|
As woodworkers, we all know that setting up shop can be
an expensive and time consuming task. Acquiring all the specialty tools
needed to complete a project can mean an investment of many thousands of
dollars, and often tens of thousands for the more equipped shops. The next
biggest expense is purchasing the raw material to build your projects, and
we all know that wood is not getting any cheaper, especially the harder to
find or more exotic materials. Even so, plain pine, poplar and other less
expensive materials are always slowly rising in price. So how can you
acquire some nice wood at much less expense? Invest in your own low cost saw mill of
course!
Chainsaw mills are becoming very popular among
woodworkers who choose to mill their own wood, often for convenience and
variety, but more often for cost reasons. Apart from initial setup
(purchasing a good chainsaw and a basic mill) it is far cheaper to mill
your own wood than to buy pre-milled wood from a supplier. And chainsaw
mills are considerably cheaper than larger milling units. Your next
biggest challenge will be sourcing the logs to mill!
Today we are taking a look at the Westford Mill; a
device that attaches to your chainsaw and allows you to mill your own
boards and lumber for downed trees or salvaged logs.
Selecting a Chainsaw
This is a hotly debated topic. Chainsaw milling puts very heavy,
constant loads on a chainsaw, so a decent one is required. Depending on
the size of log you wish to cut, your choice of saw will vary. The purists
will argue that the biggest is always the best, and anything less than a
100cc chainsaw will not be suitable for milling. Personally, I don't
agree. I have seen people successfully mill logs with smaller electric
chainsaws and saws as small as 40cc. Naturally, cutting with lower power
saws does take a lot longer, but smaller saws are less expensive. They are
limited in the width of log you can cut too, as they can really only use
shorter length chain bars.
If
you want to cut large diameter logs, you do need quite a big saw to handle
them. Most of the logs I cut are not more than 20 inches in diameter. I
found a Stihl MS380 saw (72.2cc) on an auction site not long ago brand new
for less than half the retail price. I couldn't resist and scooped it up
and this is the saw I now use for most of my smaller milling tasks. It has
enough power to tackle 18 inch logs without waiting all day to finish a
milling pass. Basically, when choosing a chainsaw, go for a name brand
(easier to find parts later and they are generally more reliable) and grab
the largest one you can afford, but bear in mind that larger saws also
weigh a lot more, so you have to balance weight vs practicality and
fatigue considerations too.
Generally speaking, a basic milling saw should be over
70cc, and larger if you plan to mill wider logs. I'd certainly love a
120cc saw, but I haven't been able to justify the several thousand dollar
price tags they come with just yet.
The Westford Hobby Mill
Chainsaw mills are quite simple devices. In fact, basic versions can
be made by anyone with fair metalworking and welding skills. I,
personally, crafted one of my own not too long ago using RHS steel. It
wasn't the fanciest mill going, but it did an OK job. Now that I am doing
a little more milling at home, I went looking for a better, adjustable,
easier to use, and more cost
effective option. The Westford mill caught my eye.
It is similar in overall design to the well-known
Alaskan style chainsaw mills (most small portable mills are) but its
simplicity is the key to its success. Westford (based in Australia) also make larger mills
using the same overall design, so whether you have a 16 inch bar, or a 50+
inch bar, there will be a model to suit. Additionally, if you start out
with a smaller mill, you can readily convert it to a larger capacity mill
simply by adding longer channel rails to the mill (and perhaps a few extra
rail support pieces to maintain rigidity and prevent rail channel flex
over the longer span.
The biggest advantage of these
smaller mills is that they can be taken straight to the log, rather than
having to bring the log to a larger stationary mill. This allows you to
access fallen logs wherever they drop, as opposed to having large
machinery on hand to haul logs to a larger mill located somewhere else. Plus, these mills fit
readily into the trunk of any car, but be aware that you might need
something larger transport-wise to carry all those nicely slabbed
boards/posts back to the shop!
The Westford mill is constructed from durable treated
materials. Steel components are zinc plated to AS1789 and yellow chromate
passivated to AS1791. Castings use aluminum alloy (type 401) and are
machined to high finish standards. The handle support bar is galvanized
round bar. The unit as a whole is very ridgid and solid, but not
cumbersomely heavy as far as mills go. It is definitely much stronger and more ridgid than my
basic homemade mill.
The mill can clamp to any chainsaw bar, and no
modifications to the bar are needed. There is no drilling required and
fitting the chainsaw only takes a few minutes. The bar is clamped at two
spots, one near the powerhead, and the other are the distal end of the bar
(but not right at the tip, so sprockets - if you have a sprocket bar - are still free to spin).
Non-sprocket bars may offer a little extra milling capacity however. This
two point clamping system also helps keep the bar rigid during a cut,
delivering a smoother cut surface with a more consistent thickness across
the length of the bar. Once the saw is attached, the depth of cut can be
adjusted via the two sliding RHS depth rods. These can be raised or lowered in
reference to the mill's square platform base to adjust cutting thickness on the
log. Scales on both rods allow both to be set at the same depth for
accurate depth of cut setting. A central round bar holds a horizontal hard foam grip handle
which provides the user with a comfortable hand hold to guide the saw
through a milling cut. A second vertical hand grip at the front allows an optional second grip position that may be more suitable or comfortable
depending on the cut dynamics. Generally when beginning the cut, the front
vertical hand hold is the best to use. Once the whole frame of the mill is
rest on the log surface, the horizontal bar hold seems more comfortable
and practical to use.
The underside of the main base rides along a flat
surface provided by the user which is attached to the log to make the
first cut. This flat surface could be a flat board, or a section of
steel ladder, or a handmade guide rail system. The idea is to have a flat
reference surface to make a flat first cut through the log. For the second
and subsequent cuts the mill can just ride along the surface of the log
cut with the first milling pass. Simple!
The minimum cutting depth (or resulting board depth) I
was able to achieve was about 28.5mm ( approx 1 1/8").
It can go a little lower here because only the end of the bolts that clamp
to the chainsaw bar are preventing it reducing depth of cut any further.
These could be cut shorter to allow close to a 1" minimum cut if needed,
but be sure to check your bar can be clamped properly with the reduced
bolt length and that the clamp nuts have enough bolt thread to secure
properly. Maximum depth of cut is around 13 inches (33cm). Rarely will the
maximum depth of cut be used, at least I have never even gone close to it.
Remember that the larger the depth of cut, the heavier the chunk of wood
will be that is pressing down on the chain and bar while you make the cut.
You would definitely need to use some wedges in the cut to ensure
clearance between the chain and the kerf of the cut. I find that for most
slabbing cuts, I use a maximum of 2 inches. Although, if you are slabbing
for posts, you might want a little more. Since most of the wood I mill
ends up being used in furniture projects, a 2 inch cut allows me the
flexibility to further machine the slabs down using the bandsaw or planer,
or table saw to the dimensions of stock I require for the project.
However, the wide range of cut depth available offers flexibility to cut
logs to sizes needed for your specific requirements. Also, be aware that
if you are milling on your own, the resulting boards from larger logs can
be very heavy to lift and move.
In terms of maximum cut width, this will be less than
your actual bar length, because the mill does not allow the tip of the bar
to engage in the cut, plus you lose a little width due to the clamps
themselves needing to clamp to the bar forward of the motorhead. On the
hobby mill, the maximum cut width is about 440mm (a little over 17
inches). In general, the mill will result in a loss of about 5 inches from
your regular bar length. The mill is adjustable however. So the hobby
mill, for example, will take saws from 14" up to around 22 (with a
sprocket nose bar). The end
casting can adjust along the channel rails as necessary to fit the length
of your bar correctly (up to its maximum width). If you reach maximum and
need more, you need the next size mill up, or longer mill rails to accommodate
the longer bar.
An aluminum plate piece wraps around the far end of the
mill, providing some protection from the tip of your chainsaw bar. This
will help prevent any undesirable contact with any obstacle (or person),
in the path of the tip as you make a cut. It also prevents the tip
contacting any object and preventing a kickback event. It is an essential
safety feature on a chainsaw mill in my opinion, and it is implemented
well on the Westford mill.
Making a Milling Cut
First and foremost, ensure your chainsaw is topped up with petrol and
chain bar lube. It can be a pain if either run dry during a cut. Next, if
your chainsaw has an adjustable bar oil feed setting, put this to maximum
flow. You will need all the lubrication you can get during a cut. For
chainsaws up to 25" generally the onboard oiler will be sufficient if it
has a decent pump and good oil flow, but for larger saws most milling enthusiasts use an
auxiliary oiler that drip feeds oil (under gravity) toward the tip of the bar.
Next, ensure your chain is sharp. Milling places a huge,
continuous load on your saw, so anything that helps reduce this is a must,
plus, your milling process will be quicker and produce a cleaner, more
consistent result. Skip tooth chain is recommended by most millers, and
low profile chain is also often recommended. Some chainsaw millers will
recommend regrinding the chain teeth to a low degree profile, such as 5 or
10 degrees. I will leave that up to you to decide whether that works for
you. I have found that for smaller milling of sub-20" width logs, regular
skip tooth chain at 25 degree tooth angle does the job quite well. For
larger stuff, it would be worthwhile investing in some of your own
research to get the best outcome regarding chain regrinding or specific
milling chains available.
Next you need to setup your milling guide on top of the
log. This needs to be as parallel to the length of the log's lengthwise
centerline or grain as possible for a proper rip-type cut result. You can
use packers or wedges under the guide as needed for this. Once you have it
set, secure it down as appropriate for your guide rail. Ensure the chain
will be clear of any fasteners you have used to secure your guide rail
down before making the cut. Now with the depth of cut set on the saw mill,
and after a check that everything is secure and safe, place the front edge
of the mill on the guide rail (or the whole base of the mill if it fits) and get ready to mill!
Power up the saw (ensure you have all safety gear on)
and allow it to warm up if it is cold. All you need to do is keep the mill
evenly running on top of the guide rail you have set up to make the cut.
The Westford mill is holding the saw in the right position (assuming
correct setup). Slowly guide the saw and cutting chain through the log as
it cuts, applying full power to prevent the saw bogging down. Take it
easy. It is not going to cut as fast as a regular docking cut in a log so
don't expect miracles (they will come later when you uncover the beauty of
the wood slab you just milled!). Allow the chain to do the cutting and do
not force it into the cut. Guide the saw through carefully and evenly, and
on longer logs, be sure to insert wedges in the cut kerf as you go to keep
it open and prevent binding on the chainsaw bar and cutting teeth. Use the
sound of the saw as your guide to correct cutting speed. You will easily
hear when the saw is under too much load, so back off slightly and try to
mill with a constant cutting speed (or constant sound speed). Take is
slow as the chain exits the cut, and be sure to take your finger off the
trigger as soon as the teeth emerge from the end of the log. Power off the
saw and remove it from the log, then remove the board or slab you have
just cut. Now turn it over and check out the beauty you have just uncovered!
With the first cut done, you no longer require the guide
rail. The next cut will be made running the mill over the cut surface you
just created with the first pass. You may need to adjust cutting depth on
the mill, and this cut will not require the extra depth to compensate for
the guide rail it was running on during the first pass. Once set, proceed
to cut in the same manner as mentioned above. Be sure however, to check
fuel and oil levels in the saw after each slab cut. The saw will use up a
lot of juice and bar oil making these types of cuts, and the tanks can empty
surprisingly fast. Additionally, after about every 3 or 4 slabbing cuts,
check the chain sharpness and sharpen as required. You might even need to
touch it up after every second cut if the logs you are milling are quite
long or you are milling dryer hardwoods. A sharp chain is the key to milling success.
Continue milling until the log is completely milled.
Just be careful as you make the cuts closer to the ground or surface the
log is sitting on. Ensure there is adequate clearance to make the cuts
safely.
Surface Finish and Further Prep
The surface finish created by the chainsaw mill will obviously require
more work before the lumber can be used for project work (unless you are
doing some rough carpentry that requires only rough sawn material). The
cut surface is generally quite rough but is relatively easy to clean up to
a useable standard. Bear in mind that slabs and boards cut from logs
generally need to be dried before they can be used. They can be kiln dried
or air dried, the latter being the most popular as it does not involve any
real extra expense, but takes a lot longer. In fact, it could take more
than a year for boards to dry to a useable state for furniture or building
work. (8-12% moisture content is a good figure). Generally the boards and
stacked and stickered to dry before being checked later on with a moisture
meter for moisture content.
When I am slabbing from logs, generally I don't cut more
than 2-inch thick slabs, and for these (after proper drying), I simply
pull out the portable circular saw, and with a straight edge guide,
rip off the bark edges to give a fairly trued edge to work from. I might
then run one face over the jointer to flatten it, then square up the
adjacent edge to give me a perfect 90 degree edge to work with. From there
I rip the adjacent bark edge square on the table saw, before finally
running the opposing rough face through the planer to square that up and
clean up the surface. That process results in square, flat and surface
finished boards ready to use for woodworking or furniture projects. The
process may change depending on the size and width of the boards slabbed
from the log.
But all this follow up work is really irrelevant to the
Westford Mill. What matters is that the mill turns logs into useable rough
cut boards and that it offers this functionality at a price that is
affordable to most woodworkers. You do not need a large bandsaw mill or
dedicated milling machine costing tens of thousands of dollars to produce
your own supply of woodworking material. In fact, your biggest problem
will be finding enough downed logs and salvaged material to keep your
chainsaw mill in regular use!
Conclusion
The portable chainsaw mill, in my opinion, should meet two specific
requirements... a) be cost effective and affordable for the average
woodworker looking to generate their own lumber supply, and, more
importantly to... b) Allow repeatable, accurate and safe cutting of
logs using a chainsaw. I think the Westford mill meets both these
requirements. It is simple to use, very affordable, durable and delivers
the results it is designed to deliver.
If you haven't considered milling your own lumber
before, look into chainsaw mills. You will be amazed at how much material
you can produce from one decent sized log. If you know a local arborist,
you might be able to source logs for free too!
The Westford hobby mill is designed and made in
Australia and retails for AUD$471 (including GST) and is available from Westford
Enterprises at
http://www.vianet.net.au/~jemal/
A list of Australian and International dealers are also available on the
site.
Their larger size mills are priced as follows (prices in
Australian Dollars):
36" $483 Max Bar 42" Cut 31"
48" $556 Max Bar 56" Cut 43"
66" $716 Max Bar 72" Cut 61"
For U.S. readers looking for a
comparable portable chainsaw mill, we recommend the Granberg Alaskan
Mills:
|
Westford Mill Photos
All photos copyright onlinetoolreviews.com. Use without prior
written permission prohibited

The assembled Westford hobby mill.

Horizontal grip handle provides good control when saw is engaged in the
log.

Solid and strong casting brackets.

The MS380 chainsaw attached to the mill ready to go.

Note the bar end protection piece. A vital safety element.

Milling some short boards for box work from a salvaged log using the
chainsaw mill.

Closeup of some sliced boards. The surface will require further milling
or finish work. Usually a pass or two through a planer/thicknesser is all
that is needed.

The larger version of the Westford mill used to cut a wider log.
(image from Westford website).

A much larger mill used with a longer chainsaw bar, used to mill this
large log. Note some slabbing rails are fixed to the top of the log in
this example
(image from Westford website).
|