Dial caliper question

[93 FORD BRONCO]

Recently had to go out for a dial caliper. I got it home and wanted to test it just to be sure it's accurate. I went online to check the width of a quarter and a nickel. I checked both and it seems like my caliper is inaccurate. I've made sure that when it's completely closed the needle points at the zero but I'm still not getting the rights readings. Can someone shed some light on this for me.

 

[reddevildemo]

What kind/brand did you get?

 

[93 FORD BRONCO]

What kind/brand did you get?

I got it second hand so I'm not 100% sure but it has nsk printed on the dial face.

 

[SMR 510RR]

post a pic of it on the quarter or whatever with the dimension it is supposed to be.

How far off are we talking?

 

[93 FORD BRONCO]

Ok the normal width of a quarter is .955 inches. I'm showing .925. Pretty big difference.

Here's a pic. Maybe I'm reading it wrong but I don't think I am.

Sorry for it being kinda blurry. U can sorta see that its at .925

 

[SMR 510RR]

Yes it does indeed look off. You could use one of the other surfaces to see if it is just the jaws or if the mechanism is just that far off.

Try behind the caliper on the backside.

I checked one with mine and it is .950

 

[93 FORD BRONCO]

When the slide is at 1 inch the dial should be at zero. Am I right? I noticed that once it hits the 1" mark it the dial is either past the zero or before it.

 

[SMR 510RR]

Yes and the dial should spin 10x around.

 

[WooPigSooie]

Is the dial at zero when your calipers are at zero?

 

[93 FORD BRONCO]

Yes and the dial should spin 10x around.

Well for some reason mine has 1-10 on each side of the dial.

 

[filotr14lsdude]

The little screw on the bottom of the dial can be undone,you turn the dial around until the need is at zero with the caliper closed.

If the needle is already at zero with the dial closed the size of the coin could be different.
Make sure you close both jaws together and see what the reading is.

 

[93 FORD BRONCO]

The little screw on the bottom of the dial can be undone,you turn the dial around until the need is at zero with the caliper closed.

If the needle is already at zero with the dial closed the size of the coin could be different.
Make sure you close both jaws together and see what the reading is.

Yes the needle is at zero. Both jaws close at the same time anyways they are both connected. I've checked it with a quarter and a nickle. The reading is to far off for it to be the coin. I guess i just snagged a bad caliper. There could be no other explanation that I can think of

 

[filotr14lsdude]

Yes the needle is at zero. Both jaws close at the same time anyways they are both connected. I've checked it with a quarter and a nickle. The reading is to far off for it to be the coin. I guess i just snagged a bad caliper. There could be no other explanation that I can think of

Yeah,sounds like something internally.
They are fairly scratched up,probly had a hard life.

Find something thats flat,square that is a know sizes. Have a couple of measurement to see if it's consistent.

If it is you could just add or subtract that from your measurements. It's not idea but would work

 

[93 FORD BRONCO]

Yeah,sounds like something internally.
They are fairly scratched up,probly had a hard life.

Find something thats flat,square that is a know sizes. Have a couple of measurement to see if it's consistent.

If it is you could just add or subtract that from your measurements. It's not idea but would work

Hmmm. Not a bad idea. I'll have to check for consistency

 

[BigSki]

I use a ground dowel pin for a quick check on my calipers, you need something with a know constant dimension to check them. What unit of measure is the scale on the top of the caliper?

 

[93 FORD BRONCO]

I use a ground dowel pin for a quick check on my calipers, you need something with a know constant dimension to check them. What unit of measure is the scale on the top of the caliper?

Cm on top an inches on bottom.

 

[Charlie-III]

About the last frikking thing I would use as a "standard" is a frikking coin.:roll:

I highly doubt it's the caliper, it's the "test subject" used.

I would be happier using a 1/4-20 bolt to test for 1/4".

A dial caliper is a VERY basic rack/pinion system. It either works or doesn't.

 

[SMR 510RR]

Well for some reason mine has 1-10 on each side of the dial.

Your right, it should spin 5 full times to go from 0 to 1 inch. I have never seen a dial like that, usually its just 1-100 not two sets.

I guarantee it is not consistent if it reads 0 closed and is off at another measurement, the only way it could be is if there was a dead spot somewhere where the dial did not turn. You should be able to see that happen while you slowly open or close them.

 

[93 FORD BRONCO]

Interestingly enough. I threw it in the tool box and just picked it up to check the quarter again and its almost dead on. It's wierd though when I picked it up the needle was no longer pointed straight down when it was closed all the way. Like maybe throwing it in the toolbox jossled the needle around. Gona make a few more test measurement to see if it's accurate or not now

 

[bob1961]

use a 6" metal machinists ruler and try it at 1/8" and 1/4" and so on measurements to see what readings you get on the dial to where you are at on ruler......bob

....