I have a Vandercook 4T press here in Prague. Now after 5 years of not being used (here in Prague – it could have been unused for longer than that), I have decided that I should give it a go. I had to change the plug, but all seems to be working fine, apart from one little detail – not all the inking rollers are getting enough traction (or friction, sorry for my English) from the first two. So only the first (rubber) and the second (small metal one – the one closer to the cylinder) roller are spinning.
First, that came to mind was to make sure that the big metal roller (the biggest on top) sits properly on the rubber rollers. But not even pressing the rollers down (by hands) helped.
Second, that came to mind was that – maybe – they will start to spin once there is the ink applied. The true is that they kind of want to spin – when I try and help the rollers to spin (by hand), they do seem to go, but then immediately stop when I don’t help them. I did not have the chance to try that, but even though it might work, I am thinking that perhaps it isn’t a way of thinking anyway – after all, they all should be spinning even without the ink on, right?
As soon as I try it with the ink, I will let you know how it goes, but now I would like to know, what you think.
It could be that the rubber rollers are old and that their properties changed or they shrank in size, I don’t know. The problem is that I am new to it and don’t exactly now how the rollers should look (if they should be hard or soft, sticky or smooth…). Anyway, I do have a spare two, so I could try and change them, once we run out of options. They seem to be slightly harder than the once that are on.
Many thanks for any sort of help / thoughts that you give.
Have a nice day.
Kind Regards
Karel
. . . and there is also an adjustment of the upper frame relative to the form rollers for parallel. Between the ends of the tie rods are two blocks that can be moved horizontally for skew.
After five years or more the rubber rollers will be out of specification. Their diameter should be 2.5 inches (6.35 cm). There is also a specified durometer, or hardness (20 on the “A” scale) but this is less important. In general, they should be somewhat soft when you squeeze them.
Rollers shrink and harden over time, so your spare set may not be useful, but it’s worth examining them.
The large steel roller is called the oscillator because it moves laterally. The small steel rollers are called riders. The entire assembly is called the top frame assembly.
The riders are hollow tubes with wood bushings (sleeves) on each end and turn on the tie rods. The bushings can slip into the hollow causing the tube to hang low and not contact the rubber evenly. This will cause the ink to distribute properly.
The end of one or more tie rod may also be bent thus preventing the whole top frame assembly from sitting parallel in the carriage and in relation to the rubber rollers.