|
Whether it is chopping down large trees, cutting down logs
or ripping boards from logs, a good quality chainsaw will likely make the
job easier and quicker.
I recently had the chance to look over and test two saws
from the Husqvarna range with the goal to decide in my own mind, whether
it is worth spending more money on a high quality chainsaw rather than a
lower-priced model for the general cutting and ripping work the average
woodworker might undertake.
Many features are similar to both saws, so unless
specifically noted, you can assume those features are identical or at
least function in the same or very similar manner.
One of the determining purchasing factors when it comes to
chainsaws is the displacement of the motor, which often relates to its
power in a lineal fashion, but not always. If you are looking for a
chainsaw to handle crosscutting of small logs, or for basic use around the
home for keeping your trees in check, you you probably don't need much
more than a 40cc saw. You can get away with an electric chainsaw for these
tasks too quite easily. For more serious sawing requirements, you might
want to look for saws in the 50-70cc range. For chainsaws dedicated to a
life of ripping boards from logs, you would be best to look at a saw
around the 80 to 100cc range, or higher! Choosing the size of saw also
often depends on the length of the chain bar you wish to use (and hence
the thickness of material you wish to cut). Obviously, with larger
diameter logs, there is more wood engaged with the cutting teeth at any
one time, and hence you require more power to handle the larger load, so
generally speaking, the larger the bar used (or larger the diameter of
material to be cut) the bigger the chainsaw required to make this cut
efficiently.
The Husqvarna 570 and 575XP saws offer engine displacements
of 67.9cc and 73.5cc respectively. This equates to 3.6kW or 4.9HP for the
570 model and 4.0kW or 5.4HP for the 575XP model. These are rated above
the average size chainsaw for general use, but a powerful option for the
general tasks an arborist might undertake.
Both machines feature hardened plastic casing around the
motor and main handle in stock Husqvarna orange color with padded
auxiliary handles offering comfort when used vertically or horizontally.
There is nothing extraordinary there. Fuel and oil tanks feature tool-less
caps that wont dislodge or unscrew under the vibration of the saw in use.
Fuel capacity is 0.7 liters and oil capacity is 0.4 liters.
The Husqvarna branded guide bars appear solid and well made, and the
length can be chosen when you purchase the saw (default bar size is 18
inches), although there are
recommendations for minimum and maximum guide bar lengths for each model
(15 inches to 28 inches for both saws).
Each guide bar features a 7-point Rim sprocket nose, again the design and
implementation of which is quite standard. Be sure to set proper oil feed
rate for the task at hand, and grease the sprocket regularly to prevent
excessive heat buildup and component wear. Chain tension is an important
factor when it comes to cutter performance, and more importantly, user
safety. On the Husqvarna saws, the chain tensioning screw is located on
the lateral edge of the body, just behind the screws that secure the bar
to the saw. This allows quick and easy access to chain tension adjustment.
You might find on some less well-thought out saws that the chain tension
screw is hidden away on the inside edge of the bar, deep in the body near
the drive sprocket. Obviously, this is much harder to access to make
adjustments. Check chain tension regularly, as new chains can "stretch"
after a little use as they become worn in or heat up during use. An overly
tight chain can cause wear on the chain itself or wear on the guide bar
and other components caused by excessive friction between the two. A loose
chain can jump off the guide bar, and as the chain is traveling up to 22
meters per second at full speed,
When you look at chainsaw design over the years, very
little has actually changed from the designs of earlier years, and it is
interesting to see that with these two chainsaws, Husqvarna have made some
interesting changes in basic design to the tools to enhance their features
and functionality.
To begin with, both saws use the standard manual cord pull
start feature of most chainsaws, but to make starting easier and reduce
wear on the starter cord and other starting components, the Husqvarna saws
feature a decompression valve. By pressing in the small decompression
button on the top lateral side of the motor (accessible via the outside of
the motor casing) the piston pressure is reduced when starting the engine,
This means the pulling force required to kick the engine over is reduced.
The decompression valve pops back out as the engine is cycled so it
automatically returns the motor to normal operating configuration. I must
say that these particular saws did start a little easier than my cheaper
chainsaws I have in the shed, but if the saws themselves are used
regularly and maintained well, they shouldn't have many problems starting
anyway. Regardless, any addition to help make engine start easier is a
welcome one, if only to save some back and arm muscle strain through
repetitive starting pulls.
Another feature is the combined stop/choke lever. When the
choke is pulled out, it automatically moves the START/STOP lever to the
START position. This ensures you aren't trying to start the chainsaw with
the START/STOP lever in the STOP position, which of course would not allow
you to start the saw. I have been guilty of cussing saws in the past when
trying to start them and not noticing the saw ignition switch is in the
STOP or OFF position. I am sure we have all done that at one time or
another! At least this will not be an issue with these saws. When it comes
time to stop the saw after use, the red lever is pushed down to the STOP
position and the engine ceases.
For the technically minded, both saws use a CD ignition
system and have an idle cycle speed of 2700 RPMs. The carburetors are
manufactured by Zama.
To reduce user fatigue, the chainsaws implement Husqvarna's
"LowVib" system. Basically, this "separates" the handle and fuel tank from
the engine and chain/bar to reduce vibrations being transferred to those
areas. This is not an uncommon feature of many newer chainsaws on the
market, but on these saws, the system seems to work a little better than
with others I have used. It's not a totally vibration-less experience of
course, and it could be argued that feeling some vibration during a cut
can help the operator gauge how well, or how poorly, the saw is cutting the
material, so a little vibration is unavoidable. The LowVib system is
definitely needed on these more powerful saws however. It does seem to do
the job, and vibration is equal to that experienced with my cheaper and
smaller 52cc saw, so I can't deny its effectiveness.
Perhaps the most significant improvement in the saw design
is the implementation of the X-Torq system. This engine system
offers more power with less emissions and better fuel economy. How so?
Well, in a normal engine, combustion with fuel helps drive the piston to
cycle the piston/engine. With the X-Torq system engine, the piston has a
relief milled in one edge side and a matching relief in the piston casing,
When these two line up in the piston cycle, a burst of air is injected
into the combustion chamber, assisting in driving the piston back down,
hence requiring less fuel combustion to do so, and because less fuel is
used, there is less fuel-burning emissions. It is claimed the system also
results in 10% more power over standard engines, and that the torque is
available over a wider RPM range. After using both saws, I have to say
that this is true. A good test we undertook was to make a cut (with proper
safety precautions) using a lower RPM, then while the cutting teeth were
engaged in the wood, try to power up the saw to a higher RPM to cut
faster. On many saws, if you try to do this, you won't get much of a
result.... i.e. to increase the RPM, you generally need to remove the load
from the bar/chain, and hence engine, to increase the RPMs. With the 570
and 575XP I was readily able to increase RPMs with the engine under load
making a cut! This was quite impressive, and hadn't I tried it for myself,
I wouldn't have believed it. With a sharp blade and properly tuned engine,
both saws can cut extremely fast with plenty of power. It's almost scary
in a way! Be sure to have all your PPE (Personal Protective Equipment) on
and practice safe cutting techniques!
To prolong life of the blade, and cutter bar, the automatic
oil system and oil pump should deliver enough oil to the chain and bar to
reduce heat buildup. It is said that with each petrol refill, you should
also need an oil refill, i.e. when a full tank of petrol is used, so
should a full tank of oil. When the oil delivery rate was bumped up (it is
adjustable on both saws) we did indeed use up a full tank of oil with a
full tank of gas. So there was no problems found with oil delivery. Of
course, keeping the drive sprocket area and oil outlet free of debris will
prevent blocking of the tube and allow free oil delivery.
Dual spike bumpers add to the safety features of the saw.
Spike bumpers should be engaged with the side of a log whenever possible.
They not only help stabilize and align the cutting bar, leading to a
cleaner cut, but should the chain grab or bar pinch in the wood during a
cut, and engaged spike bumper will stop the saw being thrown forward and
engage the chain break generally a little quicker.
The mufflers located at the front of the saw are designed
to direct exhaust gases away from the user, and also to reduce noise
emissions. In addition, the mufflers on the chainsaws feature a spark
arrestor, designed to inhibit sparks exiting the saw and hitting
combustible material. In use I never saw any sparks come from the muffler,
so I guess this feature is working well.
One other test I wanted to undertake was to mount the saws
to my home-made Alaskan-style chainsaw mill frame and cut some boards from
logs. With the chainsaws rigged up, I proceeded to cut some two-inch thick
boards from a log of seasoned spotted gum. This would really test the saws
out. Sawing boards from logs is very tough work for a chainsaw, and
generally slow going as well. Both the 570 and 575XP handled the task
reasonably well. Obviously not as well as a 90cc or 100+cc chainsaw, but
certainly well enough to handle the odd milling task the home or hobbyist
woodworker might undertake when they come across some free logs. The
torque of both saws again impressed during the cutting. These are
certainly well-made saws both inside and out.
Conclusion
So, to answer my own question... is it worthwhile investing in these
higher priced saws for the average woodworking tasks? Well, after
comparing the Husqvarna models to my el-cheapo Chinese 52cc saw, I have to
say that yes, if you can gather up the money to purchase one, and want to
purchase a quality saw without having to buy again in a year or two when
your budget saw bites the dust, put the Husqvarna on your shopping list.
If you only very occasionally use a chainsaw for crosscutting logs only,
then you might not get the use of out the saw to make it worth your while,
or your full wallet. But for everyone else, I'd have to say these saws are
definitely worth the asking price in terms of features and performance.
Now, I have to start saving my pocket money to buy one of my very own.
|
575XP/570
Photos
All photos copyright onlinetoolreviews.com. Use without prior
written permission prohibited

The starter assembly on the 575XP

Combined STOP/Choke Lever

Trigger and main handle

Spike bumpers

The decompression valve

The muffler...

Guide bar with chain fitted

The nose and sprocket

The large air filter on the 575XP

The 570 in action crosscutting a log

A large log reduced to smaller ones using the 575XP.

Boards ripped from logs using the 575XP.
|