Falling Icicles

[Matt_Edwards]

Lytnin showed off some LOR kit over a can of Ginger beer. The brain started ticking.
I have been toying with a couple of ideas for Falling Icicles.
My definition of Falling Icicles - clear tubes with LEDs spaced about 30mm apart that turn on in a sequence.
the hardware will probably be based on 500mm sections of flexible PC strip using SMT LEDs and SMT HC595s driving the LEDs

I see the following options:

Option 1 - single colour, 1 channel
DMX Ch1 set falling rate assumes full intensity

Option 2 - single colour, 2 channels
DMX Ch1 set falling rate, DMX Ch2 set intensity

Option 3 - RGB colour, 4 channels
DMX Ch1 set falling rate, DMX Ch2, 3 & 4 set RGB intensity

Each icicle will be able to be cascaded to 1.5 metre long with out hardware changes by simply soldering them on to each other. there will be some sort of a controller on the top of the strip to convert DMX to Serial

Another option will be to run DMX down the the strip board thus allowing it to be connecting in even longer lengths, however requiring greater number of control channels. Flexible PC material will get around the voltage drop issues with RGB lights.

Where am I at?
still in the blue sky area,
I see the main issue to resolve is the flexible PC material. Waterproofing is always a challenge and this project is no exempt.


Any thoughts or considerations? I have to say I don't know if the project will get become anything greater than a couple of rambling ideas. Of course the CFO doesn't know about it yet yet, so who knows what the outcome could be.

[David_AVD]

I've been thinking about a similar project Matt.

For the housing, I've emailed a supplier of clear conduit (16mm OD I think) to see how cost effective it would be.

Some of the best examples I've seen in videos are where the droplet length was more than one LED. Even better is when it has a fading trail but this is more difficult for hardware and software I guess.

[budude]

Interesting - I was thinking of trying something similar - basically make a self-chasing RGB LED strip that I was going to hang from my tree branches. I was thinking of having maybe 30-40 total strips but haven't even started on it yet. I've been following these other LED matrix threads but would prefer a self-chasing mode to simplify things (at least for this project).

[jrock64]

For a housing check out florescent tube guards.
Unbreakable clear polycarbonate.
Available local and 4 or 8ft in lengths.

Joel

[David_AVD]

Just got a price on 20mm (OD I think) clear conduit and it's about $26 + GST per 4 metre length.

Also priced 15mm OD (11mm ID) acrylic from plastics supplier but that's $32 + GST and only a 2 metre length!

Maybe clear flexible PVC tubing (like fish tank tube but larger) would be good enough? I'm sure that would be a lot cheaper and easy to cut the right length from a roll.

[Matt_Edwards]

if I stay with flexible PC, clear PVC tubing will be usable. only issues I see is keep it straight, and PVC is not as UV stable as other stuff.
There is another product I am looking for similar to heat wrap. it is very thin, very clear heat shrink.

[frankr]

I had been thinking down these lines and even bought some of the commercial versions at after Christmas prices.

One slight tweak to your DMX config. I would like to see a DMX channel to strobe the whole strip at once.

From what I noticed of the "Commercial" versions it appears that they have 32LEDs grouped in batches of four. The wiring is all single strand wires, i.e. no PCBs. I have not down a full tear down on them but they appear to be exceddingly simple in design. I would think that we should be able to build something that would emmulate the desing for a low cost.

I know that Ponddude has built something similar but his design was more expensive then the after Christmas sale (of course his design is more robust).

I think the key to this would be to get a cost point of about $5/ft of drop.

In terms of tubing, Tap plastics has acrylic tubes 1" OD with 1/16 wall for $4.05 for 6' sections.

Regards,

Frank

[Matt_Edwards]

I had been thinking down these lines and even bought some of the commercial versions at after Christmas prices.

One slight tweak to your DMX config. I would like to see a DMX channel to strobe the whole strip at once.
Do you mean an additional channel that controls all falling icicles?
Option 1 below would sort of to that. setting DMX level to 1 may mean strobe.



From what I noticed of the "Commercial" versions it appears that they have 32LEDs grouped in batches of four. The wiring is all single strand wires, i.e. no PCBs. I have not down a full tear down on them but they appear to be exceddingly simple in design. I would think that we should be able to build something that would emmulate the desing for a low cost.

I know that Ponddude has built something similar but his design was more expensive then the after Christmas sale (of course his design is more robust).

I think the key to this would be to get a cost point of about $5/ft of drop.

is this what you paid for the after Christmas sales? on what basis did you decide this should be the price break point?



In terms of tubing, Tap plastics has acrylic tubes 1" OD with 1/16 wall for $4.05 for 6' sections.

Regards,

Frank
I want to look as a solution that remains flexible and therefore would prefer to stay away from rigid pipe as a criteria. sure it can be used in some applications but not all.

How about some photos of your "commercial" solution?

BTW do you mean Poly Carbonate tube or Acrylic tube. my understanding is acrylic get brittle in UV.

[budude]

In terms of tubing, Tap plastics has acrylic tubes 1" OD with 1/16 wall for $4.05 for 6' sections.

This is what I used to house Frank's RGB strips. I bought 6' sections cut into four 18" sections - I'm lucky enough to have four TAP stores within driving distance. They have plastic caps also - you can see them here: http://doityourselfchristmas.com/forums/showpost.php?p=76153&postcount=22

They work great but they're a lot bigger than what I was looking for anyway. I'm thinking something a bit thinner if possible.

[David_AVD]

The plastics supplier I spoke to this morning said UV may affect the acrylic tubing when I mentioned it was for outdoor use. I guess brittleness and yellowing would be the result.

I'll stop off at Bunnings hardware on the way home and see what they have in the way of clear PVC tubing. As has been said, getting it to hang without curling up may be a problem.

For the DMX control, being able to trigger a single trickle would be handy. That way you could make them as random or sequenced as you like assuming they're on separate DMX channels.

For construction, what about standard 5mm white LEDs and thin white (wire wrap?) wire to hook them up? In its simplest form, one common + one per LED (or group of LEDs) would be easy for people to wire. The only problem is the amount of wires potentially obstructing the LEDs, especially towards to top end.

[Matt_Edwards]

For construction, what about standard 5mm white LEDs and thin white (wire wrap?) wire to hook them up? In its simplest form, one common + one per LED (or group of LEDs) would be easy for people to wire. The only problem is the amount of wires potentially obstructing the LEDs, especially towards to top end.
You could use thin enamelled cooper wire as is keeps the bulk down.

[David_AVD]

You could use thin enamelled cooper wire as is keeps the bulk down.

That's true. As far as I know, all modern enamelled wire has insulation that melts and fluxes when soldered, so it's not too hard to work with.

The Altronics 0.5mm variety (http://www.altronics.com.au/index.asp?area=item&id=W0405) (AUD $10) is about 60 metres to the roll, but you can probably buy it in larger rolls for better value.

[frankr]

I'll snap some photos and post them. I know the commercial supplier went after someone on another site that used the trademarked name so I am playing coy here.

As to the Acrylic, you are right about yellowing and brittleness but that is really a decision for the person doing the assembly. The wire wrap wire idea would work great. Using old white wire from minis would work as well.

Price point was a guesstimate really. The cost of Pondedude's solution is ~ $24 for a 20" section. Given what I saw from the commercial versions I am betting that a "simple" version, like the commercial ones I mentioned, should be able to be done cheap.

Now that said I don't want to constrain your design goals with that. I think to get to that price point you would probably need to have one control circuit and then a separate chip for each of the strands. Hence; multiple strands acting in sync. This is probably not what you had in mind but is a thought I had been toying with as a way to keep costs down.

And good call on the DMX. I am not used to designing with DMX as a protocol but I can see using the intensity to trigger different behaviors is a powerful trick! (i.e. stips chase up, down, go all on, chase middle out, chase ends in...)

[David_AVD]

OK, just dropped in to the hardware store (Bunnings) and had a look at PVC tubing.

It was all "Moss" brand tubing with "Neta" brand tee pieces. The tubing has a pale blue tinge to it so would probably look ok. Without any LEDs (to trial fit) it was hard to tell which size would be best, but the 10mm & 12mm look promising.

Interestingly, the 20mm size is available in a 1 metre stick and seemed quite straight. I wonder if the smaller sizes would straighten out after being cut from the roll? Maybe threading the cut tube over a suitably sized piece of dowel and leaving it in the sun for a while would be enough.

There were also L and T pieces in the 10mm and 12mm size. With a bit of fiddling I think you could feed the wires through and use them as the supporting joints for each icicle.

The big question would be where the electronics could be located. The smaller tube suits the LEDs better (and is cheaper) but the larger tube suits the PCB better I suspect.

A 10 metre roll of 10mm tubing was AUD $17.40 - seems like a lot to me. The 20mm was $5.30 per 1 metre stick. Anyway, hope that give other food for thought. :)

[n1ist]

I started a design using the TLC59116 as the LED driver, with one processor driving multiple tubes of LEDs. The TLC59116 is an i2c controlled 16 channel constant current chip that handles the dimming as well. The only drawback is that it only comes in TSSOP.
/mike