0:16 Now here’s my filter mark 1 and you can see from the colour of the wadding
0:22 that’s around the edge here just how much rubbish it collects. It collects a
0:30 lot of dust on the surface here that you can see it just brushing off all right
0:36 so I’ve increased the area by probably 30% in fact I’ve increased the area more
0:43 than that because there’s a bigger open area on the new filter. Well the machine
0:48 will now become an assembly station for at least part of this assembly I’m going
0:53 to be using this WC 1 2 3 PETG weld cement. Now although it’s
0:58 designed for PETG it works very well with acrylic just takes a little
1:03 bit longer to cure off so sometimes we have to wait maybe thirty Seconds to a
1:08 minute to get it to, get it to go off. So we’ll produce the pieces out of a hat
1:14 as we go and the first two pieces we’re going to assemble are these two pieces
1:19 here which are the locators that go into the the air spout at the back. So we put
1:26 those together and this has to go together a certain way so bottom right
1:33 hand corner and then we’re going to poke these through it like that now I happen
1:39 to have a 14 millimeter block of acrylic here which is just the right height to
1:43 keep this level. So the idea is what we’re going to do is we’re just going to
1:46 put a little bit of glue into each one of these joints
1:53 and we should see it running in the joint as we put it in and we don’t have
1:58 to worry too much about the excess on the surface because this is a frosted
2:01 material and it doesn’t really show but we will wipe the excess off and then
Transcript for Fume Pre Filters Design Mk2 (Cont…)
2:07 we’ll just lean on these for about a minute. Now while we are we doing that we may
2:12 as well put a little bit up here as well
2:24 just move it around from time to time to make sure it’s not stuck today to the
2:29 work table. Now it’s very convenient that these blocks also when I rotate them
2:34 around they sit a little bit taller than that which is what we need as well
2:41 because we’re going to turn this over now. Now what we’re going to perform now
2:45 is a bit of a tricky operation so you’ll need some masking tape and youneed to do a
2:50 little bit of preparation work. Tear up a piece about four inches long and on
2:57 these pieces with holes in
3:02 we’ll put a piece on each end. These pieces here with the lugs on are going
3:10 to go upwards and you will see that there are matching holes
3:17 in these pieces. So plug the corner together and hold it together with tape
3:25 like that now it’s starting to be a little bit more stable. We can do the
3:30 same with this one and then finally we can do this one, we don’t need to do the
3:37 tape up too tight at the moment we still need some flexibility in here because
3:43 we’ve now got to squeeze this one into this other set of holes. So we can pull
3:52 the ends, pull the large sides away to start with and tuck these into the slots
4:02 on the end
Transcript for Fume Pre Filters Design Mk2 (Cont…)
4:05 and then we can try and do the same on the other end but we’ll have to push
4:11 the sides out
4:16 like that
4:19 and then click these in these. There we go so now we can have a go holding the
4:26 corners a little bit tighter squeeze the tape up
4:32 and that’s our basic assembly done so now we’ve got to glue it now we need a piece
4:39 of scrap material six millimeter thick underneath this bottom face here so that
4:46 we can press down on the top here without putting any strain on these
4:51 joints of the corners we’ll take the load directly down onto this flat
4:54 surface. Because what we’re now going to do is we’re going to put glue in these
4:58 little spots along here and we’re going to stick these down tack the whole thing
5:03 together so
5:17 you’ll see the glue
5:20 running into the joint as you tuck it into the end of these
5:43 there we go, just wipe the excess off as we take two or three minutes and hold
5:50 the whole assembly together. This is the right way up with this at the bottom
5:55 right hand corner okay when I let go I want to make sure that these dark
5:58 patches which are along here where the gluing goes doesn’t change shape which
Transcript for Fume Pre Filters Design Mk2 (Cont…)
6:03 means it has actually locked
6:07 okay now we can carefully turn it over 180 degrees and we can do the other side
6:14 exactly the same the other long side
6:18 there we go that looks stable now we’re going to turn it through 90 degrees
6:27 I might have to just peel the tape back a little bit from some of the tabs
6:33 and then the other end
6:47 okay now we’ve tapped it together now we’ll put our blocks back on here again
6:53 and now that that’s sitting upright we’ll go round and we’ll just run a bead
6:58 of glue
7:16 along the edges there and that will secure that in a few minutes we can then
7:24 turn it over and
7:32 we do exactly the same thing
7:38 so we just leave that to dry for about ten minutes now while that’s drying off
7:44 I’m using a piece of let’s call it scrap acrylic it’s a funny color blue which
7:51 I’m unlikely to use you could use a piece of MDF piece of cardboard even
7:57 corrugated cardboard so what we’re doing we’re making a template so that we can
Transcript for Fume Pre Filters Design Mk2 (Cont…)
8:02 mark the wadding to cut it to go into the filter now here’s the wadding you
8:07 can see you get a lot for very little there’s probably enough there to do four
8:11 or five filters and that cost probably I think about three or four pounds trust
8:17 me you need a template because it’s got a mind of its own now what I’m going to
8:23 try and do is to cut this in one piece and fold it in half now I would advise
8:28 you to use these rather than a Stanley knife because yeah it it tends to rip
8:35 okay so there’s our filter material well here we are back with our blocks on the
8:43 table again for the final part of the assembly now here’s our piece of
8:48 polyester wadding that
8:53 fits in there quite nicely
8:59 it’s a little bit too full which is great because it means it’s going to
9:03 fluff itself up and sit tight against the front cover and here is the front
9:10 cover bear in mind we’ve got a plug here at
9:13 the bottom right hand corner and these pieces here which are the funny shaped
9:18 slots sit at the top but before you attempt to
9:21 put those in thread these little pieces at the bottom in and just catch them
9:28 under the lugs and then you can push the top down over those and from the top you
9:37 should be able to just slide it underneath the tabs like that. That’s how
9:41 easy it is to assemble and disassemble let’s just do that again we can just
9:46 push it up and the whole thing comes off we need to tuck these little bottom
9:52 corners in first one material thickness then we can push the top in put a bit of
10:00 pressure on it and pull the whole thing down and it locks down nicely there is a
Transcript for Fume Pre Filters Design Mk2 (Cont…)
10:06 chance that you can knock this and lift it off during assembly so here we’ve got
10:12 a couple of little T type t tape so here we’ve got a couple of little t-shaped
10:17 tabs that will slip in there like that and they will prevent this from coming
10:24 apart so they will just lock the whole
10:28 assembly together now the smaller one that I had before was very easy to get
10:32 into the machine this one is a bit more like a Chinese puzzle you have to
10:37 thread it in very carefully now we shall need both the front and the side doors
10:42 open now we’re going to lay it down let me see how does it go I don’t think I’m
10:49 going this way, let me just check
11:05 oh yeah now that I’ve made it smaller, slightly, it goes in the side door hopefully
11:11 there’s just enough light in there
11:16 for you to see that what we do is to lift it up and we just offer it into the extract
11:25 spout and just in front of that spout we’ll just push it in and it clips in so
11:31 there we are it’s sitting in the back of the machine it’s a very large area because
11:35 the principle of any pre-filter is to keep the air velocity as low as possible
11:42 as it passes through the filter so you need the largest area possible and the
11:47 freest flow now the flow might be free through that
11:52 Wadding but it’s a very very tortuous path for any particle of sticky stuff or
11:58 dust to try and get through that wadding it’s offering no extra resistance to
Transcript for Fume Pre Filters Design Mk2 (Cont…)
12:03 flow to the Purex unit
12:09 it’s doing what it always does hovering around about the 310
12:17 well hopefully that simple device a lot lot cheaper to replace than this rather
12:24 expensive bag filter so it should hopefully prolong the life of this
12:28 filter quite a lot I’ve had one of these in my machine now for over a year I
12:33 don’t use it a great deal but hey you saw the state of the filter when I took
12:39 it out of this machine that’s about the third filter that I’ve had on this
12:44 machine and every time I’ve taken it off it’s been as dirty and as mucky as that
12:49 so it’s doing a very good job so I hope it works well for your application and
12:55 thanks again for your attention
