For Heidelberg, when it came to developing the Stitchmaster ST 350 it was more a case of evolution than revolution. So, rather than going back to the drawing board, it took many of the key features of it's forebear, the 1998-launched ST 300, but incorporated some of the key attributes of its bigger sibling the ST 400. It proved to be a successful formula, with more than 30 installations subsequently racked up in the UK alone, despite stiff competition from the likes of Muller Martini and Horizon.
Targeted at trade finishers, the Drupa 2004-launched A3-format stitcher could hold upright or flat signatures, in any desired sequence and, according to Heidelberg, effectively handle an unlimited range of jobs. Improvements on the machine meant it could also synchronise the timing of the feeders to the speed of the saddle chain.
"It allowed us to take advantage of what we've learned to enhance and improve automation," explains Mark Hogan, UK Heidelberg marketing manager. For example, if you're running seven or eight feeders, each time you need to change format or speed, the feeders have to be re-synchronised with the saddle chain, which takes time. By equipping the saddle chain with its own servo drive, Heidelberg claims it's able to reduce synchronisation by 62%.
Feeding options
There are three types of of feeder. With the vertical feeder, the signatures are stacked with the spine pointing down. There is also a horizontal feeder for flimsier signatures and a cover folder feeder. For the cover folder feeder, the covers are accepted flat, then scored and passed through folding rollers before being finally laid on the saddle chain. All feeders are adjustable and can be tilted back by up to 50.
The ST 350 can also take up to six standard or four-loop stitching heads simultaneously. The stitcher is also kitted out with the usual array of detection devices so it can reject any over-long or over-thick books.
"We also took what we learnt on the ST 400, which was launched at Ipex 2002, in terms of makeready," says Hogan. "We made improvements to the paper feeding and our overall goal was to bring makeready down to 30 minutes."
When it came to the trimmer, a separate drive also passes the stitched products from the stitcher to the trimmer feed.
In the past 12 months, further upgrades have been made to improve signature handling. Optional extras mean printers could do 2-up or 3-up stitching, loop finishing and hole punching. There's also an optional downstream inhibit so if a feeder fails, all feeders stop placing signatures on the saddle chain.
Heidelberg tends not to deal in used machinery for finishing products. A new ST 350 will cost £250,000-£300,000, depending on configuration. Expect to pay around £150,000 for a good used model. Check the condition of the feeders and wear and tear on the machine's cams and belts.
SPECIFICATIONS
Max speed 12,000cph
Max untrimmed format 320x480mm
Min untrimmed format 85x128mm
Max product thickness 12mm
Max feeders 16
Max stitchers 6
Price
New: £250,000-£300,000
Used: around £150,000
What to look for
Condition of feeders
Cams and belts
