Thread: XinXing Measuring Tools Factory Granite Surface Plate Vs HP Laser Interferometer

Originally Posted by Stustoys

Hi Josh,
Yes it has a block, but now that you mention it I've never actually checked or used the block, as until now I haven't had a use for the master height gauge.
I just assumed it was correct(what could possibly go wrong? lol).

But that's why I only measured over 11", so I didn't have to worry about setting an absolute zero. I set the vernier height gauge on 20mm mounted a 0.0001" DTI on it and used the adjustment on the master height gauge to zero the DTI on the 1" block of the master. Then moved the vernier height gauge up to the 12" block and used its fine adjust to set the DTI back on zero. Came up with 299.3mm, so 0.1mm short.

Being short means it cant be an out of square error of the vernier hieght gauge.

Though I didnt recheck the numbers today.

See a hole in my measuring??

Stuart

Hi Stuart
hmm. Sounds like a reasonable methodology to me.

Check your vernier again your 3" standard, use the same method.

If your scale on the vernier height gauge was slipping just a fraction it would throw the vernier off, that's assuming your using the one with an adjustable scale?

Basically I doubt that the two are that far out. they go to some length to get them accurate.

Well I rechecked the DRO with the 0.0001" DTI, I was getting repeatability to the micron!(in fact after getting 0.000 the first three times I checked to make sure the DRO was working lol)

550 on the height gauge came out as 550.051 on the DRO.

Then I checked the vernier height gauge to the 75mm mic standard, as close as my aging eyes can tell the height gauge is spot on.
Rechecked against the master height gauge and it says the vernier height gauge is spot on also.

Now to stop checking while everything agrees

I checked the setting block. It is a 0.5" block so that's good, even have a nice piece of what looks like shammy leather*. What I don't know and google couldn't help me on was how do you in fact set it for absolute measurement?(granted that has yet to be an issue for me). Winding the gauge down and using the set block as a slip gauge sounds a little rough at the 0.0001" level. So I assume you use a DTI to compare the top of the set block to the top of the 1/2" block on the master?

Stuart

*which is like new. So thats either a sign that the gauge hasnt been used much...... or it hasnt been looked after lol

Originally Posted by Stustoys

Well I rechecked the DRO with the 0.0001" DTI, I was getting repeatability to the micron!(in fact after getting 0.000 the first three times I checked to make sure the DRO was working lol)

550 on the height gauge came out as 550.051 on the DRO.

Then I checked the vernier height gauge to the 75mm mic standard, as close as my aging eyes can tell the height gauge is spot on.
Rechecked against the master height gauge and it says the vernier height gauge is spot on also.

Now to stop checking while everything agrees

I checked the setting block. It is a 0.5" block so that's good, even have a nice piece of what looks like shammy leather*. What I don't know and google couldn't help me on was how do you in fact set it for absolute measurement?(granted that has yet to be an issue for me). Winding the gauge down and using the set block as a slip gauge sounds a little rough at the 0.0001" level. So I assume you use a DTI to compare the top of the set block to the top of the 1/2" block on the master?

Stuart

*which is like new. So thats either a sign that the gauge hasnt been used much...... or it hasnt been looked after lol

Stuart,
It may not be the same model but here is a manual for some of the Mitutoyo Height Masters. The setting looks pretty straight forward and.. yeap you use the DTI to compare to the setting block, which is why it probably looks so clean.

-J

I think the master of anything would rarely get used to do anything other than calibrate other tools to, the new price of the current 515 is ~$2500
eg.
Master Squares to calibrate Inspection Squares
Inspection Squares to calibrate Working Square
etc on down the chain of required accuracy

-Josh

Hi Josh,
Thanks for that.
Mines a single row with no clock but as you say all the important info is there.
I did in fact buy a "metric" double row(up down) one but it turned out to be imp so I sent it away as I thought two imp ones was just a little silly(granted one imp and one metric wouldnt be much less silly). I allllllmost kept it lol

Now I guess I should find some Anti-corrosive oil?

Stuart

What have you done????
I've just been out in the shed measuring my 24" square. Over 500mm its about 0.0005" out of parallel and 0.0025"TI (0.00125" if you like) out of square. Which I make 0.063mm/meter. Which I think is pretty damn good?

But I've found when I tap my foot on the concrete the 0.0001" DTI wiggles about 0.0003" either way lol

Stuart

Originally Posted by Stustoys

But I've found when I tap my foot on the concrete the 0.0001" DTI wiggles about 0.0003" either way lol

Stuart

How did you find that out? Was it a stomp in anger and you noticed the dial move, LOL

Dave

Originally Posted by Stustoys

What have you done????
I've just been out in the shed measuring my 24" square. Over 500mm its about 0.0005" out of parallel and 0.0025"TI (0.00125" if you like) out of square. Which I make 0.063mm/meter. Which I think is pretty damn good?

But I've found when I tap my foot on the concrete the 0.0001" DTI wiggles about 0.0003" either way lol

Stuart

Stuart

Calibration IS serious work. Which method did you use? reversal?

Seriously 5 and 12.5 tenths over 24" is pretty awesome. I don't think it would be possible to get a of square of that size and style any better.
Josh

Here is an interesting video I found

Gauging Quality, Episode 1 - Surface Plates - YouTube

Originally Posted by Dave J

How did you find that out? Was it a stomp in anger and you noticed the dial move, LOL

More like jumping up and down that it is so close

Hi Josh,
Yes reversal.
I'll check it again later* as my first attempts lately seem a little iffy. Though either its pretty good or I was very lucky lol

Stuart

*I'd never make it a a shearer. Got to do something about the garage doors, that hit 50C+ and act as huge radiators. Might even try duct tapping foil to the back.

Originally Posted by Stustoys

More like jumping up and down that it is so close

Hi Josh,
Yes reversal.
I'll check it again later* as my first attempts lately seem a little iffy. Though either its pretty good or I was very lucky lol

Stuart

*I'd never make it a a shearer. Got to do something about the garage doors, that hit 50C+ and act as huge radiators. Might even try duct tapping foil to the back.

Stuart,
I bet you were which is how you found about the wiggle. Classic.

We have been meaning to do the same to our doors, since we insulated the main workshop the rollers doors are the worst contributor to variation in temperature, on a hot day it is bloody awful to work near them, if you put the IR thermometer on them they get upwards of 60C. There is a special paint that you can get that reflects the heat from the surface, sorry I can't remember the name but it was a little pricey. FYI that is also why the surface plate is currently sitting in the middle of the workshop, I let it sit there for a couple of days to get "settled", previously it was sitting closer to the roller door.
-Josh

Josh,
I think you are thinking NIRR paint (Near Infra Red Reflectance). Any paint manufacturer who does paint for the army should be able to mix up a batch. Around 2 years ago (previous employer) we were getting rid of some that had just gone out of shelf life, so if I'd known...
Rather than go that route, a roll down blind or awning would shade the roller door and drop the temperature for you. I should do something like that for my shed but as it's at the front of the house the good taste committee may have an opinion if I just slapped something up.

Michael

It was something like this

I checked the square again and came up with the same number, so that's good. In fact if we assume the plate curves down from the center, some of that error will be the plate.

Thanks for the link Josh I have a couple of white dust coats so that's a start
It does bring up something I'd been thinking about lately. You could have two points separated vertically while still being level.....checking local flatness would pick that up.

I've thought about shade cloth on the roller doors (north wall)but that would take more planning on my part. If the paint works or the house wrap will stay on I wouldn't have to think about it. Though I've just had an idea that might work, a couple of inches air gap from the shade cloth to the roller door should do. Great just what I need another project
I'm also thinking about a grape(or something else deciduous) vine on the west wall(which is 60% glass). Maybe we been a new thread.


Stuart

You checked the beam to make sure it is dead nuts parallel?