Jesus Boat ... Rhino

[tabycz]

I have started modeling the Jesus Boat in Rhino. There are some screenshots...

 

 

 

 

 

Edited October 7, 2022 by tabycz

[Waldemar]

 

Very nice. What (historical) sources have you used, if any?

 

 

[tabycz]

The base and main is monography --> The Sea of Galilee Boat

[Waldemar]

 

A full 3D reconstruction is intended or just the boat's hull?

 

 

[tabycz]

I want to build it . So, full reconstruction.

[Waldemar]

 

Better yet, please make it quick so I can peep how you'll handle the rigging.  🙂

 

 

[Kevin-the-lubber]

Tabycz, are you interested in talking geeky methodology? I know this can be very boring for some 🙂. I've just finished modelling a clinker built boat in F360 and had to jump through hoops to loft the planks, would be interesting to compare notes as I doubt my way was the best. Waldemar, that's the lifeboat you helped me with, couple of quick snaps below, whole moulding was perfect. I'm in the middle of painting them so the seats are not yet glued in but (IMO) these little boats look gorgeous once they're all painted up. I'll do a proper log entry when it's finished but I've posted photos of the gig and jolly boat on my cutty sark log.

[Waldemar]

 

Kevin, your boats look gorgeous both painted and unpainted. When it comes to lofting planks in CAD, I find it the most difficult task to do on a regular/systematic basis. Relatively flat surfaces are easy, but with heavily convex shapes insurmountable complications arise. Some improvisation is then needed.

 

Perhaps Tabycz would have something to say....

 

 

[tabycz]

I agree. It's a challenge.  I am still looking for right solution. So. If you have any tips. It will be great! 

I will make another planks. These are good but it isn't good enough. 

 

@Kevin-the-lubber: So. I am interested in talking geeky methodology.

 

 

 

[Waldemar]

 

Pipes could in theory be the ideal tool, but in practice they generally do not work well. Those with a fixed radius can only produce rectangular boards, i.e. having parallel edges (not very useful as you know). And those with variable radii are usually generated by software with a less than acceptable shape that is very difficult or impossible to correct. Not a bad disaster.

 

The most reliable method I've found so far is to divide the station/frame profiles by an equal number to get a run of planks. But not all the way through, as this usually has to be done segment by segment, with each segment covering only a few runs of planks. Alternatively, from one wale to another (externally) or from one deck to the next (internally). Still, quite a lot of manual adjustments are usually needed.

 

 

[Kevin-the-lubber]

I fudged it in the end. I really wanted something that was mathematically driven - I'm sure you know what I mean - but I couldn't figure out a methodology for the end profiles. I basically did what you see below; I got a smooth skin by lofting a whole-mould-based set of profiles (the green lines here) which I used to fair the shape. In faact I had very little fairing to do as (I think) whole-moulding generates smooth curves. I then drew strake profiles in a clinker pattern, evenly spaced in the station profile, and lofting rails for each strake, otherwise it all goes a bit mis-shapen; and lofted each strake individually. I had to abandon the maths at either end as the end profiles are perpendicular and don't lend themselves to mathematical segmentation, so I projected the rail lines and extended them to get the placings for the strakes and tweaked by eye until they looked right. (It gets more and more like real shipbuilding as you go along!).

 

I tried to make a single clinkered station profile i.e. to loft all 10 strakes simultaneously, but got nowhere, I think this geometry was way too complex for F360's engine.

 

Last but not least, and I'm guessing you've done something similar, I did another shell (one of the inner smooth lines on each profile), thickened, then split it (intersected actually, in F360 speak) to get the frames.

 

 

 

[Kevin-the-lubber]

ps. sorry, I meant to ask - what's wrong with your planks, they look pretty good from here? In fact your model looks way better than mine, you've already sorted out the tricky sections at the ends. Whatever you're doing, I'd carry on with that.

[Waldemar]

 

Kevin, I am about to describe my method of shaping clinker planks, but need some time to prepare the accompanying graphics.

 

 

[Waldemar]

 

24 minutes ago, Kevin-the-lubber said:

ps. sorry, I meant to ask - what's wrong with your planks, they look pretty good from here? In fact your model looks way better than mine, you've already sorted out the tricky sections at the ends. Whatever you're doing, I'd carry on with that.

 

I think I know what is involved. It's the same with my model. It's just not possible to get the course of the strakes in such a way that they have a perfect course in every projection. But the same effect must have been in real ships.

 

 

[Waldemar]

 

Here's my method for clinker strakes. Actually, I have used its simpler variant, as my surfaces were much flatter and more or less vertical. It means that in step 4 I have made even dividing in vertical direction, and not along the frame profile. Consequently, in step 5 my cutting surfaces were horizontal, and not perpendicular to the surfaces to be cut.

 

step 1: two frame surfaces, inner and outer
step 2: frames created, outer surface left for the next steps
step 3: outer surface offset by roughly the plank thickness
step 4: dividing plan for both surfaces (must follow the run of the strakes set beforehand)
step 5: creating cutting surfaces
step 6: both surfaces split
step 7: lofting the inner surfaces of the strakes
step 8: inner surfaces of the strakes offset as solids
step 9: (Boolean) cutting edges of the strakes (optionally)
step 10: (Boolean) cutting of the frames

 

 

 

 

Edited October 8, 2022 by Waldemar

[tabycz]

It is an insteresting. Let me know how you solved ending at stem and stern where planks aren't with overlap. See photo what I mean. ;o)

 

https://classic-sailing.com/wp-content/uploads/2020/11/freya-tender-bow-1000.jpg

[Waldemar]

 

It must be done by manual correcting the longitudinal guides ends. This correction should start more or less equidistant from the posts to get decent results. Quite lengthy process, but perfectly possible. And, in a way, just like in real boatbuilding techniques.

 

 

[Kevin-the-lubber]

I think we're using quite similar methods, tailored to our respective CAD packages. As mentioned, I also corrected the two ends manually. I didn't find this too time-consuming in F360, I think it was mostly a case of projecting the guide rails onto a flat sketch, then correcting the two ends, plotting their positions on the end profiles, then remaking the guide rails to incorporate the ends.

 

This is what I did at the ends, compared to the centre profiles: I used exactly the same overlapping approach as for the centres, but without the clinker offset. I didn't shape the frames to the strakes, the strakes just sit on the frames. I don't know if this is how it is in real life? At this scale (1:100) you wouldnt be able to see the notching anyway.

 

 

 

 

 

 

 

[vaddoc]

Now this is very interesting. @Waldemar very elegant way of developing the plank overlap and frame notches.

The biggest problem is indeed finding the run of the planks. I fiddled with it recently but could not make it work. Of course, CAD programs can unroll a curved surface so the shape of all spilled planks can be created. @tabycz your planks look fantastic. How do you draft the run of the planks on CAD?

 

[tabycz]

So. Further progress... ;)

[Waldemar]

 

Impressive! Clearly now you have made the arrangement of the frames more realistic by dividing them into floors and futtocks.

 

Just wondering, how it compares with the archaeological documentation, as I do not know the Wachsmann's monograph, just pictures of other models found on the internet. My guess is that the frame layout is somewhat idealised (i.e. made more regular), as I did in my reconstruction.