Danish cannons for 3D printing

[TJM]

Hi All,

 

Greatly inspired by @thibaultron's efforts to design and share 3D printable STL files for various series and times, I thought I would do the same for the very niche area of Danish Cannons. I am researching this for my own projects, and thought I would share with everyone. I will make occasional updates when I have new designs to share. 

 

 

For this first post, I have found a series of cannons from the period 1720-1750. They are from a Kaddet book and the scans cam be found here: https://www.arkeliet.no/sources/kadett_fm_1700/kadettbok1700t.htm

 

The series is one of the most complete onse I have found and includes: 3 pdr, 4 pdr, 6 pdr, 8 pdr, 12 pdr, 18 pdr, 24 pdr, 36 pdr and 42 pdr cannon designs, sometimes severel versions/lenghts of each.

 

I have started with just one lenght of each as can be seen in the table below.

 

 

Here are the drawings used:

 

 

 

 

 

 

 

 

 

Here you can see the files, except for the 42 pounder:

 

 

 

 

And then I have versions with the monogram of King Christian VI, which should be appropriate for the period (though Frederik IV and Fredrik V could also be appropriate).

 

 

 

 

 

You can see some of these (8, 18 and 36 pounders) printed in 1/32 scale in @Beckmann's build log for Tre Kroner.

 

The STL files are in 1:64 scale, but are of course easily re-sizable to any other scale.

 

I will attach the STLs in the next few posts

 

 

BR

TJM

 

 

 

 

[TJM]

3 pounder - no monogram:

3 pund.stl

 

4 pounder - no monogram:

4 pund.stl

 

6 pounder - no monogram:

6 pund.stl

 

8 pounder - no monogram:

8 pund.stl

 

12 pounder - no monogram:

12 pund.stl

 

18 pounder - no monogram: 

18 pund.stl

 

24 pounder - no monogram:

24 pund.stl

 

36 pounder - no monogram:

36 pund.stl

 

42 pounder - no monogram:

42 pund.stl

[TJM]

3 pounder - C6 monogram:

3 pund C6.stl

 

4 pounder - C6 monogram:

4 pund C6.stl

 

6 pounder - C6 monogram:

6 pund C6.stl

 

8 pounder - C6 monogram:

8 pund C6.stl

 

12 pounder - C6 monogram:

12 pund C6.stl

 

18 pounder - C6 monogram:

18 pund C6.stl

 

24 pounder - C6 monogram:

24 pund C6.stl

 

36 pounder - C6 monogram:

36 pund C6.stl

 

42 pounder - C6 monogram:

42 pund C6.stl

 

 

[Thukydides]

Super cool that you are willing to share this with everyone. Great job.

[thibaultron]

Great work! Thanks for sharing them!

[TJM]

Time for little update. With a lot of pictures! 

 

I have been looking for a specific collection of lithographies from 1860 depicting Danish bronze cannon - it is called 'Gammelt Dansk Metalskyts fra det XVIde-XVIIIde Århundrede' which translates to 'Old Danish Metal Artillery from the 16th-18th century'. 'Metal' here means bronze, as opposed to iron. 

 

I found the the royal library had several copies, but none were scanned. It turns out they offer a scanning service free of charge, at least for some documents, so I just placed a request and 3 days later I received an email with a lik to a nice, high resolution PDF scan! 

 

To say I was happy is an understatement! 

 

The drawings are absolutely wonderfull, here's a taste (btw, it is fully permissable to reproduce these for any purpose, as long as credit is given to the royal library - you can find the work now as open access here)here :

 

 

 

These are primarily from the 1600's as these from the time of Christian IV, but there are a few from the 1700's as well, and one from the time of Christian VI - basically corresponding to the 36 pounder I posted before - except now I can see the excact decoration of that cannon - the top one in this image:

 

Quite a bit more than just a monogram! 

 

Fortunately this is exactly the kind of thing Meshy can help with. I made a total of 5 Meshy runs for various parts of the decoration: 

1) the year and frame

2) the motto frame

3) wreath and crown (blank oval)

4) the portrait of Chr. VI

5) the monogram

 

Based on the mothly subscription cost, this is $2 worth of AI help 😁

 

Then it is a question of 'wrapping' the assets around the gun barrel and composing the whole model. Somone who knows Blender and the likes can do this seamlessly - I just chop the assets into strips/pieces and angle them to get an overall curve. That is a very crude way to du it, but at our modelling scales, it works just fine. 

 

Here's a few shots of the 3D model:

 

 

 

The text is made seperately, drawn in CAD, extruded, imported and placed correctly. 

 

I am quite happy with how this turned out! 

 

Here's a 1:1 comparison with the drawing:

 

So, does it print? 

 

I chose this particular cannon as I have been helping @Beckmann with cannons for his Tre Kroner and now that I had the actual drawing of the 36 pounder, it was obvious to try to make this one. 

 

I have printed a set of 1/32 scale for Beckmann and a single 1/64 scale, just to see what would show at that scale:

 

 

 

 

It is very hard to see the details on the beige resin, but it shows better under the UV curing light:

 

Painted black:

 

 

Bronze highlights:

 

 

Weathered:

(this might require some work to get good...)

 

 

Remember, these are macro shots, and it looks a bit rough in places and with the stark flash light, print layer lines are showing quite prominently in the photos - they are almost invisible in real life. 

 

I am also a bit limitet by the 50 mu resolution of my printer - higher resolution of down to 14-18 mu pixels are common for 8K-16K printers and that would surely improve the final print quality! 

 

Finally, here are some images of the 1/64 scale print:

 

 

 

 

 

The guy at the back, for scale, is also made with Meshy, based on a ChatGPT made image - double AI! 😅

 

Due to the enormous polygon count (2.55 million) , I cannot upload the STL file here - I will try to see if I can re-mesh it but I have not found a reliable program to do that with yet. I will upload if I find a good solution! 

 

BR

TJM

 

 

 

 

 

 

 

[brunnels]

1 hour ago, TJM said:

 

Due to the enormous polygon count (2.55 million) , I cannot upload the STL file here - I will try to see if I can re-mesh it but I have not found a reliable program to do that with yet. I will upload if I find a good solution! 

I can do this in Blender pretty easily if you don't find any other solution.

[Waldemar]

 

2 hours ago, TJM said:

The drawings are absolutely wonderfull, here's a taste (btw, it is fully permissable to reproduce these for any purpose, as long as credit is given to the royal library - you can find the work now as open access here)here :

 

Many, many thanks for your initiative in scanning this work and sharing the link to the scan. I have been searching for a copy of it for literally decades, without success until now. I was only vaguely familiar with its content thanks to a few reproductions in other publications. Once again, many thanks! 

 

 

[thibaultron]

Fantastic work! These are at a fantastic level of detail!

 

Have you tried Zipping/Compressing the STL file to reduce the size?

[TJM]

9 hours ago, brunnels said:

I can do this in Blender pretty easily if you don't find any other solution.

I have tried in Blender as well - the problem is that most of my polygons are in the ornaments, and very few are in the cannon, even though it takes up most of the surface. But when I re-mesh, I get a more even distribution of polygons, which means the drop in quality on the ornaments is huge and I get a lot of extra polygons on the cannon that does more bad than good! Even with adaptive voxel re-mesh. I get to 1.5 million polys, but the drop in quality on the ornamets is 10-fold! 

 

4 hours ago, thibaultron said:

 

Have you tried Zipping/Compressing the STL file to reduce the size?

I had not! but it gave a huge saving of around 50%, so here it is! 

Danish 36 pdr - 1733 - C6 1-64 scale.stl.zip

I don't why I didn't think of that - thanks! 

 

 

[TJM]

8 hours ago, Waldemar said:

 

 

Many, many thanks for your initiative in scanning this work and sharing the link to the scan. I have been searching for a copy of it for literally decades, without success until now. I was only vaguely familiar with its content thanks to a few reproductions in other publications. Once again, many thanks! 

 

 

Very happy to help! I had also seen low res reproductions in works by Niels Probst and was looking for the originals - they are available from antique bookshops, but at very high prices. So happy we have a fantastic public library infrastructure! 

 

I also afterwards found the non-shaded version already scanned at KB: https://soeg.kb.dk/discovery/fulldisplay?docid=alma99124201153505763&context=L&vid=45KBDK_KGL:KGL&lang=da&search_scope=MyInst_and_CI&adaptor=Local Search Engine&tab=Everything&query=any,contains,metalskyts&offset=0

 

But the shaded ones are prettier 🙂 

 

[Waldemar]

 

1 hour ago, TJM said:

I also afterwards found the non-shaded version already scanned at KB

 

Perfect! Many thanks again ! The 1860 edition is a wonderful addition, because monochrome mode can also be useful in some applications. And yes, indeed, I saw those few rare reproductions from Grunth's work in Niels Probst's publication on Christian IV's fleet, which I have in my home library, as well as some others from the same series, and still a few others on the Danish fleet. Among Danish authors, Probst is one of the most valuable to me, because he does and shows things that interest me the most, and yet from my favourite period .

 

 

[Waldemar]

 

Oh, I almost forgot. A large number of Danish cannons can also be found in Philip Thelott's enormous collection from around 1700, which contains many hundreds of captured cannons from all neighbouring countries. A copy is also available online in the Swedish archives. However, Thelott's collection is not as well organised as Grunth's, in fact there are no descriptions, only drawings, without even calibres or sizes, and everything has to be deduced from the proportions of the cannons, their styling and the inscriptions on them. 

 

[TJM]

18 minutes ago, Waldemar said:

 

Oh, I almost forgot. A large number of Danish cannons can also be found in Philip Thelott's enormous collection from around 1700, which contains many hundreds of captured cannons from all neighbouring countries. A copy is also available online in the Swedish archives. However, Thelott's collection is not as well organised as Grunth's, in fact there are no descriptions, only drawings, without even calibres or sizes, and everything has to be deduced from the proportions of the cannons, their styling and the inscriptions on them. 

 

That still sounds very interesting, do you have a link to work in the Swedish archive?

[Kevin-the-lubber]

13 hours ago, TJM said:

 

I am also a bit limitet by the 50 mu resolution of my printer - higher resolution of down to 14-18 mu pixels are common for 8K-16K printers and that would surely improve the final print quality! 

Beautiful work! Have you tried increasing the anti-aliasing and blur settings in the slicer? It can soften the layer lines quite a lot.

[TJM]

13 minutes ago, Kevin-the-lubber said:

Beautiful work! Have you tried increasing the anti-aliasing and blur settings in the slicer? It can soften the layer lines quite a lot.

Yes, I am running with 2px 30% AA but to be honest, I don't see much difference whatever I try with regards to AA. I clearly see the blurring on the slices, but no real effect on the print. But AA must be highly dependent on dialing in the correct exposure, otherwise 30% exposure quickly becomes much more in reality. And that is one of the benefits of the DLP printer I have: there is almost no pixel bleed, so exposure is not very critical, as anything above 'enough' will give good prints. I guess I should try to play around with this a bit to see if I can optimize it a bit.

[Waldemar]

 

 

2 hours ago, TJM said:

That still sounds very interesting, do you have a link to work in the Swedish archive?

 

My goodness, I can't find the right link to the Armémuseum archive in Stockholm right now, where one can download all three complete volumes of this collection at once.

However, to offer something quickly, here is a link to digitaltmuseum.se, where you can download or view Thelott's drawings individually, plate by plate (it seems that they are all or almost all there, over 450 – mainly Russian, Danish, German, Polish, Lithuanian etc., and perhaps even a few from the times of Teutonic Order ).

 

https://digitaltmuseum.se/search?q=philip thelott&owner=S-AM&o=0&n=50

 

The descriptions of the individual plates in digitaltmuseum also include library references. The plates are roughly grouped by country, but there is also some chaos, so it is worth looking through the whole collection. To identify the origin of a gun barrel, one need to look primarily at the coats of arms and inscriptions.

 

If you want, I will continue to search for links to download these three albums in bulk.

 

Below is an example of a typical plate, depicting a Danish cannon cast in 1613, i.e. from the period of the reign of Christian IV (or IIII, as it is written on this barrel ).

 

 

 

[TJM]

Wow, thanks! It looks like there is another 70 or so Danish artillery pieces in that collection! Thanks!

 

I will hunt for a 36 pounder from Chr. IV's time, I have not found one yet in other sources 😁

Edited Thursday at 02:14 PM by TJM

[Waldemar]

 

 

 

24 minutes ago, TJM said:

 

I will hunt for a 36 pounder from Chr. IV's time, I have not found one yet in other sources 😁

 

Good luck! 

 

 

[Waldemar]

 

Oh, I have one request for you, but only if it is not too much trouble. After identifying the Danish specimens in Thelott's drawings, would you please send me a list of them by volume and plate number? I would like to mark them as such in my copies.

 

[Waldemar]

 

To be on the safe side, I would like to add that many gun barrels have their weights engraved in the Swedish system, which can also be very useful in identifying the size and calibre of these specimens. This is in Roman numerals, skeppund : lispund : markpund, separated by a ‘:’, in proportions of 400 : 20 : 1, or metrically 136 kg : 6.8 kg : 0.34 kg.

[TJM]

I will probably not go through all of them, but the ones I do find the poundage of, I will report back on.

 

But the scale in the drawings are puzzling. It goes from 0 to 24 in increments of 4, so I assumed the unit was Swedish inches, and thus the total would be two Swedish feet. But that does not fit at all! I have a pattern of 24 pounder which is depicted both by Thellott and Grunth so I can make a direct comparison there snd use that for the rest of the Thelott drawings. The difference is huge: if I assume Thelott's scale is Swedish inches, I have to reduce to 0.603 scale to fit the Grunth drawing! 

 

Was there a unit of length used at Thelott's time that was 0.603 of a Swedish inch? Around 14.9 mm?

[Waldemar]

 

Ah, these supposed scales do not show absolute units of length, but rather a gun's calibre divided into 24 smaller parts, because barrels, and especially their small elements such as the thickness and width of the rings and other decorative elements, were designed and measured proportionally in these submultiples of the calibre.

 

This is precisely the problem with Thelott's drawings, that these ‘scales’ do not facilitate identification at all and even the estimation of size.

 

In these circumstances, it will probably not be helpful that the Swedish foot is 297 mm, divided into 12 inches.

 

... and Thelott just arbitrarily scaled the drawings to fit the available space on paper.

 

Edited Thursday at 07:02 PM by Waldemar

[TJM]

26 minutes ago, Waldemar said:

 

Ah, these supposed scales do not show absolute units of length, but rather a gun's calibre divided into 24 smaller parts, because barrels, and especially their small elements such as the thickness and width of the rings and other decorative elements, were designed and measured proportionally in these submultiples of the calibre.

 

This is precisely the problem with Thelott's drawings, that these ‘scales’ do not facilitate identification at all and even the estimation of size.

 

In these circumstances, it will probably not be helpful that the Swedish foot is 297 mm, divided into 12 inches.

 

... and Thelott just arbitrarily scaled the drawings to fit the available space on paper.

 

 

Hmm, I know it was common to measure the length of the bore in calibres, but I don't think the scales in these drawings are abitrary - I agree that the guns are scaled to the size of the paper, but the scale is matching as well. If I scale drawings (at 1/64 scale just for my convenience) to the known 24 pounder from Grunth, and then scale all of Thelott's drawings to that one, I get a very consistent pattern: all the ones i would guess would be 24 pounders (a well known series called 'konger' = kings) all end up with close to the same bore diameter (2.7 cm at my 1/64 scale - plus/minus 0,15 mm). I have also found what must be a 48 pounder and some 8 pounders. 

 

So I do think the scale is somehow absolute and can be used to infer the shot size from the indicted bore diameter. But I have not found any 36 pounders. and I think I have looked into the ones that was plausible. 

 

But there are still so many nice patterns of other sizes, so it is really a great collection! 

 

 

 

Edited Thursday at 07:26 PM by TJM

[TJM]

But perhaps I am wrong....

 

This one appeas to be a 12 pounder if I scale as described above, but it clearly states on the drawing that it is a 6 pounder 😅

 

hmmm...

[Waldemar]

 

Okay, I hope you will sort these issues out one way or another. Maybe I will also benefit somehow when you discover some pattern that will make it easier to recognise the original size of the cannons. Just one thing that makes it somewhat easier is that, unlike the copies downloaded directly from the Armémuseum, the copies available at digitaltmuseum have scales calibrated in centimetres on the scans, so at least the size of the drawings is known.

 

 

[Beckmann]

Hi everybody,

There are propably experts in the museum who know the answer to this don't you think? Or one could ask Trond Johannessen, who runs the arkaliet homepage. He is an expert on the old gun - catalogues and might know something.

Matthias

Edited Thursday at 08:49 PM by Beckmann

[Waldemar]

 

Hi Matthias,

 

In theory, it seems to be a good idea, but I know that in practice, museum staff treat such queries as a nuisance. However, it's not even a great pity, because they are usually only able to answer questions of a standard level of knowledge, so to speak. I wish I were wrong, but I know personally a number of museum employees...

 

 

[Waldemar]

 

@TJM

 

I think I have found a drawing of the Danish 36-pound cannon from the period of Christian IV that you are looking for. It is a chambered cannon, also known as a ‘drake’.

Admittedly, the drawing does say 42 pounds, but it is a Swedish made drawing, and in Swedish artillery of that period, calibre was given in skålpund, which was 0.425 kg. When converted to Danish pounds (0.5 kg), this gives a calibre of 36 pounds.

 

As in Thelott's drawings, the „scale” is a just gun's calibre divided into 24 parts, so you will have to find the overall size of the barrel by referencing to the known diameter of the gun's bore.

 

 

Edited Friday at 06:27 PM by Waldemar

[TJM]

52 minutes ago, Waldemar said:

 

@TJM

 

I think I have found a drawing of the Danish 36-pound cannon from the period of Christian IV that you are looking for. It is a chambered cannon, also known as a ‘drake’.

Admittedly, the drawing does say 42 pounds, but it is a Swedish made drawing, and in Swedish artillery of that period, calibre was given in skålpund, which was 0.425 kg. When converted to Danish pounds (0.5 kg), this gives a calibre of 36 pounds.

 

As in Thelott's drawings, the „scale” is a just gun's calibre divided into 24 parts, so you will have to find the overall size of the barrel by referencing to the known diameter of the gun's bore.

 

 

Fantastic,thank you so much! Where is this image from? Is it a physical book, or do you have a link to the source?