GR series

GR
GR
Series information
Type	Single drum
Status	Discontinued
Launched	1995
Discontinued	2002
Tagline	Greater Riso

The GR series is a mid-90s risograph family, and a continuation of the design of the earlier RA machines. It is a ubiquitous model, long discontinued, but still in use globally by artists and small presses. Different models used either an ADF or scanner input, and later models could interface with a controller to send digital files (though this was not built in functionality). While these machines require a lot of regular maintenance, they are workhorses, and if well-maintained can be very stable.

All machines use 2-button print positioning (the up/down positioning was adjusted with a hand-wheel on the paper feed tray)—4 button positioning was introduced on the series, a sister family.

Resources

Tutorials

The following user created tutorials apply to the GR series.

Maintenance

These machines are long obsolete and usually require frequent maintenance to keep them operational. However, the drum system on them tends to be more stable than in Z+Any machine released with or after the RZ line, i.e. RZ/RV/EZ/EV/SF/SE and MZ/ME/MF/MH machines. machines—they have fewer overflow errors, and when well calibrated they can have denser ink coverage—the drums are also much easier to open for maintenance.

Common repairs for the series include:

If a drum is manually extracted, the machine will need to be rotated back to home position manually. This can be done by faking the front-door switch and using the green drum removal button as a free-rotate button—rotating the main drive until the spindle at the back of the machine is vertical.
When a drum gets stuck in these machines, usually the drum itself is not harmed, but the riso will lose timing (accompanied by a very loud ratchet sound). Print position will be lost at this point, requiring retiming of the main drive.
A common source for drums getting stuck is improper home-position calibration (which is adjusted mechanically on each drum, not within the risograph). Once or twice a year, depending on usage, all drums should have their home positions checked and recalibrated.
The paper feed can become unstable over time, it needs regular cleaning and lubrication (and sometimes replacement of one-way springs in the 2nd paper feed). When well-tuned, registration jump from side to side should be 0.5 mm or less.
The plastic handles at the back of the drums are very brittle—when they break, plastic fragments can get lodged in the drum rollers, creating wide white bands along the length of the print. Fixing this requires opening the drum and extracting the debris from the rollers.
There is no automatic compensation for elongation/shrinkage, so this needs frequent calibration.
The exit belts will wear over time and need replacement in order to properly eject heavier or larger papers from the machine.
It is very easy for the paper feed tray to become damaged and bend down away from the riso. When this happens it needs to be disassembled so that the support arms can be bent back into shape (or shimmed). A bent tray will result in much weaker paper feed.
The most common failure point in the drums are the 3 drum-support rollers which support the front of the drum body. Replacing them is a simple, but frequent task, especially if running many drums.

Replacement parts

Parts for the series are discontinued, however the most common parts (the feed tires and stripper pad) are interchangeable with the newer Z+Any machine released with or after the RZ line, i.e. RZ/RV/EZ/EV/SF/SE and MZ/ME/MF/MH machines. machines. Some replacement parts (like pressure rollers, drum support rollers, etc.) were mass-produced and still available from 3rd party suppliers. Other parts, particularly motors and electronic components, are much harder to find and are generally sourced from parts machines.

Name	Part no.	Stock	Unit
Feed tire	`035-14303` `021-14301`	2 / riso	Paper feed
Feed tire	The two matching rollers in the 1st paper feed—the outer one is the "scraper" (feeds multiple sheets in) and the inner one is the "pickup" (separates the top sheet). Each is an inner plastic core and outer tire (this is the part for the tire). The inner (pickup) roller should use OEM, the outer (scraper) roller can use generic—generic tires tend to be eccentric (egg-shaped) and a smaller diameter than the originals. The RP uses 3 rollers, two of which are tires on a proprietary core, but the third roller requires a solid feed tire.
Stripper pad	`019-11833`	3 / riso	Paper feed
Stripper pad	The stripper pad puts upward force and friction on the multiple pages that are fed into the pickup roller, so that the teeth of the tire only propel the top sheet into the riso. It is the rubber part that wears the fastest and must be replaced regularly for stable paper feed. Very old risos may use a different stripper unit, which takes an older stripper pad type (a thin square), otherwise this part is universal. An alternative grey stripper pad is listed under part no. `019-11834`—it uses a harder material, which is meant to last longer and be better for heavier paper stocks.
Feed roller core	`023-12306` `021-14302`	1 / riso	Paper feed
Feed roller core	The plastic core of the feed rollers (the feed tires are stretched around these) contains a one-way bearing, which allows the paper to be pulled freely through the 1st paper feed by the 2nd paper feed and press sections. This bearing wears down over time, which will either decrease the feed power or cause the roller to drag on the rest of the system. Replacement cores ship dry, and will need oiling.
Exit belts (GR/FR)	`011-13220`	1 set	Paper ejection
Exit belts (GR/FR)	Exit belts transport paper out of the riso—a suction fan pulls air down through holes in the belts to hold the paper to them while the main motor powers the belts. In machines, the exit belts are a set of 3 wide belts with staggered holes. As they wear, they will stretch out and slip on their rollers—paper will become stuck in the exit area (particularly larger sheets of heavier stocks). Belts can be tested by dragging them with a fingertip—all the belts should move together—if individual belts slip, it's a sign that all should be replaced.
Separator collar (GR/FR)	`000-01515`	1 / riso	Paper ejection
Separator collar (GR/FR)	A tiny roller that sits on a bracket at the back of the bar supporting the separator needle. When it breaks down, the separator needle will catch more frequently on the drum, resulting in stock drums and lost timing.
Drum support roller	`000-01169`	2 / drum	Drum
Drum support roller	The front of the drum body is suspended in 3 of these small rubber rollers. As they age, the rubber will separate from the metal core/bearing, and the drum body will bounce while printing (which makes a knocking sound)

Specifications

	Print area	DPI	Year
GR1700	Legal / B4	300 × 400	1995
GR1750	Legal / B4	400	1995
GR2700	Legal / B4	300 × 400	1998
GR2710	Legal / B4	300 × 400	1997
GR2750	Legal / B4	400	1995
GR3710	Ledger / A3	300 × 400	1997
GR3750	Ledger / A3	400	1995
GR3770	Ledger / A3	600	1997

Usage

There are 54 places printing with duplicators (12% of all active places).

GR1700	La Duplicadora 🇲🇽Mara Gervais 🇺🇸Sugar Pucks 🇺🇸
GR1750	La Duplicadora 🇲🇽Pegacorn Press 🇺🇸Système Sensible 🇫🇷Volcán Press 🇲🇽
GR2710	BLINKBLINK 🇩🇪BULK Space Media Lab 🇺🇸But Whole Press 🇺🇸Rachel Delmotte 🇺🇸The Compound Gallery 🇺🇸
GR3750	But Whole Press 🇺🇸Colour Code Printing 🇨🇦Colpa 🇺🇸Delirios Visuales 🇲🇽Diskette Press 🇺🇸Entrecampo 🇧🇷HBKsaar 🇩🇪Hurrikan Press 🇭🇺Kolectivo jajaja 🇲🇽La Zineria 🇲🇽Lucky Punch Press 🇩🇪Mystic Multiples 🇺🇸Never Press 🇺🇸Paper Worm 🇺🇸Pegacorn Press 🇺🇸Pioneer Works 🇺🇸Pixeles Muertos 🇲🇽Potato Publishing 🇦🇹Rachel Delmotte 🇺🇸Risolution 🇫🇷Taller de Ediciones Económicas 🇲🇽The Compound Gallery 🇺🇸These Are Things 🇺🇸Tono taller 🇲🇽Work Press & Publication 🇺🇸Snack break studio 🇺🇸
GR3770	BULK Space Media Lab 🇺🇸Banana Copy 🇩🇪Colour Code Printing 🇨🇦Colpa 🇺🇸Common Area Maintenance 🇺🇸Cultmeal 🇺🇸D.O.C.H. 🇩🇪Die Druckstube 🇦🇹Diskette Press 🇺🇸Ediciones El Fuerte 🇦🇷Empress Editions 🇺🇸Gyros Nyomda 🇭🇺Hurrikan Press 🇭🇺IRRland 🇩🇪Independent Publishing Resource Center (IPRC) 🇺🇸Josh Freydkis 🇺🇸Kiin. 🇩🇪Klub der Kleinkarierten 🇩🇪Martian Press 🇺🇸Melo Melo Print 🇩🇪Melon Press 🇺🇸Mystic Multiples 🇺🇸NEOGLYPHIC MEDIA 🇺🇸Never Press 🇺🇸Potato Publishing 🇦🇹Replikat Press 🇦🇹Riso Riso 🇺🇸Shortt Editions 🇺🇸The Compound Gallery 🇺🇸Workshop for Independent Publishing (WIP) 🇺🇸

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A map of the 54 places printing with duplicators—as listed in the Atlas.