# Another 'Buyer Beware' or 'Am I just stupid?'



## gr8legs (Aug 27, 2020)

I had a need to measure the center-to-center distance between two small holes.

Holes were too small to use the Sorenson Center-Mike so off to the 'Bay for another tool quest.

I could have bought a $12 pair of adapter points to attach to an existing caliper and then do the math to adjust for the difference.


But I wanted an actual center-to-center measurement without the math - and correct in both English and Metric measures. Which I thought I would get if I bought a  digital caliper that had a stated range that didn't go to Zero - presuming that meant it zeroed at whatever the point offset was. 

So I found several advertised with a range like 5-150 or 5-300 and bought one thinking I would have what was advertised: a direct reading center-to-center digital caliper.





Wrong again, Stu.

What arrived in the mail was a very nice looking digital caliper with center measuring jaw points spaced at 5mm which, when you pressed the Zero button, set the reading to zero.





Since the descriptioin included " Direct measurement for center distance between holes ( Φ>1 ), by adjusting the height of left measuring bar and moving the caliper frame " I tried twiddling the left measuring bar (no difference), the right measuring bar (no difference) and multiple combinations of holding one setting button while pressing another to see if there was a 'magic' combination to reset the display to 5mm instead of Zero but I couldn't find anything that worked. So now I get to assume that 5mm==0 and do the math. WTF ? Why couldn't the Zero button be programmed in firmware to 5mm and actually take advantage of the technology and do as advertised? Oh yeah, if you work in Imperial measurements it's not an easy 5mm offset, it now becomes 0.196850" of offset. What an improvement!

Yes, I do know that if I had an analog dial caliper with a set of center-measuring adapter points I'd have to do the math - the point was, let the technology do as advertised.

The description also included "

Three function button, with depth measuring blade, with USB interface.
There is a USB interface but no depth measuring blade. Oh well.

And of course if I try to contact the seller (in China) about being unhappy about their false advertising and requesting a refund I'll most certainly get the usual runaround: Send us a picture. Send us a video. Send us something else to delay a refund past the refund date - or I'd have to send it back at my expense and then get a partial refund and  end up farther in the hole without anything to show for it. Great! When will I learn??? Do not buy from China sellers!

I'm just venting here and thought if anyone else was going to do something as stupid as I did maybe my experience will deter you from it. Here's hoping.

God luck and happy hunting!

Stu


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## mmcmdl (Aug 27, 2020)

I try to stay away from anything China other than maybe their sweet and sour chicken and egg rolls once in a blue moon . Sometimes I wish I could send THEM back .


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## darkzero (Aug 27, 2020)

mmcmdl said:


> I try to stay away from anything China other than maybe their sweet and sour chicken and egg rolls once in a blue moon . Sometimes I wish I could send THEM back .



Well Dave, you couldn't even do that. Those foods are Chinese foods from America.


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## mmcmdl (Aug 27, 2020)

LOL . Actually from right across the road .


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## C-Bag (Aug 27, 2020)

It’s sad to say I’ve been very frustrated with the same thing. It’s hard to say if it’s just ignorance or incompetence but misleading descriptions are grounds for refund, period. And it’s not just Chinese vendors, there are a ton of shady actors doing the incompetence/ignorance ploy. I just went through another where I let my excitement at what I thought was a good deal override my due diligence but all it cost me was time because eBay knows if somebody sells you something you can show is not in line with the description you get your $$ back.

I wonder if the lack of innovation is because it’s so easy to copy others or there are few who know enough to design something new? It sounds like you have the understanding and the wherewithal to make what amounts to a new and improved digital version of the Center-Mike gr8legs, why not go for it? I think there are a lot of us here who would be interested.


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## RJSakowski (Aug 27, 2020)

gr8legs said:


> I had a need to measure the center-to-center distance between two small holes.
> 
> Holes were too small to use the Sorenson Center-Mike so off to the 'Bay for another tool quest.
> 
> ...


If you remove the centering adapter from the movable jaw, you should be able to zero the caliper.  Then reinstall the adapter and measure your hole spacing.


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## mickri (Aug 27, 2020)

When I search Ebay I always set the item location to "US only."  That eliminates the hassle of returning something to China.  Then I always check the shipping method and time.  Sometimes even if the item is claimed to be in America it is actually getting shipped first from China to the seller in America who then ships it.  More and more I try not to buy things made in China.  That's virtually impossible on my budget.

One good thing from this thread is I learned about adapters to calipers to measure the center distance between holes.  I have struggled with that.  Another thing to buy.  Most likely made in China.

I bought a set from Shars.  I have been happy with everything I have bought from Shars.  I have an extra caliper that I will permanently mount this on.


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## higgite (Aug 27, 2020)

Have you tried holding the “zero” button down for a few seconds? That’s how Mitutoyo’s center-to-center caliper changes from normal zero to “offset” zero that compensates for point offset.

Also, does the caliper blade not protrude from the end of the handle when you open the jaws like most calipers do to allow you to measure the depth of a hole?

Tom


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## gr8legs (Aug 27, 2020)

RJSakowski said:


> If you remove the centering adapter from the movable jaw, you should be able to zero the caliper. Then reinstall the adapter and measure your hole spacing.



An excellent idea except when I first received the caliper the setscrew holding the centering adapter to it was so tight I thought it might be Locktite'd in place. After taking a pair of pliers to it and breaking it loose the movable jaw had only another 1.75mm of zero-ward travel before it hit the stop - so no joy on that fix. 

It's just a crappy design that should have been fixable in firmware to actually show 5mm when you press the 'zero' but just doesn't. I'd get the same result with the $12 center measuring adapters clamped on and the caliper would be useful for other things as well. Grrr.

Thanks

Stu


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## gr8legs (Aug 27, 2020)

higgite said:


> Have you tried holding the “zero” button down for a few seconds? That’s how Mitutoyo’s center-to-center caliper changes from normal zero to “offset” zero that compensates for point offset.
> 
> Also, does the caliper blade not protrude from the end of the handle when you open the jaws like most calipers do to allow you to measure the depth of a hole?



Yes, tried holding the 'zero' and no change.

No, there is no depth measurement available, there is no extension of the movable blade at all as in a normal 4-way caliper.

Like I said, it's just a crappy design that does not do what is advertised. 

Thanks for the pointer to Mitutoyo doing what I expect. I may have to pungle up the $$$ for a quality tool from a US seller to get what I want.

Stu


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## higgite (Aug 27, 2020)

Wow. You might expect that from a $10 Acme, but $80+ isn't exactly chump change. Speaking of which, I see the Mitutoyo goes for $600 +/-. I hope it comes with a can of caviar.

Tom


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## Incendium87 (Aug 27, 2020)

gr8legs said:


> An excellent idea except when I first received the caliper the setscrew holding the centering adapter to it was so tight I thought it might be Locktite'd in place. After taking a pair of pliers to it and breaking it loose the movable jaw had only another 1.75mm of zero-ward travel before it hit the stop - so no joy on that fix.
> 
> It's just a crappy design that should have been fixable in firmware to actually show 5mm when you press the 'zero' but just doesn't. I'd get the same result with the $12 center measuring adapters clamped on and the caliper would be useful for other things as well. Grrr.
> 
> ...



You’ll have to completely remove the pointed part and it’s holding clamp from the movable jaw. Then you’ll be able to press it to the fixed jaw and zero it.

A firmware setting would never work because it would have to assume that the points are always a perfect nominal 5mm or they would all have to be precisely measured, and neither of those things is going to happen.

Those adapter points you first mentioned will work the same as the dedicated center to center caliper without any math. You zero the caliper without the points installed and then just put the points on and take your measurements. As long as the points are made properly, the registry edges that sit on the caliper jaws will align with the ground points and your measurements will still be accurate.


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## RJSakowski (Aug 27, 2020)

If you go to the manufacturer's web site, you will see that they make a large variety of metrology instruments.





						Wenzhou Sanhe Measuring Instrument Co., Ltd: Metrology - Laboratory  - DirectIndustry
					






					www.directindustry.com


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## petertha (Aug 30, 2020)

I know you wanted a general purpose tool with the digital purchase, but if the holes are too small for the Sorensen in this particular case, could you just use dowel pins & measure across the tangents with a regular caliper?

I have 2 of these floating conical center finders. I engage it into a hole on the mill, ensuring the shank/floating OD is perfectly flush on all quadrants (centered), zero the DRO at that location. Then I compare that location by what I get rotating a DTI in the hole, or around a tight fitting pin within the hole.  Reason I mention this is I inevitably get a couple thou off & I've repeated this many times in different situations. I trust the DTI. All I can think of is the cone is being influenced by the condition of very small contact area (line) of the hole lip, or the chamfered edge, even though 'theoretically' a smaller angled cone should find center properly. So I'm not really fond of the 'pointy thing in the hole' technique, but I'm also not sure what kind of accuracy you require.

I've always had an idea to sacrifice one of my many cheapo offshore digital calipers & just solder (or otherwise attach) some pins to the inside of each jaw. It doesn't matter what the pin diameter is as long as they are the same which you could pre-align by resting the jaw flats & pins on a datum surface. Then I think you just measure the closest distance, the furthest distance & divide by 2. The holes could even be significantly different diameter holes & the method would work the same.


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## durableoreo (Aug 30, 2020)

If you are doing same-size holes most of the time; make dowel pins out of drill blanks.  Set your caliper to zero with a dowel in the jaws.  Now, measure across a pair of dowels.


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## AJB (Aug 30, 2020)

Maybe open jaws to 5mm and while holding it there press the zero bottom, this is assuming that with the jaws closed it is fed on 5mm.


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## petertha (Aug 30, 2020)

Might be throwing good money after bad with yet another doo-dad, but looks like jaw attachments has already been thought of, including screw in stem points.





						KBC,KBC CENTERLINE ACCESSORY KIT,1-812-110,KBC Tools & Machinery
					

KBC,KBC CENTERLINE ACCESSORY KIT,1-812-110,KBC Tools & Machinery




					www.kbctools.ca
				








						AMPG,USA UNIVERSAL CALIPER ACCESSORY KIT,1-850-Z9020,KBC Tools & Machinery
					

AMPG,USA UNIVERSAL CALIPER ACCESSORY KIT,1-850-Z9020,KBC Tools & Machinery




					www.kbctools.ca


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## Toolmaker51 (Jan 3, 2021)

C-T-C distances can be frustrating......I'd be 100% disappointed engineering of that specialty caliper was not appropriately coupled with correct means to accomplish measurement. 

Centering points on a caliper work well, provided attachment and 'calibration' are right. If you mic the OD's of said points, that adds a feature much like a Sorenson, with the same _arithmetic. _

Depending on hole size/s, drill blanks, pin gauges, dowel pins are reliably checked with outside micrometer or height gauge. Lacking the right sizes, a small pin clamped in height gauge works, if the part is perpendicular to reference surface. Knowing the diameters, arithmetic process is the same. Be mindful of edge combination used, or being a diameter off will seem correct. Yeah, I scale the distance first to predict outcome......

A mill can sub as CMM, once hole centers are parallel to axis of movement. Also an easy way to measure DBC of meshed gears. If not parallel, use X & Y and trig the solution. Without DRO, use travel indicators or careful axis movement to avoid backlash.

Another old-school way depends how you are equipped. Unbeatable when holes are roughly punched or flame cut. It's trammel points, hole centering balls and calipers with divider setting marks. Everything still available used online, except tin of deft touch and coupon book of patience.


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