Help - Relationships or Flexibility ?

[[-Skint-]]

Hi Guys, I have no experience at all with flexible components or relations and I am not sure where to start. I have been reading various internet articles for the past few hours and have learnt a bit about flexibility etc, but I am not sure what I need to get this job done...so help

Here is the scenario. I have created a spring cassette ( for a lever handle set ) which consists of a Steel Casing, Two Nylon Blocks, A Cam and a set of compression springs. Now I want to be able to simulate the cam rotating (about the centre axis as shown ) and the blocks moving accordingly with the connecting faces. The compression springs will have to compress - decompress too which will be my next challenge.


So far I have managed to make the springs flexible using the Profile dimension as the driven dimension, and aligning datum planes on both the casing and nylon block as the Distance variables. However when I move the blocks and refresh, the springs adjust but they just add / remove coils, how do I make the spring stretch instead of simply adding coils.


Hope all that makes sence, see picture

. Thanks for your help !

 

[puppet]

Hey Skint,

The fastest way to do what your after is via mechanism. The springs created in there will automatically adjust to any compression & extension your cam results in.

The work around to this is as your currently doing, either via family table or flexable parts. Set up the animation as you need but set different visibilites vs time. as your cam rotates. So you have your assembly in various positions and just change what you see at the time.


method 1) 5minutes

method 2) 5minutes per frame

 

[mcgowanp]

Hey Skint,


If like me you don't have access to the dynamics module in mechanism then you can get around it. Below you will find a zip file containing a very simple version of your models. I take it that its a form of key mechanism of some kind?? Firstly try going into the assy and under mechanism rotate the cam to put the block in different positions then go back to standard mode and regen, you will see that the spring updates its length accordingly. The flexible dim is driven by a measurement. Have a look at the relations and the parameters, they're quite simple, keeps the number of coils the same regrdless of length.


I have run analyses but the spring does not regen with every frame, if you figure that one out let me know.


Hope this helps


2007-02-01_204159_Flexible_springs.rar
Edited by: mcgowanp

 

[deepakbhat_nie]

HI mcgowanp,


Mechanism is a part of the basic FAP. is it not????. so I would suggest you to use MDX in this case(as explained by puppet).


Regards,


Deepak Bhat

 

[mcgowanp]

Yeah that's right. Mechanism is part of the FAP. However you only get the Kinematic module within mechanism. I dont have access to dynamics, which is where the spring options are,which is tied into Mechanica I think. I have FAP and I cant get these options, unless I'm doing something wrong or have been conned!!!


Paddy

 

[[-Skint-]]

mcgowanp & puppet


Thankyou both very much for your help. Unfortunatly I do not have the mechanism_design module to play with.


mcgowanp, thanks for the time you put into that model. It has already proven helpful, I have managed to figure out the relationships & flexibilitywith my springs so thats a great start. Time to have a go at the Cam now, the definitions of the spring/cam look a little alien to me, but the learning curve has to start somewhere eh ?

The cassette itself actually fits into a security door handle and eventually I will try to learn how to use analysis etc. In real life, I have to have these spring cassettes cycle tested to 200,000 cycles, so the design has to be bang on lol. This is an example, sry for crap render.

 

[mcgowanp]

Skint the renders not crap, its a nice looking image, not something that we normally see, most images are fancy things like engines and cars.


No probs on the models.

 

[[-Skint-]]

Haha yeah I know... somehow I feel a little inadequate when posting my door handles onto this site lol. Not quite the same effect as Cpiotrowski`s cars are theyhehe

Is maxim engineering your own company ?

 

[mcgowanp]

Yeah, I started it 2.5 years ago. Its been going well, alot better than I expected, I managed to get myself some nice clients and that was a good starting point.


The website is a bit of a work-in-progress at the minute. I'm updating it so images thre are just temp ones and only the main page works. I'm too stingy to pay out for someone to do it so its when ever I get a free minute.

 

[[-Skint-]]

Excellent. Perhaps one day you will offer me a job haha ! I have often thought of offering my services too, obviously not pro-e but im pretty good with autocad. A friend of mine had the balls to quit his job and go it alone with autocad services and is now making a small fortune, somehow ive never convinced myself to take the plunge !


Yes I had a quite looksy at the website but didnt want to be rude

.