HP CC483-40002

On the whole HP's CM3530 multifunction printer copier has been well reviewed and chosen as a printer by many corporate and individual customers. The print-engine used is made by Canon who seem to mainly sell it as the LBP-5460. (HP and Canon have a very long-running relationship where HP's printers are based on Canon engines).

Like many machines, the CM3530 has some points of weakness. The particular problem examined here is the hinge for the scanner-cover and Automatic Document Feeder (ADF). The hinge is made of fairly brittle plastic and it cracks, so that the lid breaks off the top of the printer.

The hinge used for the ADF unit on the Color LaserJet CM3530 is marked on the top part CC483-40002

The hinge is mainly plastic, but it looks as though two different kinds are used. The material mark on the top part is marked >POM< - which we are told stands for Poly-Oxy_Methylate also known as PolyAcetal. It is a waxy plastic, and they are notoriously difficult to glue. The hinge pin is bright steel, and there is a powerful spring used to counterbalance the ADF lid and make it stay open and easier to handle.

The plastic on the lower half looks different, it breaks with a granular fracture. The suggestion is that it is also POM but glass filled to about 30%. There are no marks to identify it, either a part number or material. This part descends into the scanner body is not quite strong enough and the plastic around the hinge-pin holder at the top shatters

HP (and presumably Canon) do not make the hinge itself available, the replacement is the complete ADF shell. Not only does this carry a high price but it seems it may now be being withdrawn.

There is some evidence that the printers also appear as the Canon LBP-5460, iSensys LBP-7750 and Satera LBP-7700. The first two are printers, not multifunction units and the 7750 seems likewise, although there is very little trace of it outside the Asian market. So if Canon do not make this print engine in an MFP variant the part might be specific to HP.

These are expensive printers and people are not pleased to find them being written off for want of a component. Perhaps some of the compatible parts makers out there might like to look at making the part.

HP do seem to have been struggling with this part. The partsurfer.hp.com website lists

CC483-67902 ADF Assembly Kit - no further information
CC483-67903 Automatic document feeder (ADF) assembly, no longer supplied.
CC483-67904 Automatic document feeder (ADF) assembly, no longer supplied.
CC483-67905 Automatic document feeder (ADF) assembly, Part CC483-67905 is no longer supplied. Please order the replacement, CC483-67907
CC483-67907 Scarlet ADF Single Pack

It looks as though HP have been trying some sort of redesign that causes the part number to change. However the CC483-67907 is available (as of July 2013)

Quite why HP have been insisting on a complete assembly rather than just shipping the hinges is a mystery. They do make the hinges available for some other multifunction printers (like the 2820). Other manufacturers have similar problems (Brother have a similar fault with the MFC8840 for instance).

There are no signs that HP intend to address the problem.

The part doesn't seem to be repairable. Glue is unlikely to work because:

the break isn't very clean so refitting the bits won't be perfect.
if its a waxy platic there are glues intended for the job but it probably won't be a strong bond.

Another possibility would be to screw steel plates to the outside and possibly inside of the plastic part, taking the strain away from the hinge.

The obvious answer is to get a compatible but better part made.

Compatible Part

It is only actually the base of the hinge that is failing - that is the square box with the round hole for the spring in it. This moulding doesn't seem to have a part number on it. The top part seems adequately robust. The hinge-pin and spring could be reused if users don't throw away the parts.

We are generally suspicious of compatible parts. It is possible to make them well but that isn't always true. So far as we can see the makers of low cost compatibles often take a manufacturers original and use it to make a mould. Parts lose their precision when that is done. However whilst there will be a couple of critical dimensions this part need not generally be that precise. In this case a mould made from an existing part might be adequate.

Manufacturing The Part

We believe the original part used a six-part mould and it's been suggested that developing such a mould would cost 100,000 Euros. At that sort of cost compatible part makers would probably regard this as too much of a risk - even if there is a call for thousands of spares how will they shift them all? This may also be the problem for HP; if they had the original part made in one batch and then later found more than predicted were required as spares it may simply be uneconomic to set the job up again.

We have thought of making the part ourselves. Cold cast polystyrene or polycaprolactone in a silicone mould might do the job. Whether the part could be freed from a mould might be in doubt - it would have to be at least a two part mould. We also doubt the result would have the required strength.

The problem is that the plastic above the hinge-pin breaks. The hinge part at the top of the moulding needs strengthening a bit. The existing item has ridging around the hinge and the ridges are 4.9mm thick. However near the hinge they thin down to 3.7mm and the bulk of the plastic at the point of failure is just 3.3mm thick. Adding an extra 1.6mm of extra plastic would make the hinge substantially stronger.

The plastic around the hinge area can't be changed much. It would be possible to extend the base which breaks a bit and reduce the part that screws into the ADF-lid a bit .

Alternatively a more robust plastic material - or even metal might be used. It does not seem that the material would be critical.

We'd like to think it would be possible to make the part with a 3D printer but the hinge part is under considerable strain so the material does need to be tougher than the original. It has been suggested that a 3D print job in plastic would have 50% of the strength and 30% of the stiffness of the original part. It would be useless. A metal part might work properly.

There is also a problem with scanning the part in to get a 3D print - it is quite intricately made. We spoke to a local training college about getting a 3D scan done but their 3D laser scanner would need relection targets and they think the object is too complicated for that.

One of the problems with making this kind of part is apparently cooling. There are points just visible where the ejector pins operated. The very slight indentations suggest that the part was ejected cold to retain dimensional stability. The cost of the Poly-Oxy-Methylate material and that need for dimensional stability probably explains the complex mouldings, the manufacturer needed to cool the part before ejection but cooling would take too long if the material were thicker. The complex form gives quicker cooling.

Dimensional stability might also explain the glass fill. A glass filled material contracts much less on cooling. However we don't think the lower part of the hinge has very many really critical measurements.

If HP wont supply the part then perhaps others will create compatible parts. In some cases, like older printers, there is nothing else available. Likewise in this case - If Canon or HP won't provide the part customers might turn elsewhere.

One customer tells us that from a population of about 150 printers they are currently experiencing 5 failures per week. At that rate, they will have written all these printers off in a year or so and will be prejudiced against HP in future. The failure rate is clearly unacceptable and can only get worse as the plastics in the hinges age.

Measurements for the dimensions given here were taken with hand held digital calipers so they may not be perfect. They are to give an idea of the part and its complexity. They aren't adequate to tool up for the job.

Manufacturers and other spares vendors interested in this part might like to contact us at the email address above. We are actively looking for a source of supply for the part.

Likewise if you are having this problem feel free to email the address above.