Woodworker's Journal 1993-17-2, страница 23

continuous stream of air from the motor while it's running. Sawdust inside the motor or piled up around the motor housing can also cause overheating.

Excessive Noise and Vibration

Motor noise and vibration can be caused by a variety of things, most of them mechanical. First, check to see that the motor is firmly mounted to its bracket or base, and that the mounting bracket is firmly attached to the machine. Tighten any loose screws or bolts on the motor housing (on portable power tools, tighten all screws on the tool housing). On bell-and-pulley setups, check for a loose or misaligned pulley, and make sure the belt is tensioned correctly (not too loose or too tight). Also check for a bent rotor shaft (indicated by a wobbly pulley), or blade "runout" on direct-drivc saws.

Internal motor vibration (and noise) is usually caused by worn, misaligned or defective bearings. Check the rotor shaft for excessive end play and side play. A misaligned or unbalanced rotor shaft can also cause noise and vibration. All motors have a slight air gap between the rotor and the stator. If the air gap isn't uniform, the rotor is misaligned, usually due to incorrect bearing placement. Some motors have balancing weights on the rotor shaft: when these shift, the rotor is thrown out of balance, resulting in excessive noise and vibration. Again, don't try to fix these internal problems yourself—take

the motor to a repair shop. General .Maintenance

You may have gathered by now that sawdust is the biggest enemy of electric motors in the woodshop. To extend the life of the motor, vacuum or blow sawdust out of the motor each time you use the tool or machine.

The second major cause of motor failure is overloading the tool or machine. If the motor starts to bog down during use, slow down the feed rate: also, don't force the tool beyond it's stated capacity. Keep blades, bits, and cutters sharp.

Also, check the motor periodically for loose or misaligned parts. Make sure the motor is firmly mounted to the machine and all connecting parts (belts, pulleys, arbors, etc.) are properly aligned.

If you have motor problems w ith a new or recently purchased used machine, make sure the new motor is correctly wired for the power source (115 or 230 volts). Most larger single phase induction motors can be wired for either voltage; check the voltage specifications, on the motor nameplate. If you suspect the motor has been wired incorrectly bv the tool manufacturer (this is rare, but it does happen), have the motor checked out by a qualified electrician or repair shop.

Finally, if you do need to replace a motor, make sure the new one is identical to the old. GJj

Hardware Parts

This 104-piece package contains al the hardware needed to build the jewelry chest above. Plan and wood not included. #1523 Jewelry Chest Hdw......$16.95, PKG

HOW TO ORDER: List quantity, part number, item, price & total o( order. Include $4.95 shipping & handling per order. MN residents add 6.5% sales tax Mai check or money order. Credit card customers call TOLL FREE 1-800-441-9870.

MEISEL HARDWARE SPECIALTIES

P.O. BOX 70J-4 MOUND, MN S5364

Please circle No 203 on the Reader Sen ice Card.

GIANT TOOL SALE & EXHIBITION

HOUSTON, TX

Adams Mark Hotel • March 12-14, 1993 FT. WAYNE, IN Allen City Memorial Coliseum • March 19-21 ORLANDO, FL Orlando Centroplex • March 26 - 28 BALTIMORE, MD Pikesvilte Armory • April 2-4

BOXBORO, MA

Host Inn • April 23 - 25 "DETROIT, Ml

Michigan Fairgrounds • April 30 ■ May 2

Show Hours: *Fn.Noon-6pm • Fn. 5 pm-9pm Sat. 10am-6pm« Sun. 10am-5pm

Free One Hour Seminars Save On All Your Woodworking Needs Win Tools - Take Your Project From Start to Finish - Show Specials Continuous Demonstrations Admission Charged - For More info Call:

603-536-3768

Please circle No 21 on the Reader Sen-ice Card. March/April 1993

I TRJtf

Woodcraft offers over 4,000 of the finest quality woodworking tools, books, and supplies available today ill our 140 page, full-color catalog. With Woodcraft's top-notch service, technical support, and 90 day guarantee of satisfaction, you can t afford lo pass up this opportunity for your free catalog!

Call toll-free: -

1-800-542-9115

Or write:-

WOODCRAFT

r*T< 91WM JS

210 Wood Cnuftiy Imbmrnl Purl, PO Boa I4S6

Pirfccnhurg W\ :r.|(i:-lo*'j

Please circle No. 19 on the Reader Sen ice Card.

23

JEWELRY CHEST PUN

Imagine having enough room to organize al your jewelry! Two side closets are 16' high so long necklaces can hang tangle-tree. Eight drawers provide storage for smaller pieces Hinged top reveals a vanity mirror. Patterns drawn FULL SIZE. Order hdw. parts below #W141 Jewelry Chest Plan............S3.99/EA