00:00 |
- We're now going to move on with the next step of our process and here we're going to prepare our boots for installation, although in this step we will not be recovering them down.
|
00:10 |
But this is an important step because the construction process means that if we complete the harness, we're not going to be able to install our boots further up the harness so this actually has to be done in order and it does require a little bit of just thinking the whole construction process through so that we don't end up basically building ourselves into a corner where we can't install the boot.
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00:33 |
Now what we're going to do with this is we'll focus on one of our boots for this section of our harness here, our T branch at branch point A.
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00:42 |
So that's the one we'll focus on for the main part here.
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00:44 |
Obviously everything else essentially is just a rinse and repeat of this.
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00:48 |
The rest are actually also much easier.
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00:51 |
I will point out that the boot that we're going to be placing on the back of the autosport connector, this is actually big enough that we can install it over the connector body so this is nice and easy, it's going to mean that we can install this really as one of our very last steps.
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01:08 |
The process of actually preparing our harness for our booting is twofold really.
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01:14 |
What we're going to do is wrap the branch point in our Kapton tape.
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01:18 |
This has two effects, first of all it gathers all of our conductors in the right area and the right place and the right orientation.
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01:26 |
It's also going to protect the underlying conductors from the epoxy glue that lines these boots so basically it's going to mean if we ever need to effect a repair on that particular area of harness, we're going to be able to remove that boot without basically gluing itself to the underlying conductors.
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01:46 |
The other aspect of this boot preparation is to abrade the DR25 on each side of the boot.
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01:55 |
And that's going to give that epoxy something to really key into and bite down on to help it stay located and positively sealed.
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02:03 |
The other aspect as part of this we're going to go through and install our heat shrink labelling for all of our sensor and actuators so that of course when it comes time for the pin out to be applied, we know what's what.
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02:20 |
We again won't be heat shrinking this down at the moment but we will be installing it ready for the final pinning out into our connector bodies.
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02:30 |
So let's get started with our first branch point here which again is our branch point A.
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02:36 |
I'll just get our harness out of the way for a moment and we'll get the boot under our overhead here and just have a quick look at what we're dealing with.
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02:43 |
This particular boot is a Hellermann but you're going to find essentially the same compatible products from TE Connectivity as well.
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02:52 |
One thing I will mention, particularly with these T boots, or you'll also see we will be using some angle transition boots as well for our injector and ignition outputs.
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03:02 |
It is really important to pay attention to the labelling on each of these branches.
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03:08 |
So we've got H, J and K.
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03:11 |
The important point to note here is that the straight through branch is H and J.
|
03:16 |
Once this is recovered down, you're going to find that this K branch here is going to kick right around and be at 90° so no big deal, of course that's exactly what we want it to do.
|
03:28 |
The danger is if we just haphazardly install this and get the orientation around the wrong way, we're going to end up with our harness essentially branching out in completely the wrong direction.
|
03:39 |
Again that's going to be difficult but not impossible to recover from so we don't want that.
|
03:45 |
Alright let's get our boot out of the way here and before we carry on, I'll also get another couple of our boots under the overhead here and just show you the effect of recovering these, particularly if they are unrestricted.
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03:59 |
Now I've just done this just to show you first of all how much they will shrink when they are heat recovered.
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04:06 |
But just as importantly how that length expands out so you can see that the finished recovered boot is much much longer than what we start with and this can be quite deceptive, particularly when you are choosing a boot, if you're looking at it in its raw unrecovered form, it can on face value seem a little bit too short.
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04:23 |
This also helps us understand the area of our DR25 that we're going to need to abrade.
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04:29 |
Of course all of these specifications are listed so it's just a case of looking, in this case, the overall length is a dimension P, we can see the unrecovered and the recovered dimension for each of the boots we're going to be working with, allowing us to know exactly what we're going to be dealing with.
|
04:48 |
Alright let's get our boots out of the way here, we'll bring in our harness and we'll start with abrading that DR25.
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04:56 |
Alright our branch point A, you'll recall that I've used this cable tie here just to help with the orientation.
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05:04 |
We'll be doing a final check before we recover these boots but essentially everything's pointed in the right direction so one of the first things we're going to do here is actually cut these cable ties and get them out of the way so let's get that done now.
|
05:19 |
As usual, any time we are using cable ties around our harness, extra care is required there just to make sure that we don't inadvertently damage our finished harness, that would be very very difficult for us to recover from at this point in the build.
|
05:33 |
Alright what we're going to do now is use a little bit of emery paper, like sandpaper here and we're just going to gently abrade around about 20 mm of each of the legs of our DR25.
|
05:44 |
Doesn't require too much aggressive abrasion, just basically enough to scuff the surface and give our epoxy something to key into so let's go ahead and do that.
|
06:03 |
Alright with our DR25 now abraded, what we're going to do is clean that down using some isopropyl alcohol and a clean rag.
|
06:16 |
Alright now what we're going to do is take our kapton tape and we'll just wrap the exposed conductors and basically make sure we've got everything bundled up in approximately the order and direction that we want everything to come out of.
|
06:37 |
Alright with our kapton tape installed, it's now simply a case of working our T boot into location and particularly for this one, obviously we're working it across the entire harness with all of those break outs so this one in particular, it's going to be a little bit challenging but all it requires is a little bit of patience and a little bit of care.
|
06:56 |
Again, paying special attention to the branching, making sure that we have our J branch coming out in the correct orientation so let's get that installed into location now.
|
07:23 |
Alright we've got our first T boot into location and while it is a little bit fiddly, the good news is that that is far and away the hardest of our boots to install.
|
07:32 |
Obviously we had to arrange all of our other individual break outs to get through that boot.
|
07:37 |
So at the moment I've just got it sort of located approximately where it's going to be.
|
07:41 |
Really until we actually recover this down, this is about the best we can do anyway.
|
07:46 |
Obviously as this recovers, it's going to start branching around and that's when we can do a little bit of manipulation, get it into its final location.
|
07:53 |
What we're going to do now is jump ahead and we're going to install the rest of the boots and come back to the harness.
|
08:00 |
Obviously this again is just a repeat of what you've seen here.
|
08:03 |
It's just a case of choosing the correct boot for the specific branch point based on our design that we've already done so let's get that done and come back to our harness.
|
08:14 |
Alright at this stage we've gone ahead and we've prepped the remainder of the harness and just installed all of our boots and really it's just exactly what you saw, just one point I will make, there's a couple of these boots here which are just a straight boot, we'll just get this under our overhead so we can see it in a little bit more detail, get some of our other conductors out of the way.
|
08:35 |
And obviously the danger with a straight boot like this is that it can accidentally fall off, slide off the harness if we're not careful and if we don't notice that and we go and end up pinning out our conductors at the end of this wire, then find the boots fallen off, that's going to take us a little bit of effort to depin again to go back so what I've done here is I've just installed temporarily a cable tie, I've left that cut long and that is just going to make sure that that boot can't accidentally fall off the harness and we've got exactly the same happening on the other branch.
|
09:08 |
So job done at this stage, again we aren't going to be recovering these boots right now.
|
09:14 |
Before we move on, we also need to consider our labelling and really this is just going to follow exactly what we've seen in the body of the course so we're going to be using our 3M dymo label printer and we're going to be printing this onto yellow heat shrink.
|
09:30 |
Not really a lot of rocket science going on here, what you do want to be careful of is making sure that whatever naming strategy you come up with, you're consistent.
|
09:39 |
Particuarly when you're building a lot of harnesses, this does become important.
|
09:43 |
So whatever it may be, maybe you want to call your oil pressure sensor wire oil p, oil press, oil pressure, it just doesn't matter as long as you've got a system that you're comfortable with.
|
09:56 |
Likewise, there's a little bit of preference that comes in here around font and sizing and a little bit of test printing can help you here.
|
10:04 |
So got a little sample here that I'll just get under our overhead and it is a little bit difficult to see but this is just 2 of the different sizes that we can print with on our Dymo.
|
10:17 |
And again, personal preference here, I am going to be using the smaller of those two and again just keeping consistency across our harness.
|
10:26 |
Let's get our printer underneath the overhead here and we'll just turn this on.
|
10:32 |
And we can see here I've got our IAT label ready to print.
|
10:38 |
Now one thing I will mention as well, with this particular printer, it is always a good idea to print all of your labels, or at least the majority in one shot.
|
10:47 |
The reason for this is that if you are just going to print one like this, it's quite wasteful, it's going to add quite a lot of unused heat shrink on both sides before you cut it and this really adds up.
|
11:00 |
The consumables for these, they're actually quite expensive so it is worth considering.
|
11:05 |
The process we're going to go through here is a case of printing out our labels and then we're going to be installing those over our DR25 as well as a piece of clear heat shrink.
|
11:17 |
We're going to be then recovering down the heat shrink for our label and then recovering the clear heat shrink over the top to provide some protection.
|
11:25 |
Again, at this point we're just installing these parts loosely, we are not going to be recovering them down and a cable tie around the end is a good way just to make sure that those don't fall off.
|
11:38 |
Let's go through this now with just one of our labels.
|
11:41 |
We're going to install our IAT label and I have that label here so we'll just get that under our overhead, obviously reasonably small.
|
11:50 |
I'm going to get that into location and we're going to get that clear heat shrink over the top as well so let's go ahead and do that now.
|
11:59 |
In order to install our label, obviously the first place to start is finding the correct conductor and that's where our little coloured idents come in.
|
12:07 |
I know from my design worksheet or spreadsheet that 30 is the sensor that I'm looking for so the orange and black is 30 so this is our IAT.
|
12:20 |
Now what we're going to need to do is expand out our heatshrink and get that into location.
|
12:26 |
This can be a little bit fiddly, a sharp pick or a small screwdriver is a pretty good way of actually opening that up so let's just get that open and ready for installation.
|
12:38 |
And the other thing to keep in mind as we're installing this is the orientation of the writing and again this is personal preference and really consistency is more important than anything else.
|
12:50 |
But I want that writing so it runs towards the connector body and again, personal preference and consistency is more important than specifically what we're trying to achieve there.
|
13:04 |
Alright now that we've got our label into location, we can take our clear heat shrink and get that installed.
|
13:08 |
What we want to do is make sure that our clear heat shrink is just a little bit longer than our label.
|
13:14 |
Depending on the specific sizing of your heat shrink vs your clear heat shrink, it may be beneficial to actually install the clear heat shrink first.
|
13:23 |
In this case, it's not really a problem, we can actually slide that directly over the top of our unrecovered label, we'll just slide that up for the moment, we want it well out of the way and again what I'm going to do just temporarily until we have pinned out the connector body, is I'm just going to put a cable tie around the end there and that's just going to make sure that that label can't fall off.
|
13:46 |
Now at this point we can also consider our booting material for the connector body, depending on what you're using here.
|
13:53 |
Obviously if you are using a boot, this would be the time to install that as well, making sure that that is not going to be overlooked.
|
14:01 |
It's really easy to go and pin out the connector body then realise that you can't get the boot over the top of the connector body, obviously making more work for yourself.
|
14:08 |
In our case, the majority of these connectors are going to actually run no boot on the back of them, instead we'll just be using a short section of SCL to shrink down over the end of our DR25 directly onto our conductors.
|
14:23 |
Again, we don't want to forget that, we're not going to be able to install it with the connector bodies in place.
|
14:28 |
I'm confident enough though, I'm going to be able to install that as we go along so at this stage, it's a rinse and repeat again, we're going to be labelling each of our individual sensors and actuators etc so we can complete this step and move onto the next step of our process.
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