Dado Spreadsheet

Dado Excel Spreadsheet

I have had a few queries about the original Excel spreadsheet that I created to generate my precise dado table (the one with 3000 or so combinations).

I have attached it, but here is the disclaimer:  it is nowhere as neat as Excel spreadsheets can be, but this was the easiest way I could make it to deal with the number of combinations.  Someone familiar with the latest versions of Excel would be able to do a much better job, but I haven’t used it since the XLSX format came out, so there have been a lot of changes since the last time I did use it.

Column A: All combinations must include the combination of the two outside blades, so this column is always “1″
Column B: The number of 1/8″ chipper blades used in the stack. The set I had provided 4
Column C: Whether or not the 1/16″ chipper blade is included.
Column D – G: The number and size of the various shims included in the stack.

Column H: This is the theoretical width. Add to this the additional width that is created by the runout of the saw and blades. This is easily achieved by setting up a basic stack, with the theoretical thickness from the spreadsheet. Make a dado cut, and measure the actual width. The difference is caused by the combination of runout from the various blades, and the saw.

Column I: This is the runout. At this stage I only have calculated the runout for one setup. If you wanted to be even more exact, you could calculate the runout for each blade the same way, and amend column I accordingly.

Column J: This is the money column – the final size of the stack that is built.

Column K – Q: These are the calculating columns – leave these alone.

Columns R – X: Input each of the widths of the various blades and shims.

As I said: it is not the most eloquent spreadsheet. But it works, for me at least!

Dado Excel Spreadsheet

Click here to see the dado blade at Toolstoday.com

Scratchin’ out a living

When you are used to using power tools and machines for your woodworking, it is easy to forget that sometimes a handtool is the best tool for the job.

They are quieter (much, much quieter), safer (although any sharp thing can cut), and often can get into places denied to power tools.   They also can have a different method for removing material. Where both can slice, only a handtool can scrape.  (Now I’m sure someone will tell me I’m wrong…..)

Scraping has its benefits.  It avoids tearout, as the blade is not parting material ahead of the blade – lifting and cutting.  Think of all the adverts on TV about shavers, where the blade lifts and cuts the hair.  If you are lifting timber, there is a chance more will lift than you intended, and tear out.  Scraping has the blade at a different angle of attack, with the cutting edge trailing behind, rather than leading the way.

Scraping is used in a number of hand tools.  For planing a surface with torturous grain (burls and the like), you can get planes with the blade set vertically for a scraping cut.  You can use scrapers (a piece of steel with a fine burr to perform the actual cut) as an alternative (and superior to) sandpaper.  And you can use a scratch stock as an alternative to a router.

It is a very simple tool – a piece of spring steel with the required profile cut into it.  And a holder.

You can make your own, or check out this one from Hock Tools (Ron Hock being very well known for the quality of his plane blades).

Hock Scratch Stock

This is available from Professional Woodworkers Supplies in Australia, who sell items from the Hock Tools’ range.  The body is made from a laminate of bamboo, which has good water resistance, and shape stability.  Instructions for using the scraper can be found here.

Where noone would consider manufacturing their own router bit, this comes with a second piece of tool steel so you have plenty of opportunity to create just the profile you want.

I came across an interesting concept while looking at these scratch stocks (and especially the supplied profile).  It used to be quite common for this profile to be used on the leading edge of a kitchen bench….underneath.  The purpose was as a drip arrestor.  Any liquid spilling and running over the edge would gather at the bottom of the curve of the profile and drip off, rather than continuing on its journey into one of the drawers (often the cutlery!)  Simple idea – pity it seems to be forgotten by modern kitchen manufacturers.

A very simple concept, a very simple tool, the ability to make your own profiles, and the ability to deliver that profile just where you need it, right out of reach of powered tools.

ElectroBlu is the new Blue

The double-sided melamine blade from Amana Tool, and sold through Toolstoday.com

It is seriously…..blue

Amana Tool Melamine Blade

Quite a stunning looking blade, but we will get to its looks later.  Function is much more important than looks!  Good thing this blade has both :)

The blade is an 80 tooth, 10″ (250mm), with a 5/8″ bore.  That is what suits my saw, they also have 30mm bore, and sizes from 200 – 400mm diameter.

It has 4 straight expansion slots to minimise heat distortion, with copper plugs.  The copper plugs are used as a vibration absorption, and to block up the holes at the end of the expansion slots – both of which in turn decreases operational noise.  The holes themselves are used as a crack-arrestor as they reduce the stress at the end of each slot.

The straighter the blade, (in how it is manufactured, in how accurate the teeth are ground, and the less warping/distortion caused by heat), the better the cut.  This combined with a tooth profile especially designed for melamine results is a remarkable cut.

Clean cut

The edge, on both sides of the melamine, is as clean in closeup as it appears in the above-photo.  It is a beautiful cut, and that aptly demonstrates the quality of the blade.  Getting this sort of result on both the top and underside of the cut is remarkable, and takes a special blade to achieve this.

Crosscut Pine

The blade is also very good for crosscutting, whether that be soft or hardwood.  The finish is near shiny, and showed negligible to no breakout of fibres at the back of the cut.

Crosscut Hardwood

Ripping was harder – being an 80 tooth blade there is only a small gullet between teeth, and where that is fine for crosscutting, is insufficient for clearing waste and the long fibres created during a rip cut.  It is still achievable, but you have to cut slow (risking burning the timber, overheating and distortion in the blade).  Even so, a shiny cut was the result!  Good enough to go straight to a finish, or one final light sand.

Hardwood Rip

But why is it blue?
The blade is finished with a new process, called electro-bluing. It is a smooth coating for the blade, replacing the teflon-like finishes of other blades.  It has only been available since September 2012!  This micron-thin coating is claimed to reduce heat buildup, and the accumulation of resin.  The coating includes the teeth of the blade.  It will be very interesting to see how durable the coating is!

It is also promoted as being an environmentally friendly coating.  If that is a feature you need, this blade (and this coating) offers that, which differs from many other, more traditional coatings.
So this is the MB10800.  A double-sided melamine blade which really cuts the mustard! From Toolstoday.com

Episode 91 Amana Tool Melamine Blade

Episode 91 Amana Tool Melamine Blade

A blade designed to cut double sided melamine, by Amana Tool.
Available from Toolstoday.com

The Secret Language of Saw Blades

Ever gone to purchase a sawblade and wondered just what all the codes are engraved on the side (or printed on the packaging)?

There are a surprising number of variables that are possible with saw blades, so many versions that can be considered.  Some are irrelevant when choosing between one blade and another – they distinguish between a blade suitable for wood vs plastic (for example).  Some blades do cross over – the Flai Mustang for example, which will have variables that suit both materials.

For example: ATB D250, K3.0 B30, Z40, H10

ATB

ATB = alternating top bevel – this blade has its teeth set so it is like a chisel, with one tooth cutting to the left, and the next to the right of the kerf.

You could have 4+1 (4 ATB teeth, plus one FT (flat tooth) as a raker tooth, flattening the bottom of the cut).  An ATB blade leaves a V groove in the bottom of a partial-depth cut, and the 4+1 is a way to resolve this, leaving a flat-bottomed kerf.

Other options include HATB (or HiATB), where the teeth are even more angled which is good for melamine, and timbers prone to tearout, TCG (triple chip grind, also known as triple cut, FT (Flat Top), HG (hollow ground)

D250

D stands for diameter – size of the blade in mm.  A 250 blade (or to be exact, a D254) blade is 10″

K3.0

This is the kerf of the blade, measuring across the teeth.  This does not mean the blade will actually cut a 3.0mm wide kerf however. Blades have runout (just how flat is the blade, and during use just how flat it remains as the temperature of the blade changes).  Saws (tablesaws or circular saws) also have runout, and it is a combination of both that will dictate exactly how wide a kerf you will get.  If you want to know it exactly each time, you have to measure it whenever you change blades.  The next time you mount the same blade, it could be different depending on at what point of rotation that the saw is vs the blade.  It is much easier just to do a test cut and remeasure if it is that important.  This concept is greatly (and deliberately exasperated) for a wobble dado blade, which is designed with a large amount of runout which can be dialed in, creating a dado (or wide trench).

B30

This is the size of the bore – the hole through the middle of the blade.  Depending on your saw you can either get a blade that specifically matches your saw, or one that is larger and get some saw blade bushes (or reducers) to match both the blade and you particular saw.  They are not as convenient (but are still easy to use), and they allow you to purchase blades that are suited to your needs without necessarily being made for the size bore you require.  Of course, if the hole is smaller than your arbor, you have a problem! Getting back to dado blades for a sec, when using stacked dados, I would strongly recommend getting one where the bore is correct for your saw – there are enough things to juggle without also having to try and manage a bunch of bushes as well.

Z40

Z stands for the number of teeth.  A ripping blade can have around at little as 24 teeth, a crosscut blade as many as 100.

H10

H is the hook angle (or rake angle). Large hook angles are an aggressive blade, particularly for ripping soft timbers.  Small, zero or even slightly negative for crosscutting hard timbers.

 

These are just some of the variables and codes that can be written (engraved) onto the blade.  They may not all be listed, and some blades may list a whole bunch more.  If you know these at least, you are well on your way of being able to distinguish between one blade and the next.

 

Some other variables include top clearance angle, top bevel angle, gullet size, gullet plug, expansion joints, noise reduction slots, max operation RPM, carbide type, base blade material, blade coating, body thickness and so on.  We’ll stick with the most common concerns at this stage!

 

Speechless

Well we all know THAT is an exaggeration! However.

Finally had a chance (and the justification) to fit my new 1″ 1.3TPI, TCT resaw blade on the bandsaw today.

Before I get into what I think of the blade, (and as far as bandsaw blades go, it wasn’t particularly cheap), I’ll mention what prompted me to splurge on a replacement blade.

I was trying to resaw some kiln dried hardwood (Tassie Oak), that was around 200mm wide.  I was using a 1″ 1.3TPI blade that came prepackaged from a woodwork supplier.  Not sure if it was a carbon blade, but I strongly suspect so.  I was struggling.  The blade was complaining bitterly, the amount of force needed to push the timber through the blade was getting stupid  (the range of force needed is “butter”, “easy”, “moderate”, “hard”, “difficult”, “impossible”, “dangerous”, “stupid”), and I was blowing the circuit breaker on the bandsaw circuit continuously (it isn’t rated particularly high, so trips way to easily).  To the point that I was oping for the 15A tablesaw to do the resawing, taking a couple of passes to cleave the timber.

So onto today.  More resawing required.  Fitted the TCT blade with a bit of trepidation – what if it isn’t much better?

The blade fitted, tensioned, and finally the timber ready to cut.  I touched the end to the blade (to make a mark to ensure I was centred).  Well I meant to touch the end.  Being so used to the previous blade, I put a little bit of pressure in, and immediately sliced into the timber over 5mm.  Whoa.

Checked I was centred, then fed the timber in, through, and out the other side (1800mm) cleaved in twain without beginning to try.  I need a new category for ease – “Soft butter”  And this was hardwood.  Be very interesting the day I need to resaw some serious Aussie hardwood.  Do not expect this blade to have any trouble – wonder how easy it will be!

It goes to show, the right blade, a quality blade makes it so much easier, safer, enjoyable.  So the blade was $180 or so. After experiencing what it could do, it is worth every cent.  Just a pity I can’t get blades thinner than 1″ with a TCT.  Not that the bimetal 1/2″ blade has been any slouch either.

As mentioned earlier, purchased from Henry Bros Saws if you want your bandsaw to become everything it can be!  Sounds like a sales pitch (perhaps it should be!) but no.

Handling a Knife

Damascus steel Zhen Nakiri knife blank

I recently wrote about Damascus Steel, and showed this knife from Professional Woodworkers Supplies as an example of a modern interpretation of this traditional steel-making technique.

Over the weekend, I had a chance to complete the handle for this knife, so I was able to put it to use!

Queen Ebony timber stock

I started, as always, scrounging around through my timber stocks, looking for just the right piece of timber for the job.  Not sure which is the more rewarding: having a project and the excitement/anticipation of the project commencement while out sourcing and purchasing just the right pieces of timber for the job, or scrounging around your own existing timber store, though pieces collected over the years and waiting for just the right project to come along to be able to finally do it justice.

For this project I looked at many pieces and different species.  Even tried a couple to see if there was enough detail for the project at hand, but rejected them in the end.  I finally had a look at the pack of Queen Ebony strips I had purchased at a wood show a few years ago, and suddenly realised that the bottom two strips (about 1.5m long each) were thicker than the others, and were in fact thick enough for this project, even after being machined flat!

This is a perfect scenario – it gives me a chance to actually machine one face smooth and flat, and then match the opposite side and still end up with timber thick enough for the task at hand.

The project is pretty straight forward, and follows the steps I took when doing the steak knives.  After sizing the scales, they were double-sided taped together (carpet tape).  These were then stuck to one side of the blade.  On the drill press, holes where then drilled through the holes in the knife blank, then while still attached to the blade, the whole lot were transferred to the bandsaw, and the rough outline of the blade handle cut.

The scales were then separated, glued (epoxy) to either side of the blade blank, and the rivets inserted.

Once the glue was dry, the whole contraption was transferred to the spindle sander for the final shaping.

To complete, the Festool ETS 150/5 was used to polish the sides and edges.

Completed knife

The Queen Ebony really looks the part – I am most impressed!

Finally, the real test is in the kitchen, so I gave a piece of pumpkin a workout.

Nakiri Blade in its element

The final verdict is in the use, and this knife handled beautifully!  The sharpness of the blade, the scalloped blade and a home-made stunning handle.

A fun little project, and a very satisfying result!

 

Real Smooth Shave

Gave the first new bandsaw blade a quick workout today – the 1/2″ 3TPI bimetal blade.

It has a regular tooth set, and slices beautifully.  When resawing, it vastly out-performed my current 1″ carbon resaw blade – it is obviously significantly sharper – not surprising given how easily carbon blades dull off.

So not only it is superbly sharp, because it is bimetal it will hold that edge for longer.  I guess I have found my new “standard” blade – the one that will stay on the bandsaw by default, so whenever I want to do a quick cut without going to the trouble of changing blades, this is the one that is a jack of all trades. So yes, very happy with this first blade, and looking forward to testing the others.

The general rule is to have as few teeth in the cut as possible.  Too many, and the gullets fill and clog and the blade cannot cut well.  Too few teeth, and the cut is rougher than is necessary.  Having a range of blades, sizes, tooth configurations, tooth numbers will mean you will have the best blade for the job.

Straight-faced tooth with deep gullet to remove shavings.

Deep gullet and 10o undercut face which digs in more, and tends to curl the shavings.  Good for harder woods.  I would imagine though, that it is likely to dull off quicker, given there is less material backing the tooth edge up.

Similar to Hook Tooth, but has the teeth at 90o . Chips rather than shaves – good for materials that would otherwise clog up the blade.  Effectively increases the gullet (which clears the formed chips out of the cut), without having to increase the overall tooth size.

Has a combination of teeth closer together for a finer finish, with some teeth having large gullets for chip clearance.

Bandsaw Blades

Just ordered some new bandsaw blades for my 17″ machine.  Done, as always, over the phone.  Bandsaw blades are one of those things you get made to order, not precut and packaged, sitting on a shelf.  I’d rather have a relationship with the supplier, rely on their expertise, and know they are surviving on their reputation, which means they are only as good as the last blade they sell you, so they better sell you a good one!

Blades come in massive continuous rolls, which are then cut to length and welded.

This latest order comes from my original supplier, Henry Bros in NSW, so I am expecting good things. (And no, I don’t get a discount).

I’ve ordered a 3/16″ carbon blade, a 1/2″ bimetal, and my very first 1″ carbide tipped resaw blade.  I’m rather excited to see what that blade can do!

The point about a CT blade is not that they are the sharpest tool in the shed (no, I don’t mean they are dumb!), but they have excellent durability of the cutting surface.  The resaw blade I have at the moment (which came with the saw as part of a deal) is a very basic blade, and from what I can tell is a straight carbon blade.  Which for a blade needing to survive thick, Aussie hard timbers is basically useless after a few short jobs.

A CT blade is meant to be screamingly expensive, and when I priced one for my 14″ Jet bandsaw (which has a 6″ riser block), it was quite a price that I decided not to bother.  Around $80/metre (plus GST) (and I needed 2680mm), it was over $200.  The equivalent bimetal blade cost me about $40 at the time (1.3 TPI). The 14″ Jet can take a maximum 3/4″ blade, and as it turns out, this really pushed the cost up.

This time I decided that it would be really good to get a CT blade for resawing, so steeling myself against price tag shock, I asked how much it would cost for my 3335mm length blade (which is what I need for the 17″).  $38/metre (plus GST) for a 1″ blade.  Means I am up for around $150 inc GST!  Oh yeah, bring on the carbide tips!

Just a bit on blade material, fwiw

A cheap blade is generally a carbon blade.  Carbon steel in other words.  Cheap, initially sharp, but unable to hold an edge for long.  I don’t but carbon blades for anything but the smallest blades (scrollsaw type work), such as 1/8″, 3/16″, 1/4″ (if I have to).  Anything larger than that, don’t waste your money.

As soon as I can I move into bimetal blades.  These are as they sound -  a blade made from two different metals.  The base metal is a carbon blade (spring steel), but where a carbon blade’s shortcomings are the teeth durability, there is a different metal welded to the front of the blade which the teeth are cut out of.  This is often a cobalt high speed steel, so much more suitable for teeth.

And finally, TCT blades.  Not as sharp initially as the others, but significantly longer lasting, so overall they are sharper on average over the life of the blade.  In the case of the 1″ blade, it has cost me about 3x as much as a standard blade.  A worthwhile investment to my mind.

So when the package arrives (it’ll take a couple of days for the blades to be made and shipped), I will be very interested to see how they all perform.  I pity the timber!

When Worlds Collide

Source: NASA/JPL-Caltech

Really, nothing so spectacular actually.

One of my staff is having a baby soon, so came around to ‘the shed’ so we could start working on a cot.  He’s chosen Tasmanian Oak, so bought some lengths, around 170 wide and 45 thick. (mm that is).

We were too busy to stop for photos, sorry about that!

First job was resawing, so I tried the bandsaw, but had a few problems there.  For one, I think my resaw blade needs sharpening – it really struggled.  I know hardwood is, well, hard but this isn’t the worst thing I have been able to put through this blade.

Combined with the blade dullness, is the increase of load that creates on the bandsaw and therefore an increase in power that is drawn.  Problem number 2 then cropped up – kept tripping the circuit breaker.  Now I know that isn’t related to any fault in the tool, just a underrated circuit breaker that trips at 10A (and probably less), without any threshold.  We ended up giving it away, and swapped over to the tablesaw, with the blade at full height, and two passes to split the board.  Even with two passes (flipping the board over) wouldn’t be sufficient to cut that entire width, but all we needed was actually 145mm, so ripped the board down before splitting.  Even the 15A tablesaw was pushed with such a full-depth cut, and even when changed over to a ripping blade, so perhaps the timber was as hard as the machines were saying.

So we properly dressed the timber all round (using the combination of the jointer (planer), thicknesser and tablesaw).  This obviously isn’t your garden variety DAR – the boards are left flat and true, without warp, twist or bend.

After docking the boards to their required length, it was over to the router table, where a 6mm groove was cut near the bottom in each side, so when assembled it can have a captive base.  By the end of the session, we had made the bed section itself (that has the mattress filling the area, with a maximum of 5mm between the mattress and the sides.  The standard allows for double that).

Once all machined, and edges rounded over with the Fastcap 1/8″ roundover plane, it was onto the Domino to make slots for floating tenons.

We ran out of time to sand and finish – job for another day.

This was part 1 of about a 3 part project. Good using the tools for a bit of furniture again.

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