and then reattached once cleaned up.

Regards

[EPOCH3]

more dry fitting

[EPOCH3]

Revised jack stand/hebebock as printed - I think it came out quite nice
so I made a set of four.

For anyone interested, material cost for the set was about $11.50


The version shown is the Hebebock in the retracted/traveling position.
I will make another version to see if I can make the collar around the screw
movable so that it can also be shown in the deployed position.

I also added a picture showing how the jack stands would have been used to elevate the carriage
up high enough so as to remove the trucks.

[M.S.Jensen]

Hi EPOCH3,
I follow your work here on axis and it is very interesting to see your modelling! I really like this 3D printing and your detailed descriptions of work and pricing is highly valued!

Thanks for sharing!

[EPOCH3]

Hi - thanks a bunch for the feedback. There is a lot of
info on-line regarding 3D printing but surprisingly
very little that actually showed me what I could expect
from a specific printer, what the limitations were in relationship
to printing actual models (other than simple parts) and then if it
were possible what it would cost. I am glad to hear that the info
is useful to someone other than me (ha ha).

Kind Regards
Greg

[EPOCH3]

Hi - in the interest of sharing

There is some residual uncured resin that is still on the parts as they come out of the printer. This residual material needs to be cleaned off and Formlabs provides a cleaning station so that you can gently soak the parts in Isopropyl alcohol (IPA).

Cautionary note (and lesson learned) - One must be very careful regarding the length of time that you soak the parts. The recommendation is 10 minutes but I have found that for more delicate parts, especially those with thin details, even 10 minutes is too long.

Here is a picture of my Hebebock parts that were shown above after 30 minutes of soaking - I had to take the dog for a walk so I guess I can blame her (ha ha). The parts just get wrinkled and look "pickled" if you leave them too long. The trick is to get the excess off with using as little IPA as is necessary. For small parts I now just spray IPA on using a simple spray bottle and wash it off with a brush - then rinse them off. This process seems to work quite well. I have left larger thicker parts in overnight by accident and there is little to no impact on details and or warping.

Off to reprint the parts

Regards
always have fun

[Andrzej Ditrich]

Looks like they were exposed on very heavy loads
Those jacks remind me ones used for picking up cupolas for bunkers - they were used to unload them from Culemyer.

[EPOCH3]

They actually look good together all heaped on top of one another for maybe a junk yard diorama detail

[EPOCH3]

Hi - just a quick update pic as the basic parts come together.
There are many areas where photoetch and brass would made it look
much cleaner and provide sharper/better details but for me perfect is
the enemy of good and I am happy with results so far.

I also started looking ahead for crew figures. I have always wanted to
do my own factory crew as the piece was being built but sculpting my
own figures is beyond my skill level. A few years ago I bought a cheap
copy of Poser which is a software program that allows you to articulate/pose
3D models of figures/characters/animals etc. This allows you to create
any pose so now I am only waiting to figure out how to do uniforms and
proper clothing. Next step is to figure out how well the Form 2 can actually
print figurines in 1/35th scale.

As a test, I found a fairly high resolution figure on-line for free which
I downloaded and printed as-is (in Medium resolution). I just quickly
adjusted the size but it's a bit off of 1/35th. The details on
the print shown are a just a bit "soft" so I am an reprinting it at the highest
resolution setting to see if it improves the print.

All in all as a first try, the printer does quite well printing smooth "organic"
surfaces.

For anyone interested print time was about 3 hours and material cost was
about .90 (90 cents)