The random thought thread

**blackcat4866** · 11-26-2016

Originally Posted by NeoMatrix

... In keeping with the cylinder ratio :
An unwanted periodic pattern appears on a print out, what is the length of the periodic pattern in relation to the cylinder that caused the problem ? How can we quickly find out if the unwanted pattern is coming from a drum, dev,rego roller etc..?

Given: We know the unwanted pattern on the print out is periodic.
Using the print out, we make a quick mark using a pen at the offending period marks on the print out. We can then roll the print out paper into a cylinder until the pen marks align. The alignment will leave the diameter of the offending roller or cylinder. Alternatively we could measure the distance between the pen marks and div by ratio Pi to arrive at the offending diameter ...

Do you see that 6"/150mm scale in my shirt pocket? That's what it's for.

Developing related problems are a little more tricksy. Since the developing roller rotates at a different rate and in the opposite direction as the drum, you don't get a direct correlation between interval and roller diameter. If the manual has a repetitive defect chart that's nice, or maybe you just made a note to that effect in your database for the next time.

You mean this isn't just common knowledge? I think Archimedes made the first fairly accurate measure of Pi in 250 BCE. Most of us have been calculating circumferences since elementary school. Depending on your age, that might be quite a while ... or fairly recently. =^..^=

**NeoMatrix** · 11-26-2016

Originally Posted by blackcat4866

"What do you think you're doing?" =^..^=

It's surprising how peaceful they are with each other.

**nottoosharp** · 11-26-2016

Originally Posted by blackcat4866

Do you see that 6"/150mm scale in my shirt pocket? That's what it's for.

Developing related problems are a little more tricksy. Since the developing roller rotates at a different rate and in the opposite direction as the drum, you don't get a direct correlation between interval and roller diameter. If the manual has a repetitive defect chart that's nice, or maybe you just made a note to that effect in your database for the next time.

You mean this isn't just common knowledge? I think Archimedes made the first fairly accurate measure of Pi in 250 BCE. Most of us have been calculating circumferences since elementary school. Depending on your age, that might be quite a while ... or fairly recently. =^..^=

I hadn't really thought about roller compression being as much if an issue as that previous to this post. In general I have to replace rollers for damage, or them just not picking up paper due to loss of tread before they cause timing issues. However I've had a 283 giving me fits, and you can bet I'll be checking it out Monday armed with new knowledge. Thanks.

Sent from my iPhone using Tapatalk

**allan** · 11-26-2016

I just roll up the paper until i get a cylinder where the marks line up.

**ZOOTECH** · 11-26-2016

Originally Posted by allan

I just roll up the paper until i get a cylinder where the marks line up.

I think this is what Neo and BC posted earlier.

**allan** · 11-27-2016

hehe missed that. A chart with the roller circumferences would be grate. Cant recall seeing one.

**blackcat4866** · 11-27-2016

The first time this came up for me was the Copystar CS-8030. The duplex roller wears only at the rear, making the roller slightly conical, and consequently skewing the second side, until it jams. This roller is rather difficult to examine. The trick that I came up with is to cut a couple 4mm wide strips of paper. To each I add a piece of tape. Then you can stick the tape to the roller, roll it onto the roller and make a pen mark where it laps. Then you can get a fairly accurate circumference measurement without removing the roller. When the difference in circumference exceeds 1.3mm, the paper just won't pass. And that's not very much, ~0.4138mm difference in diameter.

Misfeeds (Jam J60, J61, J62, J63) entering the duplex tray for face down delivery. Paper Z-folded in the duplex tray with the rear leading corner flipped. Duplex switchback roller wears more at machine rear. Rough test: Lay your 6" scale along top of the roller. If it touches the guide at rear, replace. Precise test: Using a paper ruler measure roller's circumference at rear. New: 65.3mm. Worn: 64.0mm. Replace duplex switchback roller (302FB19401).

=^..^=

**ZOOTECH** · 11-27-2016

Originally Posted by allan

hehe missed that. A chart with the roller circumferences would be grate. Cant recall seeing one.

HP service manuals usually have the frequency of repeating 'marks' with diameters of feed rollers, fuser rollers, etc.

**Iowatech** · 11-27-2016

Will it mow?

(Don't do this at home!)

**Lagonda** · 11-27-2016

It's Monday morning and the new job booking system inflicted on me by our wonderful IT department has sunk without trace and f#@%&d my week completely.

whatwehaveherecoolhandlukede21.jpg

Can't I go back to giving people written instructions on a piece of paper?

It works.