UNDERSTANDING GLASS FRONT MERCHANDISER VENDING MACHINESThese modern ‘glass front’ vending machines have been produced for over thirty years. Over that time period many changes have been made to these machines. The early machine had only four or sometimes ten prices, modern machines can price each column at a different price. Early machines could be priced from 5 cents to a maximum of $12.70 on some models, whereas many modern machines can be priced from 5 cents to $99.95 per item. This versatile pricing allows the operator to vend a large variety of items.DOUBLE COILS VS SINGLE COILS ON SNACK SIZE COLUMNSA lot of vendors ask about newer machines having double spirals on the snack size columns and what the advantage of that is. All early glass front merchandisers have single coils on the snack size selections. Over the years, as time went on some manufacturers starting making their snack columns with double spirals. The main reason this was done was to make larger items stand up straight and to prevent user or route man error due to improper loading of the products. Single coil machines will usually work well in most cases with standard snack products if loaded properly but with larger, specialty products they may tend to fall sideways and give erratic vends.Earlier model machines that featured these double spirals standard on their machines were Lektro-Vend model VS99, National model 147, and others. Automatic Products made this an option on their machines starting with the 7600 model and the machines that came after that.MDB (MULTI DROP BUS) MODELS VS LOGIC MODELSMDB has become the ‘standard’ for vending machines of all types for a while now. It started with the soda machines in the later 1990’s but did not really catch on in snack machines until a few years later. Many operators had ‘logic’ style glass front machines for many years and so they continued to order new ‘logic’ glass front machines for many years to keep uniformity on their routes.A logic glass front machine will use a standard three tube logic mechanism, either 110 volts for the earlier machines or 24 volts for the newer machines. These machines will usually use a serial or pulse type dollar bill validator and many of them cannot accept five bills.Newer machines that use MDB can use a four or five tube mechanisms and dollar bill validators that can accept five dollar bills, as well as one dollar bills. The high capacity coin mechanisms allow for extra coins to be available.