Need to improve square gun port cutouts

[Guest]

I have decided to build the Batavia by Kolderstok.

I just jumped over here from another vine I started about being not completely satisfied with my build quality.

One area I would like to improve is the precision and consistency in which to cut the gun port openings in a 17th century

Dutch ship. I have done the Prins Willem already but not to my satisfaction.

I am looking for any tips or tricks to get a precise cutout of the hull with sharp corners and clean lines.

Maybe I just don't have the talent to get what I want but any tips would be helpful.

 

Thank you 

 

JMS

[lehmann]

Are your difficulties related to laying out  or marking the ports, or from cutting them out?  (or both?).  

 

I have found over the years that accurate marking is the key to good results and the best way to mark is with a knife, not a pencil.   With a line scribed by a knife, you can carve, file, sand right to the line, and you'll end up with straight edges and sharp corners.  The smaller the scale, the more critical this becomes.  

[Richardjjs]

On ‎10‎/‎03‎/‎2017 at 8:18 PM, lehmann said:

Are your difficulties related to laying out  or marking the ports, or from cutting them out?  (or both?).  

 

I have found over the years that accurate marking is the key to good results and the best way to mark is with a knife, not a pencil.   With a line scribed by a knife, you can carve, file, sand right to the line, and you'll end up with straight edges and sharp corners.  The smaller the scale, the more critical this becomes.  

I use a scalpel to cut the gunport. Replacing it regularly. Also make sure its square by using one of the Gun Port lids attached to a small nail to ensute its square

 

[Ulises Victoria]

I had this same problem before.

What I do now is carve smaller amounts of wood, instead of taking big chunks, carving one cut vertically and one horizontally,

and always make the end of the previous cut, the limit for the next one.

By being conscious of this, I improved my carving to a more acceptable degree.

Not sure if this will help you, but surely it did for me.

Best of lucks

 

Ulises

 

 

[vossiewulf]

Safest way is edge tool of some kind until you're close (knife or skew chisel), then needle files/rifflers to finish. Pretty hard to screw it up that way, and generally just need a touch up in the corners with your edge tools.

[Lucius Molchany]

I drill 4 holes at each of the corners and use a new xacto blade to carefully cut them out.A needle file is used to make them square.Takes some practice but you will soon get the hang of it.Accurate layout is essential of course.

[Ulises Victoria]

Hello.

This may help you. I have been watching from video one to ten. Very entertaining.

 

Go to episode 10

https://www.youtube.com/watch?v=51VT0eYWkxs&list=PLGC1fmQp8LDsu0EKRM9nen3HqOzD8Y3F2&index=10

 

[Dziadeczek]

This is all fine what he is doing, but gun ports which are towards the stern and, to some degree the bow, are progressively les and less square, and become rhombs (parallelograms with other than right angles) because their vertical lines remain true vertical and the horizontal lines follow the decks.

Hence, his handy plastic square template cannot be used there, I'am afraid.

Unless he has different templates for those ports, each with different shapes...

[Ulises Victoria]

On 3/15/2017 at 8:47 PM, Dziadeczek said:

This is all fine what he is doing, but gun ports which are towards the stern and, to some degree the bow, are progressively les and less square, and become rhombs (parallelograms with other than right angles) because their vertical lines remain true vertical and the horizontal lines follow the decks.

Hence, his handy plastic square template cannot be used there, I'am afraid.

Unless he has different templates for those ports, each with different shapes...

 

Agreed, however the question was about how to precisely cut the gunports, not finding their placement or shape. Of course you would need different templates if that is called for in your ship.

Best regards

 

 

[*Hans*]

On 3/16/2017 at 3:47 AM, Dziadeczek said:

This is all fine what he is doing, but gun ports which are towards the stern and, to some degree the bow, are progressively les and less square, and become rhombs (parallelograms with other than right angles) because their vertical lines remain true vertical and the horizontal lines follow the decks.

Hence, his handy plastic square template cannot be used there, I'am afraid.

Unless he has different templates for those ports, each with different shapes...

We can start a nice discussion about this  - as a parallelogram shaped gun port  where the turning axle of the hinges are not in the same line  simply cannot be opened. Two hinges beside each other need the same axle line to function properly. And if you mount the hinges under a specific angle so there turning lines are the same then the form of the port gives trouble to open. 

 

The vertical sides of a gun port were vertical - that's correct, but regarding the horizontal lines: the lower one could follow the deck (but this was surely not always the case), but the upper one was always under a 90º angle with the vertical sides. So a square gun port is very original.

Attached a photo of the Vasa (Wasa) which is the excisting proof of how it was done (this is the original ship from 1628 - same time as the Batavia). Due to the back light the form of the gun ports is clearly visible.

 

[amateur]

Hi Hans,

 

This is a topic getting quite a lot of interest in the Vasa forum: Fred Hocker states that the frames are not vertical in that area of the ship, and that the gunport-sides are not coinciding with the frames.

Besides: when looked at exactly at 90-degree, the aft gunports of Vasa are indeed not completely square, but it is the angle of the picture that suggests more than there actually s. Most of the gunports of Wasa are (almost perfectly) square and not trapezoid....

see this drawing (issued by the Wasa-museum) http://forum.game-labs.net/index.php?/topic/4220-wasa-1628-swedish-warship-with-plans/

 

 

Jan

 

[Guest]

Thanks for the information.

I think I have been doing the cutouts about how most do it. I just need to refine my technique

and the template is a good idea.

However, I just watched episode 13 of the video that Ulises suggested and that is what I will do 

on my current build. 

Take a look.

 

JMS

[*Hans*]

I drill four small holes on the four corners (about 0,6 - 0,8 mm) - in such a way that the hole is complete inside the outlines of the gun port.

Then cut out with a sharp knife and as last thing with a square file make the corners square