Uneven inking on a Vandercook 4

How old are your rollers? What are you using for packing on the cylinder?

Daniel Morris
The Arm Letterpress
Brooklyn, NY

After you set the rollers did you tighten the center screw?
Once your rollers are set do a stripe test to the drum. That is, lift the rollers while everything is turning, then turn off the motor and let the drum come to a stop. Drop the rollers then lift them. You should have an even stripe across the drum, something like 1/8” to 3/16”. An even stripe show rollers parallel to drums, an uneven stripe can show uneven setting, also swollen or shrunken roller ends.
If the rollers are out-of-round, you would get mis-inking that varies its position rather than in the same place every time.
Such problems sometimes can be from the form rather than the rollers, as when poor lockup causes lift. Planing a solid form, or sounding the form by striking it with the palm of your hand, gives a different sound than a rising form gives.

I would also suggest you troubleshoot the impression issue separately from the inking. Make an impression with the inking rollers disengaged. If you are finding that the impression is inconsistant from one side to the other you need to deal with that problem before fiddling with the roller settings.

Dan

Dan, Im really unsure how old the rollers are. Im suspecting pretty old. I bought the press “as is” from my professor, which was the very same press I learned on when I was in school. 10 years ago. She said she hasnt repaired or changed anything since shes had it.

I also did a stripe test and the line is thinker on the ends than in the middle. Im attaching a picture. Does that mean time for new rollers?

photo.JPG

The ends are swollen, pretty common for old rollers, and at that age they would be pretty hard. Good rollers are the most important investment you can make.

dan, I did an impression without the rollers and its still uneven. any suggestions how to troubleshoot?

What is your printing surface?
Are you printing from type or a plate?
Does your press have a galley thickness bed plate?
If so, is it in good condition with no dust or dirt under it?
Is the packing on the cylinder set correctly?
What is the cylinder undercut on your press, .040?

I’m sorry to be asking so many questions, but these possibilities must be dealt with before I could tell you that the press eccentrics need adjustment!

Dan

Right now im printing a 5x7 surface. and its a plate using the boxcar system. Yes its in good condition. I clean it before and after ever pressing. The packing may not be set correctly. Ive never changed it. I havent had any issues till now. and the cylinder undercut is .070.
Thanks for the help dan.

A good start would be to take off the packing and replace it. .070 is a rather deep undercut so there is a lot of room for the material to become compressed. You want rigid packing, no blankets or rubber in there. The total packing plus the thickness of the paper you are printing on should add up to .072 or a little more depending on how you like your impression.

Do you have some fresh tympan to try?

Dan

No I don’t have any. Where can I get some and do you know the type / brand I need for the vandercook 4? Also are there instructions for changing packing online? I’ve never changed it before. Thanks again Dan.

NA Graphics sell what you need -just get the standard .006 tympan precut for the #4. You should get the press manual for the #4 while you are at it. I’d suggest 100 undersheets and 50 tympan top sheets. That’ll last you a while.
http://order.nagraph.com/vandercook-tympan.html

Do you have a .918 roller setting gauge? They sell those too.

Dan

Dan, thanks so much for info and your time. I actually do have the roller gauge. I’ll let you know how things turn out.

Regards,

Brandon