Alibre - A First Attempt

This was one of my own attempts. The groove is a bit unsymmetrical, and any resemblance to any real Vee-belt size living or dead is purely coincidental. Oddly though I managed to make that Revolve Cut tool work on this, but not at all in the tutorial exercise.

Just spent half the morning fighting my way through that MEW tutorial to draw a scribing block.

I'd already fitted the column to the base, but with a parallel rather than tapered fitting.

So this morning, I've completed the parts but omitted the two threads and the knurling. In fact the text suggests the threads impose a huge overhead on the system, and to use a note on the 2D drawing instead: the convention of course is a thin rectangle to show the thread, and a dimension-note. I judged it too difficult anyway.

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The scriber-point is meant to be drawn as was the column taper - a "Revolved Cut". That kept failing as well, with every attempt raising error-messages the user is presumed to understand. To Hell with it then: I created it as a long chamfer.

Something I found too, was where you are meant to enter a value for some features, it won't let you. You have to scroll or step through a counter instead. The Escape key is not always very prompt either, needing several presses. Could be a keyboard fault but I'd be surprised on a unit only about a year old.

I did though discover how to draw two lines of set length at a set angle directly, in this case for the scriber's centre-line; using the inside angle [180 - external] rather than by dimensions afterwards. (There's a proper mathematical name for that type of angle, but I have long forgotten it.)

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It has you produce an orthographic drawing for the Clamp. That went moderately well but I was unable to dimension the width of the slot, nor to add the overall length dimension in the way it describes. It tells you to dimension the width next to the radiused end, and a special slot-dimension menu will appear. Oh no it didn't.

The little rendering is all at some peculiar angle of its own, as well, as the image below shows.

I had picked ISO which gives First-Angle projection but the menu also mentions something called "J-ISO" or something like that, and ANSI. I know ANSI is American but the 'J' one is new to me. Is that also American?

There might be a way to carry the colour over into this drawing's rendering, but I didn't see it, and it's not that important here!

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I've now an Assembly drawing with five separate parts, none in the orientations shown in the instructions, and I can't find anything that will rotate them individually. The clamp is lying on its side, for a start.

Trying to align the two pairs of planes is a nightmare. It kept doing all sorts of strange things. The text says three pairs but the display had only two pairs plus one plane on its own. The text also refers to a 'Flip' command under Assembly Constraints, to turn individual parts the right way up, but wherever it really is, is not there!

I was unable to reduce the started assembly drawing enough to show all the parts. I thought I had done, but clearly not.

To my mind Nigel, you are making very good progress!

Nigel,

If you are having issues entering values into dialogue boxes, it is possible that you are suffering from one of two known issues. These could easily wreck your attempts to learn the software.

1. Grammarly is known to conflict with Alibre - it may be possible to workaround this with compatibility settings, but if you have Grammarly installed, simplest is to remove it.
2. Win11 for some users causes flickering of input boxes - a reported fix is detailed in this post on the Alibre User Forum

JIS - is a Japanese norm.

The projection angle (first vs. third) is inherited from the chosen drawing template, but can be overridden. Templates can also be customised to suit your own preferences. For example these days in UK ISO sheet sizes are typically used, but I see both 1st angle (as in mainland Europe) and 3rd angle (as in USA) projections both used. A customised template can combine ISO sheet size with 3rd angle projections, plus perhaps a Logo and some preferred dimensions styles.

The orientation for the 'Front view' in the 2D drawing is set when you select the part or assembly - there are controls to manipulate the model orientation before you commit to make the projections. All other views are relative to this Front view, so no you can't rotate them individually - it would mess up the projection angle for the views.

Please save these files - and please also accept my offer of help. I could talk you through this so much quicker than all these long complaints....

A Drawing of the Assembly would usually be of the assembled parts, not individual parts. Though you can add views of individual parts to the drawing should you wish.

Asking 'how can I?' is so much more positive than saying 'this doesn't work' or 'that can't be done'.

Jason showed the Flip command in a recent post which you seemed to acknowledge. The MEW tutorial is from about 5 years ago, the Atom3D user interface has moved on since then. If working from outdated screenshots is causing problems, perhaps leave that particular tutorial for the moment.

It looks like you've actually achieved quite a lot - you have most of the parts (maybe all) for the scriber - seems like you need some help getting to grips with assembling them, and then how the 2D drawing system works. Maybe later go back and look at revolve cuts for tapers and why you are struggling with that operation.

In assemblies one common issue we see is that if the user doesn't fix the first part in space after adding it to the assembly, then when constraining the next part to it things can fly off in unexpected directions. I strongly recommend fixing the first part in the assembly. To begin with the simplest way to do that is to place the part on the assembly origin, then to apply an 'Anchor' to prevent it moving. There are other options, but that will get you started.

You're doing fine from the looks of things

Just keep plugging away, things get easier and easier until one day you realise that you don't even view CAD as a challenge anymore

It's actually a lot like learning to drive, at the very start you wonder how anyone ever manages to do it, then after enough practice you're getting competent, then one day you're an old hand at it

That's how you get ahead of the curve, set a task and do your own stuff

CAD is pretty cool in that you can set your own homework

Edited By Ady1 on 01/05/2023 15:18:20

Thank you for your encouraging comments!

David -

I recall the first exercise I tried did use the anchor tool, but I don't think the MEW one (the scribing-block does. Unless I failed to spot it. It still locked the clamp in place on the screen though.

Ady -

You can set your own "homework" yes, but with care not to be too ambitious. Both of my attempts used moves I'd already seen in the set exercises. Though having made something simple, like a pipe-flange or a flywheel, say, you can at least experiment with it.

Nigel,

The Anchor is a quick way to fix a part in space, but it gives little control. Typically all you can do to define the position is to deliberately insert at the workspace origin, or at some other inserted point. Orientation will be whatever it was when the part was first modelled.

The MEW exercise showed the alternative of showing the reference geometry of an inserted part, then constraining that to the reference geometry of the assembly workspace. This takes longer, but gives full control - you can alter orientation of the inserted part, position it wherever you wish, set it at an angle....

Both methods are valid, and for the first part in an assembly are largely interchangeable, unless you want to set a particular orientation for the part.

I only brought it up because you'd mentioned problems constraining, but were not very clear on exactly what. Failure to fix the first part in an assembly is quite a common issue for beginners and can give really weird behaviours.

Good progress

The flip command was there a couple of days ago as I pointed it out to you and you used it. You may have it layed out slightly different in Atom but same two red/blue arrows

Well, I certainly make Alibre Atom behave in very weird ways instead of what I'm led to expect. When that happens, all I can do is scrap the whole drawing so far and start all over again without having the slightest idea why I failed. Which is very off-putting if well into a complicated Part.

Following instructions is all very well provided you can make your results match theirs, but the text's author assumes you can understand the instructions and their effects fully, and never make mistakes.

So even if you manage to copy the image as intended, you still do not really know why, nor what can go wrong and how to put it right. If you don't, you have no idea what you have done wrong, especially if the result is an error-message written in computer-speak.

It's like trying to learn turning from the tool-geometry diagrams in a Sandvik catalogue.

Why scrap the whole thing and start again, only a couple of days ago the UNDO tabs were mentioned, if it goes wrong first thing to do is hit that UNDO tab and you just go back one step.

on an assembly you also have close rather than accept if the part move where you did not want it to and in 2D sketching you have OK or Cancel on a lot of the boxes, click cancel if it is not looking right

This is why DavidJ's offer should be taken up as he will talk you through things if they don't come up as expected, he will understand those error messages

Edited By JasonB on 02/05/2023 09:55:50

Also your saved files (with the 'errors' may well point to exactly what went wrong. Much more instructive to talk through a file that exhibits some issue, and look at what may have happened / how to fix it. You'll learn more than from getting it right at a first attempt.

I've looked at the MEW exercise again just yesterday. At some steps, I had to stop and read it again carefully as the wording perhaps isn't what I'd have used myself (though my wording may have been just as ambiguous in its own way). I sometimes had to turn the workspace slightly to be able to select and edge. I sometimes found that I had to hide a part to be able to see something that the text told me to constrain in an assembly.

So yes there are potential barriers, which can be very frustrating if you don't realise how to get around them.

In addition to Jason's comment about using Undo, you can also delete or suppress individual features in the Design Explorer (on left side of workspace). You can also go back and edit sketches or features you previously completed.

I know the purpose of the Undo / Redo arrows - as in almost any Windows-hosted software - but I'd met situations where I seem to have gone too far for them. I don't know if they have a maximum number of steps by the application or the electronics, but I'd made mistakes whose effects only appeared much later.

The Flip arrows on the assembly menu did nothing on the one occasion I tried them, so I must have been using them wrongly.

Though I did discover the Assembly tools themselves can rotate a part to the right orientation when being added to the fixed one, with a rather wonderful visual effect as it operates. At least, right for the mathematics: it is aligning surfaces and does not know if I have made them the right size and the right way round. A mistake there makes the added part sink into the host, not lie on it..... I found.

I have found how to correct simple drawing errors like a wrong size, rather than Alibre-operating mistakes as such; by deleting the appropriate Sketch and making a new one. I did that with the scribing-block to "re-drill" the tapered hole in the base to parallel, after finding I cannot taper the column.

Think of assembly much like having a box with all your parts rattling about inside. As you take them out the box they could be any way up. It is not until you assemble them that shafts go into holes and faces mate. CAD assembly is no different.

Nigel,

If something in a sketch is wrong size, don't delete the sketch - just edit the dimension that is incorrect.

One of the biggest advantages of 3D CAD is how easy it is to make changes with throwing work away.

You realise after completion of model and having made your 2D drawing, that (for example) a hole should have been a different size. Edit the dimension in the sketch that defined that hole, exit the sketch, regenerate part to last feature and Save.

Next time you open the 2D drawing of the part, it will update automatically to the new hole size.

Sometime you have to "force" an item into its position by using the constraints in two stages

First stage you get it into a basic ok position

Then you DELETE those constraints and it will stay in its new position/direction

Then apply the constraints you wanted originally

It can be a bit fiddly, but it works eventually

Just another skill you have to master Nigel, practice practice practice

Ady,

Much simpler to hold down the Shift key whilst dragging the part in assembly - that will roll/rotate the part freely in the assembly. Combined with a standard drag to position it, you should be able to get the part close enough that applying assembly constraints becomes straightforward.

Sometimes the order you apply constraints can be important (that is often down to experience or trial & error) - occasionally I have to temporarily suppress one constraint to allow the application of another, then un-suppress it again.

Well, as with using a sledgehammer to crack a nut, that might be dangerous. I can't speak for Alibre, which I've never used, but the usual procedure is to edit sketches, not to delete them.

By analogy, say we're building a house and a crack appears in the attic. The mistake is traced to a pillar in the cellar, designed and installed much earlier. In a model, the pillar can be moved and resized within reason by altering the sketch and this won't disturb whatever else in the model depends on it.

Deleting an early sketch is the CAD equivalent of blasting out a real pillar with dynamite. Might work, but there's a high risk the whole structure will be compromised, with further work failing unexpectedly because of internal faults caused by not sorting the pillar out safely.

Better to learn how to edit sketches than torpedo them.

Dave

Thankyou - I can see the point there. It may be just as applicable to Alibre as any other CAD system of similar type.

In the first exercise I tried, I missed an important step so when the thing would not assemble properly. The Parts were legitimate in computing ways but I had put two features in the wrong place; one by a small dimension error, the other by the missed step.

Trying to correct that, I deleted these features and redraw them because, if I understood the error messages aright, I was trying to overlap the new sketches with the original ones. I don't know, certainly didn't then, if you can simply move them.

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That building analogy has its own for me!

I spent an hour this evening modifying one of my steam-wagon's tank fittings, already soldered in place, so I can raise the tank for better clearance above the rear axle for the water-pipe going forwards. I had made the tank, oh, I don't know, maybe 15 years ago....

Do I sense a lightbulb moment? It sounds as though you are getting to grips with Alibre.

A friend and I nearly bought a full size road going steam lorry. He had an Austin 10, Mk2 Jag, 1948 Bedford 2 or 3 tonner, not sure which, and a 1938 Morris commercial. I had my Austin 7. We never did buy the lorry, but my near neighbour here in Cornwall has a couple os steam traction engines. He took one to Trevithick day a few days ago. I heard it chugging up the road on his return.

Keep us informed please Nigel. Your progress is very interesting.

How on Earth did the designers of those fine old vehicles manage with loose Tee-Squares, 2H pencils and a book of log. tables?

Light-bulb? I'm afraid the bulb's blown.....

I have just spent some two hours going back over that scribing-block exercise to work out why and where the Clamp ends up on its side, making the Assembly process even harder. So I set out to re-draw that one part from new. It's the orange block in this picture, with the hole and keyhole-shaped slot; and is on its side there: the column goes through the keyhole.

I followed the words very carefully but it all went to pot, even worse than first time.

I had enormous problems with various tools' selections taking many clicks to respond. The Escape key often took several presses to clear, and the Undo arrow suggested big stacks of hidden moves by taking many presses to turn to grey.

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To cut the slot you extrude a sketched rectangle through it. That bit was easy but the Rectangle tool just would not respond at all. I had to construct it by separate lines away off the block itself then struggle to chivvy it into the right place without knowing how to move sketch objects properly.

Eventually I managed it, though somehow missed radiusing the outer ends. The photo is of my first attempt, not this second one.

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Then tried to Assemble it as the exercise text tells you. It just went haywire.

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Could the mouse I've just bought be faulty? I don't think it is. A dodgy switch might account for tools not responding to being clicked on, but other mouse moves work. Nor would it account for the Escape key not always responding immediately. I could test this by reverting to the previous device, though it has no proper scroll facility.

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Progress? Interesting? One way to describe it....

Aye - Alibre is easier than other CAD makes I've tried, and I was making "progress" at first; 2 steps forwards, 1 back.

It's now 2 forwards, 3 back.

Any complicated software is a long uphill struggle for me; but I expected the footpath to reach the summit eventually, not fade away in the foot of the scree-slope.

I don't think you've mentioned the spec of your computer, but from what you say about slow responses et al, it would seem to be short on processing power, RAM or both. Or you have an awful lot of stuff running in the background (intentionally or not) which is using resources.

Rob