Not all straight line ripsaws are
created equal.
When purchasing a straight line ripsaw a number of factors are
considered to ensure you are getting a machine that fits your needs. You need to ask yourself what are you going to
do with the machine. Do you require a
glue joint cut? If so how long of a glue joint do you require? How deep do I need to cut? What is the maximum ripping width?
Below we explain some of the key differences between
straight line rip saws which will aid in your machine selection.
LENGTH OF HOLD
DOWN & NUMBER OF HOLD DOWN ROLLERS
When looking at a
ripsaws one of the critical factors for glue joint accuracy and cutting
precision is the length of the hold down assembly. This is the total length of
the pressure assembly that holds the material on to the chain track
assembly. For instance we offer a range
of (4) straight line ripsasws. The range
of hold down length goes from 19” up to 33 ½”!
That is a difference of 14 ½” of hold down length resulting in a glue
joint of 4’ and 15’ respectively. The
longer you hold the material to the chain track assembly the more precise of a
cut you will achieve.
Most all straight line ripsaws have either (6) or (8) hold
down rolls. The additional hold down
rollers also assist in cut quality as they are holding the piece more firmly on
to the serrated chain assembly. There
are typically (1) or (2) rows of full width rollers before the blade, (4)
rollers surrounding the blade, and (1) or (2) full width rollers after the
blade. The rollers on either side of
the blade ensure that the work piece is being held during the cutting process
to eliminate vibration and movement.
CHAIN & TRACK ASSEMBLY
In addition to the hold down assembly, equally as important
is the chain & track assembly. Most
all straight line ripsaws utilize a Double “V” guide rail system. The double V rails ensure the chain assembly
travels precisely straight along the track assembly with no lateral movement to
affect the cut quality. The chain track
assembly is lubricated by an automatic oiler.
As you have one cast iron surface being pulled along another you need to
have proper lubrication or run the risk of wearing out both surfaces due to
friction. The best type of lubricator is
a mechanical type. The operation is simple. It is directly connected to the
chain feed so when the feed is on it is pumping lubricant. When stopped, it
stops. An alternative system which is very good is an electronic lubricator.
The issue with this type of a unit is that it is on a timer rather than being
physically tied to the feed chain. The
mechanical unit will start instantly as the feed chain moves whereas the
electronic unit will be set off after a certain time running.
A new feature for our line of Cantek ripsaws is heat treated
and hardened chain & track assembly.
This process hardens both surfaces and provides more than 3 times the
life over the original design. This
means less wear and improved accuracy over a longer period of the life of the
machine.
ARBOR / SPINDLE
ASSEMBLY
As you can imagine a precise saw spindle is critical in
providing a smooth cutting surface. The
use of poor quality bearings and lower quality steel can result in a spindle
that will deteriorate quickly after installation and ultimately result in
reduced cut quality.
SAFETY KICKBACK
FINGER ASSEMBLIES
Safety is an important consideration when purchasing any
machine. Many ripsaws, including Cantek,
are equipped with either (3) or (4) rows of anti-kickback fingers. (2) or (3)
top rows and one bottom row. These fingers restrict kickbacks in coming back
towards the operator. Some machines are
only equipped with (2) rows of anti-kickback fingers and many without a proper
row in the table. Safety is something
you do not want to overlook as your staff are the most valuable resource to
your company.
What to Look For When Purchasing a Used
Straight Line Ripsaw
When purchasing a used straight line ripsaw it is most
critical to go through the machine in fine detail to ensure it will perform to
your desired needs. If not properly
maintained the cut quality will most certainly not perform a glue joint. Check the wear on the chain and track
(race). If there has been significant wear it may have lost its precision and
potentially can move side to side during the cut. Normally the track or race is chamfered on
either side with a flat portion on the top.
If this flat portion is very narrow or non-existent you will likely need
to replace the complete assembly. The
chain and track have to be replaced as a pair as they wear evenly and this can
be a costly undertaking both in parts and time to replace. If you only replace one it will wear very
quickly to match the worn piece.
Also check the radial run out of the spindle by putting a
dial indicator on the plate of the blade from the table. Make sure all spindle and thickness
adjustments move smoothly. These
typically are moved by ballscrew and you want to ensure they are not worn. The pressure rollers from above should all
be in contact with the work piece. If they are not then they must be adjusted.
If they do not turn properly then it could be a bearing issue that needs to be
addressed.
Be diligent in your analysis of a used straight line ripsaw
because it may not perform the job it is intended for.
