Drawing mechanisms

I have got a number of projects on which call for mechanisms of varying complexity. My question is are there any drawing packages ( the simpler the better ) that will allow me to draw linkages, levers and gearing in such a way that they can be moved to check clearances and operation. How do the more experienced designers on this forum go about the creation of such things. I'm tempted to get my stepfathers mecano out at the moment.

Thanks in advance.

David.

David,

I'm sure there are plenty of [expensive ?] others, but

Try SketchUp ... with the SketchyPhysics plug-in

MichaelG.

A quick search on Google will find you plenty of videos to show what can be done.

There are line sketch geometry programs about but you will have to learn the syntax

If you find a good one which is easy to learn quite a few people would be interested

I have used CASIO ClassPad Manager v3 (90 Day Trial) which is a computer emulation of a very high spec calculator but the syntax can take a while to get your head around

Very handy for mobile geometry stuff though

Any 3D CAD package that supports assemblies will easily handle linkages and interferences - gears are much less commonly supported, but may be able to be 'fiddled', depending upon exactly what you want to check for.

If just checking a basic concept, rather than taking the design through to real parts, there have been packages that allow you to do this with 2D sketches - though I'm struggling to find anything on the web at present.

You could do what we did in the dark ages :- draw on a board and make levers , rods etc. out of card and drawing pins. Sounds crude but a lot can be done. Use simple maths to get exact dimensions after trying the card and string.

.

Like this

MichaelG.

Hello David,

All CAD software can accurately draw levers and linkages. For layouts, draw the gears as circles using the PCD (pitch circle diameter). Drawing the shape of involute teeth is a bit more difficult. I use Solidworks and Autocad which can draw to an accuracy of 0.0000001 mm.

There are many free packages like Draftsight or TurboCad which can be downloaded. Trial versions of professional packages like Autocad can also be downloaded and used for a limited time. As with all software there is a slow learning curve before you can use it properly. The more complex the software, the longer it takes to learn.

Draft sight - this may help ..... http://www.solidworks.com/sw/products/draftsight-fundamentals-flipbook.htm

Andy.

Many thanks for the replies. I will have a look and report back.

David.