View source for Drum safety test (Z+)

{{Tutorial
|difficulty=Beginner
|time=5 minutes
|type=Maintenance
|series_type=Z+
}}
The ''drum safety test'' is a quick test of the most critical mechanisms in the drum. It is used to evaluate if it is safe to insert the drum in the riso. This test should be performed:

<ol type="a" ><li>Before and after doing any maintenance on a drum.</li><li>On drums of ''unknown status'' (used drums, drums which have been shipped, or not used in a while, or might have suffered damage).</li><li>On any drums which are behaving strangely (regularly printing weird, making strange noises, etc.).</li></ol>

{{Warning|If a drum fails any of the parts of this test it <u>should not be run in the riso</u> until it can be repaired.}}

{{mbox|text=<h4 style="font-size:1.2em;">Drum safety test (Z+)</h4>

''The drum safety test is most easily performed on the drum while it is sitting in the rails of the risograph (but not pushed into it). Remove the stencil by hand before performing this test.''

'''① — Clamp'''

The tolerances inside the riso are very small (~1 mm for the separator needle and <5 mm for other sensors and components), and the drum is spinning very quickly—so anything protruding too high off the surface of the drum is in danger of getting caught in the riso. The clamp is already the part of the drum which protrudes the most—so anything wrong with the clamp can result in catastrophic failure.

<ol type="1"><li>The clamp should easily flip open when pressing the orange clamp lever, and snap closed when released.</li>
<li>The master ejection bar should lift up easily by hand and snap back down when released. Check that the ejection bar sits flat against the drum, and is not bowed out in the middle.</li>
<li>Check for the presence of two rounded metal clips near the center of the clamp (they can fall out, or become bent/mangled).</li>
<li>Check the two white wheels and white peg at the end of the clamp—the wheels should be unbroken and spin freely; the shafts they are mounted on should be parallel with the axis of the drum (not crooked).</li>
<li>Check that all 4 screws are in the clamp.</li></ol>

'''② — Screen'''

The drum screen is attached via two bars in the ends of the screen—each of which is attached at the front and rear of the drum. Anytime a tensioned surface is only attached in the corners like this, the bars will bow up slightly in the middle—it's important to make sure that the bars are not bowed up so high that they will catch on the separator needle.

<ol type="1" start="6"><li>The heavier bar (2 screws) should not raise higher than the surface of the metal lip of the clamp assembly next to it. Check it in the middle by dragging a finger tip from the surface of the screen mesh onto the clamp assembly—there should be a distinct ''step up'' to the clamp.</li>
<li>The thinner bar (4 screws), with the rubber strip along the edge, should not raise higher than the surface of the ejection bar next to it. Again, check in the middle, by dragging a finger tip from the surface of the rubber strip onto the ejection bar—there should be a distinct ''step up'' to the ejection bar.</li>
<li>Check that all 6 screws are in the screen, and that there is no damage to the screen bars.</li>
<li>Check around the screen for signs of major tears—if the mesh separates too high, it can also get caught in the riso.</li></ol>

'''③ — Rotation'''

When the drum is inserted into the riso, its rotation is unlocked, so that it can be spun during operation. When spinning, a series of internal rollers are engaged, which help distribute ink along the length of the drum. If the ink is very old/oxidized it can glue the rollers together, then when the riso tries to spin the drum it will either break the gearing inside the drum, or overload the main motor in the riso.

<ol type="1" start="10"><li>Click the manual unlock button (small round button at around 2:00 along the front blue/grey plastic flange) in and out a few times, it should move freely and snap back into the locked position when released.</li>
<li>Rotate the drum slowly in the print direction (counterclockwise) while holding down the unlock button. The drum should spin easily, and sound smooth during the whole rotation process. It can be compared to the feeling of rotating a working drum by hand. If the drum can only spin in the ''opposite'' direction (clockwise) it is a sure sign that the rollers are glued together by old ink and need internal cleaning (the rollers only engage when spinning in the printing direction).</li>
<li>While rotating the drum check for any major dents in the drum body—small dents won't cause additional damage, but heavy dents can deform the drum body enough that it can collide with the insides of the riso.</li></ol>

'''④ — Ink'''

Lastly, check for signs of separated ink. This can appear as an oily residue on the surface of the drum body (usually underneath the drum when it's in the locked position), inside the ink tube holder, in the ink tube itself, or even in the drum case. If a drum has heavily separated ink in it, it's quite likely it needs an internal cleaning before it will ink properly, and that it might be heading toward more issues.

It's also important not to use separated ink tubes in drums, as this will cause further issues with them. Instead, separated ink should be [[remixed]] before use.{{Warning|If a drum fails any of the parts of this test it <u>should not be run in the riso</u> until it can be repaired.}}}}