How To Choose Between a Gravity-feed chipper & Hydraulic-feed chipper?
November 19, 2012
The following information will guide and assist any potential customer when confronted with the above-mentioned question. This article indicates the main differences between gravity-feed and hydraulic-feed chippers.
Gravity-feed Chipper
Description & Features
– Material is fed through an inclined in-feed hopper (using gravity to guide the wood to the blades).
– The blades pull the material through.
– No mechanical or hydraulic in-feed rollers to regulate the feeding.
Advantages
– Easy to operate
– Less capital outlay is required to acquire a gravity-feed machine
– Fewer working parts to service and maintain
– Chips short material well, for example sawmill waste
Disadvantages
– Branches needs to be relatively straight in order to reach the bottom of the in-feed hopper without getting stuck in the hopper.
– Material needs to be no longer than 2m for it to be pulled in all the way
– Extra time and more labourers are needed to prepare certain wood types for a gravity feed machine
– Not for chipping solid logs all day long
– Inconsistent chip size
– Chip size cannot be manipulated
Application
Gravity-feed chippers are ideal for:
– Garden services & smallholdings
– Chipping brush
– Small quantities at a time
– Chipping when there is no time limit
– Sawmill waste
Hydraulic-feed Chipper
Description & Features
– Equipped with 2 hydraulic in-feed rollers
– Dual hydraulic in-feed rollers pull material in
– Variable Speed: the speed of the in-feed rollers is adjustable to
manipulate chip size (extra option on all hydraulic chippers)
Advantages
– Large Horizontal in-feed hopper requires less effort and energy to feed chipper – making it more effective& more productive!
– Produces a more uniform/ finer chip than gravity feed machines due to the controlled feed rate
– The Forward Reverse Bar gives the chipper operator constant control over chipping process and operates as safety device
– The Reversing Auto-feed function protects the engine, v-belts& drum
– Pulls bushy material in with ease and requires much less preparation of material
– Able to chip logs all day long with ease
Disadvantages
– Hydraulics make the chipper more expensive
– Marginally higher maintenance and running costs
Application
Hydraulic-feed chippers are ideal for:
– Fruit farming where there are lot of side branches
– Tree-felling where chipping needs to be done in a certain time frame
– Landscaping and thatch roof waste
– Clearing large quantities of green waste
Added Safety Features
– The Forward Reverse Bar enables full control over chipping operations and enables the operator to reverse the rollers at any given time in case of emergency.
Note
– Although the feed rate can be adjusted on hydraulic-feed chippers, the slower material is fed into the chipper the smaller the chips. Slower feeding results in lower production and higher machine wear per hour.
– The larger the chips the higher production would be and cause less machine wear per hour.
