Dynamic block ?

Hello folks!

I've just started using dynamic blocks and they're a little confusing to me. I got my first one working really well today using Visibility States, Geometric Constraints and Rotation Parameter+Rotate Action.

 

I can think of literally WEEKS worth of work updating previously static blocks to all kinds of dynamic goodness, and I could use some pointers here.

 

The first thing I want to do is make a chain hoist. If you don't know what a chainfall looks like, it's basically two hooks connected by chain that runs through a ratcheting mechanism. Work the ratchet and the distance between the hooks shrinks or lengthens, depending on which direction you go. So, what I would like to do is to have the distance between the hooks connected by "chain"... Previously, I made a block of about 6 links, aligned that block between the two hooks and did Copy/Paste several times until the whole length was done. I'd like now to add a Rotation Paremeter+Rotate Action to the hooks so I can (A) paste the chainfall in with the top hook at its correct location and (B) align the hoist from that location to the bottom hook's location. The next part (that I will need help with) is to somehow be able to drag the bottom hook to it's correct location AND have the distance in between automagically filled in with "chain".

 

Obviously, the chain links must have a certain length, so the length in between hooks would very rarely coincide with an even multiple of links... this is okay and I can tolerate a little overlap.

 

I can already see how to do this with fixed lengths (i.e., 5'-3", 5'-6", 5'-9", 6'-0", etc.) and visibility states, but I would like the length to be infinitely variable i.e., I don't want to be limited to discrete "stops" of predrawn lengths.

 

THANK YOU FOR ANY IDEAS!

Would you not use a repeating pattern of two links and drag for what ever length you want. Did you google for something like dynamic block repeating pattern. If you cant find anything let me know or some one doesn't post, there is a repeating pattern dwg example in CIV3d I have posted it here before.

 

Anyone similar example done by Autodesk but for Autocad ? There is a lot of sample stuff when you install but no real mention of what they do.

Can you post a copy of the block you have so far, I can roughly visualize what you mean but how does it all fit together at the junctions of the rotate and the chain lengthening

CHAINFALL START.dwgBIGAL, a repeating pattern sounds like what I need, but I'll have to google to see how those work. Sounds right though. Attached are the pieces that I've got so far. I haven't made an attempt at automatically lengthening the chain, but I think the dwg should help clarify what i'm trying to figure out. thanks y'all!!!

The extending chain wasn't too much of a problem once I figured out the array direction, but I have placed a wipeout in there to hide the first part of the chain behind the body, this is fine whilst the first link is moving but as soon as it arrays the new chain link pops in front of the wipeout, I only use two links more than that and you are just repeating, anyway is this the sort of thing you are aiming for.

CHAINFALL START(1).dwg

That's really nifty steven-g I was thinking more along of using a custom line type but yours is better.

Really appreciate your help there steven-g!

 

I've been messing with this for a bit today and have a couple other questions:

 

1) What was the purpose of setting Chain Action to Yes in Distance1?

 

2) Can I make the array direction something other than vertical? I'd like this to be able to be used at a variable angle, so ideally I'd want to have the chain link copy along a line between the top hook and bottom hook.

 

3) How would you handle adding some different views in? I'd like to have the option to show a front and side view for EACH of the body, chain, top hook and bottom hook. That's a lot of combinations to have to draw them each and us vis states, especially since I'd have to add all the parameters and actions to each one! Is there some way to have these different views of the four components individually switchable?

 

THANKS AGAIN!!!

chainfall.zip

 

I cleaned up the block I a was working with, and have been trying to reproduce what steven-g did except I wanted to use a linetype instead of an array. It kind of works, but I have a gap at the start and end of the line, anyone know what's going on there?

 

Looks like the gap at the start and end of my chain type polyline is the exact same length as the original distance that I drew the chain-line. This is the same distance later set to be Distance1. Weird right?

Edited February 6, 2017 by ColinPearson

Sorry for not answering, I've just moved house and getting internet is going to cost a couple of days apparently, the chain action is because that one parameter is driven from another action, setting chain to yes allows that to happen. Unfortunately other answers will have to wait as I need to be behind the internet (not in company time) to try things out.

No problem. I'd definitely appreciate the help whenever you can find time, but no rush, thanks you very much!