Ryobi 3302 intermittently skewed feeding

[robbg439]

I've been working with this press for years. I recently replaced the lower feed roller with a new one, and it seems like ever since I have been having trouble getting it to feed straight. Seemingly at random (and approximately 10% of sheets on a given run) a sheet will feed skewed, with the trailing edge of the sheet skewed about 4mm towards the non-operator side of the press. So far I've tried adjusting the paper stop fingers (they are to spec) the feed roller parallel and overall pressure (to spec) and of course I've got all my feed table springs and wheels checked and double checked. One other data point is that this only happens with text weight stocks. When I print cardstock, it runs fine. Any ideas would be greatly appreciated.

 

[keith1]

I could be reading wrong. It sounds like the skew is happening before the paper reaches the stops & feed roller, so why adjust them.
I usually found the rubber rollers where the paper first comes off the feed pile to be the reason. If you've been battling this I'll presume you've tried adjusting the pressure on these. Moving them inwards & outwards also helped sometimes. You don't need much pressure. Even moving the suckers seemed to help at times.

 

[SteveSuffRIT]

Maybe place a digital camera at feeder and video record running. Then you can play it back, maybe in slow motion, to see it in better detail, when and what the issue is?
Steve Suffoletto

 

[robbg439]

Maybe place a digital camera at feeder and video record running. Then you can play it back, maybe in slow motion, to see it in better detail, when and what the issue is?
Steve Suffoletto

Yes thanks! I took a slow-mo video with my iPhone and realized that the problem was my spring placement. The paper was occasionally curling up on the edge that was coming in contact with the spring, rather than being pushed against the lay, causing it to skew away from the lay. I had that spring all the way to the back (closest to the feeder) so it was exactly in the gap between the long retainers and the feed board retainers. There was nothing to hold thinner paper down against the feed tape. Also explains why the problem would be worse when printing one side of a stock than the other—if the stock had a very slight curl in it, when the curl was pointing down it was a lot less of a problem.

 

[pdan]

Glad to hear you found your solution. Fwiw I spent a lifetime with the lightweight springs. Perhaps text weight would not curl up against them as opposed to the heavier set. For the last three years in a new shop they basically insist on the heavy springs. I can't win all my battles so that is what I use now. The presses don't register nearly as good in this shop. Just sayin'.

 

[keith1]

95% of my time spent running this equipment was without the spring. Way better & faster results. The only time I used the spring was for poorly trimmed paper. Even then it was usually quicker & easier to trim a shave off the paper. Same story with Hamada's when I ran those that had a push registration system. Those register springs created more problems than anything. I ran many tight register jobs without them.

 

[robbg439]

95% of my time spent running this equipment was without the spring.

Interesting! How do you run without them? Do you set the stationary side so that it is exactly touching the edge of the sheet when the oscillating side is fully "in"?

 

[keith1]

That's right. Just kiss the stationary guide (the one that formerly had the spring attached). Obviously make certain the guide is square to the paper. Square a sheet to your front stops, then square the push register guides to the sheet - 90 degrees.
You'll find this will save you a ton of fiddling about with setup. Run several sheets through 2 or 3 times to test register. On a long run I'd pull sheets at different intervals and when I had a reasonable amount (10 or 15) I'd put them through again and that gives an idea of register accuracy throughout the run. You'll find the feed roller setting won't be as critical as well. Find a good setting for 24lb, or whatever your often used paper is. From there you'll get to know you can raise the rollers maybe 5, 6 notches for light card, a bit higher for business card weight etc. Beats dicking around 1/2 the day finding the perfect symmetry between feed rollers, spring and every other nuance on the feed table.
I always found those springs to be pretty much useless. Hopeless at higher speeds.