(rumbling intro sound)
- So, as we continue our series of videos on LED strips,
something he still calls LED tape.
Today we're going to look at the do's and don'ts
of cutting LED strip.
- Or some people even call it LED ribbon, Gary.
- An LED ribbon.
Okay then, so we're going to cut it.
That's all we are. - We're gonna cut the ribbon.
(laughs) We're gonna cut the ribbon.
So we're gonna get straight in,
and I'm gonna do what you shouldn't do,
and I don't suggest you try this yourself.
So here's my LED
tape. - You're gonna cut it live?
- I'm going to cut it live.
It's only 24 volts.
I'm not liable to do that, but we'll see what happens.
- So before you cut it,
you're cutting it to the length required
to fit maybe the profile or the dimensions that you need.
- Yeah.
- So, exactly where you want to cut it.
- Exactly where I want to cut it.
So I'm thinking, well, I need this at 280 millimeters.
(electricity zapping) Oops.
- Okay, it's ruined?
- Oh, so we've got three there not working.
It's the right length.
- It's the right length.
- But you got three LEDs now that don't work.
- Yeah and there's a slight burning smell in the room.
- Okay. (laughs)
- Yeah
- So, that's obviously an issue
if I wanted to cut something, let's say,
I don't know, 750 mil,
I could only cut it you know, where I needed to cut,
you now got three LEDs that don't work.
- Yeah.
So, the advice LED strip, LED tape,
comes with some defined cut points.
- LED ribbon as well.
- Yeah, and people normally, first mistake people make,
not reading instructions and just cut it where they want
and you find that you lose three LED at the strips.
- However,
- [Gordon] Yeah?
- At least it still works.
- [Gordon] Still works, yeah.
- but we've lost three of those, okay so that's obviously,
we've gotta overcome that problem.
So how do we overcome that problem Gordon?
- We overcome that problem,
so let's look at a practical example.
So we've got this piece of LED extrusion,
as he would call LED profile,
and here's some LED strip, tape, ribbon.
- Okay. We're gonna cut this one as well?
- Uh, we're gonna cut this one here.
So we'd say 650 mil, this is 750 mil length.
The cut points are 100 millimeters apart.
- Ah, so we got a 50 mil problem there.
- Yeah, so I can only cut it shorter.
- Okay, so we're gonna cut it shorter.
- So I'm gonna cut it right in the middle of the cut point.
- Okay, yeah.
- Which also is where the connection points are.
- So, that's where we soldered to in the previous video
and use insulation-displacement connectors as well yeah?
- [Gordon] Exactly, so I'll just cut through there.
- [Gary] Okay.
(scissors dropping)
So it's not long enough now?
- So it's not long enough.
So now you've got a choice, (mumbles)
put it in the end-to-end with a big dark patch
which probably centralize it.
- So, we may have a little spot here,
and a little spot at each end where we haven't got the light
that we we're expecting because we've had to cut it
at the cut point and that cut point
meant we had to cut, ah you said it was 700 mil or only 650?
- Yeah.
- So, we've now got that down to 600 mil, 50 mil gap shared
across the two ends?
- Yeah.
- Okay. That's the compromise you have to make,
I understand.
- Now that might be fine in lots of applications,
especially where the light's going quite a distance
in a corner, surround a room shiner with a ceiling
- Okay
- You probably won't see that,
but if you're in something where you're closeup
and you absolutely need light to the end of the profile,
you've got a diffuser on there
and you want light right to the end like a bookcase,
or some other cupboard you like,
where people can see the strip,
- [Gary] Yeah.
- You'll probably want light right to the end.
- Okay. So are you gonna remanufacture the piece of bookcase
to make the LED strip or you've got another solution for us?
- Good idea. And the solution is,
from this OSRAM range here, you can also get a short pitch.
- [Gary] Okay.
So is that mean there's more LEDs in that space?
- Yeah. So when you buy LED tape, strip, ribbon,
you'll see that it has a normally specified,
numbers of LEDs per meter.
- Right.
- And this one, short pitch has more LEDs per meter,
and interested or not, this is 24 volt LED strip.
- Yep.
- There are six LEDs between each cut point.
- Okay, and the one you started with first of all,
what volt? - That's six,
but they were further apart, so half the number of LEDs.
- And what voltage was that?
- Again, 24 volts.
- Okay, yeah, fine.
- So I'd always say, in most cases
24 volt tape is more efficient than 12 volt LED tape.
- Right.
- And we'll look at that in another video,
'cause there are some other complexities to look at there.
- So we've got more LEDs and therefore our cut points
are now 50 mil apart, is that true?
- 50 mil apart, yeah.
- Ah, so we're in a good place now,
'cause you told me originally this was 650 mil long,
- Yeah.
- So we should find that a cut point is, that's perfect.
- I'll line it up there, yeah. I've got my cut point there,
ah, so I'll go straight in.
- Okay.
- [Gordon] Cut that.
- Lovely, okay.
- All done. Now I'll connect the end up.
We'll use some of those, we'll use the IDC connector
we used in a previous video.
- Be careful not to squeeze them together.
- Nope, not gonna squeeze them together
(mumbles) that's good tape right there.
- Yeah that is.
- Please to remember that.
- Yeah
(Gary and Gordon chuckling)
- So we're gonna stick it down,
we're gonna put the insulation-displacement connector
on first.
- Yep.
- Okay.
Good eyes there. I'm glad you're doing it and not me,
so we're sliding that one in.
- Sliding that one in.
- [Gary] Got it in?
- [Gordon] Got it in. Yep, press through.
- [Gary] Press it, and that's it. So you're done?
- Yep, I'll-
- We'll know in a minute when we're loading it up
- Well I'll put it in the tape first.
- Oh brave.
- In the extrusion first.
- Okay.
Profile. - Profile
- So you're sticking the profile.
So you're gonna try
and go bang in the middle of the profile?
- Yeah.
(Gordon quietly conversing)
- We learnt in a previous video that the profile,
or extrusion, whatever you wanna call it,
is actually helping the LEDs
with their temperature management,
and also when we stuck it to a wooden surface,
we also helped manage it's temperature,
but it's worth checking out that video,
because we also left it in free air,
and it's every interesting to see
what happens to the temperature and how quickly it can rise,
where LED strip is left off a surface which
affectively is working as a heat sink,
so I'd recommend you checkout that video,
in the "I" about our heads.
- So I'll just, there. Right.
- So we're ready to go, are we?
Moment of truth.
- Power it up
- So it's exactly the right length.
- It's exactly the right length
- So you've cut it halfway through the cut point,
and lo and behold all the LEDs have now illuminated.
- So I'm gonna put our diffuser on.
- [Gary] Okay.
- [Gordon] And there we go.
We've got even illumination
for the entire length of the strip.
- Okay, yeah that's good, and we used more LEDs
and what'd you say was the pitch called on that?
Just to remind.
- The short pitch.
- Short pitch, yeah , okay, and that gives you a little bit
more flexibility in the distance between cuts,
making it 50 mil.
Is 50 mil the standard shortest position between cuts?
- Uh, no it depends on the manufacture of the tape.
- So then Gordon,
just remind us of those top tips when cutting LED strips.
- Okay top tip. Cut here, not anywhere in-between here.
So stick to the connection points
which are also the cut points,
sometimes they're marked, sometimes they're not
and read the instructions before you start.
- There's plenty of other videos
in this series of LED strips.
If you haven't already checked those out,
please look in the description below
or the "I" above our heads,
or the end-card in order to catch-up
with the other videos in this series,
and look out for more videos in the future on LED strip.
(rumbling outro sound)