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Is CAD for Me?

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Barrie Lever23/06/2019 10:38:27
244 forum posts
38 photos

Nigel

You really must take a look at the youtube link

https://www.youtube.com/watch?v=2l7Uxwxzfik

No need for a scanner it all can be done from 2D drawings.

The best hobbly level 2D reverse engineering is done with domestic flatbed scanners rather than photos, that is the subject of another thread though. The 2D section can then be sweept down 3D lines. All another subject though.

Regards

Barrie

Barrie Lever23/06/2019 10:40:05
244 forum posts
38 photos
Posted by Gary Wooding on 23/06/2019 08:13:55:

Barrie.

Fusion has a facility called Attached Canvas, which allows you to insert images onto any plane or surface you like. Each image can be scaled as needed and used to guide the creation of the model features required. The visibility of attached canvases can be controlled independently, from the model, and from each other. The opacity of any canvas or model can be controlled from almost transparent to fully opaque.

I don't know MOI, but from the video it would appear that organic shapes are created from sets of contour lines defined as splines. Fusion is quite different. It has a facility known as T-splines which allow the direct creation and modification of surfaces in 3D - rather like moulding sheets of clay. That's how the shoes were created. I would like to make it clear that I didn't create the shoes - I'm nowhere near that level of expertise.

Gary

I have looked at attach canvas. looks useful.

Thanks for the tip.

Regards

Barrie

Nigel Graham 226/06/2019 10:51:42
298 forum posts

Barrie -

I asked about scanners following your remark about photos.

That could have even helped my own project, as I have nothing but old archive photos and a few dimensions.

The big difficulty though, is a photo is usually at unknown angles to its subject, and from an unknown distance, so simply scanning it would give a distorted result. If the subject is long, such as railway locomotive or a building, the photo may also be affected by perspective.

I recall an article a long time ago, I think in ME, that described how to correct for these manually, provided you know a few key dimensions. For the locomotive this may be the coupled-wheel diameter (by its height, if all visible) and track gauge.

For my wagon, I used the wheel diameters and overall length and width, quoted in old trade reviews, but to make it more fun, E.S Hindley & Sons did not appear to worry too much about standardising theri products, and the reviews' illustrations were not necessarily of the wagon the reviewers test-drove!

I don't know if the software you describe can correct for both of these distortions.

As far as I am aware, TurboCAD doesn't read scanner files, which are images types at least from my scanner; but I think it will accept other drawing files. Its default saving is in its own " .tcw " format; but you can save its fully-rendered pictures as .bmp (and .jpg?) images.

+

Alibre's sales people don't seem to talk to their agents, but they do want you to buy their software!

A lady from its own American offices no less, asked me yesterday how I was progressing with the trial.

I replied I had failed; explained why, and that as the trial and its licence have expired I'd now have to buy the full version but it would be silly to spend £250 on something I can't learn! Then added I had already deleted Alibre from my computer ("Deleted" it, files and folders, as I could not remember how to "uninstall" it.)

I'm not expecting a reply of course, but I would not surprised if she tries to persuade me otherwise, since she is paid to sell it.

Tomfilery26/06/2019 11:11:29
110 forum posts
4 photos

Nigel,

Although TurboCad won't read your image files directly, you can insert them into a "drawing".

I frequently insert images (usually jpeg ones, perhaps copied from a book, or magazine) into a drawing, then blow them up to the correct size for my project. You often have to scale them separately for X and Y and most drawings do have some degree of distortion, so you won't be able to "trace" an image ultra accurately.

I usually draw my drawing, based upon the information in the image, then move the image over the drawing to check it looks about right.

Have done it with all sorts of locos and rolling stock - even used it to draw out a wagon, based on a few key measurements and a photograph.

Regards Tom

Neil Wyatt26/06/2019 11:16:35
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16084 forum posts
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73 articles
Posted by Tomfilery on 26/06/2019 11:11:29:

Nigel,

Although TurboCad won't read your image files directly, you can insert them into a "drawing".

I frequently insert images (usually jpeg ones, perhaps copied from a book, or magazine) into a drawing, then blow them up to the correct size for my project. You often have to scale them separately for X and Y and most drawings do have some degree of distortion, so you won't be able to "trace" an image ultra accurately.

I usually draw my drawing, based upon the information in the image, then move the image over the drawing to check it looks about right.

Have done it with all sorts of locos and rolling stock - even used it to draw out a wagon, based on a few key measurements and a photograph.

Regards Tom

That's exactly how I did the drawings for much of my Southam loco.

Neil

SillyOldDuffer26/06/2019 11:50:00
4405 forum posts
957 photos

Posted by Nigel Graham 2 on 26/06/2019 10:51:42:

...

A lady from its own American offices no less, asked me yesterday how I was progressing with the trial.

I replied I had failed... Then added I had already deleted Alibre from my computer ("Deleted" it, files and folders, as I could not remember how to "uninstall" it.)

...

Deleting files manually is liable to leave a mess causing mysterious trouble later.

Problem is that Install usually does more than simply copy files and folders to your computer. For example, on Windows, an Installer is likely to put DLL's into system folders and update the registry. It might also monkey with permissions and other internal system features the owner is unlikely to understand.

Usually best to Uninstall software as recommended by the vendor.

Dave

Nigel Graham 226/06/2019 11:50:21
298 forum posts

Thankyou Tom.

I didn't know you can do that!

It's not something really covered in the only two CAD "primers" I have found anywhere, by DAG Brown and more recently, Neill Hughes; and sold by our very valuable specialists, TEE Publishing

I don't think Mr. Brown describes it at all; whilst Mr. Hughes tells us more what can be done than how to do it. His example of using a scanned 2D drawing to guide the CAD version seems much as you describe, and he notes the value of the original drawing's scale-bar.

Hughes also mentions 3D scanning, but only briefly and fairly clearly as what's done industrially. In fact his book's sparse bibliography lists only reference-works for professional designers and production-managers. Having said that, versions of such books written early in the 20C are very useful when trying to replicate an Edwardian machine without its original drawings, for showing contemporary practices, component proportions, etc.

If really stuck I have sometimes gauged details by parts that need literally be measured in "hands" (well, the machine develops or absorbs 'horsepower ' ... ) and other anthropocentric proportions, such as handrails, steps and the grips on the ends of levers. Essentially, think in likely full size, and how it was operated, first.

JasonB26/06/2019 12:15:44
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15518 forum posts
1594 photos
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Nigel, although it does not go into much detail about the initial working from a scanned drawing this thread is a good example of all the CAD, CAM, 3D printing, CNC, etc methods coming together to make a model pump.

Nigel Graham 226/06/2019 15:28:47
298 forum posts

Jason -

I am impressed! I can still appreciate the skill involved even though disappointed by my attempts.

I've know for a long time you can make machine-control files from CAD drawings but I hadn't known you can translate even images like that catalogue engraving into the CAD drawing to start with.

I read their remarks about the distortion given by the angle of view, and so used known vertical heights to start establishing the correct horizontal dimensions.

I don't think the SolidWorks and AutoCAD they used are available to private customers in the UK, but I imagine you can use Alibre or Fusion for similar? (Fusion and AutoCAD are by the same company anyway.)

I first met CAD as SolidWorks, at work, but just by observation not experience; around the time TurboCAD was being advertised in ME. It was there too that I encountered the practice of putting a pictorial rendering in the corner of the orthographic drawing, to help visualise the work-piece. Hemingway Kits follow the same practice.

'

SillyOdDuffer -

Thank for you for that advice. I found "Uninstall " eventually. However, it could not remove Alibre because it could not find what I assume are Alibre components. I tried to repair / recover the programme to uninstall it properly, but to no avail.

So I am stuck with a programme I wanted gone because I could not use it, but I've now damaged so badly it cannot be used, repaired or removed anyway! I will have to hope it just lies there and causes no trouble.

I don't know if this will work or be at all possible, but I'd wondered about re-loading so it sweeps up or disables any intact fragments it can find, then uninstalling it properly. A bit like using new oil to remove dried-on oil. Unfortunately I doubt I still have the last Alibre e-post that offered it.

David Jupp26/06/2019 15:33:25
678 forum posts
16 photos

Nigel - if you wish to re-install Atom3D so that you can then uninstall it correctly, you can download the installer from

**LINK**

JasonB26/06/2019 15:33:46
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15518 forum posts
1594 photos
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All those programs are available to any private customers. It is just that many can't justify paying that much for hobby use, the suppliers will take your money whoever you are.

Nigel Graham 226/06/2019 19:20:48
298 forum posts

Thank you David.

Even if in fact I decide to leave installed, it should at least remove the risk of the difficulties SillyOldDuffer cites.

Jason -

My thoughts on availability come from reading the publishers' web-sites, which don't mention costs but certainly don't mention private sales. There are companies in all sorts of areas that sell to the trade-only, so I took it these software firms are the same.

Nigel Graham 227/06/2019 12:52:51
298 forum posts

Advice taken. Thank you chaps.

I can't use it because the licence has expired, but at least I shouldn't have those problems.

And it is there if I have a change of heart, though I know that will be expensive.

David Jupp27/06/2019 13:07:42
678 forum posts
16 photos

Nigel - you can use Atom3D as a Viewer if you wish (without a licence) - but note you'll have to follow the instructions previously linked to remove the reference to the 6 month trial to unlock that possibility. Obviously it's only useful as a viewer if you have some files to view - so there may not be any value to you.

Nigel Graham 227/06/2019 14:11:18
298 forum posts

Thank you.

I remember the Viewer-only limit being stated, possibly in MEW. I did follow the first instalment in the magazine, but I have deleted the resulting file.

Though I had found by experiment how to enlarge and recess that scribing-block's base similarly to a real one I own, to make it more stable!

I lost heart after missing two editions of MEW despite being sure I'd specified my first subscription issue correctly, at the same time as meeting big, insoluble difficulties with TurboCAD. I had bought the first edition in WH Smiths, on the strength of the Alibre ads in ME magazine; thinking with the serial as well I'd find Alibre Atom simpler to learn.

Colin Heseltine27/06/2019 14:58:25
306 forum posts
67 photos

Nigel,

I know you have lost heart but are you aware that there is a full copy of the MEW course available to load as pdf file from the Alibre site. I believe you should have had a link to it when you had the trial version. This is significantly easier to follow as all the Alibre screen prints are a size where they can be easily read, rather than the magnifying glass I had to use for the screen prints in MEW.

Colin

Nigel Graham 227/06/2019 16:11:39
298 forum posts

Thank you Colin.

I remember seeing that edition of the course mentioned, yes.

Not only a readable size as-is, but can also be enlarged a bit further by the normal screen controls (as I have often done with pdf documents.)

I doubt I still have the link as I no longer have the original trial version, but although the Alibre short-cut's there on the screen, trying to open it fails immediately with a Licence Expired message.

I re-loaded it yesterday to avoid operating-system problems SillyOldDuffer warned me may occur by my having merely deleted the programme, rather than removing it properly. (I'd forgotten where to find the control.)

'

BTW I had an amusing moment when I followed that CAD/CAM link JasonB posted a few message back. I have set my PC's protection fairly high, but I'd not bargained for making a model water-pump to arouse the "BT Parental Controls" into asking if I wished to authorise my reading it! smiley

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