FSwart

HMS Triton 1:24 Crossection by FSwart

Good day all.

 

Started my build of the Triton crossection today in 1:24 scale.

 

This is my first attemp at scratchbuilding and also my first model from the age of sail.

 

May I request the moderators to grant me access to the rest of the drawings?

 

 

Attached are a few pictures of as things stand at the moment, with the keelson, keel and false keel cut and lightly sanded.

post-17240-0-94186100-1437399113_thumb.jpg

post-17240-0-16354600-1437399450_thumb.jpg

post-17240-0-31406000-1437399516_thumb.jpg

mtaylor, Canute, UpstateNY and 1 other like this

Share this post


Link to post
Share on other sites

Glad to see another build starting here.  Will be nice and big at that scale, will be able to put alot of detail into it. Looking forward to more.

Share this post


Link to post
Share on other sites

Good day all.

 

Unfortunately no further progress on the triton as i have been out of the country for a few weeks. I am also moving house soon so i am forced to pack all the projects away...

 

Keep well

Francois

mtaylor likes this

Share this post


Link to post
Share on other sites

Small Update:

 

Having recently acquired a CNC Mill/Router I decided to machine most parts for my Triton build. The CNC software is quite powerful, and has the ability to import toolpaths from images directly; however it does generate a few errors from the images. Maybe I’m just a perfectionist, but I decided not to use the image import function and instead redraw the plans…

 

I sent a PM to Chuck, just to check if redrawing the plans doesn’t violate the copyright terms, and luckily it does not.

 

So it was back to the drawing board (CAD workspace???)…

 

I use AutoCAD2012, and I know just enough to be dangerous. Fortunately I found a feature which is quite useful, more on this in just a moment.

 

I am not going to go into much detail about redrawing/tracing plans; Wayne has written a superb tutorial regarding this. I started using this method, first converting the PDF drawings to Jpeg images, importing into CAD and then tracing the lines, a very tedious and labour intensive process…

 

Now to the new (Better?- I don’t know, but it works quite well for me) method:

 

By chance I stumbled upon a feature in AutoCAD (Not sure if Turbo Cad etc. supports this) called PDF Underlay, which as the name suggests puts a PDF underlay into the workspace. I figured it was a bonus, now I don’t have to convert the drawings to Jpeg files first. Upon further examination however I discovered that the lines in the PDF underlay had object snaps, so now I can start a pollyline or spline at one of these snaps, and simply follow the snaps on the line I wish to trace.

 

I’m not going to post the entire procedure for every part being redrawn here, just show the basic steps involved. I am only posting this as I think someone might find it usefull.

 

First up is structuring the drawings (method borrowed from Matrim, Amphion Drafts MK3).

 

Second will be tracing the imported PDF file. Copy will be saved as a *.DWG file extension.

 

Third will be converting the file to a *.DXF for the CNC software. While the software can automatically compensate for cutter radius, it is a potential pitfall. The part to be cut will be treated as follows:

  • Join all lines/splines/pollylines/arcs to form one continuous pollyline or spline.
  • Offset the continuous pollyline or spline with the cutter radius towards the waste side of the wood to get the new center toolpath line.
  • Checking for any gaps or crossed lines in the line.
  • Scale the parts from 1:1 to 1:24.

 

Fourth will be importing the *.DXF into the CNC software to generate the necessary G Code.

This is the process explained with a few pictures:

 

1: Inserting PDF Underlay.

post-17240-0-78836000-1479825890_thumb.jpg

 

2: Scale PDF Underlay (Scale factor 1219.2 was determined by multiplying 25.4 (1 inch in mm) by 48 (Scale of drawing)).

post-17240-0-52609300-1479825913_thumb.jpg

 

3: Start tracing at object snap.

post-17240-0-71193700-1479825934_thumb.jpg

 

4: Continue tracing following object snaps along line.

post-17240-0-00560900-1479825967_thumb.jpg

 

5: Result of tracing.

post-17240-0-07357000-1479825999_thumb.jpg

 

6: Join lines and splines.

post-17240-0-63845600-1479826046_thumb.jpg

 

7: Offset procedure 1:

post-17240-0-59553100-1479826072_thumb.jpg

 

8: Offset procedure 2:

post-17240-0-76965200-1479826085_thumb.jpg

 

9: Offset result:

post-17240-0-72152400-1479826109_thumb.jpg

 

10: Change layer of new line from keelson to toolpath.

post-17240-0-81053400-1479826128_thumb.jpg

 

11: Delete original trace line and save as DXF.

post-17240-0-51644900-1479826145_thumb.jpg

 

12: Import DXF into CNC software and generate G Code, note that the software calculates the length of the cut, which in this case is 563.056mm and also calculates the time for the cut, which will be the length divided by the feedrate  and multiplied by a compensation factor (compensation for acceleration and deceleration which occurs at changes of direction)

 

 post-17240-0-69511800-1479826167_thumb.jpg

mtaylor, Pete38, GuntherMT and 2 others like this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now

  • Recently Browsing   0 members

    No registered users viewing this page.