Daniel Morris asks if the No. 3 and No. 4 roller assemblies are interchangeable. I am answering in a new post so that I may add images –PM
The top frame assembly (one large diameter steel oscillating roller and two small diameter steel riders) is identical (and removable). The difference is in the bottom frame assembly (rubber form rollers), which in the No. 3 is attached via a bracket to the lift arm. Attached to the lift arm is a rubber feeder roller with a hand wheel that helps distribute ink. It may be possible to detach the bracket to use a No. 3 bottom frame on a No. 4 and vise versa. Let us know, Daniel! See photos and drawings below.
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The photo below is another view of the same press as above (with both form roller gears on far side of press as configured on a No. 4). More importantly, it shows that these gears use the same rack as the cylinder gear. Original photos by Steve Miller.
Eric is correct that the gears and roller cores are not interchangeable. While focusing on the commonalities of the complete assemblies, I neglected to describe their differences: on the No. 3 (which has no motor) the gears are fixed on the core end so that both always turn together, while the No. 4 gears have a two-part clutch that is separated when the carriage is at the feed board. This separation allows the rollers to spin independently of the gears when lowered and the motor is running. When the carriage is moved forward, the clutch parts engage locking the gear and roller to mesh with the gear rack.
I am not advocating this frankenstein approach, just wondering whether it is doable. I’d rather see the complete No. 4 assembly matched with a press that is missing one.
Having said that, the person with the No. 3 should be able to use a No. 4 top frame assembly with the bottom frame and bearing blocks, but would need to use No. 3 roller core and gears. I would think that NA could supply these, but perhaps not the the brackets and feed roller. Without the feed roller the only way to distribute the ink would be to roll the carriage back and forth over the whole length of the bed (with the type form removed) again and again–an awkward and tedious work around. Hey that printmaking!
I don’t have a No. 3 nearby, but have put out requests for more photos. I do have a manual but it curiously doesn’t show any form roller gear racks in the top view drawing.
Paul and Eric,
Thanks for the information. I put out an ad looking for Vandercook parts and I had someone say that they had a #3 minus roller assembly and another saying they had a complete assembly for a #4. I thought I maybe I should introduce them to each other, but it would appear this still not going to make a complete press.
It’s very nice to see such informed technical responses here.
Daniel
The whole “Bottom roller frame assembly” wouldn’t be interchangeable between the 3 and 4. Perhaps the lower frame by itself is common to both models, but the rollers/cores/gears are completely different. “Assembly” includes all those parts.
I notice that in the photo, no form roller gears show on the near side; but in the parts drawing, the rear form is driven by gear on near side. Looks like there is indeed a rack on near side.