6-Inch Benchtop Jointer
If portability is key and you don't have the room or muscle to lug around a full-size jointer, your best option may be a 6-inch benchtop jointer like the Delta JT160. This tool is 30 inches long and weighs only 35 pounds. Its bed and fence are aluminum (rather than cast iron, as on the full-size machines). Its 10-amp universal motor has a variable-speed dial for speeds of 12,000 to 22,000 cuts per minute with a two-blade cutter head. The old rule of thumb would have this jointer straighten boards no longer than 5 feet long, but cleaning up longer sawn edges is a good use for a benchtop tool. One complaint is that the thin aluminum bed surface isn't very flat and smooth; the deep machining grooves on the surface add a lot of feed friction. (Delta JT160, $270.)
Cutting depth is set by adjusting the height of the machines' infeed tables. The Delta ( left), Craftsman, and Grizzly use long levers that move the table quickly but are difficult to set with great accuracy. The Delta lever has the added advantage of being bent forward for easier reach and has a trigger device that stops the table in roughly 1/32-inch increments.
Crank adjusters are our preferred style because of their greater accuracy. They're found on the Jet (center), Ridgid, and Rikon. Cranks move the tables much more slowly; the larger cranks of the Rikon are the fastest to operate.
Cutting-depth gauges should be used only as a rough guide; we visually set each tool at 1/16 (.0625) inch and ended up with measurements ranging from .0530 inch (-15 percent) to .0835 inch (+33 percent). For repeatable settings the Craftsman, Delta, and Grizzly have top and bottom table-travel stops that can be custom set by the user.
All of the machines have lockouts that require a manual override to set the depth of cut greater than 1/8 inch. Since infeed tables have to be moved upward into position to avoid inaccuracy caused by gear lash, these lockouts often engage even when you are setting finer cuts. The spring-loaded pins of the Craftsman, Jet, and Rikon are especially annoying, since they totally immobilize the table – like hitting the tilt function of a pinball machine – but the friendlier design of the Ridgid (righ) has a pin that moves in a slot and allows free adjustment back up from the 1/8-inch mark. The pivoting-plate lockouts of the Delta and Grizzly also allow this free movement, and they – like those of the Craftsman and Ridgid – are located on the front of the machine for much easier reach, especially for right-handed users.
Changing out knives is an important part of jointer use: Some busy users sharpen and replace them every week. Light honing can be done with a flat stone from the infeed table, but sharpening the knives requires removal. All of the jointers in our test have very similar knife-setting adjustments consisting of a knife-clamping bar called a gib with four tensioning bolts, and two recessed blade-height adjustment screws that the back of the knife sits on called jackscrews. The Rikon (right) also includes knife-raising springs that can be used instead of the jackscrews, but the certain action of the jackscrews makes them more reliable (in our experience). We preferred the captive jackscrews of the Jet, Ridgid, and Rikon over the loose ones of the Craftsman, Delta, and Grizzly, which fall into the tool's dust-collection chute whenever the cutter head is rotated. We also preferred the four-sided heads on the gib bolts of the former three machines; the hex heads of the latter were not as easy to reach and tighten. Rikon also has unique spindle-locking holes to pin the cutter head in place for easier knife maintenance. Setting the outfeed table so the locked position is top dead center for the knives helps with fast and accurate knife setting.
Setting the knives flush with the outfeed table is important for even cutting, and since no machine's cutter head measured exactly flat with its outfeed table, we recommend against using setting jigs that reference off the cutter head. Instead you should set the top dead center of each knife so it just touches a lightweight straightedge – or zeros out a dial indicator – cantilevered over from the outfeed table. You'll know the knives are set correctly when each knife makes a faint scraping sound as it's rotated backward against the straightedge, which shouldn't move or lift.
After painstaking work setting knives this way, we took the recommendation of one of our testers and tried out a magnetic jig called a Jointer Pal. This tool has two flat beams with strong magnets that hold the jig flat to the outfeed table and lift the knife up flush with the beams. After a little practice, the method proved to be very accurate, and it saved us a lot of time-consuming trial and error during knife setting. (Woodstock Intl., Jointer Pal W1211, $48.)