Member postings for brian jones 11

Indeed SOD I am dyed in the wool reactionary too

I still think in "thou" despite being fully metricated since we went over the the MKS SI

I cant relate to mu happily.

Indeed wise words here

I support the notion - forget 2D tech drg, it will only confuse you

Start with 3D concepts from the outset

• you make sketches on a plane - normally XY - and these must be closed to make shapes that can fill and become a face (an exception here is when we create a path - later)
• no extra lines, points, duplicates on top, lines crossing without intersection They wont extrude - non manifold , line crossings will give you grief - dont do it. Your 3D CAD app probably warns you not to break these rules
• A shape/face in 2D has zero thickness and is unrealisable. Dont leave tabs in your model. Dont have two shapes touching each other
• When you extrude a face it becomes a solid in 3D and the original face is the datum
• Extrusion is always normal to the face and the face has a direction

For example

Imagine a cup drawn with a cylinder and a bottom face. The surfaces have zero thickness. Indeed your 3D CAD app should not allow you to draw it. However If you sketch your cup with a 2D circle base and an inner circle for the wall thickness, you can extrude the inner circle (bottom) first and the cylindrical wall next and you will have a 3D solid - a real cup with an open top.

If you do it the other way round you end up with a tube

So following conventional 2D CAD practice will give you grief

FYI from above this is how CAD was enabled on screen and on pen plotters (remember those HP?)

https://en.wikipedia.org/wiki/Bresenham%27s_line_algorithm

Edited By brian jones 11 on 10/09/2021 23:50:44

Now here's a question

premise

I believe that SE can accurately position a vertex of the intersection 2 arcs (or circles)

but circles are displayed default as 36 segments - can go to 96 under View options

When you zoom in you see the intersection of two segments but they dont form a vertex. You have to use the Trim tool which seems to provide the required accurate vertex AFAIK

2D we take this for granted drawing a radius to get an intersect

OK so far?

Now the interesting bit comes when you intersect 3 spheres to get an accurate radial point and line in space draw from the origin say.

Can SE do this?

You need this for example when you want to rotate faces or solids to an intersection

I havent got as far as making a sphere yet - not ready for a revolution

still sharpening my clutch pencil

For example try a simple tetrahedron

Further to Ian valuable input

Immersive Reader?????????????????????

What he means is

Firefox Browser top left/View/Enter Reader F9

I never knew that its brill.

The above article (too big for here) deserves tobe read in full IMHO

Edited By brian jones 11 on 10/09/2021 16:05:52

Indeed you need to get familiar with a different way of using mouse,ctl alt shft and spc bar

I cant just click on a solid or a face and move it for example

q

I'm not sure I'm following everything is this thread but I would agree that moving from 2D to 3D requires some rethinking of the way you approach things.

uq

you might say "ive been driving a car all my life, now I want to learn to fly"

if you listed the difference between a car and a plane, it might total up to how different 3D is to 2D

Note

you dont need to know how to drive a car to fly a plane but it sure helps you to get to the airport if you can drive

thats what you are facing as a noob

Yes DJ you are plastered with all their )(**(&*&*)(* hype

it wastes loadsa time wading thru it to get to the meat.

Hence my posts on the subject here

I am up and running with SE CE and it seems a very capable package and its FREE

I am also trying to get to the fundamentals of 3D cadding which seem largely glossed over

The industry wants you befuddled with blurb

of course all this is directed toward the home hobby guy

Younguns will go on professional training courses

I note the comments on industry trends that say that CAD packages and CAM packages are being split up by industry demand so that large corp can no longer hold the mfg's nuts in a vice. Also sme's can use the new tech without large up front costs demanded by the big corps

I dont propose to go into CAM apps cos thats way out of my league but perhaps some else skilled in the arts could pursue a similar intitiative as i am trying to do with 3D CAD

Brian

Does anyone know what we all take for granted in CAD

ie drawing of a line (vector between two points (vertices) on screen

Yes it started with some guy in 1950 with his sketchpad app

Two points in 2D plane yes got it

Then there;s a clever little algorithm that draws a line between the two points taking into account your screen resolution. Note that line does not pixilate no matter how much you zoom in

If you ascribe dimensions to your line say

then draw 3 or more lines to make a shape

you can scale up or down x millions (within 13bit range of FP calcs)

That line stays solid on screen

That I believe was the dawn of CAD

Your 2D sketch became a chart of xy vector data as per DXF format

Note that the sketch could be tied to a point origin 0,0

I think this is how Acad got started.

Ive tried googling this point with all bluff and glossing over.

Where is this going

Well I want to show how we made and important transition to 3D (not the half baked attempt by Acad to tie 2d views to make a 3D wire frame

I think its all to do with extruding from a sketch face but one step at a time

Trying to see how it came about is even more nebulous smoke and mirrors

example from siemens

https://www.plm.automation.siemens.com/es_es/Images/WP_2D_to_3D_DesignEngineer_tcm52-21760.pdf

the most egregious management - speak claptrap

dont waste your time

Why is this visceral inspection needed? You just load up the app?

Well it helps to understand what you are really doing with your models and why they are likely to go wrong

Because there's the difference 2D drafting was simple both in concept and geometry

3D opens up a potential can of worms as you are sketching in 2D - your pc screen - and this is translated by the app into a 3D space model. That is a BIG jump

Which ever 3D app you choose they all have to follow the same route and an important concept of Historic vs Synchronous listing

Get the new hall effect c clamp type meter. it can measure DC Amps just by clipping on a wire and NOT breaking the cct. Its a godsend and quite accurate

UNI-T UT210E about £65 worth every penny

Dont knock the old analog Avo type. you see things on the needle sweep you d never pick up on a digit display.

cheapo ok for LV

If doing serious mains work get proper kit for the job.

IMHO get cheapo digit one for auto work cos you are bound to blow one up with current range wrong.

Well siemens have CAM pro but are very coy about price. Perhaps if you find out , let us know

Is it possible to collect your parts designs and export into another CAM app like meshcam? $250-500, Mark4 $280?

I know zero about CAM but it seems to be a black art

Perhaps it needs a separate Topic heading of its own Monsignor

On the other hand for hobbyists there is something called MDI where G code instructions are input piecemeal by the machinist but I dont know JS

came across this

https://www.cnccookbook.com/cnccookbook-2018-cad-survey-results-customer-satisfaction-awards/

BUT WARNING its a sales pitch but seems to offer some insight.  Seems a bit of snakeoil salesman here but maybe someone with knowledge might shed light.

Edited By brian jones 11 on 07/09/2021 18:47:55

Well I remember Turbocad from the days when Acad was still DOS and difficult for the amateur to access, so it was an alternate cheap route into 2D drafting so you became competent enough at CAD operator level and could access ACAD commercially and get your skills up. (anyone remember Intergraph)

When Acad tried to do 3D modelling for platforms and I saw how painfully slow and tedious it all was - for me a complete turn off then along came Sketchup and suddenly it was 3D for numpties, instant visuals but ultimately a bad route to follow for eng work

I can see how desperate it would be if your 2D drafts didnt keep in step with your 3D manipulations

Many thanx Ian very valuable insight here, will process

Indeed most mews are in or approaching their dotage i guess

I only mentioned that younger members need to keep eyes on the prize and back a popular industry horse.

We cheap charlies will not be commercial or gainful but the possibilities of 3D CAD are just too good to ignore

This post aims to demystify CAD apps for the noob cos the choice out there is massively hyped and bewildering (then so in 3d printing and CNC

I still cant get my head around Covid bits for tools

All this new tech which 5-10 years ago cost mega bucks is now within the reach of the home hobbyist

Just look at the galleries for some of the work examples from real amateurs - though you need to rule out the pros and the "look how clever I am self promoters" who try to dominate the scene

Does anyone know a site for genuine amateur stuff? JB has shown what he can do with Atom3D

Hi JB grinding my way thru Atom3d tutorials, so far very impressed, shows me how blind I was to real 3s design - ie blow out of the water. I can see how my spiral flute tap could be done in say 10mins max, while it took me 3 days struggle with totally inadequate SU - a junior toy by comparison Im afraid.

the free tutorials are thorough and professional (not like some yahoo making loadsa noise, looking for yt presence, likes and subscribers - what a waste of time they can be - specially if they are jinglish or silent "watch the mouse" type.

IMHO a product with professional tuts is a big big plus

It begs the question

Atom can be used to make proper shop drgs with manual placement of dims, why would you need to use an external 2D drafting app? It also imposes a certain discipline on you at ground level to ensure you make enclosed non intersecting shapes with unique lines and vertices.

Well Brian, I used TurboCAD D/L (2D) for over 20 years and it did have a 3D capability but frankly it was very hard to use. There was a 'Pro' version which was quite significantly more expensive but the base products were similar I believe. However, it worked OK for much of my 2D drawing for many years.

So why move to Solid Edge? Well, I started to draw/design more complex things (such as my Midland Compound engine) and it became increasingly difficult to do so using a (non-parametric) 2D product. Going back to correct errors or make changes becomes very time consuming. I also purchased a 3D Printer and whilst Open SCAD was easy to get into initially, it wasn't a solution for my drawing needs.

With Solid Edge, I can update a Part and everything in the Assemblies above changes. I can open the (2D) drawings I've made of that part or assembly and hit the 'Update' icon and all the drawings are updated automatically. It works for both my 3D Print & engineering needs.

AFAIK Atom uses what is called 'Ordered' drawing, which effectively means that you have to step back (to the point you wish to change) to make that change. Solid Edge does support 'Ordered' tends to use 'Synchronous' drawing. If something is changed, then do so and update no stepping back.

Comment from a member

Means changes in 3D model are reflected automatically onto 2D drg? I think

Many thnx for your i/p exactly what we need for our knowledge base - will be added

My concern is the comparison with Solidworks which seems to be an industry std and I dont propose to dwell on it as its way out of the hobby league BUT

take a young wannabe starting out, would he not be better pursuing the market leader? although both products have super hype claims. Of course SE offers a free way to get on board and I think SW is more difficult and costly, but I think some unis provide a certificated module

I just looked at employment agencies and SW came up a lot, no mention at all of SE

Indeed JB users should be aware of their OS and know that CAD requires a capable m/c. PC requirements are usually well documented on sites up front so the user should know enough to check. MY SS is intended as a helper for those reasonably PC savvy, and also a means of gathering collective wisdom on which CAD for the hobbyists.

After all you should have at least a basic experience of conventional 2D eng drafting - this is a forum for machinists wishing to design

The other route to 3D from visual arts is not my bag (and as with Sketchup will lead to other problems)

Clearly I dont wish to compare commercial product with the hobby needs. As will be seen these are totally over endowed with 95% of features that a home sketcher will never use.

The overriding concern is ease of use leaving you energy for design work rather than battling with the learning curve

We dont want a Ferrari to potter around town when a mini will do.

I have been encouraged by members to look at SE CE and went through the process to instal this humungous bloatware (4GB and 20 modules). It took all evening.

It didnt send me a Free use licence key, so I had to sign in to the 2D drafter

Is that all I get for this sweat? As a noob here I must have got it wrong. I thought it gave you access to the full 3D features?

Can anyone shed any light?

Or have I been click baited?

It asked me to sign in with email, then asked me for pw but during registration it never asked for this so this will fail

I sent an email forgot pw - it said we sent you an email - never recieved

This is giving me a bad feeling - Big corp contempt for the little guy. Not what I expected from siemens

I hope its my mistake

Brian

more fretting. I discovered through the convoluted installation that I had to activate the installer again and it obtained the licence number given during the 2d app and I now have a 3D version I think

What planet are these people on?

BTW SE CE 2021 only wants to work with W10 enterprise pro, NOT Home edition so whether it will fall over on my W8.1?

I hope some member will come forward and show me all this grief is worthwhile

Talking about bloatware, Adobe is famous for it.  eg Photoshop has ca 20GB associated with its creative suite.  I have a version of PS CS3 which fits on my thumb drive - is portable and uses 3MB.  for 99% of my use I dont notice the difference - that says it all.  I thinks its been with me 15 years

Edited By brian jones 11 on 07/09/2021 01:46:19

Indeed JB

you have CNC listed but I expect what you really mean is CAM which takes the 3D model and produces the toolpaths that can then with the use of a post processor create the G-code that the CNC needs.

yes I mean CAM output but not having experience here it needs better definition from those who know

A shop drg is what i consider to be a conventional 2D dimensioned drg that can be used in a machine shop. I also assume it can produce different line style eg broken, dotted, dot dash etc and also fill in hatched areas for x sections, that kind of thing

Will update the list from further input

Which goes to show what a minefield it all is with competing product claims confusing the noob as to what he should invest 100hrs study in first

subjective inputs will be quoted in italics

cont

Here are some features I i put together pls add omissions/corrections . These will form the fields of the table

Pls highlight notable limitations which I will place at the end along with misc comments

Much of the boxes I will try to get website info. User personal exp will be highlighted in italics

Hope this will help to clear the mist

1. Product ver
2. Year started
3. Owner/parent
4. Home desktop
5. Local hd storage
6. File type export
7. File typ import
8. License
9. Subscription
10. Cloud
11. 2d shop drgs
12. Multi assy
13. CAM simulation
14. CAM 2.5axis
15. CAM 3axix
16. An industry std
17. Marketable skill
18. Hobby use
19. Learning curve
20. Tutorial quality
21. 3^rd party exts
22. Bugs
23. Crashes
24. Non manifold warning
25. 3D printing
26. CNC
27. Best for
28. Entry method 2D to 3D, 3D+2D
29. Sheet metal
30. Scripting
31. Parts families
32. Rendering

Q

No smoke screens with Alible, click the "detailed" tab near the top of this page

uq

that s great JB a fine example of what we need

I will start my collection, my problem is how to display this, a large wide format spreadsheet would be best IMHO but cant upload this here. I noticed one suggestion for an XL file is to use dropbox which I believe is user friendly and the xls can be downloaded for personal viewing hoping this doesnt break any rules

Perhaps this needs to be done by pm

advice pls