Preparing Timber – Resaw (part a)

Over the course of a number of posts (not necessarily consecutive), we will follow a piece of timber through a whole range of machining and processing steps, until it becomes a finished product.  You may not need all the steps – it depends on your particular source of timber for one.

Sourcing timber is always a bit problematic, and I will be looking further into the whole timber supplier thing later on.

Unless you have purchased a kitset (and even then in some cases), timber does not come in any sort of finished state, and particularly a dimensioned state ready for your project.  Even if it is sold as DAR (dressed all round), you can be pretty sure it will have twists, warps, cupping etc, even on a minor scale.  Perhaps difficult to pick up while shopping, but painfully obvious in the final project if not dressed properly before it is used.

However, first things first. If timber is too thick (or if you want bookmatched boards), the ability to resaw timber (which can be considered to be taking a board and splitting it into two thinner boards) is an incredibly liberating function.  You are not restricted to the thickness of boards you buy (or having to resort to wasting to sawdust good timber), or even if you are provided/manage to scavenge branches and sections of tree trunk, you have the ability to turn them into useable, rough-sawn boards ready for drying and processing.

The tool to achieve this is one of the most valuable in the woodworking workshop, and one of the most versatile: the bandsaw.

This is not what I’d call a (and apologies if anyone gets upset by this) toy bandsaw 8″- 10″ (and smaller) – you need something with a bit of power, and the capacity to take a reasonable blade, and they don’t start until you get into the 14″+ size.  There will be some who’d still call these toys until you hit at least 24″, but a 14″ bandsaw should be able to resaw a 12″ diameter log.

This does get into bandsaw sizing, and when you first come across the bandsaw, you’d think the size (8″, 12″, 14″ etc) refers to the resaw height – the depth of cut.  It actually refers to the diameter of the bandsaw wheel (at least on a 2 wheel bandsaw), which dictates the maximum throat depth.

Depth of Cut vs Depth of Throat

What I have found in the past, is (as a general rule) the smaller bandsaws have real tracking difficulties – not only in following a line, but also in simply keeping the blade running on the wheels.

A bandsaw blade needs a fair amount of tension to work properly, and the little bandsaws just cannot get the blade tight enough, which makes them worse than useless.  I’m sure if you pay good money that there will be small bandsaws that can do a good job, but if you are forking out $100 – $200 (or less!), then you might be better saving your money.

My current bandsaw is the 17″ one seen above.  I still have a 14″ Jet which I am still very fond of – with the 6″ riser block, the Jet is capable of resawing 12″, and still has a reasonable throat.  This 17″ one does pick up some things that make my life a lot easier.  The tension wheel is underneath the top wheel (hard to see in the photo), and is at a good working height to crank the tension on easily.  Both this, and the Jet have a quick tension release, and both can take a reasonable resaw blade.  3/4″ for the Jet, 1″ for the Carbatec.

Blade Comparison

A bandsaw may come with a single blade, but it most certainly should not be the only blade you own.  In fact you should be seriously considering changing blades for each job you do (assuming they are inherently different tasks).  A blade that may be suitable for cutting tight circles (such as the 1/4″ 10 TPI blade seen fitted here) is completely unsuitable for cutting through thick timber, where you have a much deeper depth-of-cut, or for resawing.  The other blade seen here is my primary resaw blade.  1″ across, 3 TPI, it will not leave anywhere near as smooth a finish as the small blade, it cannot go around a corner (well about as well as a bus can, compared to a mini!), but it can handle significant blade tension, will stay very straight during the cut (including not bowing, so the cut remains vertical, and flat!), and won’t result in burning as it has significant chip clearing capacity.

I’d suggest having 3-4 blades of different widths, and different teeth counts to cover the range of typical tasks.  The blade that came with the saw you can keep (put aside), and use it for jobs where you wouldn’t want to subject a good blade to, such as sand-encrusted timber, aluminium etc.  (Yes, cutting aluminium on a bandsaw is a perfectly reasonable task, as is plastic).

The bandsaw is, in my opinion one of the safest cutting tools in the workshop – certainly much safer than the tablesaw, SCMS, or router table.  You can still do significant damage to oneself if not careful, but it is a tool I’m more comfortable in using (standard guards and safety gear all still bought into play of course).  The cut direction is down, into the table so work is much less likely to be thrown at you, and if there is a failure (such as a broken blade), it doesn’t fly around the workshop and instead simply stops moving.

You can still cut yourself though – no tool can be used with impunity.  A bandsaw has teeth, and any tool with teeth is designed to eat.  If it has no trouble with hard timber, then your hand/arm/body will prove no problem if you happen to offer it up as a sacrifice.

So the bandsaw – one of my must-have workshop tools.  Whether it is for resawing

Resawing

or scrollsawing,

Scrollsawing

circle cutting (as will be covered in the next edition of ManSpace magazine)

Circle Cutting

Circle Cutting

or anything in between, it is often going to prove to be the go-to-tool.  In this case, (for the purposes of this article), its ability to break down logs and resaw boards is invaluable in the workshop.

Episode 59 Circle Cutting on the Torque Workcentre

tbc

Some Torque Functions

Getting ready for the jaunt across to the US in a week’s time, I put some time running through some of the basic Torque functions.

Firstly, I wanted to do some refinements to the overall setup – getting the centreline of the router as perpendicular to the workcentre top as possible.  I’ve touched on this recently, using a dial gauge mounted directly to the router collet.  That provides a significant level of accuracy, perhaps beyond that which is required.  I’ve also been using the Wixey Digital Angle Gauge directly onto a rod mounted in the collet, and that is a pretty simple system to use.

First step is getting the main arm parallel to the table.  Using the Wixey is the best way to achieve that – zero off the table (with the gauge parallel in alignment to the arm) then place it on the arm itself, and get it level.

Zeroing the Wixey

Next, repeat the process, this time zeroing the gauge then check the rod is at 90 degrees.  Repeat the process for the other axis of the router.

Aligning the Router

(You can see in this photo the router is out a significant 1.4 degrees around the Y axis).

I’ve also tried using the simplest technology – a square, and that is also quite successful.

Using a Square

The use of a straight rod in the router collet is so successful, I’d almost suggest it would be a useful inclusion in the Torque Workcentre package, and later it could become one of the set of copying attachments (although the copy attachments would need to be increased in size from 12mm to 12.4mm, but I’d see that as an advantage).

First job I did was finishing off the downsizing of the 4″ pre-separator bin.  It needed a new base, and although I’ve cut circles by other methods in the past, the TWC is by far the easiest method.  There are justifiable times that the bandsaw will still be better (thin kerf of the blade vs router bit width), but if that is not a consideration, then the TWC wins.

Circle Cutting

A circle is cut by placing the workpiece on the TWC pin (by drilling a pilot hole in the underside of the material), offsetting the router by the radius of the required circle and locking it’s X and Y axis.while rotating the workpiece, slowly plunge the router into the work, cut a circle, increase the depth, rotate again, rinse and repeat until the circle comes free.

New Base for Dust Bin (Pre-separator)

Next, I wanted to try some of the pin-routing technique.  This is a 2 stage process.  First you need to create the path that the pin is going to follow.  In this case, I have secured down the body of the racing kangaroo.  A couple of extra supports are added so there is no issue with the panel rocking on a too small-a pattern being duplicated.

Setting up the item to be duplicated

This is flipped over and run against the pin, with the router directly over the top of the pin, a channel is cut.

The path created for the pin

This is the path that the pin will fit into for the actual duplications.

All the parts for the racing kangaroo

Flip the pattern over, mounting it on the pin, and attach the blank board on top.  With the pattern captive on the pin, a perfect copy is made, and this can be repeated as many times as is desired.  The only thing I need to do is get a better match in size between the pin diameter and router bit diameter – they need to be a matched pair.

Pattern Copying

The other method is using the copying attachment.  This has a pin that follows the original path, and moves the router over the workpiece, rather than moving the workpiece relative to the router as happens with pin copying.

Resulting sign

In this case I used a router bit larger than the pin, so the thickness of the letters were increased.  Signwriting is only one use of this technique.  The ability to easily and accurately duplicate an object or pattern is a very powerful tool.  (As you can see, I was using the same workpiece to test this technique as I did for the pin routing)

Producing raised (bas-relief) lettering is as easy (if not easier!)

Triton Workcentre Dust Bag Modification

Dust collection in the workshop is critical for having a healthy, and an enjoyable work environment. In Australia, all wood dust is classified as carcinogenic, which should be encouragement enough to have a good dust collection system, but it tends to be when every tool that you are looking for has disappeared beneath layers of wood shavings that a decent collection system is considered!

One of the things that first impressed me about Triton was that they consider dust collection as being an integral part of their systems, rather than just an afterthought. Each item in the Triton range has provision for a dust bag and/or vacuum collection.

Before the advent of the Triton Dust Bucket, the original dust bag for the Workcentre had a vacuum offtake. The original dust bag then evolved into the current passive system where a bag beneath the table collects the dust and shavings.

dust-4-in-6-of-8.jpg

 

Photo 1 – The current dust collection system (sourced from http://www.triton.com.au)

Funnily enough, the current dust bag lends itself very well to being adapted to active dust collection. Particularly the rigid ring that the lower bag connects to is excellent for supporting a funnel. You can choose to fit a ready-made funnel, or make one of your own. One of the best ideas I have heard recently was to cut the top of a commercial spring water bottle for a water cooler- it makes a great funnel.
You can collect the dust using the standard Triton Dust Bucket, but this results in a very narrow end to the funnel, which is prone to blocking. The alternative, is to use a full 4” collection system, where the high volume, low velocity suction and wide tubing copes a lot better with larger debris.

Since acquiring a 750W Dust Extractor from Triton’s new parent company (GMC), I have fitted out the workshop with 4” tubes for dust collection from all my major workshop tools (blast gates are used to prevent suction from tools not in use- see Photo 6 which includes inline blast gates). This provides a superb dust collection system. For the Workcentre, I adapted the dust bag with a funnel that reduces the diameter down to the 4” tubing. (Note, in future, I will be going for a much more powerful extractor – 2HP is preferrable!)

dust-4-in-1-of-8.jpg

 

Photo 2 – GMC 750W Dust Extractor

Now, instead of collecting the sawdust in the lower bag which requires frequent emptying, the 4” tube feeds all the sawdust and scrap wood directly to the Dust Extractor.
For the funnel, I chose to go the hard way, and make my own.
Starting with a single piece of MDF, a circle is cut with a 50cm diameter. This can be done on a bandsaw or the Triton Jigsaw Table. Next, a number of concentric circles are cut. However, these are cut with the work set at 35 degrees to the blade, producing cones.
Three additional rings are cut with straight sides. These are to produce the cylinder that the dust extraction hose will fit on. This cone is being made for a 4″ dust collection system, however there is no reason that the normal Triton hose could not be used if the cone is made to come to a smaller diameter.

dust-4-in-2-of-8.jpg
Photo 3 – The cut rings and cones

The cones are then inverted, and placed on top of each other, producing a funnel. The first ring is quite a bit larger than the next, creating a lip that will locate on the hard ring in the upper section of the dust bag.

dust-4-in-3-of-8.jpg

 

Photo 4 – The funnel, ready to be glued

dust-4-in-4-of-8.jpg

Photo 5 – The funnel in position, ready to be attached to the 4” tubing

I have had some questions in the past about whether the bag will collapse in, restricting the funnel, when suction is applied. I am happy to say that I have had no problems with that, and in fact the dust collection is even better than before (and not just more convenient), as air is drawn into the bag through all the gaps, preventing dust escaping. It will also be beneficial for the saw itself, as the positive suction draws clean air in through, and around the motor, and discourages dust getting into the circular saw’s housing.

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Photos 6 & 7  4” Hose connected, leading to a Blast Gate and Y section

Episode 06 Bandsaw Circle Cutting

Episode 06 Bandsaw Circle Cutting

Bandsaws have always been great at cutting curves. With a simple jig, perfect circles are a breeze. This video demonstrates this homemade jig, and also briefly shows some minor mods that I have made to my 14″ Jet Bandsaw to keep the tyres clear of sawdust.

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