Feeding issues on 110# Lettra
Hi, we finally got our windmill up and running after 3 months! Now we are having problems with picking up 2 sheets when trying to run 110# Lettra. Tried all the normal adjsutments, still picking up 2 sheets at a time. Any ideas?
1- Lots of TILT(3 - 3 1/2) and lots of air between the sheets.
2- Open pump valve a bit. Play with the air valves at the feedboard, sheet blowers and the reception board.
Pile height at the feedboard is also very important…
you need the headboard front seperator springs in place protrude about 1/8-3/16 set the pile height so as not to impair the top sheets ability to lift witheach puff off the blowers, ideally you want two to five sheets to blow up at a time , set the blowers at the second click on the adjuster and when one sheet has been carried away the next one must remain below the seperator springs use tilt to maintain that, you need two to three sheets to feed through before the pile raises, you do not want the feed table to lift with each sheet ,the aim is to maintain a gap between the seperator springs and the top sheet of the pile to give the air chance to do its thing.
Sometimes it takes time and patience to find the correct combination of air, lift and tilt. Try different speeds, fanning the stock, smaller lifts. Maybe bending the stock (without damaging) may help. Also, if you have stock from a combination cut, keep the piles separate because the grain could cause problems.
All of the above suggestions are great but there is one more I can think of.
Adjusting the spring at the tail of the sheet so it is looser than you think it should be can be a great help.
Not so loose that the sheets move back but loose enough to let the blowers do their thing and let the sheets float up.
Also to get more air you can close the air going to the Delivery harp thus “stealing” air to the feeder.
It is the silver lever on the right side of the press near the delivery. Move it to the close position
Doug
Dennis is right. Try different speeds. It changes the air flow.
Doug advise is also good. Try as many settings as you can.
Tried all of these and still not working. Does anyone know of a service guy in Wisconsin or Illinois?
What we don’t know concerns the use or non-use of suckers or sucker slides on the press. A photo or two to go along with these questions showing how the press is set up would aid greatly in understanding the problem rather than having to guess. Just a thought to speed the process of finding a good solution to the problem. And this goes for just about every other problem on Briar Press where our imaginations have to take the place of good, solid information.
One other thing to check is how clean a cut on the stock itself. With soft paper like that, a burr can form if the stock is not backcut. The knife drawing through the stock can form over the edge, sort of bonding multiple sheets together at the edge. If this burr drags against the sheet underneath, it can cause double feeds. If air blast is sufficient to separate the sheets, this may not be your issue, but it is something to check as you troubleshoot.
Although it seems incredible, the suction can also be carried through the top sheet to the one underneath, as Lettra is very porous, so you need to run a minimum of suction, just enough to lift the top sheet properly.
Have you had success feeding other types of paper stock?
John Henry
Cedar Creek Press
Try then a downward bend in your stock so the air is forced to lift the paper up rather than an upward bend .