I have a friend who has an SP15. She was having trouble getting the inking smooth and I stopped over to see if I could figure it out. Turned out that the roller and the drive gear were acting independently of each other. Once it was printing the gear that should drive the form roller was slipping (generally speaking it was rolling but the roller itself was just sliding across the surface of the type). I came back and looked at our SP15 which was the same way, but the rubber of the roller on ours was locked to the gear. On hers you could rotate the gear quite easily.
One difference in our rollers is that the rubber end on hers is cut off square and on ours it is tapered as you can see in the photo below.
We suggested making a washer out of a non-stick sheet to see if she could get more pressure between the roller and the gear. That at least worked to reduce most of the slur she was getting.
Can anyone explain how this should work? Is there a way to essentially glue the rubber to the gear or do you not want to do that?
Sounds like the rubber has tore loose from the the core. The only fix is new rubber.
The gear collar should be press-fitted onto the gear. For gear alignment to the rack the collar should be on the outside as in the photo of your press.
I’ll try measuring our rollers, but we’ve not had any problem with ours that we’ve noticed.
We couldn’t get it tight enough. There are two pieces to the gear – the gear itself and then the gear collar. The gear collar was SLIGHTLY longer than it needed to be so it essentially contacted the rubber first. It was a small amount but it added to the problem. No matter what we did we couldn’t get the gear and the roller pressed together enough to keep it from slipping.
All your should need to do is tighten the two set screws on the gear collar with a hex key (aka Allen wrench). The photo shows that the form roller is undersized. The diameter should be 2.5″. Otherwise, when the roller height the gear may bottom out before the rubber contacts the printing form. Being in spec is essentially when printing photopolymer.