Preparing Timber – Resaw (part b)

Before beginning a resaw, we obviously need the resaw blade fitted and properly set up on the bandsaw.

Opening both top and bottom doors reveals the blade, tension mechanism, drive mechanism (motor is at the back) etc.

Covers open, revealing the wheels

The top wheel is the tensioning wheel, the bottom wheel is the drive wheel.

Tension wheel and gauge

Around the back is a quick-release lever which takes significant load off the blade and bandsaw when not being used, and during blade changes.

Table support pin

The table support pin is removed – there is a cut through the cast iron table so the blade (which is an endless loop) can pass through to the centre of the table. The support pin prevents the two sides from becoming displaced / moving independently of each other.

Completely release blade tension

Once the quick-tension lever is released, the remaining tension is quickly wound out of the bandsaw, leaving the blade loose on the wheel. It can then be carefully removed.

Coil blade for storage

It is very good practice to coil and store the blade. An uncoiled blade is difficult to store, but in one respect at least if you have the space there is a benefit not coiling. The smaller blades (1/4″ etc) have little spring in them, however the large blades (1″ for example) can have a great deal of energy stored in the coiled blade, so care is needed, particularly when uncoiling. Still, space is a precious commodity – I coil all my blades.

Check out my second-ever episode on Stu’s Shed (1 Jul 07!!) for a bit of a video on bandsaw coiling.

Back off guides

Before installing the new blade back off all the guides, especially when fitting a much-larger blade such as the resaw.

Insert new blade

Slide the resaw blade through the slot in the table then fit it over the two wheels. First retension with the quick-tensioning lever, then wind on the tension until the blade is at the required tension (pluck it, and if you get a High C note, it is about right.

only joking!! But you do want decent blade tension , with minimal sideways deflection when pushed).

Side guides alignment

Bring the side guides into position (just behind the teeth gullets)

Side guides clearance

Then adjust the gap – post-it notes make a good feeler gauge. Don’t forget there is a second set of guides below the table. Bring the thrust bearings up behind the blade as well. Again, a Post-it note provides a good clearance. My take on guide bearings is that they need to be almost touching (but don’t rotate) when the bandsaw is on, and the blade is not loaded up (aka cutting).

Sometimes you need to be able to reach a hex bolt, and the short, power end of your allen (hex) key can reach, but there is no room to operate it. The long end can reach, but you can’t generate enough power to turn it.

A trick I picked up while in the Navy is using a ring spanner to get extra power on the short-end of a hex key.

Ring spanner trick

You can generate significant power this way, so you need to be a little careful not to over torsion the hex key.

Once the blade has been changed, it is time to do the resawing. Depending on how accurate you need to be, you can either free-hand it, or use a fence. When free-handing it (especially when following a line drawn on the timber), you will notice you have to feed the work in at an angle to the blade. This is called blade drift. All bandsaws do it, and it is a combination of the blade, blade tension, and the timber. If you are using a fence, you still need to take this into account.

There are many fences available for bandsaws. Some come with the saw, some are aftermarket. My favourite though, are the MagFences from MagSwitch. They use switchable magnets to lock down onto the cast iron table wherever you need it, and at whatever angle to the blade that you want.

Ideal resaw fence (MagSwitch)

The single-roller MagFence has the roller set proud, with the remainder cut away (again, so they don’t get in the way of the drift).

MagFence clearance

My method of using the fence is to lock it down at the distance from the blade that is equal to the thickness of timber (or veneer) you want to produce.

MagFence alignment

The rollers are set to line up with the teeth, and again I choose to line them up with the bottom of the teeth gullet.

Ripping a veneer

Ripping mm (or less) veneers is easy once everything is set up correctly.

Accurate resawing

If you want to split a board down the middle, you can either measure and assume it is accurate (including taking into account the kerf of the blade), or while holding the work against the fence, touch the blade with the timber. Then, flip the board over and touch the blade again. Between these two cuts is the true centre of the board.

This will give you the boards you need. If they are still green, you need to leave them to season. Next, we need to start the machining – joint/plane and thickness.

Addendum:

As Larry has correctly pointed out, I tend to use “bandsaw tracking” when describing the phenomenon of a blade running at an angle to a drawn line (or “track”) on the timber, and “blade tracking” to describe how the blades are running on the bandsaw wheels.

The common terms however are bandsaw “drift” when it cuts at an angle to a given line, and blade “tracking” for how the blade runs on the wheel.

I don’t like the term “drift” – it implies the bandsaw is not working correctly, and it is drifting all over the place instead of cutting straight, but for the sake of clarity, I have amended this article to the common nomenclature.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: