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Harbor Freight Pinpointer Mod

Briman05

Elite Member
Joined
Apr 18, 2011
Messages
4,414
Location
Jersey Shore
I had a 25% off a item from harbor freight so I went down to Delaware this weekend and picked one up along with a soldering pen and some solder. I looked up some mods that I want to do mainly change the buzzer to a vibration motor. Now I just need to find a cell phone and a small enough screw driver to to open up the phone to get to the vibration motor.
 
Ok so I opened up the pinpointer and adjusted the sensitivity pot screw and in the air test I was getting about 1 1/4 to 1 1/2 on a silver dime. For some reason the smallest Phillips screwdriver doesn't fit the cell phone I am going to take apart
 
You can also buy a vibration motor at Radio Shack for about 4 bucks if ya can't get the phone apart?
 
The one from radio shack is out of stock. I did find one but it is rather larger and I'm not sure how fast it spins. I know it is a Phillips because it is the cross of a phillips
 
fyi, you may have to readjust the blue pot again in the heat of summer otherwise it will sound off no matter where you turn the exterior sensitivity knob. I did mine. kinda like summer and winter settings. haven't added any other mods though, just couple things to keep dirt out.
 
fyi, you may have to readjust the blue pot again in the heat of summer otherwise it will sound off no matter where you turn the exterior sensitivity knob. I did mine. kinda like summer and winter settings. haven't added any other mods though, just couple things to keep dirt out.

Add the thermistor to solve this one! Pretty vital imo.
 
If you just replace the switch with another momentary switch there is no over heating issue. This was not built to be on all the time. The blue pot is only a trimmer to allow the main outside adjustment to be more or less centered. It does not increase range at all. This is obvious if you look at the schematic. The problem with heat is the fact that people are trying to use this at 100% duty cycle with a non Momentary switch.
http://www.findmall.com/file.php?22,file=218436

By altering the blue trimmer pot all you do is change where external pot stops the beeeeep
 
Well I checked the size of the motor I found and it is to big so I have to go back to the drawing board and get a new motor I'm not sure how much room is between the top of the pointer and the board. Has anyone used one of those flat coin looking motors. I don't have a screw driver that is small enough to get into a old phone. And last time I looked radio shack was out of stock of there motor
 
If I can't get something open, I plan to scrap for parts, I get destructive. Case isn't all the useful. The two flat coin-style motors I have, didn't vibrate as strong as the other styles I had. I also tested how much current the used, wanted to stay under 100 mA, which wasn't a problem (28-53 mA). Just went with the strongest vibration. Should be plenty of room in the case. Never took apart a toothbrush, so no idea how big they are.
 
If I can't get something open, I plan to scrap for parts, I get destructive. Case isn't all the useful. The two flat coin-style motors I have, didn't vibrate as strong as the other styles I had. I also tested how much current the used, wanted to stay under 100 mA, which wasn't a problem (28-53 mA). Just went with the strongest vibration. Should be plenty of room in the case. Never took apart a toothbrush, so no idea how big they are.

Where did you get your motor?
 
I just did this mod the other day. Didn't replace the switch yet..but I did put a vibration motor in it from radio shack, and soldered it to the buzzer wires.
 
Ok I soldered the wires together and tested it out where do you guys glue the motor. I noticed one person attached it next to the probe but there isn't any room in mine for that
 
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