Mega Tree for a beginner

Martin Saunders

New elf
Joined
Nov 26, 2018
Messages
3
Hi all,

Sorry if I am asking questions already answered multiple times or have posted this in the wrong area.

Looking to start using pixels next year and wanted some guidance regarding a mega tree. I've just ordered an F16v3.

My initial thoughts are 12v, 180 degree (as kind of backs against a wall) 16 strings of 70 (3 inch spacing) .

Things I am unsure of:

How best to connect to the controller - better to run off as few outputs as possible or use multiple outputs? I was thinking of using 8 outputs on the V16 with each string doubled over but is 140 pixels too long for one string without power injection ? Was thinking 30% power should be enough as I have houses directly opposite ... ? And if using this method, one 350w power supply should be enough for the whole tree or have I got the calculations wrong ?

Pixels - which type is best ? 2811, 2812, 2813 ( does 2813 even come in string form) ? They seem to be available in 100 pixel lengths but if I need 140 in a string can they be cut and joined ?

Open to any advice please !

Many thanks
Martin
 

Jay.S

Full time elf
Joined
Dec 31, 2016
Messages
221
Location
Narangba
At 100% white you will not have enough oomph in a 360 watts power supply for what you want. At 30% yes, but you should always engineer for 100%. Also, you are looking at 16 X 70 pixels, at 20 cents USD a pixel (that's a good average) you are looking 225 dollars US, add 200 for a Falcon, you are looking at 425 USD or about 575 AUD (current exchange rate). Add at least 150 for other materials and you are looking at over 700 dollars AUD. So why try to skimp on a 30 dollar PSU?
 
Last edited:

AAH

I love blinky lights :)
Community project designer
Joined
Dec 27, 2010
Messages
4,188
Location
Eaglehawk
I think the 2812 and 2813 are "led on chip" models and will therefore only be available in 5V.
With strip based trees it's fairly normal practice to go with using a 5m length of strip. The strip can be joined but it's hard to maintain the uniform spacing between LEDS as there's "tails" fitted on both ends of the strip. Strip must also be rigidly fixed to something like conduit as it's fairly fragile and whipping around in the wind will cause failures.
If you want the extra height but want to avoid the hassles of joining the strip just start the tree 1m off the ground to increase visibility and potential put a simple pixel star on top.
Strip will generally go 1 length at 100% brightness without needing injection. At lower brightness you should be able to go with injection just at the bottom of the tree.
Personally I'd design around a 100% load even if you run at 30%. With that in mind you should just squeak by with 2 360/400W supplies.
 

Martin Saunders

New elf
Joined
Nov 26, 2018
Messages
3
Thanks for the replies. Completely get the advice re power and relative cost of power supplies so i will base requirements on running at 100% !

I was actually thinking of using strings and not strips.. are strings easy to extend/join?

And does anyone have a view on whether it's better to use multiple controller outputs or less outputs (and add power injection) .. ? Or is it really just down to personal preference and whether you want to keep outputs to use in other ways ?

Thanks
 

fasteddy

I have C.L.A.P
Global moderator
Joined
Apr 26, 2010
Messages
6,648
Location
Albion Park NSW
I would use multiple outputs where possible because if you have a long length of pixels that zig zags and you loose 1 pixel along the way that doesn't pass data then you will have a lot more lights out because everything after that will not work. there are some pixels that sometimes can still pass data onwards with a faulty chip but this is dependant on the failure mode
 

Ellis

Naughty Elf
Joined
Aug 21, 2017
Messages
207
Location
Gold Coast
My 2c and I'm a newb too...

Definitely 2 power supplies, run them at 80% or less and it will be fine.
I run my tree at no more than 50% but most of the time around 30-40%

If you are ordering pixels from Ray Wu or similar you can order lengths of 140 pixels and also get the pigtails attached if you wish. Otherwise just solder and heatshrink yourself if comfortable doing so.
Depending on what % you end up running them at you may get away with power from one end of the 140 string, if you go bright then inject at the other.

As far as connecting to the F16, I'd spread over as many connections as practical for you and your setup, but I personally allow a spare connection or 2 off the controller, just in case.
 

OzAz

Senior elf
Global moderator
Joined
Dec 29, 2015
Messages
997
Location
Newcastle
One other thing to consider - Roughly how far away are viewers of your tree, and what sort of effects do you have in mind for your tree?
The closer the spacing the higher resolution, 3 inch spacing isn't very good, especially if you only have 16 strings, if you want to do singing faces on it.

8 outputs with each string doubled over (zig zag) is a good compromise, but with 12V pixels you'll need (be better off with) power injection for 140 pixels.
 

QLDKing(Brad)

Senior elf
Joined
Dec 28, 2016
Messages
561
Location
Albany Creek
My tree is a flat 16 string with power injected at string 1 and 9 (and data as well at the same location). But I run mine at %20-%30 (can’t remember which). And I think I ran from same power supply but different outputs.
Take a look at the 14:15 mark.
 
  • Like
Reactions: roy

Derf

am now a 5v hypocrite
Joined
Dec 1, 2016
Messages
251
Location
Narellan Vale, NSW
61dca43b3bf137a632a129b6f51731a3.jpg


I use 12v and I run Two Strings off one port of my falcon (200 Pixels per output no power injection). Ideally this would need power injection but the tree has been working for quite some time flawlessly @30%. Each Boscoyo Strip Vertically has 100 Pixels from bottom of tree to top of tree. as you can see its plenty of brightness at 30 percent. The whole tree can be full white without and dramas. I use 2 inch spacing on the megatree mounting strip and the whole tree runs off two power supplies (one for each side of the falcon). The PSU's do run quite warm even with the small vent but it hasn't got the concerning degree of temperature as of yet.
This tree is about 5.5-6 meters tall (Haven't measured the thing.) and I use a star wire frame from ikea I got for $3 which I just attached 50 pixels with zip ties (this runs at 100% brightness).

This works in my circumstance but may not work in yours. There are way to many variables to account for. you really just have to give it a go and see how it turns out. Just use calculators to see everything checks out and constantly monitor your props / controllers when they are running.
 

Martin Saunders

New elf
Joined
Nov 26, 2018
Messages
3
Thank you all for the very helpful replies. You are raising things I had not really considered very much, eg viewing distance. Our front garden is not very deep so standing on the pavement on the other side of a typical UK residential street is about as far away as you can get.. I'd say about 9 - 10 meters max . Perhaps 2 inch spacing would be a better idea?

Very happy to use up multiple outputs - I think my mind will find it simpler that way too.

Derf - how many strips is your tree in total, looks like 24, maybe 32? 360 degree ? Looks really good. Don't happen to have any video of it do you ?
 

roy

the confused elf
Joined
Apr 25, 2019
Messages
18
Location
Mickleham, Victoria
Been thinking about my Megatree build and was thinking about using an old mini tramp for the base circle connecting to a 3m centre pole, has anyone done anything similar ?
 
Top