More stupid problems from a noob

I think you’ll find D loft far more forgiving and less frustrating. Then trying to model developable surfaces in Rhino alone.

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I think you might struggle to get an accurate shape for the cover with the geometry in this dxf, - it especially needs cross-sections to build the surfaces.

I haven’t done this type of job so others may have better ideas, but I considered how I would approach this task and came up with a few thoughts. I would re-measure with the 3D modelling in mind.

While measuring, imagine building the surface in the model, i.e. maybe digitize both sides of a fillet radius, or flange, - the actual fillets can be added in Rhino and much easier to model up the base shape without the fillets initially. Measure the radius sizes though, to add into the model.

Ignore bumps for fittings in the base measure and treat them seperately - same story with fillets as the surfaces can be extended to intersect in Rhino.

Digitize cross-sections where you think they would be needed to help with the surface modelling. Try and keep them aligned nicely, maybe run along masking tape.

Ideally you would end up with 2 digitized complete rails and 2 end cross-sections and for each surface and maybe a central section (or more if curvy). This creates the geometry for a surface on each part of the boat where the cover makes contact. Some string would be handy to see where the contact areas lie, or seam lines, could measure the string lines as a guide for the finished cover.

The Proline datum should be somewhere you can return for additional measurements if needed. The geometry can be aligned and levelled in Rhino. A Tee in masking tape on the Cline might work, or fixed parts on the deck?

The following sketches are how I would align the input before starting any modelling…

tonneau05 new orient box05 (Test).3dm (1.1 MB)

Yes, it’s my main job, have been modelling boats and boats bits, big or small, to turn out drawings or cut-files for a while now … Enjoy coming here to learn new tips and techniques every day.

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Wow Brian that’s a lot of work you’ve done to help me out. I owe you a beer or three :grinning:.I knew there were a few things wrong with that ski boat when I got it onto my laptop, that was attempt 5 . The boat was on a trailer standing on gravel so I think the leaps I had to do have too much deviation in the Z axis , you can see that if you look directly at the bow from the front and the snap locations I measured twice on the starboard front. When making this cover with a plastic pattern I would only really pattern to the snap fasteners then in the shop lay the pattern flat and add 3/4" outside the snap marks so was thinking more about the fasteners than the hull. I didn’t plan on measuring so much hull but when on the job thought I might as well go ahead and do it. And you’re so right about layers, I just plain forgot to layer my measurements and the 3 point reference, which on the 5th go I had moved the box outside the boat so couldn’t get to the boat deck inside to place the triangle there. You might also have noticed I completely missed the snaps midships on starboard side :grinning: partly because the proliner screen is really hard to see in the sun. I’ll have to ask the customer if he can put it back on the trailer and do it again… sitting in Tesco carpark right now but will study your post in detail tonight and post a pic of the boat
, thank you so much for your help. I thought you had to be a boat guy hehe. Richard

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I’m sure. It’s also the cost that puts me off for now . It’s another big expense when I’m starting out on this digital adventure. Buying rhino and the proliner wiped me out for now. If only there was a price plan for people starting out to help them get going then we couldn’t do without it when established. A bit like Google did when starting out , or drug dealers hehe .

Trying unflatten double curvature surfaces is always going to be an estimate. We don’t do boat covers, but it is an industry I know very well as we have designed many products for the cover maker.

As you get better at Rhino, try out other options for unflattening and setting up cutting patterns. We do tensile fabric structure work for one customer, primarily form finding work, and use MPanel. They also do a module specifically for cover manufacturing so definately take a look at that.

Pascal is right, nearly all boat canvas work would be symetrical if care is taken manufacturing frames correctly.
The data taken with a proliner will produce unclean curves that need cleaning up and we do this, a true faired curve is often the correct curve.

with expirience you will learn to build panels that will flatten.
Sometimes you will need to segment panels, build up the structure with seams that will form the 3d shape.
If templating with plastic, the plastis will distort to give you a clean finish, imagine templating with something akin to kraft paper with no distortion.
if you had to make a cover for a beach ball, the only way to build using a 2d material is to segment and use the seams to build the shape, imagine an old fashioned football.

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I agree, steer clear from mesh surfaces for canvas work. You need to create panels which can be unrolled.

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That’s interesting. I got asked if I could make a Capri tent by August in black is that something your customer could do ? I went ahead and bought d.loft but as far as I can see it’s more of a pain in the bum than rhino loft

Cheers for the advice jaybee. When I flatten a surface is there a way to predict or check that it is a valid pattern ? Only thing I can think of is actually run a tape measure over the boat at a few points and check against the surface back at the shop.

Hi Richard,

We have not really used check measurements and have found Rhino to be accurate using the proper techniques.

You could cut out your project in templating plastic and tape the seams, perhaps with 1 row of stitching to try.

I guess we have been lucky, we had canvas fitting from day 1.

However, we had used 2d cad for years prior and had already been using Rhino before using a Proliner so skills were already embedded.

I think its key to learn to simplify, clean up curves, know when and where to split surfaces so that the shaped seams pull in the shape you want.

When you learn these techniques, it does become easier and much, much quicker. With cleaned up geometry its much quicker to generate surfaces that flatten as you’d expect.

Personally, I’d recommend always building 2developable" surfaces, surfaces that can be either unrolled, or unrolled UV. If they need squish, perhaps they should be segmented.

I tell our staff to imagine you are working with kraft paper, wall paper or similar. Sunbrella works in a similar way, you can’t compress a 3d shape into it or extensively stretch it. You need seams to build in the shape, so imagine you are on the boat templating and you will know where you’d would expect to have to have a seam or dart and draw these lines in the cad and generate surface’s based on the perimeter and these seam lines.

Here is a link to the “first” project we did with Proliner data and Rhino and it fitted first time., i reckon this was close to 10 years ago.
http://www.tecsew.com/cockpit-enclosures-motorboat/elektra-tender-cockpit-bimini-enclosure

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Hi JB
Yes i’ve been told a few times now to clean up my curves and i’m working on that, the more I do the better I am getting at spotting where and how to do the clean up work. i’m being super cautious as I don’t want to change the geometry to a point where it doesn’t fit any more. I measured a building for one of my industrial customers today with the proliner so doing some design work on that and I have a digital made cover to fit asap, i will let you know if it fits or not hehe . New guy starting Tuesday so hopefully i will get a bit more time on Rhino but we will see.

Not a bad cover at all for a first go with a proliner i’m sure the customer was happy :slight_smile: I have one this week moaning about this one !!! you can grow to dislike customers sometimes :wink:


,

Looks like a good job to me, what’s his complaint?

What we do is copy all the original geometry onto a layer with a different colour and only turn that layer on when we want to compare modified geometry to the original.

Only the copied geometry is modified.

Create a template with your layers and make use of them and also use of different colours.

Best regards

John

more golden advice, i’ll copy the geometry from now on, thank you.

he has a huge list… I was patterning the cover and his wife said " when you’re done i will get a new stainless frame made" … I told her it doesn’t work that way so agreed to make a frame first for her… so another trip right there . and so it goes on, you know those jobs you get and you just can’t satisfy them no matter what you do. . the top actually fits better than the pic as I was only half way through fitting in that pic.

I’ll remake it but they will be waiting 8 weeks at least while i get jobs done that actually pay :slight_smile:

Richard

We all get one or two clients who are troublesome, good luck with keeping them happy.
WIth cleaning up the geometry, you will see that most of the changes that are made from the original are what you would expect. Wind, vibration and human error build slight inaccuracies into the digitised data and you are just cleaning this up and getting back to good clean curves.

hee cheers JB, I told him i’m not going to spend a week adjusting and messing about so will remake the cover but at the end of september and he needs to bring the boat to my quay so i’m not driving miles…

I have been worried about fiddling too much with the geometry but with the great advice I am seeing the errors in a different way and need to get stuck in smoothing and rebuilding etc …