How to Measure FLATNESS Perfectly with Jack Stands 

Manual inspection is almost becoming a lost art with the rise of CMM equipment available to the shop floor. The aerospace company I worked for had Maxichecks, Zeiss and a monster L&K CMM in our layout inspection area. We also had an old guy named Bud who could inspect a part with a height stand and indicator, a tilt rotary table and a calculator faster than a CMM could. We compared his readings with the CMM and he was spot on every time. The man was an artist at his craft.

Travis is the best quality guy I have worked with, especially considering he's an incredible Machinist as well, you don't find that very often. Great video man!

Excellent video. We need more QC content on here. It is especially important for the machine operators making parts to know how a part is to be checked for various requirements. This only benefits everyone.

The quickest way to do this is to have the surface you want to check facing the granite. Set it on 3 blocks the same size( Gauge blocks are fine). Then run an indicator on the bottom side. This eliminates the need to indicate in flat.

More videos like that!!! Pure educational gold!!! :D

Man why can't I like this video twice, an amazingly valuable information please Travis everyone does machining videos on youtube but no one does inspection, please more inspection videos especially old school inspection methods.

One is a point…two is a line.. three are a plane. Simple and effective…. Most machinist will have this inbred but for the rest of us who watch to be educated and amazed its always good to have things to latch onto for our hobbies and work. You must be a super high performing genius not to learn something from these videos….. consistent learning..magic.

Thanks man, you're a good teacher with clear explanation Travis.

This is a good content, back to basic to things that most people forgot or simply cheaper methods that can be done immediately, especially for a machinist....

Thanks as a mechanic support machinist we don't always get the best of inspection equipment (cmms) this can help alot of people Keep up the tips!

Keep on giving!!! Watching before work starts

That is badass. Love the way you clearly explain things. Very easy to follow your teachings. Much love and gratitude

As an inspector in aerospace, I would agree with everything said in this video. That's how you do it :)

Reminds me of when I worked. I was In aerospace/medical. I spent 35 + yrs as machinist, T&D maker and in metrology.

Please do more of these. Excellent demonstration.

Appreciate the QC & Inspection videos. Please do more of these. Thanks a lot!

Very good work... This knowledge will help many...

Excellent content! Everything that I have is manual....but these principles still apply. Great explanation. Thanks!

Really enjoying you videos.

Very good tip! This is extremely useful! Thank you! :)

He does such an excellent job in explaining the Procedure !!

Very cool. Thank you

Be careful using sharpies on Stainless steels, they can lead to long term corrosion. Lots of applications forbid anything other than low chloride/low halogen marking implements on a finished surface.

very useful, thanks team

Love the video 💕

Amazing! Thank you Travis. Will you be doing more old school gd&t measurements.

Great video!

Excellent video thank you!

Very nicely done, great job explaining things. Thank you.

Thanks! It amazed me to watch u fellas doing a tool.setup a while back. Yall started with joblocks and the surface plate as your root reference. Johanson was smiling down from heaven ;)

I like this method. I usually set up the surface to be inspected upside down on three points and sweep under with a long stem indicator.

great video more metrology videos needed to our comunity great job

Super helpful!

Awesome man

Thanks for sharing

Thanks great explanation.

Love it!

this is exactly how I would do it, great demonstration

Thanks 🙏 great video

Great explanation espacially when adding the comparison of CMM

Flawless demonstration on how accurate Old Skool in your Kit Bag of TRUTHS Travis. Your average goes without saying Ya Turning Skills kick the Foot Pedal of Knowledge, Titan keep on B💥💥MING on

Just because these boys have everything, doesn't mean they forgot everything that got them there. Always good to rely on accurate, proven conventional methods to check the accuracy of your parts. Great Video Travis!!

Very cool.

Excellent video! Simple, clear, concise. Well done. Could have mentioned temperature stabilization for such a heavy part. That could take a full day if you want to get down to tenths. Also you could mention on thinner/lighter parts the need to wear gloves to keep body heat out of the part.

If the face your inspecting has more of a cupped or dish shape, would you then have too indicate from the tallest points of the piece? And would you also have to indicate the "roundness" of that sort of shape?

I am sill learning, but a few questions come to mind: 1. Aren't you measuring parallelism when you set your reference on the bottom and then measure off the top? Taller stands would let you sweep the underside where your plane is established. 2. Adjustable jack stands seem unreliable for precision work with call outs in the .005 range, just setting the part on them could cause more movement then that on the threads, adjustments aside wouldn't fixed stands that have been run through the surface grinder together be more accurate as a base? You guys are awesome and I like how everything is broken into manageable sections for the widest audience, this is a trade that will always have a place in the world and it's great to see enthusiastic teachers of useful skills.

Would have been interesting to know what flatness the cmm gave yall but anyway nice and easy way to check parts!

excellent

seen it done it, show us more complicated QC practices. This is TITAN!!

I would have thought it better to check the 3 points on the bottom plane and then vs the top plane, that would establish flatness and parallelism. Because I would think they are very relative to one another, especially with that part being part of a hub of some sort. Correct me if I'm wrong. 🤷‍♂️

We have some Renishaw Equator CMMs at work. They take longer to inspect the part machined then it does to actually machine it. Pretty crap when the cnc machine producing them needs to run constantly to hold size..

Thanks Travis for another great video. One thing I don't understand is the reason for the three jacks. Is it because we cannot assume the bottom surface of the part to be flat? Ciao, Marco.

I've seen the indicator point angled almost straight down to the part. Way back learned to keep at least the point as parallel to the part as possible. Seems to be so different with newer machinist

So satisfying to watch as a machinist lol

Cool! Now we wait for next level, how to chech parallelism :) I have never seen how it's done.

I love metrology 💖

Some old dude I use to work with would do both CMM and this way just to make sure to bad he never really like sharing the knowledge. Unlike myself I enjoy teaching those who are interested.

Do you have any GD&T explanation video?

Am nearing retirement.. the reason I mention is! I have been watching these videos for some weeks now.. I've had a good working career, but it's never felt like I really was in the right profession. Anyway I think I should have become a machining engineer 🤔 I have really enjoyed the provisional side of this videos..

The way you are doing this we’re you are looking for parallel and surface planter accuracy.. you are relying on your step ups as perfectly level after adjustments you have done. What you should do is either set your surface parallel with a know parallel surface gauge, or do as you have done but take your measurements three times by moving the part in rotation 120 degrees and recheck your intended surface. This is the only two ways you can accurately measure parallel surface for planier accuracy. One you have determined planier accuracy is parallel, then you can check your intended surface accuracy, however.. this is also determined by the bottom surface be planier accurate as well. By rotation 120 degrees you can immediately determine your bottom surface accuracy. Mil Spec T5400 quality assurance standard.

I would love to see you do projection, symmetry, and true position without CMM.

Nice demo. It would have been good to see the cmm output to compare. I can’t help watching anything like this in imperial units without thinking how much easier this stuff is in metric though 😂

Was this in mm or inches? I'm a R&D worker and if that's inches I think that's a lot of runout to have. I'm used to work within 0.003 mm

Great.

Looks like it would indeed show you flatness but would not tell you perpendicularness from that face and the face against the jacks correct ? Kyle F. Lead Machinist from Tulsa ok thanks

Hello sir, could you provide more videos about other geometric tolerances ?

Measure flatness with an optical flat or auto collimator. I made several up to 12"(305mm) diameter in that size flatness, was 1/20 of wave length, monochrome green.

Dear sir, what should be tripod position angle ??

This guy seems to be on the level.

We have a leveling plates various sizes alot safer than using jacks. They are about 1/4 inch steel plates drilled and threaded holes with bolts with rounded ends that sit on the table. I think they date from the 1960's

I have 6 of those same jacks

Super cool technique! Thanks for sharing! I have a question though. Why does the bottom not get measured? Because couldn't there be high and low spots on there too? That the jacks might not be on.

Great video, but you could of just used three 1-2-3 blocks (or 3 gage blocks) to do a rough check like that. Just a suggestion.

The problem I have with this method of checking flatness is that if one of the 3 points you set the initial plane is low (if the flatness happened to be way out in that one spot), then your whole plane is now bad and you don’t know about it. When I manually check flatness, I set the part on three points on the surface I’m checking flatness on, then sweep my indicator under the part. The points that it sits on give more surface area, compared to the indicator ball which is has an infinitely small contact point given its spherical shape, for the part to locate on. In this instance it wasn’t an issue due to the part being dished and the flatness essentially got worse as you got farther from the center in every direction, but it could be an issue on other parts. All this being said depending on your tolerance this method is probably always fine. Might be worth mentioning the reason for using 3 points and not 4 too. Just thoughts. Source: my name

How do I contact Titan, I have a idea that can revolutionize the auto industry.

Make a video on how to check parallelism with the indicator. Thanks

5 thou flatness, I wish. I could check that with a flat edge. I can see that with my eye. 😂

"Isolating a plane" is the name of the technique.

How do you calculate the Measurement errors? I am afraid there are many of them.

Yup that's how we did it before CMM became more common. About the only thing I would ad in the video is cleaning the table and working surfaces before you start. I know you checked it but for any newbys it would be good to show it.

The other way to measure flatness is to have 3 gauge blocks. Flip the part over with the surface needing verification supported with the guage blocks. Sweep the surface with a dial test indicator. Flatness is the difference between min and max indicator reading. This works fairly well.

"One is a point, two are a line, three are a plane." These are my thoughts about everything. It's been years that I want to write things down. 😅 Things only become real with a 3-point framework. And it's just everywhere.

I see you used a sharpie on your part. Honorable mention if you are making parts for Boeing big no no. We had a major finding where I used to work because we’d write with sharpie marker “MRR” (Material review request) for non conformance parts, but every now and then the parts would be looked over by engineering and deemed conforming. With the sharpie though I guess it can do something to the metal later on down the line which etches it or something. So Boeing actually makes sharpie markers that are to be used with their parts to meet their spec which we found out during an audit. Just thought I’d mention maybe you guys are more familiar with it than I am. I forget the full reason or the actual spec it was under it was years ago now.

Pretty level guy !!😅😅😅

As long as your table has zero variation, this is great! I would have my doubts about a table being perfectly flat in such a large area, but I'm sure you guys are very aware of the tables flatness and levelness. As usual, great job!

JUST A FRINDLEY BIT OF ADVICE . NEVER PUT SOME THING DOWN ONTO THE GRANITE . THE BEST WAY IS TO SLIDE IT ON AND SLIDE IT OF . NICE WORK . ⚘⚘⚘⚘

What’s the benefit over using the stands to the surface table ?

I wonder if you'd get less than .0033 flatness reading if you zero the high and low points...

I’m sorry @ Travis Jarrett, but you are incorrect or ignore a lot of things in this video. I noticed you already replied to someone else’s comment that you are ignoring cosine error of the indicator, an important thing to state, although in this video your indicator was at a shallow angle so not a big deal in this video. However the biggest issue is that the method of checking flatness is incorrect. Using the ‘put the part on 3 jacks method’ , just zeroing out 3 points on the top surface and then sweeping the indicator over the surface and looking for the total variation doesn’t check the actual flatness. What you need to do is move the indicator back and forth all across the surface, constantly adjusting the jacks up and down to bring the indicator variation to a minimum. This can be a very difficult and time intensive process, which is why using a CMM is usually the best method. And why using a scanning CMM that can measure 100s or even 1000s of points would be best, rather than using a touch trigger CMM that only takes individual point hits. Your method will most likely give you a good idea of what the general flatness of the surface is, but at a fundamental level it is not technically correct. FARO has an okay article on their website that talks about this issue somewhat: www.faro.com/en/Resource-Library/Article/how-to-evaluate-flatness-in-gd-t under the section ‘using a height gage to evaluate flatness.

Some times old ways are still the best . Don't forget optical flatness gauges as well . Then optical comparator to ensure concentsity and parallelism between surfaces are Absolute

Jacks are not needed really. This inspection method is 100% appropriate if the goal is to quantify flatness. Assuming the reference surface is not in a "rocking condition", if the measured surface is parallel to the reference surface (the one with jacks) then one can determine that it is also within the flatness spec BUT if the measured surface it is not parallel within the flatness specification it MAY still meet the flatness spec. There's an overlap here. Parallelism also controls flatness but flatness does not control parallelism. The parallelism and flatness tolerance zones are the same. The main difference is that orientation (parallelism) error may add to the "flatness measurement". Sometimes speed is needed, sometimes accuracy. It all comes down to what you're trying to achieve. Nice video.

Machinist stone and granite table have one thing in common - I have only seen these on RU-vid. XD

Give us more manual please!

why put the part on jacks when the surface plate is already flat? doesn’t make sense to me since the height gauge is on the surface plate anyway

We are constantly fighting flatness on our aluminum (or any material) plate parts

oh, i get it, because it references against that three point plane

Thanks for raising a low spot in my metrology knowledge.

This is basically how 3d printer beds are calibrated.

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I guess you saw my flatness comment the other day.