Kevin-the-lubber

PietFriet, thanks, I never noticed that feature (note to self, to spend some more time on study). That would give a flat topped but properly wrapped cypher - is there another or better way to create the interwoven letters within F360?

Yes, it can easily have the height reduced and the profiles made more true to casting reality - rounded edges, a curved top - but I fear at even 1:48 it would end up looking like a smudge, let alone any smaller scale. Right now we are having a very cold snap (or a slightly cold day for you north americans and canadians) but once the weather warms up and I can print, I'll do some sampling.

I think '3D Printed' is just a logical extension of CNC production techniques. The computerised machine can't give things 'soul' the way a craftsman can, but 99.99999% of the time it can do it more accurately, reliably and efficiently. I think I'd feel more comfortable every time sat in a vehicle built by robots than humans - provided the design and programming are good, it's much less likely to be a 'friday afternoon job', if anyone is familiar with that expression! The materials and kit people like me are using are just toys, industry is using some very exotic materials and processes that presumably allow for much better quality control than in years gone by. What springs to mind is when I worked in shipbuilding: I could lay down as reasonable a weld as anyone but every now and then it might not be so good. In contrast, the submerged arc machine did perfect welds all day every day!

A bunch of us are creating STL's of a range of English cannons, a group project led by Allan. While the barrels are simple to model in CAD programmes, the cyphers take a bit more work and I agreed to share the way I did this one. First, a bit of preamble: I work entirely in Fusion 360. The method I'm going to describe is undoubtedly not the only way even in F360 so feel free to chip in. I played around with the surfacing mode first but that way led to madness! Extruding the shape from a 2D drawing is very straightforward in F360 but left me with two issues; it doesn't properly wrap to the cannon barrel i.e. the edges would be uniformly vertical when they should follow the curve, and it doesn't allow the interweaving of the letters. So what I did was use the 'sheetmetal' function, so that I could correctly wrap, and lofting to get the interweaving. It goes like this; Step 1: create a dummy barrel section. It needed to be hollow in order to be 'sheetmetal'. I use a thickness of 20mm but any thickness will be okay. This dummy section gets 'discarded' later Step 2: Cut away half vertically Step 3: add a flat flange in order to unfold step 4: convert to sheetmetal and unfold. this allows me to create the cypher in the flat, and wrap it at the end step 5: create a centreline sketch. I form the cypher 90 degrees off it's correct position, so that it doesn't sit astride the split/flange. If it sat astride, I'd have to made it in two halves. The important thing here is that this centreline is not vertical, but is set to the correct angle in the flat step 6a: position the cypher sketch on the centreline step 6b: an explanation of the cypher sketch. I'm making this in two parts - the crown, and the lettering. For the crown I simply extrude aspects to different heights in order to create the 3D relief. For the lettering, I create section profiles at different points in each letter and then loft the sections. This creates the sweeping under and over effect. The placing of the section profiles is entirely subjective and a bit of trial and error is needed. The centrelines through each letter are essential; the outer lines are only a rough guide and don't really dictate the finished shape. step 7: create planes at at angle (90 degrees) and section profiles step 8: loft through these sections step 9: extrude either side, and that's the first part done. step 10: repeat that process for all remaining parts of the lettering. A point of detail here is that lofting centrelines can't 'loop' so you have to break those sections into segments. This requires a lot of planes and section sketches, roughly 30 in this case. I worked to this photo to more or less replicate the interweaving (and have just noticed a little mistake on the 'R') step 11: make the crown via straightforward extrusion step 12: combine (join) the crown and lettering to the unfolded dummy cannon section step 13: refold the section step 14: cut away the flange and dummy cannon section step 15: rotate the cypher parts through 90 degrees step 16: combine with the cannon barrel and we're finished I hope that helps, happy to discuss and learn a better way!

I'd love to see the finished product. I know of a bridge being 3D 'printed' in Amsterdam, and I'm sure this kind of thing will become commonplace in years to come.

That vaseline tip is going to come in handy. As the accolades and plaudits reflect, your painting is simply jaw-dropping. As a side project I've just built a WW2 bomber straight out of the box and my pilots face STILL, despite all the wisdom and advice on forums like this, looks like a pink blob. I'm sure everyone reading knows exactly what I mean. Meanwhile, you're doing flesh tones and shading on a piece this small? It's like looking at the sistine chapel!

Great work Bill. Your experimentation with resin casting is very like the learning process with resin printing - 2 steps forward, 1 back, but bit by bit you figure it out.

This is one very intriguing project Ian - like some others, the arduino stuff goes way over my head but I can't wait to see the sea trials.

First off, that new version of the figurehead is stellar. Even though I'm more or less capable of doing quite a lot in 3D modelling myself, it won't surprise me if I head over to Daniel's shop for things like this when I go back to my Victory. Headband magnifiers - I only use mine in extremis because I find it so difficult to work with this on my head. It's when you need to look away that's the problem, i.e. to pick something up or whatever. I also have a lamp like Ross, but it only magnifies to about X2. Every now and then I look on the web for something 'perfect', which would be like this: it must be glass, not acrylic (the latter scratches too easily); it needs to go up to X4; it needs to be BIG! At least 5" or 6". I'm not sure such a thing exists or, if it does, is affordable. Even at X2 I'm hitting the lens with my brushes, but one day I'll probably cut down a set to suit.

Spyglass, that’s interesting and makes a lot of sense. The stays on the Cutty Sark are wire hawsers, for reasons which are now obvious when reading your post. I think I kind of understand the logic of raking the masts - I assume you’re trying to get the wind to fill / flow down to the bottom of the sail, as close as possible to the hull, but I’ve also read of masts being raked forward, which makes less sense as that must make the bow ‘dig in’. Either way, I’ve settled on the rake angles given by Underhill and kept them in line.

Thanks for your replies. Allan, no, in fact that hadn’t occurred to me so thanks, that’s a good suggestion. I was thinking that maybe it was a norm in tall ships, to possibly counter the increased flex you’d have all the way up there, but googling and searching on here hasn’t thrown up anything to back that up, so I’ll just assume it is indeed an artistic or printing error and keep them in line. But having started this train of thought, it’s got me wondering as to how much difference the rake angles made anyway. I’d have thought that the masts would bend forwards to varying degrees under the wind pressure. I imagine all of this was a somewhat inexact science that was sometimes beneficial and at other times, not.

Hello all, I've been working on 3D modelling masts for the Cutty Sark in recent weeks and noticed something odd on the Campbell ship plans and would appreciate some advice. I'll explain the question through two drawings; 1. I had assumed that the different mast sections (lower, topmast, topgallant) would all be in line with each other, as shown below; However, the Campbell drawings suggest the topgallants in particular are raked further than the lower and topmasts; The Campbell drawings are more illustrations than technical plans, so is this just artists error or did the rake indeed vary? Incidentally, I know the Campbell angles are slightly wrong, it should be 86', 85' 84' fore, main mizzen respectively.

It'll be a little, I think, while until I'm ready to 'show & tell'. The masts and yards are the final bit of 'making', other than blocks etc, and are a kind of gateway to finishing off quite a few other things. I've been looking at your sails - they are simply fabulous. I've only had one brief play around with the modelling tissue and didn't really get anywhere useful, so that's something where I'm still very undecided.

Bill, if you don't mind me saying so, one of the nice things about dropping in on this log from time to time is seeing how self-assured you've become - you seem to have a clear plan for this ship, know where you're going and are just getting on with it. That's an enviable trait, I always struggle with completing/finishing. Hope the COVID remains not so bad. I got it last year and the worst of it was that everything tasted of salt for a couple of weeks.

Vitus, there’s a lot to be said for 3D as part of the toolkit. Feel free to ask for tips, I’m no expert but I think I’ve probably travelled the main learning curve now.

Not quite, but he did give me some very expensive hardware that should make it fun going through airport security 😁

You're welcome Leo. In other news, I've had my ankle fused this week, ever worsening arthritis from a climbing accident in my youth which was taking all the pleasure out of physical activity, so I'm hoping the 2 or 3 month lay-off will see me finish modelling and making the masts. They've required a mixed media approach - some resin printing, carbon fibre stiffeners, wire eyebolts etc - and the cold winter has made this heavy going. Resin doesn't like being printed cold, paints don't like it either, and the failures/poor results get a bit exasperating after a while. So, I'll spend a few weeks doing all the remaining 3D work and resume the 'making' in the spring, when I'm weight bearing again.

Allan, I might have time as well. The barrels are quick and easy in Fusion 360, the fiddly bit is the decor on top. This is where it would be good to have a repository somewhere, for the drawings and .stl's.

Fourth & final set uploaded. https://www.dropbox.com/s/hqbl3se9q96kwjl/set4.zip?dl=0

Bill, interesting stuff - how brittle or tough is the epoxy casting? Sometimes you can get fantastically detailed resin prints but they won't bear being used, and I sometimes think I should try making molds for casting instead.

I haven't had much time for modelling stuff for the last two or three weeks. Set 3 of 4 is now posted. https://www.dropbox.com/s/pvovnu96bffc66k/set3.zip?dl=0. I may only leave this up there for a week as I'd like to be done with this now! I'll re-post set1 at the end, probably in two halves as it was so problematic last time.

Liquid bitumen of Judea… another art products lesson! Apparently used to caulk Noah’s ark. It seems to be readily available here in the uk (googling) so if you get stuck, shout out.

Have you looked at regular CAD type software e.g Fusion 360, Rhino, FreeCad etc? I may be totally wrong but when I started out myself a couple of years ago I got the impression that Blender wasn’t ideal for precision engineering, which is where you’re headed. What you described in post #1 is straightforward and quick in F360 or Rhino once you know how.

I don't want to muddy your water but can I ask what your end objective is? Is it to create purely virtual models or are you using Blender as a means to create components for 3D printing?

While waiting for the resin printing equivalent of paint to dry - a 10 hour print of the revised version of the lower topsail yard and topmast - I've been playing around with my recently purchased, second-hand Olympus OM-DE-M5ii. Trips off the tongue nicely, doesn't it, Olympus marketing staff definitely missed the memo about catchy names. Anyway, I thought I'd share these two pics to illustrate something which might be of interest to others. This camera has built-in focus stacking. That's a large part of the reason I bought it, as I also like taking macro shots of flowers, insects and whatnot, and it's always a little disappointing to have parts of the subject just out of focus, or a grainy (noisy in digital speak) result through stopping down too much. On the left is what stacking delivers - see how the yard is in focus for the entire length, without compromising the quality. On the right is the same shot without stacking. (The design of this yard has been re-done already, this one, with lots of errors, is just for illustration)