Modified Harbor Freight Pinpointer w/ pics

[dr_maddog]

Originally Posted by Clodhopper View post
Been there, done that. Bought the HF body pointer, made for finding guns, knives etc on someones body. Modify'd it, added vibrators, and all to it! I was impressed.......till I got my hands on a Garrett Propointer, thats when I learned just what a pinpointer was. Now you can yell B.S. and enjoy your little toy, but if you ever get your hands on the Garrett (equelled by no-one) you'll toss the HF in the round can! It's like going from a Whites 1960 BFO detector to a Minelab. No joke.......! Naw, I don't work for them. They make an Exceptional pinpointer, that's all. When you get a penny about 2 inches away from it it starts making a slow ticking noise. The closer you get the penny the faster the ticking gets. Then theres the penny trick. By preloading with a penny, you can find a .177 cal BB or a small nugget about an inch away. I kid you not. That's my 2 cents worth. For what it's worth.

I agree the Garrett Propointer is a better pinpointer however it is hard to beat the cost of the HF pinpointer. I actually own a Garrett now and prefer it but it is nice to have a backup that I can loan out if needed as well.

[Billvert]

Dr Madog,
Good to see you back here on your thread.

I have been doing a little modification and experimentation on a couple of HF pointers myself. I have already purchased the RS 3 VDC Vibration motor and was going to connect it in parallel with the buzzer. I would probably put the motor before the current limiting resistor because it will draw a max of 95mA

I was looking closely at the Printed circuit board when I saw that it has to pads marked "Motor" and a space for component placement marked on the board. I don't have my VTVM at home now so I can't test the voltage or polarity right now but I was wondering if Cen-Tech made another model with the vibration option and the correct voltages and switching are already present on the board?

Addendum: I took another look at the circuit board and I see that there is a circuit and six pads for a DPDT switch (SW2). the two poles are marked BZ and VB which I take to represent buzzer and Vibrate. I am going to take a look at my mouser catalog and see if they have a six pin pc mount DPDT switch in that format. If they do you could simply mount the LED/Vibrate toggle. to the board and drill a hole in the front of the unit right below the sensitivity potentiometer for access.

Note: two pads are jumpered to close the circuit on the BZ side of the switch location. They are open on the VB side.

[dr_maddog]

Billvert,

Yeah, I noticed the motor markings on the PCB as well. I don't know of another Centech pointer. My guess is that maybe there is another model and they get rebranded with these features added.

Good idea with adding the DPDT switch! As you know, there is limited space in the case however I am sure Mouser will have something that fits, maybe check Digikey or Jameco as well.

My next project was to work on increasing the range of the pointer but I just haven't had any time to work on it. I was going to try and wire a new coil however the coil in the wand is currently firmly in place with epoxy. The wires are so small I am not sure how to remove it without damaging it or melting the coating on the wires. Even if I got it apart, it would be hard to make a better coil then the one already in place. Takes alot of skill, practice and patience to make a coil. Maybe someone else has tried this or has experience in this area?

Good luck with the mods!

maddog

[Billvert]

Mr Maddog,

Thanks for the reply, Your thread is very informative and has saved me a lot of time with my mods, no sense reinventing the wheel.
I was curious why you used a current limiting resister to reduce the current to 50mA, I am using the Radio Shack Vibrating motor. It is rated at 85mA. I was wondering if it were connected directly would it steal to much current from the piezo speaker or do you feel it is spinning too fast.

I noticed a mounting spot for the motor on the PC board. but I feel that this is poor design. I would be wary of hot gluing the motor to the board for fear of damaging the traces or shaking some of the components loose. I am using you idea of mounting it on the back cover with the straw fitted.

[dr_maddog]

The main reasons for adding the resitor was:

1) Not add to much extra draw on the circuit or other components.
2.) Save battery life.

I felt the motor gave enough vibration when it ran at a ~50mA draw. Honestly it is most likely fine to run it at a higher setting as you are doing however the battery will just not last quite as long. The benefit is that the motor vibrations might be more pronounced so you can feel it better through gloves.

[bobabbey]

I did this also. I just added the motor in parallel with the beeper. It works fine.

[Riffmeister]

i did a different mod to mine---- had many problems with the terminals getting dirty inside the switch- so i installed a different reasure type switch and put a automotive rubber vacum cap over the sensitivity dial so no dirt wouldnt get in it and have had no problems at all since- works good now im thinkin about the vib motor !!! soundin' pretty good

[BountyHunter]

I just enjoy posts that take readers to a higher level of satisfaction.

Way to go !

Push yourself toward higher knowledge and accomplishment !

[Billvert]

Originally Posted by Riffmeister View post
i did a different mod to mine---- had many problems with the terminals getting dirty inside the switch- so i installed a different reasure type switch and put a automotive rubber vacum cap over the sensitivity dial so no dirt wouldnt get in it and have had no problems at all since- works good now im thinkin about the vib motor !!! soundin' pretty good

I changed the switch on mine too. The switches all seem to go bad eventually.

http://metaldetectingforum.com/showt...816#post452816

[TrailChaser]

Thanks for the info. I normally stay away from any of Harbor freights electronic devices after a few bad experiences with devices failing for no good reason at the worst possible time.

After reading this and a couple of other post I decided to go pick one up for myself and put off buying the pistol if this works one works out...

Long story short, I took apart one of my ancient cell phones that I knew had a vibration option for silent.
Took the pinpointer apart and clipped the wires to the noisy speaker and soldered on the tiny motor and used rubber cement to glue it down between the battery and board. I also put a stiff piece of foam over it to keep it secure even if it vibrates loose.

I really like it, and have much better luck finding my targets FAST. No sound option now, but I kept the LED.

The store where I bought mine is in Sugarland, TX and still has two on the shelf.

[Et Cetera]

Is it possible to take all the parts out and put them in a sturdier case?

[John W.H.]

Nice ideas, I'll have to try it. Love to tinker!!

[TopPop]

Originally Posted by Clodhopper View post
Been there, done that. Bought the HF body pointer, made for finding guns, knives etc on someones body. Modify'd it, added vibrators, and all to it! I was impressed.......till I got my hands on a Garrett Propointer, thats when I learned just what a pinpointer was. Now you can yell B.S. and enjoy your little toy, but if you ever get your hands on the Garrett (equelled by no-one) you'll toss the HF in the round can! It's like going from a Whites 1960 BFO detector to a Minelab. No joke.......! Naw, I don't work for them. They make an Exceptional pinpointer, that's all. When you get a penny about 2 inches away from it it starts making a slow ticking noise. The closer you get the penny the faster the ticking gets. Then theres the penny trick. By preloading with a penny, you can find a .177 cal BB or a small nugget about an inch away. I kid you not. That's my 2 cents worth. For what it's worth.

Thout is was BS until I got one. It is fantastic and yes I have also found BBs and metal so small i had to sift though it for a couple of minutes before I found the tiny little buggger

But remember the Garret was 150 and the habor frieght is like 19 So enjoy

[Silversmith45]

I tried to get a motor at Radio Shack, but they said they didn't carry them. I haven't had any luck at finding one from a cell phone either. My pin pointer works fine, but I have to have the speaker turned toward me to hear it.

[Slimpickuns]

Just picked one of these PP's up at HF, did the button mod and the vibrating motor mod and its working awesome!!! took it out for a spin today, first time ever using a PP and man what a difference it makes in recovery time!!! Love the price of this thing too. Thanks for the info!!

[dr_maddog]

Originally Posted by Et Cetera View post
Is it possible to take all the parts out and put them in a sturdier case?

Yes however I think it woud be difficult finding a sturdier case without increasing the size of the pinpointer.

If you do proceed please share your results.

[dr_maddog]

Originally Posted by Silversmith45 View post
I tried to get a motor at Radio Shack, but they said they didn't carry them. I haven't had any luck at finding one from a cell phone either. My pin pointer works fine, but I have to have the speaker turned toward me to hear it.

Yeah, Radio Shack has really reduced their in-store component inventory, it can be hit or miss.

I am not 100% but you might be able to use one from an old toothbrush or razor (disposable type).

Here is another option, although shipping may make this impractical for just 1 part:
http://www.sparkfun.com/commerce/pro...oducts_id=8449

[deerhunter]

Has anyone had problems using the HF detector in the heat?? If it gets about 100deg. it will not shut up!! Anybody else have this problem?? I havent done any mods to it yet. Another thing, sometimes when it is working right, if I turn the shaft towards the ground ie. upside down it goes off also(no metal around) almost as if something is loose and moving inside...... Any help or ideas???

EDIT- Ok, I tested out my theory.
1. Put a mark on sensitivity knob at the point it wouldnt beep
2. Put the detector in the sun and got it warm
3. Try it out in same spot and it beeps like crazy until I turn sensitivity knob way down.
4. Put on A/C vent to cool it down and now I can turn the sensitivity knob alot higher than in step #1

To sum it all up heat has a very negative effect on this detector, guess I have to bring a cooler with me!
Anyone else have this problem with any other brand of PP? Or is it just the HF one? Or just mine lol

[rickomatic]

I left mine out in the sun a couple weeks ago and the same thing happened. Even with the sensitivity turned all the way down it squealed by just pushing the button. Once it cooled down, it went back to normal operation.

[Bearharold]

I have seen warnings before on regular big detectors to only operate them below or above certain cold and hot temperatures so heat will probably effect any detector if it gets to hot . Those don't have any vent holes ether from the looks of them so case works like a oven and heat builds up inside when its in the sun or hot weather..




Harold