Thread: Which SawStop

Originally Posted by rrich

......... there is a drop. That equals a scrapped blade and a new cartridge.

Just life in the big city.

Thanks, Rich

I only know one person with a Sawstop and his experience is quite similar.

For those less unfamiliar with Sawstop than me, when a sawstop is triggered an explosive charge releases a half inch thick aluminium brake which slams into the spinning saw blade and stops it within about a quarter of a turn. Its a mechanical action, very violent and a lot of enrgy is expended stopping the blade. Energy = heat!

SawStop.jpg

The blade is treated very roughly, the heat may weld the brake to the blade and often the blade needs replacing. Cost of a Sawstop cartridge is around $150. Plus blade. Plus cost of down time until the cartridge and blade are replaced. Occasionally there has been other damage such as to the saw bearings.

My acquaintance reported a similar number of Sawstop firings from green timber, metal contamination, etc, as you mention, and a repeated but seemingly inexplicable "false firing" with clean dry timber. Eventually this was traced to one of his favourite timbers - celery top pine (Phyllocladus aspeniifolius) - which when dry is a mild electrical conductor. For about 40% of his business when sawing celery top he has to disconnect the Sawstop which rather defeats the point of having it.

I suspect that he will soon upgrade to a slider!

Originally Posted by RossM

Haha - ya can't beat the old cast iron!!
Mass certainly has its advantages in smooth running.

What's the difference in mass of a ton of cast iron and a ton of aluminium?

Originally Posted by derekcohen

...
This is also one of the reasons why I have not felt I am missing out with a long slider. .....

I like this technique with a slider - cut to approximate length, rip, then joint, then thickness. Often the slider will cut so smoothly that jointing is optional.

You must be a little more careful to keep pieces in strict order so than grain patterns match.

Originally Posted by GraemeCook

What's the difference in mass of a ton of cast iron and a ton of aluminium?

No difference in mass, but roughly a 3 times difference in volume (density of aluminium in g/cm3 about 2.7 vs iron about 7.9)

The point however (and it was tongue in cheek) is that the old cast iron machines in general were built much heavier than modern counterparts, and that does contribute to machine stability and vibration reduction.

I have an upgraded sawstop contractors saw, with the cast iron tables. It does most of what I need. It struggles slightly with a dado stack - the additional power of the cabinet saws would be welcome.
I bought second hand, so got what was available. There was the bigger 52 inch cabinet on the market at the same time, but that was just too big for me.

To limit the danger of kickback, I have a set of Jessem Clear Cut TS guides. More $, and likely to get even more $ now that our AU$ is in freefall. They work very well, and make cutting so much easier - I wouldn't be without them now.

My blade guard has never fired. (When it does, I will do some crying as it's $120 for the cartridge plus the blade cost. And much more if it's the dado cartridge + stack).
Note that it will not fire when the blade is not spinning, so touching it or metal tape measures will not trigger it at rest. You can also test material you plan to cut by touching it against the blade at rest - the warning lights will flash.
I know that there have been some firings at the men's shed when the blade was touched on spin down - you do need to make sure it has stopped completely before touching it with the tape etc.

Slight pain in the 4rse bits: The left tilt - means recalibrating the measuring guides if you change to a blade of different thickness. Takes 15.73s. Fence against the blade, zero, go. You also need to fine tune the distance between the blade and the cartridge when changing blades - in practice this tends only to be when swapping from a single to a dado set. It's also a quick operation (27.29s). Both of these are #firstworldproblems.

I also have two pieces of 2nd-hand Hammer machinery. They are fantastic quality. The sale guys knew the history of both machines when I called them up about them (oh yes that's at such and such isn't it? We last serviced it a year ago. They didn't use it much because they bought xyz). So that's what you're paying for, and pay you will - the last quote I had from them included a separate line for screws.

If a decent reasonably recent hammer C3 appears on the market, I'll snap it up and sell the sawstop. If a K3 appears at a very good price, I'd be tempted

Originally Posted by derekcohen

I purchased the kit for a long rip from Felder about a year ago, having viewed this video. And it has remained on my shelf ever since.

I do plan to build one, but not for rips that long - perhaps about 700mm longer than I have, which would give me up to 2000m ripping on the slider of my K3.

Why not longer, and why is it still on the shelf? Well, I simply cannot imagine where I would need to rip that length. Ripping long also assumes that one will joint and thickness long, and that is an inefficient way to prepare boards. With cups and warps, etc, you end up removing more wood, and thereby losing more thickness, as a board gets longer. The better method is to cut everything to approximate length (still longer enough to securely run through a thicknesser), then joint the faces and edges.

This is also one of the reasons why I have not felt I am missing out with a long slider. It does not fit with the work I do with solid wood. That would change if I worked with sheet goods.

Regards from Perth

Derek

Mine likewise sits on a shelf never used, in fact I haven't seen it for so long I am not sure where it is. I actually had to do a long rip yesterday and used my long rip fence.

Do you have 15amp power, or just 10amp? This may be the decider.

The Contractor saw is 10amp, the PCS and ICS(single phase are 15amp).

Originally Posted by LanceC

Can you explain why you need to measure between the fence and blade with every rip operation? I thought the normal procedure was to measure once then calibrate your fence, so that all future operations use the rail measurements. Perhaps I’m. misunderstanding what you’re trying to say.

What I've heard from users and the school. AND These are 2004/2005 time frame model owners. Things may have changed since then.
If the blade moves and is touched by a metal tape, the blade drops.

And, oh yes the Left vs. right argument.
Every table saw blade is different. The blade disk thickness, can vary. The set of the teeth can vary. All of these contribute to a noticeable error. And that doesn't account for a narrow kerf blade.
On a right tilt, the arbor flange is closest to the fence. The variance in the set of of any blade is small and barely noticeable. The Set of a saw blade is about 1/64 inch or 1/8 MM.
On a left tilt the distance from arbor flange to the right side of the kerf can vary to noticeable differences. If you are trying to make parts that are all identical width and the fence is moved it becomes difficult. When it was explained why my old RAS seemed to have a mind of it's own, I realized that the ruler I had placed on the fence was of little use for accuracy. It was then that I only considered right tilt saws for my personal use.

Thanks Rich, that explains it well.

Originally Posted by rrich

about 1/64 inch or 1/8 MM.

Just for the sake of accuracy 1/64" is about .4mm NOT .125mm.

I'd never considered these differences between right and left tilt saws. Glad to have it brought to my attention. Thanks, Rich.

Good article here with a lot of detail on the left vs right tilt debate:

The Myth of the Left Tilt Saw - Canadian Woodworking Magazine

The author is a strong "right tilt man" "..I believe the safety of left-tilts is exaggerated and used mostly to sell magazines and saws...in the real world, the hypothetical safety benefit of bevel-ripping wide solid wood boards on a left-tilt saw is of far less importance than the cursor accuracy of a right-tilt..."

Originally Posted by RossM

No difference in mass, but roughly a 3 times difference in volume (density of aluminium in g/cm3 about 2.7 vs iron about 7.9)

The point however (and it was tongue in cheek) is that the old cast iron machines in general were built much heavier than modern counterparts, and that does contribute to machine stability and vibration reduction.

I realised that, Ross, which is why I had my tongue even further in cheek....

All the sliders that I have seen have had very solid and rigid aluminium slides or carriages. I agree that some cabinet saws are built too light, but that does not seem to apply to sliders. [Caveat: I have not seen any Chinese look alikes.]

An interesting rule of thumb used by boat builders is that if you have plans for a steel boat, then you can replace the steel with aluminium 50% thicker. You finish up with a hull that is as strong and stiff as steel, but only half the weight.

• eg Replace 4mm steel plating with 6mm aluminium.

Originally Posted by aldav

Just for the sake of accuracy 1/64" is about .4mm NOT .125mm.

I'd never considered these differences between right and left tilt saws. Glad to have it brought to my attention. Thanks, Rich.

Ah yes. My FUBAR.

Originally Posted by rrich

Ah yes. My FUBAR.

Winston Churchill once said that England and America were two countries separated by a common language.

Well, you initially beat me with FUBAR, but google saved the day.

I concur with you!


Graeme


PS: I will not copy and paste the definition of fubar and will thus save our ever vigilant moderators from the need to delete this post!