Woodworker's Journal 1992-16-5, страница 66

M»t ikhIi *>« i»tli iln U u< h «Iwu you'rr iltrimi'h u> otg ill* ut hv * ihiii.isI. (lie |Jt>lM H'/« hi lluililii't Saw Minnie I ♦ i«u > -i. ,umI piumrtly lor rtp-l>t»t(f ¹ i \ ilniiiTi-niital lumber and pis ,>,*<.! j■.iri■ i mi sue. Tlte Delia ii-- .« | (m%f tt> - » utttng dcplh of a 10 in.

........ Hit <n>wiii eapabilities of the

M.iliin ik Kynhi, hui it's an accurate.

hui It machine that packs a jtowerful punch in a lightweight <40 lb.) package.

Cutting Capacity

This refer* to the maximum size of the stock you can cut on the saw. The two most important figures are maximum depth of cut (blade height above the table) and rip capacity (distance between rip fence and saw blade).

Rip Capacity — Most manufacturers list the maximum rip capacities on both the lefl and right side of the blade. On all saws except the Makita. you can install the fence on either side. Some offer optional extension tables (Delta. Skit. Rvobi BT-2500), or guide rails (Ryobi BT-3000) to increase rip capacity.

Depth a) t 'm The chart on page 68 liMs the specs for the maximum depth of cut at 40- and 45-degree hlade positions. In order to rip or crosscut dimensional "4-by" lumber in ttne pass (without flipping the stock), you'll need a maxi mum cutting depth of ai le.tsi ¹ ut which only ihe Makita 2711 and Iwo Ryobi saws have (see charr Hut tin depth-of-cut figures don't mean you t an always achieve the full depth ol cui ut one pass—especially on some of ilk-smaller saws. For deep cuts, it's Ivsi to make several passes, elevating the blade a bit each time, lo avoid placing loo much stress on the motor and the blade.

Table Size —- A less-direct measurement of a saw's capacity is its table size, l-arger tables provide better support for large boards and panels. Saws with larger tables also have longer rip fences, which translates into more accurate cuts and less chance of binding the saw blade in the cut. While it's possible to rip a 4 ft. by 8 ft. ply wood panel or 10 ft. long board on even the smallest benchtop saw. cutting accuracy and user safety will be compromised. Again, table extensions (and other work supports) will help, but the smaller benchtop saws in our chart really aren't designed to cut the brg stuff.

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Perhaps more important than the overall si/e of the table is the amount of table space in front of the blade. The table must provide sufficient support for the stock when you first feed il into the blade. For this reason, manufacturer's specs often include the distance between the front edge of the table and leading

Photos I and 2: With the exception of the Ryobi BT-3000 with its belt drive (below), all benchtop saws have direct-drive motors, such as the Skil 3400 shown above.

edge of the blade (usually at a blade height of I in.} One last consideration: All ol the saws accept stacked dado sets. Tlio i hart on page 68 gives specs for all ol ilie above mentioned capacities.

Motors

Of ' our * \<>u m ed to consider power when choosing ,uiv j>ower tool. But vou can't alwav<. determine how powerful a tool is by manufacture!'«. specifications alone. For cxampk a couple of manufacturers list die s.iv. \ minimum developed fuirwpiiwei. IhiI most don't assign horsepower ratings to ihe if saws All except the X in Seats imodel 22If>21 have universal-type motors Mmh ,m typically rated in amps onK Uui even amp figures can somenim . I* mi U i.l ing: For example, in my tesv, I notu. that the Makita 2711 I rated ,u I .mipsi seemed to have more guts than most >>| the saws rated at 13 amps.

The story is a bit more complex than this, however, so I've covered the whole business of manufacturer's power r.u

ings in a separate article on page 22. Interestingly, the Sears saw has a 7.2-amp induction (brushless) motor: a scaled-dow n version of the type commonly used for large stationary machines. Although of lower amperage than the universal motors on the other saws I tested, it performed satisfactorily in my "blade bog-down'' tests. The motor is well-matched lo the blade size, although not quite as powerful as the other saws tested.

On the 10 in. Sears. AMT, Skil. and Reliant, the I3-amp motors looked virtually identical, and I really didn't notice much difference in power between them—all were much gutsier than I expected, given the low prices of these tools. Several of these manufacturers concurred that they were buying the motors from the same source, which is typical with most stationary machinery. Power-wise, the 13.8-amp Ryobi BT-2500 has a bit more spunk than the 13-amp saws above: during the 2 years I've owned mine. I've run some stuff through it that I didn't think a benchtop saw would handle. The 8'A in. Delta also had lots of power, but ! suspect that's because the 13-amp motor (made by Porter-Cable) drives an S'/i in. blade instead of a 10 in. one.

The two most powerful saws of the group are the Ryobi BT-3000 and the Makita 2711; they're also of better overall quality. For the price, though, you can expect ihem to be.

Drivetrains

All but the Ryobi BT-3000 are direct drive saws (Photos I and 2). On the 8 in. Sears saw. the blade arbor is an extension of the motor shaft; because induction motors run at a fixed speed <3.800 rpm), the blade speed equals motor speed. On direct-drive saws with universal motors (all the rest), the blade arbor is connected to the motor shaft by means of a single helical reduction gear inside Ihe motor housing. The gear meshes wnb the splmed end of the motor shaft, offsetting the arbor tow ard the lop of the motor housiii|- flits arrangement not onlv allows toi ,i ■,-reater depth of cut. but also serves lo retime the high rpm of lilllieis.il inolois ill oil) I4.IKX) to 18,000 ipini down lo a no-load speed suitable lor sawing <3,800lo4.800rpm). Several of the saws have the same motors, but ihe gearing is slightly different, therefore

The Woodworker's Journal