Member postings for blowlamp

The pendulum decelerates for two reasons - it's climbing against gravity, and losing energy. If the attractive force just balances the friction force (or rather the energy given equals the energy lost), the pendulum won't know the difference except that if the "centre of gravity" of the impulse is not at BDC the timing will be affected. If the magnet was repelling it's exactly the same principle, except that you don't want permanent magnets anywhere near a steel bob or iron base as the magnetic force will affect the effective gravity.

I'd love to see Dave's presentation but alas it clashes with the AHS AGM where they have some talks on the Big Ben restoration.

Edited By John Haine on 25/04/2023 11:09:16

Thought I'd made significant progress today until I made the mistake of testing it!

Wiring needs a tidy up but the slotted beam breaker works well.

Bad news is the electromagnet isn't powerful enough to self-start the pendulum, which is essential after the works are sealed inside the vacuum. Can't think of a simple answer and will have to sleep on it.

Pesky details...

Dave

Edited By SillyOldDuffer on 22/04/2023 20:39:17

I'll wait till I've something worth showing. Not necessarily complicated, perhaps a version of something I've already made, or in a plan set, but not simply one of the tutorial drawings by rote.

'''

I've not given up on TurboCAD because I can use its 2D mode to a reasonably practical level and anyway have a lot of drawings on it. To develop using its 3D mode, though, I'd need a lot more practice. From studying IMSI's web-site recently, I might also have been unknowingly trying to use the 'Deluxe' edition for apparently simple tasks but beyond its as well as my range, so becoming confused and frustrated why it doesn't do as I expect.

Last of the summer wine, loosely.

Foggy. We need to think a little.

Clegg. No. we need to think a lot, it's thinking a little that gets us into trouble.

I'm with Clegg on this one as I now find myself in the same boat. Cad wise.

Martin:

Did you intend to reply by copying my entire post or was it some blip by the forum?

To answer your question though, my plan (using the term loosely) is first, some careful thinking!

Jason -

Yes, exactly what I want, with 3D as an extra aid to the initial design. I know the orthographic elevations can be derived from the isometric representation.

My problem was not of "make" of programme although Turbo CAD was the only proper CAD system at the time (about 8 or 10 years ago) readily and affordably available to home users; and with the advantage it still has, of outright, simple purchase.

TurboCAD's 2D mode is probably no harder to learn than any other, and it was sold with a tutorial CD made by its agent, Paul ('The CAD' ) Tracey who realised the potential market in model-engineering. Indeed, he decorated the CD's box label with miniature-locomotive sub-assemblies drawn in 3D.

'

Rather, my problem was not knowing the basic principles of CAD, not TurboCAD, just CAD, common to almost all makes. The two books I have already cited (by Brown and by Hughes, written for amateur engineers) are the ONLY ones I have found that explain them!

Unless you know these principles, you will will not know why Snaps, Work-planes, Layers, Blocks, etc. If you don't know it's probably because no-one tells you. Most of the tutorial material, if any, from the CAD publishers is rote exercises without explanation. So when you try your own drawings, failure part-way through can just leave you floundering.

.

No doubt some makes are easier to learn than others, but it was not knowing the common principles that caused me more problems than the individual programme. It took me quite a while, for example, to realise a Snap is vital because it is a mathematical meeting-point far, finer than the visual image, and necessary for many other tools to work!

'

Similarly, Individual programmes can have traps for the innocent beyond simply not knowing which little symbol to select.

I have only just learnt that the three versions of each edition-number of TurboCAD differ by more than just menus and peripheral functions. Those differences result from of two fundamentally different ways to represent solid objects; and it is very likely not knowing that led to many of the difficulties I, and perhaps others, have with its 3D mode.

A tool might "work", but behind the screen might not be acting as you see and think, leading to frustration later. And you don't know that because no-one has told you.

.

As far as TurboCAD goes, once you've grasped the common CAD basics and its own basics and expectations, its 2D mode is relatively straightforward, yet very powerful and flexible indeed. Just be careful to draw in 2D, only on a 2D template!

.

(If I understand the web-site correctly, TurboCAD's basic 'Deluxe' versions draw "solids" as surfaces, whereas the 'Professional' and 'Platinum' versions, to which you can up-grade the 'Deluxe' forms, treat them mathematically as if actually solid. The whole thing is very enigmatic though, thanks to the different generation tools it offers to do ostensibly the same thing.

I am guessing that Alibre (and SE?) uses the mathematically-solid principle entirely for such tools as the immediate "negative"-extrusion cuts, and fillets and chamfers, to work as fully and immediately as they do. TC's 'Deluxe' versions at least, use Boolean subtracting a second "solid" to create a recess or hole; and their chamfer and fillet abilities are very limited.

.

I am tempted to try Alibre again, via its one-month free trial; and I have indexed its web-site. The purchase price looks reasonable and seems outright, not the first of some disingenuous "subscription" model. I did try it a while back with the MEW series, but "lost" it. I found SE very confusing by its drawing tools and by its rote-learning exercises based on assuming already knowing Siemens' own quirks.

Edited By Nigel Graham 2 on 16/04/2023 11:14:03