John Deere ET-3103-J Manuale Utente

      

Cordless Impact Wrench Operator's Manual   

                  

             19  

1.  Resting the unit after continuous work:

 

After use for continuous bolt-tightening work, rest the unit for 15 minutes or so  

 

when replacing the battery.  The temperature of the motor, switch, etc., will rise if  

 

the work is started again immediately after battery replacement, eventually    

 

resulting in burnout.

 

2.  Cautions on use of the speed control switch:

 

This switch has a built-in, electronic circuit which steplessly varies the rotation  

 

speed. Consequently, when the switch trigger is pulled only slightly (low speed  

 

rotation) and the motor is stopped while continuously driving in screws, the    

 

components of the electronic circuit parts may overheat and be damaged.

3.  Tightening torque:

 

Refer to Fig. 16 for the tightening torque of bolts (according to size), under the  

 

conditions shown in Fig. 17. Please use this example as a general reference, as  

 

tightening torque will vary according to tightening conditions.

 

Tightening torque varies, depending on the battery’s charge level. Fig. 18 shows  

 

an example of the relationship between tightening torque and the number of  

 

tightening. As shown, tightening torque gradually weakens with the increase in  

 

the number of tightening. In particular, as the torque decreases very close to the  

 

complete discharge (“a” margin in graph), the unit’s impact weakens, the number  

 

of time impacts declines and tightening torque drops off abruptly. If this occurs,  

 

check torque level, then recharge the battery if necessary.

4.  Use a tightening time suitable for the screw:

 

The appropriate torque for a screw differs according to the material and size of the  

 

screw, and the material being screwed etc., so please use a tightening time   

 

suitable for the screw. In particular, if a long tightening time is used in the case of  

 

screws smaller than 5/16" (8 mm), there is a danger of the screw breaking, so  

 

please confirm the tightening time and the tightening torque beforehand.

5.  Work at a tightening torque suitable for the bolt under impact:

 

The optimum tightening torque for nuts or bolts differs with material and size of  

 

the nuts or bolts. An excessively large tightening torque for a small bolt may   

 

stretch or break the bolt. The tightening torque increases in proportionate to the  

 

operation time. Use the correct operating time for the bolt.

6.  Holding the tool:

 

Hold the impact wrench firmly with both hands. In this case hold the wrench in line  

 

with the bolt. It is not necessary to push the wrench very hard. Hold the wrench  

 

with a force just sufficient to counteract the impact force.