Friday, January 12, 2007

A new table saw (part II)

So, it’s been almost a month since I’ve bought the new table saw (DELTA ShopMaster TS350), but believe it or not, I have yet to try it out. We have to do some furniture re-arranging before we can put it in the dining room: the room that was selected for me to make some saw dust in. I think God is continuing to teach me patience and self control because I’m like a little kid not able to play with his new toy and it is torturing me inside. The other day I did scratch that itch a little by turning on the saw (I was very surprised at how quiet it was - see the induction motor comment below), but that is as far as I’ve gone. Oh well, I’ve got to be patient.

In the meantime I wanted to compile thoughts about saw options and why I’ve learned that they are important (or not).

Cast Iron vs. Stamped Iron Tabletop
According to two articles written by American Woodworker, cast iron wing have “four valuable benefits that are worth the extra money.” The first advantage is the ruggedness of cast iron wings: you will not risk bending them as you might with stamped iron wings. The second is the added weight which dampens vibrations. The third is that they provide a great “dead-flat” surface which can be extremely useful for furniture assembly and more. And the fourth is that the table top, due to its solid flat nature, can be a very convenient surface to sharpen tools.1, 2

Belt-Drive vs. Direct-Drive Motor
The general consensus is that belt-driven motors are a preferred option. By connecting the motor to the saw blade with the use of a belt, stress on the motor shaft bearings is reduced, vibration and noise are decreased (if the belt is healthy or if you have a segmented belt), and shaft elevation in less impaired.3 The motor is usually hanging in the back of the saw, on contractor models, or inside the cabinet, in cabinet saws. For contractor models, this decreases the mount of saw dust that the motor is exposed to, therefore causing the motor to last longer.4 It also makes it easier to replace the saw motor with more generic models instead of having to buy overpriced replacement motors for the original manufacturers.
On the other hand the advantages of direct-drive saws is that they are more economical3, they require a little less preventive maintenance (no belts and pulleys to check), and they transfer more of the motor’s power to the blade. Thus allowing a lower horsepower motor to do more work4.
Of interest is that fact that when American Woodworker in October 2002 published an article entitled “Small Shop Table saws”1 in which they explain what they consider to be important features a saw should have, they did not mention the belt-drive vs. direct-drive issue.

Induction vs. Brush Motor
In case you were wondering what the difference was, an induction motor is a brushless motor.
Induction motors have a longer life time and are quieter, more efficient, and heavier than brush (or universal) motors. In addition induction motors, apparently, are “more of an "off the shelf" item.” The main advantage of brush motors is that they are cheap, lighter, and usually smaller.5

Evaluating the DELTA ShopMaster TS350
The TS350 has two great cast iron wings, definitely a plus. This makes the saw weight over 170 lbs, which makes it a pain to move, but more importantly, it makes it nice and solid.
The TS350 is a direct-drive motor saw. This is probably the one feature that I did not like on this saw because it decreases that the cutting height, possibly adds more vibrations, and might decrease the life of my motor. I think I read somewhere that it might actually be a belt driven motor, but that the belt is encased in the motor housing. Even if that is the case, blade height is not improved, vibrations might still be an issue, and if there is a problem with the belt, DELTA only sell the motor as a unit, so it only helps with a possible decrease of stress on the motor shaft. Again, I am not sure this is the case with the TS350, but I think that I read that somewhere.
The TS350 has an induction motor, which is a great plus.
The TS350 also is very enclosed with a dust port at the bottom, ready to be attached to a vacuum system. Dust collection was an important criteria for the American Woodworker1, but I’m not sure if this was what they had in mind.
I’ll be honest, the ultimate keeping point for the TS350 is that I bought it for $270. I saw many saws that might have had a belt driven motor, but were twice the price and had stamped wings.

I look forward to testing this saw out and writing more about it in the future. BTW - I did download all the needed manuals and drawings directly from the DELTA website.

1. American Woodworker, October 2002
2. American Woodworker, September 2004
4. Lowes Home Improvement
5. Ridgid Forum “Can’t decide on the saw” discussion


Anonymous said...

I'm not sure which is more "blah, blah," this or Alan's blog.

Maël said...

I'm taking it as a compliment that you are putting me in the same category as Alan's blog, Mr./s. ANONYMOUS, whoever you are.

Alan Knox said...

Yeah, I think you know who said that... I'll be talking to her real soon about this.


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