Electronics-Related.com
Forums

Repaired Harbor Freight digital caliper

Started by P E Schoen November 19, 2011
On Sun, 20 Nov 2011 06:41:03 -0600, amdx <amdx@knologynotthis.net>
wrote:

>On 11/19/2011 9:01 PM, P E Schoen wrote: >> I have two Harbor Freight digital calipers, item #47257, and I've had >> problems with one of them especially, where the display will go blank. >> It seemed to work sometimes if I squeezed the enclosure, and I thought >> it was a bad battery or bad connection. But a fresh battery didn't work. >> > >That's why I like the Dial calipers vs Digital Calipers, no concern >about batteries or electronics. >(Dial Calipers, Item # 66541, Out of Stock) > >Although a couple years ago HF had the 6" Digital calipers on sale for >$9.99, I bought two. They are still in the boxes and I use my Dial >calipers. I think I might give one away as a Christmas present. > Mikek
I bought one of those and really like it. It seems comparable to calipers costing many time more. The only problem is I have to remove the battery when I am done using it or it is dead the next time I get it out. I have a feeling that is why they were selling them for $9.99. Fortuneately, it is easy to remove and reinsert the battery.
Dave Plumpe <lastname@mindspring.com> wrote in message
news:dcCdnbxH1tldnVTTnZ2dnUVZ_qednZ2d@earthlink.com...
> Not only do they remember where Zero is, they even keep track of any > movement that occurs while they're turned off. Smart little devils. > > I find myself more & more reaching for the digital ones for the ease of > swapping between inches & millimeters. > > -Dave > -- > http://plumpe.home.mindspring.com > email: lastname@mindspring.com > ANTI-SPAM: To email, replace "lastname" with "plumpe" > "N_Cook" <diverse@tcp.co.uk> wrote in message > news:jaatmo$4n4$1@dont-email.me... > > > > I've never used the new-fangled ones - do you have to do a clean jaws, > > close > > jaws, zero calibration check/0 reset ,every time you use them ? as the > > count > > must be lost each time it is switched off > > > >
An engineer told me never close the jaws of a micrometer or vernier calipers for storage, leave the jaws open slightly. Do these digitally things require the jaws closing before switching off ? How do they know of any movement of the jaws when switched off elsewise?
<stans4@prolynx.com> wrote in message
news:0156c7a7-8bb2-4f32-922b-89bdd893a682@u6g2000vbg.googlegroups.com...
On Nov 20, 6:03 am, "N_Cook" <dive...@tcp.co.uk> wrote:
> amdx <a...@knologynotthis.net> wrote in message > > news:4756b$4ec8f55d$18ec6dd7$12472@KNOLOGY.NET... > > > On 11/19/2011 9:01 PM, P E Schoen wrote: > > > I have two Harbor Freight digital calipers, item #47257, and I've had > > > problems with one of them especially, where the display will go blank. > > > It seemed to work sometimes if I squeezed the enclosure, and I thought > > > it was a bad battery or bad connection. But a fresh battery didn't
work.
> > > That's why I like the Dial calipers vs Digital Calipers, no concern > > about batteries or electronics. > > (Dial Calipers, Item # 66541, Out of Stock) > > > Although a couple years ago HF had the 6" Digital calipers on sale for > > $9.99, I bought two. They are still in the boxes and I use my Dial > > calipers. I think I might give one away as a Christmas present. > > Mikek > > I've never used the new-fangled ones - do you have to do a clean jaws,
close
> jaws, zero calibration check/0 reset ,every time you use them ? as the
count
> must be lost each time it is switched off
Used to be, they've improved things. On at least some, the count is kept live and just the display is switched off. It all goes away when batteries are switched, but that can be lived with. Stan +++ So that explains , down thread, the drawback of dying batteries when switched "off"
On Sun, 20 Nov 2011 06:41:03 -0600, amdx wrote:

> That's why I like the Dial calipers vs Digital Calipers, no concern > about batteries or electronics.
I prefer a "proper" vernier. At least you can verify those by eye.I never did trust digital calipers to hold their zero and not skip under workshop conditions, Half a lifetime dealing with incremental encoders has made me wary. I *might* trust a Mitutoyo digital caliper or height gage in inspection room conditions. Dial calipers have all sorts of racks and gears to go sloppy. I suppose nobody under fifty knows how to read a real vernier, or a slide rule for that matter ;-( -- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)
N_Cook wrote:

> <stans4@prolynx.com> wrote in message > news:0156c7a7-8bb2-4f32-922b-89bdd893a682@u6g2000vbg.googlegroups.com... > On Nov 20, 6:03 am, "N_Cook" <dive...@tcp.co.uk> wrote: > >>amdx <a...@knologynotthis.net> wrote in message >> >>news:4756b$4ec8f55d$18ec6dd7$12472@KNOLOGY.NET... >> >> >>>On 11/19/2011 9:01 PM, P E Schoen wrote: >>> >>>>I have two Harbor Freight digital calipers, item #47257, and I've had >>>>problems with one of them especially, where the display will go blank. >>>>It seemed to work sometimes if I squeezed the enclosure, and I thought >>>>it was a bad battery or bad connection. But a fresh battery didn't > > work. > >>>That's why I like the Dial calipers vs Digital Calipers, no concern >>>about batteries or electronics. >>>(Dial Calipers, Item # 66541, Out of Stock) >> >>>Although a couple years ago HF had the 6" Digital calipers on sale for >>>$9.99, I bought two. They are still in the boxes and I use my Dial >>>calipers. I think I might give one away as a Christmas present. >>>Mikek >> >>I've never used the new-fangled ones - do you have to do a clean jaws, > > close > >>jaws, zero calibration check/0 reset ,every time you use them ? as the > > count > >>must be lost each time it is switched off > > > Used to be, they've improved things. On at least some, the count is > kept live and just the display is switched off. It all goes away when > batteries are switched, but that can be lived with. > > Stan > > +++ > > So that explains , down thread, the drawback of dying batteries when > switched "off" > >
I have the HF digital calipers and I need to pull the battery when not in use other wise, it'll be dead next time I need it. It seems to drain quite fast. Other than that, it seems to work very nicely.. Jamie
N_Cook wrote:

> Dave Plumpe <lastname@mindspring.com> wrote in message > news:dcCdnbxH1tldnVTTnZ2dnUVZ_qednZ2d@earthlink.com... > >>Not only do they remember where Zero is, they even keep track of any >>movement that occurs while they're turned off. Smart little devils. >> >>I find myself more & more reaching for the digital ones for the ease of >>swapping between inches & millimeters. >> >>-Dave >>-- >>http://plumpe.home.mindspring.com >>email: lastname@mindspring.com >>ANTI-SPAM: To email, replace "lastname" with "plumpe" >>"N_Cook" <diverse@tcp.co.uk> wrote in message >>news:jaatmo$4n4$1@dont-email.me... >> >>>I've never used the new-fangled ones - do you have to do a clean jaws, >>>close >>>jaws, zero calibration check/0 reset ,every time you use them ? as the >>>count >>>must be lost each time it is switched off >>> >> >> > > An engineer told me never close the jaws of a micrometer or vernier calipers > for storage, leave the jaws open slightly. Do these digitally things require > the jaws closing before switching off ? How do they know of any movement of > the jaws when switched off elsewise? > >
And the engineer was correct in saying so. Jamie
greenpjs@neo.rr.com wrote in
news:e70ic7h9g57un7siiftqmdtkfp1tdej9bd@4ax.com: 

> On Sun, 20 Nov 2011 06:41:03 -0600, amdx <amdx@knologynotthis.net> > wrote: > >>On 11/19/2011 9:01 PM, P E Schoen wrote: >>> I have two Harbor Freight digital calipers, item #47257, and I've >>> had problems with one of them especially, where the display will go >>> blank. It seemed to work sometimes if I squeezed the enclosure, and >>> I thought it was a bad battery or bad connection. But a fresh >>> battery didn't work. >>> >> >>That's why I like the Dial calipers vs Digital Calipers, no concern >>about batteries or electronics. >>(Dial Calipers, Item # 66541, Out of Stock) >> >>Although a couple years ago HF had the 6" Digital calipers on sale for >>$9.99, I bought two. They are still in the boxes and I use my Dial >>calipers. I think I might give one away as a Christmas present. >> Mikek > > I bought one of those and really like it. It seems comparable to > calipers costing many time more. The only problem is I have to remove > the battery when I am done using it or it is dead the next time I get > it out. I have a feeling that is why they were selling them for > $9.99. Fortuneately, it is easy to remove and reinsert the battery.
The battery life in even high end calipers is highly variable. I have a couple Mitutoyo calipers that are pretty good, but some of their micrometers are terrible. I have an SPI micrometer that looks suspiciously like a Chinese cheapo I have. They both need to have the battery removed if you aren't actively using them. The SPI is a 24" job, so it rarely gets used. There is no way the battery would last if I left it in palce. I discovered the hard way that the little cube electronic levels also eat batteries, and they require a diet of the larger more expensive coin cells (2032?). Most of my electronic measuring widgets use 357 style button cells, and I buy them in quantity off eBay. Radio Shack is a real ripoff for those things. Doug White
On Sun, 20 Nov 2011 13:38:36 -0000, "N_Cook" <diverse@tcp.co.uk>
wrote:
>An engineer told me never close the jaws of a micrometer or vernier calipers >for storage, leave the jaws open slightly.
True. With gear type calipers, the lubricating grease tends to migrate to that position. If a sufficiently filthy environment, an lump of dirt encrusted grease will be left in that position. If it happens to be at 0.0, then it will be difficult to accurately calibrate the mechanism. There are also some minor reasons, such as the tendency for two parallel surfaces to trap moisture between them and rust.
>Do these digitally things require >the jaws closing before switching off ?
No.
>How do they know of any movement of >the jaws when switched off elsewise?
Only the display is turned off. The pulse counting mechanism is still operating and functional. The downside is that the battery will be dead in about 6-9 months. Most include a spare LR44 battery. I had to buy a pile of them to keep my calipers going. Somehow, the battery is usually dead when I need to use them. 50 batteries for $3.75 <http://www.ebay.com/itm/220751739681> I have an expensive set of Starett calipers (both metric and US). I use them more often than the electronic variety, mostly out of habit. My most useful measuring tools are my 6" pocket steel scale and a tape measure. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
On Nov 19, 10:01=A0pm, "P E Schoen" <p...@pstech-inc.com> wrote:
> I have two Harbor Freight digital calipers, item #47257, and I've had > problems with one of them especially, where the display will go blank. It > seemed to work sometimes if I squeezed the enclosure, and I thought it wa=
s a
> bad battery or bad connection. But a fresh battery didn't work. > > So I took it apart, which meant peeling off a foil backing to expose four > small phillips head screws, which removed the electronics module, and the=
n I
> removed the PC board with four even smaller phillips screws. The LCD disp=
lay
> connects to the board with a flexible conductive strip, which relies on > pressure to maintain contact. I cleaned it and the mating contacts on the > PCB, reassembled it, and it now works fine! > > My house is always very humid and I think that's what caused the problem. > It's hell on all my tools. Everything is rusty or mildewed. > > It's quite interesting to see the mechanism that is used to make > measurements. There is an array of PCB traces that are aligned with an ar=
ray
> of stripes along the length of the caliper, and (I assume) these create > pulses that are counted as the head is moved. But it also needs to know > which way the head is being moved. Probably something like a quadrature > encoder as used for rotary position sensing. I'll have to look it up. > > Paul
http://www.biotele.com/digital_caliper.htm -- Cheers, James Arthur
Jamie wrote:
> I have the HF digital calipers and I need to pull the battery when not > in use other wise, it'll be dead next time I need it. It seems to drain > quite fast.
... I have one & the battery lasts quite a while (doesn't get used much). Maybe a different model. Or a different batch. Or different spots on the quality curve <G>. Bob