Jump to content

9 Pound Naval Cannon (1786) by AON - 1:12 scale - Finished


Recommended Posts

A question for people out there that have some expertise with 3D printing.

I have two sketches below.

One has the cannon divided into two pieces, almost equal halves, whereas the other has it divided into five unequal pieces.

 

What advantage or disadvantage is there to these divisions if presented as individual 3D vertical prints?

 

The first bad thing that comes to mind for me is that the ribbon of hot PLA plastic having no support at the bands when printed vertically... they may droop or simply fall away... even if they are rotated and printed upside down where possible.

 

The first possibly good thing is that the smaller sections allow larger detail in the 8Mb limited STL file.

 

Is there a better way to divide this?

vertical split - 2 pcs.JPG

vertical split - 5 pcs.JPG

Link to post
Share on other sites

Update....

 

I received a PM from a forum member who took my file and attempted to print the small section at the insignia horizontally with his printer.  The results were similar.

 

He made many suggests: print vertically, 2 to 3" long sections; divide at an top or bottom of a ring not through it. Layer height no larger than 0.2mm. Infill of 20%. Wall thickness no less than 1mm (1.2 seems to be ideal without being overkill) Print with Brim of 5-8 lines (this will be a layer surrounding the parts that helps them adhere to the bed).  He concurred that printing the insignia separately and flat would likely result in better quality.

 

I have a considerable amount of info to discuss with the library staff.   Now I need to make smaller model sections.  This should be easier by reusing the original sketch.

Link to post
Share on other sites

Had my meeting about 3D printing at the local Library this afternoon.  I brought in my list of suggestions supplied by one anonymous forum member (thank you again!) and it was very helpful.

 

Their machine is a 2 year old commercial printer.  I was told the 8 Mb file size limit is set by the Library's internet file transfer size limitation.  If I bring my files in on a thumb drive (stick) they can be any size I care to save them at.  By this logic I can split the gun into merely two pieces, a muzzle half and a breech half.  The split will be at the edge of the 2nd reinforcing ring just past the trunnion to keep the printing supports under the trunnion short.

 

We discussed printing the insignia flat as the wrapped version has a maximum offset of 0.01 inches (0.254mm) at 1:12 scale.  As the PLA filament diameter is  1.75mm (0.069"),  or x12 = 0.828 inches full size, this would be one layer of plastic on the machine bed.  They feel it would be very difficult to lift off without breaking it.  They asked if I could print it thicker (taller) part as two layers might be easier to "peel" off the bed.  I've just e-mailed them a couple more questions regarding this... trying to understand the difference between filament diameter (1.75mm) and layer height (0.15mm) as it relates to my build scale (1:12).

 

They also suggested I print a second breech end of the barrel with the insignia on.  They are not sure how this will turn out but they don't have any problem with trying.

 

So that is what I will do.  As Christmas is around the corner they are swamped with requests to print stocking stuffers.  I told them mine was not a Christmas present so I haven't any problem waiting.

 

Meanwhile (soon) I will cleanup the parts I have, acetone slovent weld them together and paint the insignia with my version of yellow ochre.  I am back to re-making frames for my 74 but won't be posting there until I have something worthwhile showing.

 

Link to post
Share on other sites

I picked up my new 3D prints from the local library this afternoon.  This was extremely fast, they must have enjoyed the challenge.  It was different from the usual mundane items they print.

 

Two sections printed vertical (standing on end). One muzzle and two breeches with one version of the breech with the insignia.

This is what was on the note they sent me:

 

 In terms of the flat insignia, it didn't come out very clearly when we used the file's default thickness, but when we added another millimeter to its depth it came out much more clearly. You should be able to sand this thicker version down to get the look you want. The version of the breech with the insignia on it also looks surprisingly good.

All files were printed on the "Hyper" resolution setting with a layer height of 0.8mm. When printing the insignia, I slowed the print speed down to 20mm/s to ensure the details came out as precisely as possible.

 

They look a million times better than the earlier horizontally printed halves.

Judge for yourselves...

1 all pieces.png

2 barrel halves.png

Link to post
Share on other sites
On 12/15/2018 at 4:18 PM, AON said:

I picked up my new 3D prints from the local library this afternoon.  This was extremely fast, they must have enjoyed the challenge.  It was different from the usual mundane items they print.

 

Two sections printed vertical (standing on end). One muzzle and two breeches with one version of the breech with the insignia.

This is what was on the note they sent me:

 

 In terms of the flat insignia, it didn't come out very clearly when we used the file's default thickness, but when we added another millimeter to its depth it came out much more clearly. You should be able to sand this thicker version down to get the look you want. The version of the breech with the insignia on it also looks surprisingly good.

All files were printed on the "Hyper" resolution setting with a layer height of 0.8mm. When printing the insignia, I slowed the print speed down to 20mm/s to ensure the details came out as precisely as possible.

 

They look a million times better than the earlier horizontally printed halves.

Judge for yourselves...

1 all pieces.png

2 barrel halves.png

Very nice.  From my 3d printing experience (MakerBot3), I would have done a couple of things differently.
For one, I would have made the trunion a separate item with a cast hole for it).
For another, I would have laid out the 3d model only semi-vertically about 5º skewed from the vertical, with all "appearance" items, crest, touch hole, etc., on the Positive Z face thus made (that to avoid issues with support structures).
Lastly, I would have set this up to fall on a suitable brass tube as an armature.  The brass tube could be blackened, but would provide rigidity and form to the construction. 

Come to think of it, I would have put a tapered overlap at the joins, too--but, I've also had problems with MakerBot not "respecting" model geometry dimensions.

 

But, that's just my 2¢

I think the texture turned out just fine.

Link to post
Share on other sites

After recovering from my worst yet needle in the eye ....

I cleaned the supports off the trunnions and glued the two pices of the cannon together.  I will not be touching the piece up at all as I want it to be realized to be 3D printed.  I had smoothed off the cannon balls a bit which resulted in a dull finish and they are almost unrecongizable as having been 3D printed.  I am happy with them but do notwant the gun looking anything like this and do not want to have to paint it black.

 

We had had a presentation on Adhesives (Glues) at our September meeting of the Model Shipwrights of Niagara (  https://modelshipwrightsofniagara.weebly.com/blog  ) and were told about the websites https://www.thistothat.com/ and  http://www.thebestglueforplastic.com/

 

I found the best glue for PLA was a 2 part epoxy and it worked wonderfully.

 

I also painted** the royal insignia by applying a small amount of paint to my finger tip and dabbing it to the raised insignia.

Literally waiting for paint to dry now.

 

**NOTE: Please see post #124 dated 26 Feb 2012 for update on painting the royal cypher

 

65 - cannon glued and painted.jpg

Edited by AON
Link to post
Share on other sites

You are correct! **

 

The problem is that it is practically indistinquishable in black shiny plastic on the black shiny plastic... and worse when forced at a distance (through an acrylic case).

I even strayed by making the insignia a little larger this time in the hopes it might make a difference but it did not.

What the eye cannot see (even my good eye) is sometimes unbelievable. 

I learnt this lesson during my industrial heat treatment furnace designing career with safety yellow perforated machine guards.  The eye will not see through them but will look through black so I would have portions of my machine guards painted black so operators and maintenance people could see motion through them.

 

I did not agonize over this decision as I did with a few others.

It is pretty nice looking... and I like it.

 

Unlike learned people like yourself and others on this forum, most people won't know and will hopefully be focused as I am at how damn good looking it is.

 

Father, forgive me, for I have sinned.  :rolleyes:

 

**NOTE: please see post #124 dated 26 Feb 2012 for an update on painting the royal cypher

Edited by AON
Link to post
Share on other sites

I don't mind you painting your cannon any way you like, Alan. However, X years from now, someone will look at your model and say "Gosh, they must all have been painted like that!" and every cannon on every model thereafter will be gilded. And the rest of us will all have been wrong.

 

Merry Christmas!

Link to post
Share on other sites
On 12/21/2018 at 4:29 PM, druxey said:

However, X years from now, someone will look at your model and say "Gosh, they must all have been painted like that!" and every cannon on every model thereafter will be gilded. And the rest of us will all have been wrong.

Or not.  A couple minutes' more research will also show that the carriages were painted verious colors as well.  And that cannon often have significantly more rigging than shown.

 

2¢ doesn't much buy what it used to.

Link to post
Share on other sites
  • 1 month later...

some updates!

 

I purchased a 3D printer with the capability to print my cannon in one piece.

 

I resized the insignia on my CAD model to the original proper size, converted the file to .stl, loaded it into the slicer program, loaded this "gcode" file  into the printer and pushed print.  (Don't I seem smart... it is all smoke and mirrors)

 

14 hours and 35 minutes later I had a cannon.

 

I took it to our last club meeting and John, a fellow with years of painting model experience (with 1st place ribbons to prove it) suggested if I gave it two or three light spray paint coats of Beauty Tone Flat Black Enamel Acrylic paint it would eliminate the shininess, bring out the insignia and all my concerns would disappear.

 

Here it is below with three light coats!  12 hour minimum drying time between coats as he recommended.

 

I'll be taking it to our club meeting this Friday and then switching it out on by build.

 

I've tried printing the cannon multiple times (tweaking slicer settings) at 1:64 scale for my other build (HMS Bellerophon) with no success.   So I've ordered smaller extrusion nozzles (0.2 and 0.3 mm versus the 0.4 mm nominal size provided with the machine) in the hopes one will do the job at the reduced scale.  They have been shipped from China.  Now I wait.

3 - 1to12 scale 9pdr painted flat black.jpg

Link to post
Share on other sites

They are getting affordable and print in Wood/PLA mix that is sandable and can be stained!  That has got me thinking about parts for my build ... i.e. gun carriages?

 

You need a clean stable enviroment so mine is on top of the low file cabinet in our study (fancy word for where we keep the computer).

 

I decided on the JGAurora A5 as it has a good size heated bed and print height... good reviews and an active online forum for help.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...