Hi, I’m Bob with LPS Computer Today I’m
going to show you how to replace the carriage belt on a designjet 500 series
plotter. The procedure is exactly the same for
the 24 inch in the 42-inch, it is also exactly the same for the designjet 800
series. I will be using the instructions that come in a kit provided by LPS. These are written instructions that are
taken from the the service manual which is also included in its entirety on
a CD that also comes with kit. The service manual has got troubleshooting tips theory
of operation error codes assembly disassembly instructions it has got all
the parts and and the break down drawings that sort of thing. In the kit
we also include a 39 piece tool kit that’s got all the tools that you will
need to complete this job, in fact anything else you ever want to do with
this printer with the exception of two specially extended torques they’re going
to need to get this thing apart and back together correctly. The kit also includes non evaporating
oil which is kind of important because you want to keep the friction as low as possible
on the the rails at the carriage ride on. When the machine is first calibrated
machine measures the friction left and right and creates a voltage offset to
compensate for differences in the friction left and right and then it
never looks at it again, so that friction changes it’s going to affect your print
quality so the best thing to do is keep the friction within the proper range you
would do that with the oil. Something that you spray on is going to get sticky
overtime and evaporates and it will actually increase the friction and you
will definitely see it in the quality of your output. it also includes a belt that comes
packaged like this. The belt itself is made of
high-density polyurethane and kevlar from DuPont. Half of the belt has got
teeth on one side and ribs on the other side The teeth go toward the motor pulley
because there’s teeth on that pulley that drives the carriage back and forth
and the ribs ride in the idler pulley that keeps the belt centered. Now there are belts coming out of Asia and
other places that are have teeth all the way around it so you can use the OEM
pulley and you lose that centering feature to some degree. These belts are made in the United
States and are the only designjet belts made in the USA and are made on a mold
owned by LPS computer. We had a made for us and the company
that makes these a very reputable, a big company that the does a fine job for us
their quality control is really good. We hold the length variants on this down to
40 thousands of an inch. That’s about half the width of one of these teeth and
that’s plenty accurate. We found out after we got all this together that HP’s
tolerance is much wider than that so we over-engineered just a little bit. They are extremely strong. If you’re going
to go to the trouble of putting in this belt I highly recommend you get
this belt or get an HP belt. We have heard lots of horror stories from people about the other belts that come out of Asia.
They’re all neoprene and fiberglass and their their
yesterday’s technology. Their quality control is not very good, and that’s being
generous. The kit also includes calibration media.
This is a type of plastic film. We like to use plastic because originally that is
what HP used to give for this calibration. Plastic is not going to expand or contract
with temperature or expand or contract or changes in humidity so you
will get the most stable calibration with this media then you a more stable calibration with this media than you would with paper. You will get the calibration
as accurate as you can possibly get. As close as the machine can get it. The piece for this one is 36
inches wide and it’s five or six feet long. The instructions say to load a role of
photo gloss media and so this is lowered as a roll. Tthe reason it is so long is to make sure the machine thinks it is a roll. You are going to have some left over. Well let’s take this thing apart and
i’ll show you how to change the belt. The end covers need to come off first. There are five screws in each end cover
but they are not in the same place left and right. The first screw we are going to look at is the one on the inside cover here. There is one down here this kind of out of
site. We have already taken it out and the rest are on the backside. I have to swing
this around and show you. OK, the next one is right here on top. This is on the right side cover only.
There is one right here. You have to have this lid open to get to it right there. And the last one is down here in this
corner. And this cover is ready to come off. I’ve already removed all the screws
except the top ones so they should just slide right off. OK, the left and cover has five screws
the same two in the front same location as the right side, but here we’ve got one
here here and here. The top center cover needs to come off.
That has got three screws total. One, two, three. I will take those out. Now, you open the front cover which is
part of this, then there is a finger sticks out here on each side and this
Clips down over so I’m just going to nudge this up and pop it off on each side and
the covers are off. OK, we start the procedure to get the carriage out from the right side. Now the carriage
is right here and is locked in position over the service station. So the first thing we need to do is
unlock that and get it out into its mid-range. The easiest way to do that is
to rotate these white gears down here. just like that. Just push them until they stop and that
will have unlocked the carriage. Now just push them until they stop and that
will have unlocked the carriage now it will just slide out. O, we need to disassemble just about
everything that’s on this side of the machine so we start out by unplugging
the all the connectors on the interconnect board here. Move them out of the way. This board can
stay on this assembly but the display itself has to come off. Now this needs to get out of the way.
There is a locating pin down inside here. If you pull that out this will lift out.
Now this just pops off like that and we can set these aside. OK, we need to get the encoder strip
loose. The encoder strip is the strip right here goes the full length of the
machine and it’s a little bit tricky to get it back on this side if you haven’t
done it before so what I’m recommending is that you take a variation from the
instructions in the release it from the other end. One screw 0n that and
we’ll take loose. This screw right here, loosen that. Sometimes it pops loose like that.
Sometimes you have to pull it off. OK Now there are several screws holding
this assembly on. Will get to that in a minute. First I am going to take the
service station out. The service station is this black assembly that generally
sits underneath the carriage. It is held in in place by two screws, one
here and one here. We will take those out now. Keep these screws separate. They are
shorter than the other screws. If you put a longer screw in here it’s going to
generate an error for 21:10 error when you put the screws back in because a
longer screw is going to interfere with the motion of the
service station. Now once they are out you can grasp this by the bottom and slide
it right out of the machine. OK, now we can remove the belt from the
other end. And now what we’re going to do first, and is that this is kind of a an
important detail, this is the tensioner assembly for the
belt right here and there is a strong spring right here. This is the the end of
the belt or part of the belt and pulley it rides on his right here and that’s
spring-loaded towards the end here by this piece. now this piece will latch the spring
down like that, so now this is loose it is going to make it
much easier for us to put the belt back on That is the good news. The bad news is
sometimes people forget to unlatch this and the belt tension is wrong and they
get checkprint head errors because the belt is not tight. So when we are all done one of the
last things are going to do is unclip this to tighten the belt. To take
that pulley out and loosen the belt we’re going to take the belt off of the
motor pulley on this end – you see it is nice and loose it’s easy to do. Now if we push the belt out, that pulley
will come out of the machine and now the belt is free on both ends. it is a good idea not to lose the pulley,
you may want to use it again later. OK, now this whole end needs to come off
and that’s just a lot of screws. We have got four or five screws in here and
they’ll be pretty obvious. We have got one here here, here , here. There are two underneath that are not so easy to find. one of them is this one and the
other one is this one, so they’ll both have to come off. And in addition to that there’s one more
in the front and that is right here. That is on a little arm the sticks out of
the end assembly. I’m going to leave the encoder strip
attached to this and just because it makes it much easier for the
installation to go back go back together. We will take a little break here I am going to
get all these screws out and i’m going to pull this off for you. OK, I removed the screws from this and I am just going to lift this off the machine and you see the encoder strips following
along here The encoder strip is is fairly tough but we don’t want to bend it or a crimp it or
anything like that. Good idea to clean the encoder
strip with a soft cloth and warm water while you have got it out. don’t use detergent or chemicals on it. There are real fine lines printed on here and
detergent and chemicals will take the the lines off – in which
case you get to replace the encoder strip. It won’t be any good after that. OK, now we have to get the carriage ready to come out of the machine. There are couple of things we need to do here. First we’re going to take the print heads out. Next we have to take this screw out. This
is one of those extended small torx bits that come with the special ones. You have
got to use it for this. The book says this is a T9. It is not, it is a T8. It is captive screw so it only comes
out so far and then it’s free, so we just stop right there. We will bring it down here to this
area and there’s a little latch right here and need to pull that forward and this
will lift out and we can let that hang out the back. That is going to be fine just where it is.
The next thing we need to do is take off the trailing cable. The trailing cable is
this piece right here and there’s a latch on the side here and just push this in and this will pop up and come off just like that. Now we can easily undo these. There is a little plastic piece here. It usually breaks when you take it out. That one didn’t break, it just went into orbit.
And there’s a finger underneath here. We can pull this loose and get that out of
the way. I generally run this out the end of the machine just we don’t damage it
in any way and it stays flat and out of the way. OK, this carriage is ready to come out of
the machine so you can just pull this one through. You will notice there are two bushings on
the back. This flat one – this clips in – and if gets broken your carriage
height is wrong. If it gets knocked out and it is not put back you get terrible print
quality (shadowing). The thing that loads this thing this way
is a spring-loaded finger which can also be easily dislocated. So be cautious with both of those, they
both have to do with carriage height. OK, if we look at how the belt is
actually attached to the carriage here, the belt teeth go our match up to
some teeth here. I usually like to try to feed this thing
up through and pull it out this way so I am not fighting the little
channel on the other side. You can use a flat blade screwdriver
then pop this up for your handy dandy Boy Scout knife. If you do not have a Boy Scout knife, a Girl Scout knife works, and that’s how it comes out. It is going to go back in the same way
with some of the teeth this way so its ties in with this and
can not slip and of course the ribs are going to have to go on the opposite side
you put together at the transition point between the ribs and
the teeth. You don’t stick it in just anywhere on the teeth that’s not going
to work. It is going to be at the transition . So I will
put the new belts on Where did I put it? OK, here’s the new belt and i’m going to
feed some of it through here like this just going to roughly into position and
then I put in the channel. OK OK, there’s only one in the channel OK Just like that. OK, I am going to put this back in the machine now. I am going to start off by getting this
bushing on this and then going to be very careful about the back bushes.
Number one not to knock this thing loose, number two, to push this finger up so it slides into the channel easily and then lastly the the third bushing on
the front here. Actually I should give myself some belt
here to go through first. And pull it into the machine OK, then reassemble is the exact opposite
of taking it apart. You don’t actually have to put the trailing
cable on just yet. We will put this end one first. The key on this… there’s a hole here in the plastic where
the end of the carriage rail goes. If you line up on that it is pretty
hard to get this thing on wrong. I don’t think you can. So once that’s in
you go ahead and replace all of the screws I thingk I said there were seven screws and what I’m going to do that then we’ll be right back. The screws are back in this and it is nice and solid. So i’m going to put the encoder strip back on mainly just so I don’t step on
it or damage it in some way. The most fragile thing we’re dealing with at
the moment is the encoder strip. It is going to go through a slot straight up from the
the the rail and it’s it’s a vertical slot. There is a senser inside there that that watches this thing go buy and counts the the lines and so on. so I’m just going to feed that through, move the trailing cable out of the way first. It is just going to pop right through
there for me, right? OK, that goes right on here. Now, the piece
on the other end the mounting is a piece of spring steel that is going to
keep this tight so we need to bend that. You need to do that by pulling on this pretty hard. there is a little numb right here. This was worn off. We can pull it up usually over that nub and it will stay. That is not going to happen with this one
so we’ll have to pull it up tightly and put a screw in it. You do not want over tighten it, you are turning into plastic and you can strip it, so don’t do that. OK, we will put the trailing cable back on at
this point. We will start out by putting it over this little finger first. That
locates everything for us right at the bend and then put it in the channel here. It should just fit in there like
that These are somewhat fragile so you don’t
want to be rough with them in any way but we can make sure they line up very
well and then go straight down with them and it is actually pretty easy to put them in. just don’t come in slideways. OK, and you
put that X in next, except I don’t know where it went. it’s on the floor here. It is not going to
go anywhere I will put it on when find it. A small piece of Duck Tape works too. OK, let’s put the carriage top back on.
There is a tab right here. it fits through a slot. Tab A in slot B.
Just like that, and it clicks in. Now I can put the tube system back
on. That just fits into place What you want to do is get this slot
right here over this edge in the slot this edge. When you push down this thing
is going to click into place. Now all we have to do is tighten the
screw that we took loose a little earlier. That was the T8. OK. I will straighten this out. OK, we are ready to put the belt over the belt tensioner. Remember we compressed that to make it easy to get it back on and so
will feed the belt through the top of the hole for them the belt tensioner and you put the belt pulley in that loop then just pull it in. We are not going to decompress that spring yet because we
have to put the belt over the motor pulley so we go to the other end and just slip it
over the motor pulley and check to make sure we’re not twisted anywhere. Apparently, the belt is twisted somewhere. Here we are. Slip it over the motor pulley. Now we release the clip that’s
holding the the spring compressed on this. See right here, try to get it loose with
this. Sometimes these break off.
That really doesn’t hurt the performance but it is going to make it harder to change
the belt next time. With these belts may very well be
never. OK, we are going to put these print heads
back in. OK The carriages all back together. OK, next thing we have to do is put in
the service station. The service station goes on with the gears
facing toward the end. These guides here have to go into these guides up here so actually push it in a small distance and then lift up and it should go all the way back against the frame, just like this. Now I want emphasize again that you use
the short screws that came out of here, otherwise you’re going to have a problem.
You will have to take it apartright and put the screws in. That’s not a T15! OK, now we’ve got to get all the wires
reconnected. Don’t pinch this cable here. This has
been a problem area where this has been pinched or roughed up in some way
that damages it and then you get errors from the ink supply station or from
the service station. This carries all the signals from this
board back and carries the signals to the display. So you want to be careful not to damage
this cable. All of these are keyed you can not get
them in wrong unless you really put some effort into it. I don’t know anybody who would do that it – except for one guy that used to work for us. He had a problem. OK, we can put the display back on. This is the finger that actuates the cover interlock switch. This could fall off –
if it does it’s no big deal. Just put it back on just put on like that. There is going to be a couple of extra empty – actually just one extra pin connector
that is not used. They used to put fans on the service stations but they
don’t do that anymore but the connector is still there so when you end up with
an extra blank connector that’s normal. Don’t worry about it. OK This one has got a fan. OK, we are ready to put the covers back on.
I am going to wash my hands first so we don’t make a mess of the covers and
I’ll be right back. OK, we start by putting the top cover on. Here are the
fingers I mentioned earlier that the top cover is going to clip on to. These are
the clips right here, so I’m just going to line that up and snap it on and then
there are three screws that go into the back and that cover is on. The the right side cover – I am going to open up the lid so it will slide by the ink cartridges
and get it into position. When this top screw is in position you
know you have the covers on right, and there are five screws that i mentioned
earlier to put that back. One on the front one on the inside, top, and the two in the
back. The left side – this is the easiest of all put it on.
You have got the one on the inside on the front and three across the back and
that is it. Its back together once again. I am going to take a break and put some
screws in the covers the hold it together and then I will be back and we will do a paper advance
calibration OK, I have got the printer back together.
Covers on, I powered it up and let it come to a ready state. I loaded the calibration media from the
back and I told the machine that it was a roll, not a sheet even though it is a
very long sheet and I told that it was high gloss medium. So what I’m going to do now is show you the right buttons to push and everything to do the paper advanced
calibration we’re going to go to the paper menu. That is the top icon here and
hit enter, and then the advanced calibration is already highlighted. It is
the fourth item down so I hit enter on that. We are going to CREATE the pattern.
So push the button and what is going to happen is that it will print the pattern
and cut it into that the right length of a of a sheet. So while the printer is doing that we are
going to take another break and once it is done I will show you what to do with
the sheet once it’s printed. OK, the the printer has printed the the
pattern and it cut it off. I unloaded what was left of the the the rest of the
sheet. What we need to do now is to go back
into the paper menu and advance calibration. What we want to do is load sheet. I will hit enter, and doesn’t really matter what
kind of paper here is because we are going to be reading this anyway. So
hit enter and now we have to go ahead and put in. One of these
edges has dots on it and it is the dots that go in first. we are going to load it that way. That is
what the machine is expecting. So, the dots edge is in first, and then use the blue
lines here and with a little luck we will get it straight enough that the machine will
like it. And we have to wait until this thing
checks the paper. OK The paper loaded now we’re going to go to
the paper menu again, the advance calibration and this time we’re going to
MEASURE the pattern. The machine does the rest from here. It
looks at the various things on the pattern and it makes its own adjustments
from here. It is totally hands off from from here on. The reason this adjustment is
important is because it makes one inch of paper motion exactly equal to 1 inch
of carriage motion. And the importance of that is that it
prevents banding so that the width of each printed scan is exactly lined up
against the next one. So you don’t get gaps and you do not get
overlapping. So if you are seeing banding in your print out. This is the calibration that will get
rid of it. Hold on to this sheet because a year from now, if you want to
check the calibration you do not have to write it again. You just put it in and read
it again the same way. The calibrations finished and so is this job! So good luck with your with your project
and see you next time. Good Bye.