Topic: Dynamic block for mech services Y branch?

[smudge]

Hi Guys

I’m after a dynamic block that draws a 2D plan of a “Y” branch for a mechanical services (A/C) duct.

If anyone knows if they already exist can they point me to them and I’ll download them.

If they don’t exist can someone please give me a hand by creating these blocks (I can simple scales, arrays, stretches, flips, rotate & do visibility states* so far but that is about it)


There are 2 types of “Y” branch that I want to use (I’ll just use visibility states to swap between the two types).

Branch type 1.
I want to be able to size the width of the incoming duct (incoming duct), change the duct length (incoming duct length) because sometimes they can look a bit weird by either being too short or by being too long, the outgoing duct width I want to scale from the point of their radiused transitions (OD1 from point PA and OD2 from point PB). My problem is the intersection of outgoing ducts 1 & 2 (point PC). Ideally I’d like to get them to meet perpendicular to the other outside duct (like a virtual intersection).   

Branch type 2
Again I want to be able to size the width of the incoming duct (incoming duct), maybe change the duct length, scale the outgoing duct width 2 from the start of it’s radiused transition (point PA), scale the outgoing duct width 1 (from points PB)*. And again my problem is the intersection of outgoing ducts 1 & 2 (point PC). Ideally I’d like to get them to meet perpendicular to the other outside duct (like a virtual intersection).
*I’m willing to forgo this if it all gets a bit hard, in that case the incoming duct and the outgoing duct 1 can have the same width.

I’d appreciate any help you can give me with this as it’s driving me nuts.

[Crank]

Hi smudge,

Without making a block for you, I can point you into the right direction. I don't do ductwork, so let's start with some questions that you also have to ask yourself:
- What are the default diameters?
- What's the radius of the arc?
- Do the incoming duct and the outgoing ducts have some relation? (formula?)
- Do you need to support all diameters or do you want to use lookup lists?

Basicly the problem for both blocks is the same. So you can work to one solution.
A dynamic block property is fine for switching the visability, but what you want is a parametric block. This is much easier for your problem(s). I think parametrics were introduced in Acad2010, is that an option?

I'm not sure I understand the scaling you want for the outgoing ducts. I would think the scaling should start at the end of the arc. Perhaps with a parameter for the radius? When you make a parametric block, you can make formulas and scale your vectors with a (calculated or fixed) factor.

[smudge]

Hi Crank.

Thanks for the reply.

- The diameters of the input and outputs vary all over the place with no relation to each other. The only constant is that they are going to vary by 50mm increments.
- The radius going from incoming to outgoing ductwork is half the outgoing ductworks width
- I haven't used look up lists so far, this block may be used for some whacky (small and large scales) so I don't want to limit myself with the parameters that are contained within a list.

My real problem is getting the two outgoing ducts to intersect at point C (just because the X/Y is going to vary all over the place).
option 1.
I was just going to have a stretch option so that I could extend them by eye (which is really dodgy)
option 2.
Get it in there and then burst the block and manually fillet the intersecting outgoing duct lines to a point C (this is pretty much giving up).

Parametric blocks hey? Thanks for the tip. I'll look in to them. We are mainly running 2007 in the office at the moment. There are a few guys on 2011 and they'd like to have an "exclusive" DB that only they can use. Some people will only make the jump from 2007 at gunpoint