Where to find boat-specific geometrical info or 3D computer model of Catalina 30

[Hope_I_Float]

Top of the New Year All,

I'm wanting to use a 3D computer model of my Catalina C30 MkI as a tool to help plan and manage various projects and upgrades. I know ... don't say it!

Poking around on the internet hasn't yet surfaced any models I could use as starting points which surprises me considering this particular boat's popularity, but no luck so far (I may well not be searching in the right areas).

There are of course all sorts of software packages which could be used to model it from scratch, which is where I am presently, but my challenge initially isn't 'how to create a computer model' (I have some basic modelling experience in other areas), but rather where to find the technical information required to model the boat properly (e.g. reasonably accurate hull profile, sole and liner profiles, dimensions of internals/equipment, etc.).

I have the original owner's manual which contains some useful information for this purpose (e.g. wiring diagrams, etc.) but little of the detailed physical geometry needed to model.

Design parameters for the main dimensions as well as for some of the equipment aren't overly difficult to measure off (time-consuming though) but the trickier shapes like the hull, and cabin sole as well as the location of stiffening ribs etc aren't so easily captured. Given that this is a hobby, i'm ideally trying to avoid resorting to point cloud technology to acquire this information (unless this can be done for a few hundred bucks; everything I'm aware of on that front would reach costs into the 4 digits).

Short of contacting Catalina directly (my guess would be that they would be understandably guarded about releasing that information for commercial-sensitivity reasons), does anyone know of either a fairly complete model to start with or where this type of modelling information could be found?

Thx.

[Raven Odyssey]

Originally Posted by Hope_I_Float

Top of the New Year All,



I'm wanting to use a 3D computer model of my Catalina C30 MkI as a tool to help plan and manage various projects and upgrades. I know ... don't say it!



Poking around on the internet hasn't yet surfaced any models I could use as starting points which surprises me considering this particular boat's popularity, but no luck so far (I may well not be searching in the right areas).



There are of course all sorts of software packages which could be used to model it from scratch, which is where I am presently, but my challenge initially isn't 'how to create a computer model' (I have some basic modelling experience in other areas), but rather where to find the technical information required to model the boat properly (e.g. reasonably accurate hull profile, sole and liner profiles, dimensions of internals/equipment, etc.).



I have the original owner's manual which contains some useful information for this purpose (e.g. wiring diagrams, etc.) but little of the detailed physical geometry needed to model.



Design parameters for the main dimensions as well as for some of the equipment aren't overly difficult to measure off (time-consuming though) but the trickier shapes like the hull, and cabin sole as well as the location of stiffening ribs etc aren't so easily captured. Given that this is a hobby, i'm ideally trying to avoid resorting to point cloud technology to acquire this information (unless this can be done for a few hundred bucks; everything I'm aware of on that front would reach costs into the 4 digits).



Short of contacting Catalina directly (my guess would be that they would be understandably guarded about releasing that information for commercial-sensitivity reasons), does anyone know of either a fairly complete model to start with or where this type of modelling information could be found?



Thx.

Call me skeptical, but I highly doubt you will be able to find dimensional CAD drawings. If they were available, it would give a competing manufacturer a huge head start in the R&D of a new boat and potentially theft of the design itself.

[Hope_I_Float]

Thanks for touching base Raven.

I hear you and that has been one of my concerns. Conversely though, a competitor who wanted those dimensions would be able to get them in a jiffy with relatively basic equipment and technology (I'd suggest under $50k, equipment, software and labour to copy the whole thing out using modern technology). While a cost of that magnitude or even a portion of it would be completely out of line for me relative to what I'm trying to do, it would be a drop in the bucket for a manufacturer setting out to build a new boat.

I've seen hull profile drawings for other boats but not mine.

I do agree with you though that the odds of finding such drawings are quite slim. I'm hoping that someone as silly as me might actually have gone to the trouble of modelling a C30 and would be interested in sharing their model (I know I'd be glad to make mine available after I was done with it) or that someone knows of some relatively low-cost machine vision or point cloud technology which would be used to do this cheaply. I know how to do it but only with the high-end stuff.

[GordMay]

Greetings and welcome aboard the CF, Hope.

[UNCIVILIZED]

Other than being curious as to WTF you're going to do with this info, I highly doubt that anyone considers it as sensitive. Since as stated it would be easy to measure with very precise accuracty, & anyone wanting to do R&D based on the design would be stupid not to measure things for themselves instead of relying on theoretical drawings.

So... you might try over on www.BoatDesign.net/forums and yes, I'd try Catalina direct. Especially if you can articulate a decent answer as to why you desire such info.
Also, find out what firm designed her. They'd likely be another resource to try. As I know that some other design firms tend to assist owners of their boats if approached directly, instead of an owner going to the boat's builder.


BTW, what are you using software wise for this project?

[Stu Jackson]

2D to 3D is easy: the brochure already has everything you need. The layout plan is there, as is the boat profile.

To develop a model, you need the top and two side views.

The brochure gives you two of the three.

You have to do the work to develop the third. (Orthographic projection? Maybe, I forget, it's been 50+ years...)

Not too hard, especially if you "know" the boat.

But I sure wouldn't use what you end up with for critical measurements.

Why? 'Cuz it might be off a tad AND 'cuz while they built 6,000 of them, even with a production boat, there are variations from boat to boat.

[Hope_I_Float]

Hey UNCIVILIZED,

Thanks for the BoatDesign link ... wasn't familiar with that site. I'll check and perhaps post there too.

I've got a few projects in mind, the first being that I want to design a better winter storage frame which mounts off my cradle instead of clamping onto the boat's stanchions (the boat is often exposed to 40-50+ knot winds during the winter season and the wind loads on the tarp and cyclic loads get transmitted into the boat's deck via the tarp ribs attached which ultimately pass their loads to the stanchions ... great way to propagate fatigue cracks in my mind ... i've been inside the tarp in one of those gales and it's hardly kind to the boat).

Another project involves mods to the running rigging, add a reefing arrangement, and re-route lines back to the cockpit etc. to make life a bit easier when soloing. I like to plan in 3D and try a bunch of different configurations with the actual dimensions of the planned equipment and when I think I've got it nailed then check it out on the boat for final confirmation.

Even though I've been a bit doubtful as to Catalina wanting to release their info I was going to check with them to see ... just in case. Good idea to check with any design firm they may have used. Not sure who that might be for my boat but I'm sure that info is findable.

As for software, believe it or not, I was going to use Sketchup for starters. I could use SolidWorks or Autocad 3dsMax or perhaps Inventor but I can get started fairly quickly with Sketchup.

[Hope_I_Float]

Hi Stu,

Thanks for chiming in.

You're right about the basic principle of using 3 views and I do have a plan and side view of the boat, which I've used for starters (see image as an example; that's for a mkii but I believe the hull is identical to my mki) but the catch is with the end view because that view changes drastically cross-sectionally as you move along the boat. That's the key issue for me and I haven't come up with an easy way of getting the hull's cross-sectional profile along its length yet. It's not impossible but cumbersome as heck to measure physically with just basic tools (unless there are some tricks I haven't thought of ... and there could be many).

Totally agree with you too not to rely on the model for final fabrication dimensions of anything given the inherent inaccuracies likely to creep in.

[UNCIVILIZED]

FWIW there's software that deck hardware companies such as Harken use in order to design, or re-design such layouts. Which, at times I've seen versions of it available. But measuring a deck for hardware takes an hour, if that, on a Catalina 30. So you'd be better off just to do that bit by hand.

For a frame for a tarp enclosure, just take your cordless screw gun with you, pick up the lumber, & have at it. Again it'll be easier to build on site than to jump through all of the hoops you're considering. Though of course, do a couple of design sketches first. So that you know what size lumber, & how much, etc. And you may find it simpler to just take the framework down to ground level vs. mounting it to the boat's cradle.

Also, would any of the wire frame modeling programs be of use to you, or are they too outmoded by now?


PS: It's not uncommon to find a bit of assymetry in both the hulls, & decks of boats. Which is some of the why behind a few of my comments above, & likely those of other CF members too.

[Stumble]

If the year had it I doubt Catalina would share it. But for a 1985 boat I doubt they ever had 3D CAD files anyway. Until very recently when the plugs started to be made by multi-axis cutting machines there was simply not much need to do so. For boats at least a decade newer than yours there might be a wire frame file somewhere for FEA but only for race boats.

On the other hand there are services that will show up and get a perfect 3D map of your hull using LIDAR (I believe it is). I don't know the cost, but itisnt uncommon for high end race boats to have it done to check keel/rudder alignment and shape.

[Hope_I_Float]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Hope.

Thanks a bunch Gord. I started using this forum last year and have been really impressed with this community. Hope I can contribute as time goes on.

[Hope_I_Float]

Uncivilized,

Good idea to look to the hardware manufacturers too. I'd fully expect many of them have such programs with a pretty comprehensive library of parts to draw from. In fact I'd wondered if some of them might actually be a good source for the type of info I was after (re: where do they get their information for various boats or where do the companies which specialize in rigging upgrades get their info for the various boats).

I recently came across a piece of software which I have yet to explore called DELFTship. It's a hull modelling package. As a tool, it could well be helpful but unless it contains some of the hull data i'm looking for it its databases, I'll still need to dig out or create the basic hull data to work with.

As for building the tarp frame out of lumber, I gave some thought to that. I suspect you're right that all in all, cost and labour, it would probably be the quickest/cheapest. In fact the previous owner had built a mast stand which sits on the foredeck (looks a bit like a lifeguard chair) and a gerry-rigged support in the cockpit for the other end (this prevented access to the companionway so not good for my plans of working on the boat through the winter). I started using these lumber stands plus the boom as a ridgepole (instead of the mast, which I've laid alongside others on a storage rack at our marina) and some PVC tubing (heavy water line) arches as supports for the tarp. This is the arrangement the previous owner had used but I suspect his storage location was a lot more sheltered than mine. I'd hoped to make due with that for now and to start building myself a proper tarp frame but the first couple of storms to hit our area this fall highlighted the fact that this arrangement wasn't going to stand up for the winter (too much give in the arches and the tarp started to tear at the stress points).

I'm after something slicker which is easier to erect and take-down as well as to store in the off-season. Most of the companies doing this type of thing seem to use EMT tubing or something similar and related tubing clamps or tube fittings. The idea of building it to the ground has occurred to me though, or to tie the frame back to the cradle closer to the ground using only lateral supports either back to the upper portions of the cradle and/or jib sheet traveller track (name?).

The frame design will ultimately be an exercise in compromises. Roomier is easier for working inside the boat in the winter but wind loads (on everything) and material costs obviously go up (more so relative to the tarp) with size.

There are several other projects I have in mind which I didn't want to bore all of you with. Those will be made a little easier with a decent model to work with. I hope to leverage the model for multiple purposes as I go along.

As for wireframe modelling software, a few years back that would have been the way to go. Surface and solid modelling SW has come such a long way in the past couple of decades that it's now easier to go straight there.

There are now some fairly slick tools available on the market like the Leica 3D DISTO which export to CAD software. There are all sorts of

youtube video examples

how these things are used. But these hardware/software packages are still pricey (e.g. $10k + SW) and carry their own learning curve.

More promising for my uses are the more recent point-cloud scanners which are starting to surface for use on tablets and stuff which export to CAD. One such gadget is sold by Structure Sensor. There are many more. A company called

Canvas

integrates this sensor with 3D scanning software. They have an interesting business model where I think they charge a fee (it may be quite reasonable, haven't checked) to convert the point-cloud data to a CAD model for the end-user. I haven't used one of these small scanners yet but it's starting to look interesting and price points are more in line with my budgets (e.g. the scanner for Canvas I think is $400.). I'd have other uses for it around the home.

Thanks for the ideas.

[Hope_I_Float]

Hi Stumble,

Yeah I realize 1985 is pushing it a bit as far as likelihood of finding original files. But even 2D dwgs with cross-sectional info would have helped.

We were using CAD (and just getting into CAM) in the early 80s but I'm not familiar with the practices in the shipbuilding industry or naval architecture at that time.

In terms of quickly getting a model in hand, your suggestion of an on-site service is likely very sound. I have yet to make enquiries. My hunch is that for this to be worth it to someone to come out for a few hours (we're several hours away from the larger urban centers) would probably push the cost into >=$1k or more.

Those new iPad scanners (or perhaps similar scanning apps for mobile devices) might be the way to go (I added some comments on those in my reply to Uncivilized). I'd likely be into the same cost but I'd then own the equipment/software necessary to keep developing this.

In posting, I'd hoped someone might just have modelled a C30 and would have been interested in sharing or collaborating to improve the model. But even if I have to build it from scratch, it would be a useful learning experience.

Cheers and thanks for your help.

[Hope_I_Float]

An example of what could be achieved with a proper laser scan is illustrated in this

youtube video

. The 3D model which is shown in that clip was generated from the laser scans. I think it may have been produced using a FARO Laser Scanner.

This is a far more detailed model than I would be after but it shows what's possible.

[Eigenvector]

There are a few open source photogrammetry packages available to generate your point clouds from successive photo frames. Just google it.

I have been watching PIX4D.com over the last couple years and it looks pretty slick but I haven't had an excuse to try it yet. They have a subscription type service in which you can buy a month of time. The nice thing about PIX4D is that you're using their CPU horsepower to crank through the reconstruction which would be brutal on a PC (non cluster) system.

I dealt with scanned cloud data of of hulls and other things in the past. You don't really want the raw data but a best fit surface representation of the data you've scanned. This results in orders of magnitude less size of your models.

Assuming the boat is on the hard here's what I would do to get the hull into CAD. Set up a datum line parallel to the hull for the entire length of the hull. Take measurements from the datum line to the hull (X dim) and from the same point on the hull to the ground (y dim). Repeat at this datum location at various hull depths. Increment forward on on the datum line say 2 ft and repeat. Basically you're determining the cross section of the hull at 2 ft intervals. Pull these sections into your CAD program mirror the symmetric halves, and do a blend between the sections. This requires at least two people.

OR..............

I'd spend the $400 or so dollars for a month of CPU time. Get a a high res video of everything inside and out but break the project up into as many separate files (resulting surfaces from PIX4D) as practical. Pull in each point cloud and generate a new surface. Stitch the new surfaces back together to make your super duper cad model.