Vandercook SP20 Ink Drum Not Spinning

subtext
on 25 Sep 14 (15:10)

Though the gear and chain are moving, the ink drum on our Vandercook SP20 is not spinning. The drum does move freely when rolled by hand.

I will post to Vanderblog when my account is approved, until then any help is appreciated.

bigboypress
on 25 Sep 14 (16:58)

Here’s one possibility that I hope receives confirmation from those more in the the know. Perhaps the crescent shaped key inside the drum that tracks the drum core is broken and needs to be replaces?

Paul Moxon
on 25 Sep 14 (19:27)

A crescent is for a worm gear on an oscillator or a ductor roller. It’s probably missing or sheared screws that fasten the sprocket to a hub on the drum. http://vandercookpress.info/vanderblog/

subtext
on 25 Sep 14 (19:34)

I managed to get the drum out and discovered that the three screws that attached the ink drum chain sprocket to the drum have sheared off :( Bad news.

IMG_3802.JPG

Fritz1
on 26 Sep 14 (01:16)

I pulled the SP-20 prints earlier today on this problem and it is the 3 screws/bolts that hold the sprocket to the ink drum—but to shear them off indicates maybe another difficulty. It is a fairly simple assembly and I’d suggest taking it apart and see what’s going on.

typenut
on 26 Sep 14 (10:06)

Can you spin the ink drum Freely? The Force you need to shear them off is huge. I think it’s warranted to mechanically, not optically clean the Press from top to bottom.

subtext
on 26 Sep 14 (10:07)

Thanks Fritz and Paul! I’ll update when I get this resolved.

AdLibPress
on 26 Sep 14 (11:44)

However, if the bolts had worked loose and the drum and sprocket were working against each other for a while, the repeated impact could also have eventually sheared the bolts off — as soon as one failed the stress on the others was increased.

Bob