Cutty Sark by Richard Dunn - 1/40 scale - scratch built semi-kit prototype

[Richard Dunn]

I can do that with the pen attachment

[rshousha]

21 hours ago, Richard Dunn said:

Have you used laser? I am asking because so many people have advised me I should and I have considered it, what have you found with it? if you have used it.
I personal

My company builds frame sets for large-scale R/C boats. We have been making frame sets since 2015 and have always used a laser. When I visited my supplier, Jotika, a couple of years ago, I spent a few hours with John Wright, the owner, and he really opened my eyes about the difference between a laser and a CNC cutter. There is no doubt, for many reasons, that the CNC does a much better job. 

 

First, the precision is much higher with the CNC machine. As long as you measure your drill bit and your material, you can get more precision that with the laser. Even you account for the kerf on the laser, and you measure your material, you still have a char on the laser-cut parts. That char needs to be removed or the glue doesn't penetrate the material.

 

Second, you can make pockets with a CNC. For example, you can make parts fit without passing all the way through. Also, with pockets, you can do things like "engrave" windows in the stern panels of models. In your case, you might find that quite interesting for your model. That cannot be done with a laser-cutter. 

 

I spent about a year using a full-size CNC machine at a furniture-maker, designing furniture, and then actually using the machine and making the prototypes myself. It was great fun and taught me a lot about woodworking. 

 

So, as soon as I can find someone around here that has a decent CNC machine, I will start designing for that. I suspect the price of my frame sets will go up slightly but, when people are paying many thousands of dollars to build a big R/C model, I think they will appreciate the improvement in quality. 

 

(By the way, I am planning on building the Cutty Sark myself, in 1/48 but, hey, your model might be even more fun to do!)

 

In brackets because I do not want to market a kit in 1/40 scale. It just isn't part of the large scales that I use. 

 

Best Regards, 

Rick

 

[Richard Dunn]

I forgot about pocketing, yes true. and carving lifeboats etc.
I am happy to provide the outlines for you  if 1/40 is an option. not much difference to 1/48 in the grand scale.
For carving work I think the best example is this build, where he used small CNC for a fair bit  of it.

 

[Richard Dunn]

I have had great success with cutting the square mouldings which range from .65mm and 1mm wide, of course these will be cut from thinner stock or narrow planks so they can be released by running through a saw but the point is the accuracy is there. next I will try a v cutter pass first to create the bevel before applying these cuts.
Another pro for CNC, clean-up on these to remove charring would be impossible with out breaking them.

The cut to the right was a test but it will actually be cut from .4mm ply, but as you can see I hit the emergency stop before it hit the screw.

below I have cut full shapes but in reality I will only be cutting the arcs, the straights will be made as separate parts with correct grain direction, maybe on the CNC as well.

The cutter used here is a .98mm end mill cutting 1mm deep in one pass

Edited December 2, 2023 by Richard Dunn

[Richard Dunn]

The first fitted 2mm ply parts, interior walls of Coachhouse, green in cad image, the saloon size can be gauged from this.

The porthole openings are square because the inside is and if wanting to panel it its done.
 

 

Edited December 4, 2023 by Richard Dunn

[rshousha]

Nice-looking parts! Going back to the laser-vs-CNC question, these parts look so much more "finished" than anything that could come off a laser. It just takes a tiny bit of cleaning and the parts are pristine. The inside corners of the windows might not be square, like what you come out of a laser, but that is easily rectified with a quick pass of a file. 

 

And any work that you do with a file is directly related to cleaning or adjusting the part. It is not related to simply getting the char off in order to get glue to work well. 

[Richard Dunn]

6 hours ago, rshousha said:

The inside corners of the windows might not be square, like what you come out of a laser, but that is easily rectified with a quick pass of a file.

That's right and in this case the inner panelling will need to be filed flush to the hole anyway so it has to be done, not to mention a corner from a 2mm cutter is gone in 2-3 strokes, its pretty small, the whole square hole is only 11mm.

[Richard Dunn]

I have started to clean up the parts and dry fit all the joints.
Below is the main deck, on it rest the forward half of the keel with the fore mast step and first part of the deadwood fitted.

A close up of the joints showing how well they fit, notice also the fit of the dovetails joining the deck parts.

Below are the heads fitted into the slots, the stay plate slots are also shown forward of mast.

Edited December 7, 2023 by Richard Dunn

[rshousha]

I am looking forward to seeing the fit of the deck. I use pretty good software and can't make my deck conform to curves front-to-back as well as side-to-side. I use sheet metal fabrication to make the curved surfaces and those can only be "flattened" the way they would be with real steel. I do not have "stamping" software that is found in the high-end CAD solutions like Catia. 

 

It looks like you have some real experience with CAD. 

[Richard Dunn]

6 hours ago, rshousha said:

I am looking forward to seeing the fit of the deck. I use pretty good software and can't make my deck conform to curves front-to-back as well as side-to-side. I use sheet metal fabrication to make the curved surfaces and those can only be "flattened" the way they would be with real steel. I do not have "stamping" software that is found in the high-end CAD solutions like Catia. 

 

It looks like you have some real experience with CAD. 

I use Rhino which is used to design ships and my background is designing and doing structural modelling for ships and some naval vessels.
I also use it to design and concept furniture.
I use it as well in my day job now in TV Film and games modelling. so yes I have a lot of experience in a professional capacity.

I us a  tool in Rhino to develop non developable plates and shapes that are not able to be "unrolled"  you may know them as ruled surfaces, but Rhino has tools called squish and smash which do it and allow for stretch and compression.
its good enough to use in ship plates productions so....

https://docs.mcneel.com/rhino/5/help/en-us/commands/squish.htm

If you look at my SS Tamahine build which is assembled and made the exact same way you can see the fits and the developed inverted stern parts fitted.

 

Below is Tamahine note stern wrap part on bench, the curved part.

 

Fitted

On the TEV Wahine which is my personal project which is 4.3m long the plates are also developed with the same tool
See below, the most advanced structure I will ever do .

 

 

Edited December 7, 2023 by Richard Dunn

[druxey]

!!!!! is the only comment I can make to those photos. A builder's style model at that scale today is most unusual.

[Richard Dunn]

3 hours ago, druxey said:

!!!!! is the only comment I can make to those photos. A builder's style model at that scale today is most unusual.

The build so far is here

 

[rshousha]

19 hours ago, Richard Dunn said:

I us a  tool in Rhino to develop non developable plates and shapes that are not able to be "unrolled"  you may know them as ruled surfaces, but Rhino has tools called squish and smash which do it and allow for stretch and compression.
its good enough to use in ship plates productions so....

Wow, that's amazing. I just bought a Rhino license, but I have asked a fellow in Ontario to make the organic shapes for me. He's very good and I am sure he can use the features you are mentioning. I will have to talk to him about it. I use Solidworks and I am a bit tired of the $2000 USD annual maintenance fee. The software is really good but I don't use it enough to warrant the cost. I may buy the license for 2025, but that will be my last one. 

 

For now, I use a combination of Rhino, to create the organic shapes, and SW, to create all the internal parts, and make the 2D drawings. I suspect, from looking at your work, that Rhino can deal with the work just as well as Solidworks, for a quarter of the cost. 

[rshousha]

Here is the latest project I am working on. This is a 48" tug. Plywood is 1/4" birch. The hull was done in Rhino. The rest is SW.

[Richard Dunn]

5 hours ago, rshousha said:

Wow, that's amazing. I just bought a Rhino license, but I have asked a fellow in Ontario to make the organic shapes for me. He's very good and I am sure he can use the features you are mentioning. I will have to talk to him about it. I use Solidworks and I am a bit tired of the $2000 USD annual maintenance fee. The software is really good but I don't use it enough to warrant the cost. I may buy the license for 2025, but that will be my last one. 

If you go into the Cad section I did a live workshop on the Rhino basics for hull form a couple of years ago.

[Richard Dunn]

Here you go
https://www.dropbox.com/s/nq8liinoh9e4gqf/Hull Form Basics in Rhino.mp4?dl=0

 

If you have any issues with video playing you will need to use VLC media player, its free

 

 

Edited December 8, 2023 by Richard Dunn

[Richard Dunn]

I hope this answers your question about the fit of the decks.. side to side  at least.

 

 

Edited December 10, 2023 by Richard Dunn

[Richard Dunn]

Starting to test fit all the parts and dry assemble.
nothing is glued or forced together so a few little gaps but its fairly good, I am happy

Stern deadwood and sternposts

The Forward Deadwood minus the Stem post and cutwater

Frames 70 to 88 dry fitted and decks fitted for checks

And lastly a straight brass round to check alignment fore and aft of mast holes.

Once I have done this for all the frames its time to cut the rabbet and start gluing

 

 

 

 

Edited December 16, 2023 by Richard Dunn

[Richard Dunn]

Nearly all the forward frames are fitted now.

Note the fair line of the main deck along the sheerline, it's a pretty good indication of the accuracy.

It's looking less and less likely I will make this a kit, as I suspected it's too large for most, I had a number in my head of 10-20 requests.
I might look at selling the cad files so it can be cut  by the buyer.

 

 

Edited December 17, 2023 by Richard Dunn

[Richard Dunn]

Just laying the main deck on with a 1 meter rule next to hull for scale.

[No Idea]

The accuracy of your bulkheads is CAD perfection its almost a shame to cover them up.

[Richard Dunn]

8 hours ago, No Idea said:

The accuracy of your bulkheads is CAD perfection its almost a shame to cover them up.

Thank you, 
The aft end is even nicer, hopefully by the end of next weekend, Christmas day I will be able to carve the rabbet  and assemble the frames for good.

 

[rshousha]

Wonderful! Here is where the CNC work is shining through. This is the way it should be done. 

 

I'm glad you haven't sent the frames above the level of the deck. Once the hull is planked, she'll have to look like she has steel frames; lots of soldering! 

[Richard Dunn]

6 hours ago, rshousha said:

I'm glad you haven't sent the frames above the level of the deck. Once the hull is planked, she'll have to look like she has steel frames; lots of soldering! 

About that
what I have planned for the Foredeck is to laminate the deck substrate with its camber out of 2 or 3 layers of .4mm ply over a form  the after end is housed in the heads and its forward end in the knightheads and its sides rebated into the bottom of the main rail which becomes the margin plank, therefore the deck is strong and not needing to be supported by frames at all. this means styrene can be used to create the framing seen under.
of course the samson posts and pillars will offer support though but the planking can be reduced in thickness to take up the thickness of the substrate.
2-3 layers of this .4mm 3 ply is very very stiff when laminated with epoxy, its surprising

A couple more shots of the forward longitudinals fitted, keep in mind they need to be clamped down flush with beams.
Also  the hatch coamings are not fitted yet, I have not cut them yet.

Edited December 18, 2023 by Richard Dunn

[Richard Dunn]

Fairness of frames

Slots for break of poop

 

 

 

Edited December 20, 2023 by Richard Dunn

[scrubbyj427]

Very nicely done!

[Richard Dunn]

I had The build moved to here  as I doubt I will get more than a handful of orders , currently 3 not including the client this is being designed for.
Anyway I have started to hand carve the rabbet for the 3mm cherry planking.

Riflers are being used to remove the high spots

 

Edited December 23, 2023 by Richard Dunn

[Richard Dunn]

I can finally show a dry fitted frame almost complete.

Of course this is all just leaning together right now and parts are missing but its the bulk.
The Foredeck housed into the heads, the forward end gets housed into slots in the knightheads, leaving the underside clear for styrene framing as per the actual ship. Note this is a standin Fore deck the actual is laminated over a form from 2 layers of .4mm ply to make sure the camber and fore and aft sheer is in the deck and needs no force to shape.

Details of the Poop construction.

The slots for the counter cant frames.
The variance in steps in the counter parts are deliberate and its designed to forma definite seat for the counter bulwark ply sheet so it sits in a rebate.

 

A nice shot of the frames and Rabbet

.

The deck joints came up well, they hold themselves together dry..

 

[rshousha]

 

Great job with this model. I sure wish I could participate more but I can no longer do so. 

 

Good luck to you. 

 

Best Regards, 

 

Rick 

 

[KeithAug]

She has elegant lines - excellent work.