When i was building up my race engine, id wait until about 10am for my workshop to get up arpund 20c and then do all my measurements. The machine shops were always impressed with the accuracy i could get for a home gamer
Excellent video, Travis! I remember working with parts where thermal expansion was the difference between a pass or a fail. The heat from my hands impacted them upon inspection. I had to let them sit at room temperature for awhile, running my machine blind of any adjustments just to keep the machine up to temp.
Yep! I do the same, if I went on break I’d run my machines program without a part in it, if it cooled down for even 5 minutes and I ran a part it would change the dimension and be scrap.
Excellent topic, today. I've worked as mechanical inspector for 40 plus years and find this the subject that makes a machinist or inspector's eyes' gloss over the quickest. With todays extremely close tolerances, this lack of understanding can make a good part bad and vice versa. BTW, wear cotton gloves when handling part and inspection gage.
This was covered in year one of my apprenticeship and correctly referred to as the coefficient of linear thermal expansion. Have only had to use it a couple of times in toolmaking career due to hot summer and working on aviation and nuclear industry stuff. Whoever specified a machining fixture with a 7075 base plate that had to be jig bored to a silly tolerance was the origin of the problem. The dam thing was moving all over the show as the toolroom warmed up during the day.
Awesome video and great to see you back on the silver screen! Very informative. A while back I was reading up on calculating thermal expansion and gave me a headache. Thanks for the easier explanation. Much love and gratitude.
This is really the basic stuff in the world of manufacturing or machining specificly, with out knowning anything about this you can’t hit the quality needed. Never underestimate tempature, perfect exampel given right here
The shop that I work in is "Not" controlled environment, however we work within tenthousandths, we just basically have our instruments and workpiece at ambient temps and it seems to work. Sometimes if the workpiece gets a little warm or colder we try to work with it as close to temp as we can.
It’d be interesting to run some of the expansion equations at work and see how it varies day to day, I also work within tenths for bearings clearances at basically ambient temperature, keen to run some numbers and see how much they move around
Love it. It's not something you think about first thing but it is definitely something that can bite you in the end. We had an aluminum part that was 240" long that had some slots all down the length of it that was all tied back to one end which was the datum. We had to keep a thermometer on the part and instruct the machinist to only machine those slots if the temperature was at 70°. The part was so long that just a couple degrees would make a big change in location of the slots by the time it got to the end.
Great informative video Travis! Really helped make it simple to understand! Great work on the media team to make this video engaging and easily understandable with the different text and graphics added! 👏👏
Great video, unfortunately in my experience, a lot of CNC shops completely ignore this and let machinists work in a really hot environment, and blame the operator for tolerance differences.
Hey Travis, Great video! If your into precision its must have knowledge 👍 A little pointer for your use of the thermal imaging camera is to use emissivity tape on the part you are measuring 😊 I use it to sense check hotspots on thin wall packaging injection moulds. If you dont use it you could read the wrong temperature due to differences in the material's emmisivity, read the temperature of the object behind it (if it is transparent to ir) or read the reflection of another object if it reflects ir 😮
I have a part on the lathe with a .1000 bore, +.0002 minus nothing, my coolant gets to 90 degrees when the machine is fully warmed up we don’t have a chiller , I use the thermal coefficient to make my part bigger, to compensate for the 68 inspection room, works everytime,holding that DIM at .1003 is money, just measure fast before the part can cool. When you can do this, you can truly master aerospace machining! Even with older machines.
My machinist's training began in a college vocational-technician program that started from day one preaching that "Machining is done at the standard temperature of 68 degrees F every day of the year." The shop was kept at that temperature. It was kind of odd to see people wearing light jackets, in Florida, on hot days, heading into the building, but they were all going into the machinery class.
The biggest thing we should all be doing is storing our raw stock in the same temperature our equipment is. You guys in Wisconsin, pay heed: if your stock racks are in an unheated warehouse the parts you make in February aren't going to be the same size as the ones you make in August.
I was waiting for this my friend. There are indeed a small subset of materials that do not follow the principle. "Almost all" is more appropriate; good catch.
Loving the 'stache! I guess I'm still working under the misconception about holes getting smaller. When sending parts to be heat-treated that have drilled and tapped holes, I've always had to drill oversized and tap with an upsized tap. They always come back on size. Is there something more going on in the heat treat process that's shrinking it, or is there another phenomena going on here?
Thanks man! I imagine with threads the profile of your thread is expanding into the hole whereas a with a normal hole only the circumference is expanding. Threaded holes might be an exception based on the addition and direction of the thread contours. Great question!
I don't know the material or heat treat process in your case. We used a tremendous amount of lower carbon steel (8620 and others) which was case carburized and then hardened. The carburize process deposited carbon to anywhere from .020" to .060 depth. This would cause ODs to grow and holes to shrink. We also had to allow for this in machining prior to heat treat. We used higher GH number taps and sometimes larger tap drills to compensate. Perhaps this is also what is happening at your facility. The same thing needs to be done with parts that are subsequently coated or plated with a significant thickness.
Good old thermal expansion. Use it daily to install bearings and couplings as well as sometimes removing said items. Stick a bearing on a bearing heater till its around 240f and it will slip right on the journal and then lock in place a few seconds later as the heat transfers to the part and the temperatures equalize.
That's a legitimate question my friend. You could use that equation to figure out the temp change required to put them out of spec and from there make an educated guess based on average body temp. Might be a fun experiment.
I measured the dash of my flat black painted crown vic with all black interior on a 100F day once. dash showed 248f. seated only 150, fabric thank god but the seat belt buckles metal part was pushing 220 sitting directly in the suns path. Cooking
Great question. While I am no engineer I imagine your print would account for this. The dimensions and tolerances would likely be sized according to the anticipated growth or shrinkage of features.
U just account for that temperature in the equation, should be on print. With implants we generally have to hold there tolerance in a 97 degree enviorment, so there is no risk of the part shrinking or expanding inside someone.
Two instances when you really should consider thermal expansion. 1) Very large components that need to be machined to a tight tolerance. 2) Materials that have a high coefficient of thermal expansion and a tight tolerance. (PTFE)
Great video overall, but especially the explanation of why hole diameters increase with a positive temperature change - I knew that on a practical level, but lacked the intuition you gave about the _circumference length_ increasing.
i think i have a correction on the 10 times to the negative 6 in the example shown there is a missing 0 so its actually 0,0000013 so if we calculate all that again 0,0000013*5,001*(-22)= -0,0001430 so that means 5,001-0,0001430= 5,000857 i mean i could be wrong but i think for metal (i only work with plastics) this is actually way off
sometimes it can be a good excuse not to run something because it's way too hot, we've had 3-or-so ton rotors that NEEDED to be made done and all I can say while I try and touch it is "can't do, it's so warm I can boil pasta in the roughed pockets'
The equation can be used for either Fahrenheit or Celsius so long as the CTE you use in the calculation is the correct one for the temperature units used. That is, the same material will have different CTE values based on whether you are calculating for Fahrenheit or Celsius.
Oh yes, imagine a 30m Steel Part of a Bridge, measuring with plastic rulerband and steel rulerband. Huge differences at any temperature, This part cools out in a few days.. :-) Tolerances +- 1mm even similar rulerbands shows differences.. finally use lasermeasurement and tempcalc. Fits finally perfect at the plant.
@travisjarrett2355 Great job explaining this, as someone who isn't a machinist or use that kind of math at any given time (or use it period LOL), I was able to understand what you were talking about. Took a moment but it all clicked and I was able to understand totally. Look forward to seeing more videos like this. Keep up the awesome work.
Gonna show my boss this tomorrow. I machine In a climate controlled shop but my parts are assembled in a non climate controlled section of our building. It’s a constant argument of this bore is out of spec. Honestly never even considered this to be an issue
Put them in the fridge. They will shrink. Put them on your coffee cup. They will get bigger. I specifically run plastics. They can be very frustrating.
This should be video 101! Airbus needed to mate the prototype tail from Spain to the fuselage in Germany, and they didn't fit! (a big L₀ and Spain's hot weather)
Get a chiller for your coolant. Keep that at 20 degrees and your part is at 20 degrees. Chiller for the spindle and ball-screws. Love my Matsuura Hplus300. Precision all day 24/7/365. Non stop machining
I love these videos but this one confuses heat and temperature. Brisket takes a lot of heat, but temperature is not!desirable, a weld takes a lot of temperature, but heat is not desirable.
For a quick and dirty knowledge : Steel take ~.1mm and aluminum take ~.2mm in expension with heat. It's not precise AT ALL, but it's a good idea as to how your piece will react.
Machining plastics is not as easy as it sounds if there are tight tolerances. All plastics wether extruded, molded, cast... have internal stresses that are released as the plastic is machined. It may check out great just off the machine but can change the part over time, Even some of the great engineering plastics have these issues. To control tight tolerances on plastic parts we would rough cut the parts, anneal them to relieve the stresses then finish machine. Then there is the issue of moisture absorption; some plastics like nylons can change depending on the humidity. It is important to understand the operating environment of the finished part for temp and humidity and design accordingly. Decades as a machinist, ME and designer...
![Seungmin "그렇게, 천천히, 우리(As we are)" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/kAzmhLHePqU/mqdefault.jpg)
Travis really does look like a cop lol
The mustache is really pulling 80% of that look.
Dude is gonna pull you over just to make sure your tolerances are within spec.
@@Budabaii 💯
Reminds me of a CHiP
@@Budabaii
"Sir, were you aware that your front tires have 2 thou runout?"
That's why he's the inspector 😂
When i was building up my race engine, id wait until about 10am for my workshop to get up arpund 20c and then do all my measurements. The machine shops were always impressed with the accuracy i could get for a home gamer
10+ years as a CQI and today i learned something new. Thanks Travis. Love these inspection videos!
Thank you my friend! Glad you enjoyed the video.
Excellent video, Travis! I remember working with parts where thermal expansion was the difference between a pass or a fail. The heat from my hands impacted them upon inspection. I had to let them sit at room temperature for awhile, running my machine blind of any adjustments just to keep the machine up to temp.
Yep! I do the same, if I went on break I’d run my machines program without a part in it, if it cooled down for even 5 minutes and I ran a part it would change the dimension and be scrap.
Excellent topic, today. I've worked as mechanical inspector for 40 plus years and find this the subject that makes a machinist or inspector's eyes' gloss over the quickest. With todays extremely close tolerances, this lack of understanding can make a good part bad and vice versa. BTW, wear cotton gloves when handling part and inspection gage.
this is a really well put together video.
This was covered in year one of my apprenticeship and correctly referred to as the coefficient of linear thermal expansion. Have only had to use it a couple of times in toolmaking career due to hot summer and working on aviation and nuclear industry stuff. Whoever specified a machining fixture with a 7075 base plate that had to be jig bored to a silly tolerance was the origin of the problem. The dam thing was moving all over the show as the toolroom warmed up during the day.
I've learned more about Thermodynamics and thermal expansion than any university lecture could teach over a few weeks, absolutely fascinating
Thank you!
This could be an entire channel, I love it!
Awesome video and great to see you back on the silver screen! Very informative. A while back I was reading up on calculating thermal expansion and gave me a headache. Thanks for the easier explanation. Much love and gratitude.
Thanks brother! Always appreciate the support!
This is really the basic stuff in the world of manufacturing or machining specificly, with out knowning anything about this you can’t hit the quality needed. Never underestimate tempature, perfect exampel given right here
There was a most entertaining video on thermal expansion I've seen, officer.
The shop that I work in is "Not" controlled environment, however we work within tenthousandths, we just basically have our instruments and workpiece at ambient temps and it seems to work. Sometimes if the workpiece gets a little warm or colder we try to work with it as close to temp as we can.
It’d be interesting to run some of the expansion equations at work and see how it varies day to day,
I also work within tenths for bearings clearances at basically ambient temperature, keen to run some numbers and see how much they move around
Excellent video Travis! This is an important topic and this video is sure to help people overcome the challenges of thermal expansion and contraction!
Good calculations. But, what about the thermal expansion about your measuring tool? How long did You hold the pins in your warm hands? Think about!
Great video Travis, you did really good at the explanation of the process! 108 degrees and drizzling well I guess we need the rain haha!
Love it. It's not something you think about first thing but it is definitely something that can bite you in the end. We had an aluminum part that was 240" long that had some slots all down the length of it that was all tied back to one end which was the datum. We had to keep a thermometer on the part and instruct the machinist to only machine those slots if the temperature was at 70°. The part was so long that just a couple degrees would make a big change in location of the slots by the time it got to the end.
What type of beast do u run a 240" part on?
@@verakoo6187 It was on an Okuma MCR Double Column machine with interchangeable heads. A very big machine lol
Great informative video Travis! Really helped make it simple to understand! Great work on the media team to make this video engaging and easily understandable with the different text and graphics added! 👏👏
Great video, unfortunately in my experience, a lot of CNC shops completely ignore this and let machinists work in a really hot environment, and blame the operator for tolerance differences.
Hey Travis, Great video! If your into precision its must have knowledge 👍 A little pointer for your use of the thermal imaging camera is to use emissivity tape on the part you are measuring 😊 I use it to sense check hotspots on thin wall packaging injection moulds. If you dont use it you could read the wrong temperature due to differences in the material's emmisivity, read the temperature of the object behind it (if it is transparent to ir) or read the reflection of another object if it reflects ir 😮
Nice Video Travis and Sam!
I have a part on the lathe with a .1000 bore, +.0002 minus nothing, my coolant gets to 90 degrees when the machine is fully warmed up we don’t have a chiller , I use the thermal coefficient to make my part bigger, to compensate for the 68 inspection room, works everytime,holding that DIM at .1003 is money, just measure fast before the part can cool. When you can do this, you can truly master aerospace machining! Even with older machines.
Great video as always guys, you’re a more important force for good than you know.
Keen to run some equations!
Priceless information! Great video guys!
My machinist's training began in a college vocational-technician program that started from day one preaching that "Machining is done at the standard temperature of 68 degrees F every day of the year." The shop was kept at that temperature. It was kind of odd to see people wearing light jackets, in Florida, on hot days, heading into the building, but they were all going into the machinery class.
Sheriff of Titans Of CNC
Very informative video. Nice job you guys.
The biggest thing we should all be doing is storing our raw stock in the same temperature our equipment is. You guys in Wisconsin, pay heed: if your stock racks are in an unheated warehouse the parts you make in February aren't going to be the same size as the ones you make in August.
Such a killer video - this one will get shared throughout shops a lot.
Excellent info!
01:28 Well, not _all of course._ Zirconium tungstate for example under given synthesis and state conditions maintains a -ve CTE before decomposition.
I was waiting for this my friend. There are indeed a small subset of materials that do not follow the principle. "Almost all" is more appropriate; good catch.
Loving the 'stache! I guess I'm still working under the misconception about holes getting smaller. When sending parts to be heat-treated that have drilled and tapped holes, I've always had to drill oversized and tap with an upsized tap. They always come back on size. Is there something more going on in the heat treat process that's shrinking it, or is there another phenomena going on here?
Thanks man! I imagine with threads the profile of your thread is expanding into the hole whereas a with a normal hole only the circumference is expanding. Threaded holes might be an exception based on the addition and direction of the thread contours. Great question!
I don't know the material or heat treat process in your case. We used a tremendous amount of lower carbon steel (8620 and others) which was case carburized and then hardened. The carburize process deposited carbon to anywhere from .020" to .060 depth. This would cause ODs to grow and holes to shrink. We also had to allow for this in machining prior to heat treat. We used higher GH number taps and sometimes larger tap drills to compensate. Perhaps this is also what is happening at your facility. The same thing needs to be done with parts that are subsequently coated or plated with a significant thickness.
Good old thermal expansion. Use it daily to install bearings and couplings as well as sometimes removing said items. Stick a bearing on a bearing heater till its around 240f and it will slip right on the journal and then lock in place a few seconds later as the heat transfers to the part and the temperatures equalize.
how long will it take the heat from your hands to expand those pins beyond specs ?
That's a legitimate question my friend. You could use that equation to figure out the temp change required to put them out of spec and from there make an educated guess based on average body temp. Might be a fun experiment.
That is one of the the reasons they have necking in the middle, so that your hands won't affect the measurement. Be it heat, sweat or grease
Great video! That Texas heat is no joke!😅
I measured the dash of my flat black painted crown vic with all black interior on a 100F day once. dash showed 248f. seated only 150, fabric thank god but the seat belt buckles metal part was pushing 220 sitting directly in the suns path. Cooking
He works out in the gym and it shows! Looking good!
Travis, good to see you back on the tube. RLTW
Thanks brother. ATW
Please make a video on 5S in work shop
This guy is great a communication
Why not put a chiller on the cutting fluid .
Seems like that would also keep tooling at a semi constant temp
Thank you Mr cop nice thermodynamics BOOM 💥 ❤
8:29 : 90 - 68 is 22 without minus! 😁
Actually you have to subtract 90 from 68, not other way around.
Great video! 👍
Great video!!!!
so the CMM has thermal compensation options... does Mastercam or the machines take temps into account during production?
I needed this video in High School so I could've passed my science and math classes! JK Great video Travis, super fascinating stuff!
Nice video. But how do you account for thermal expansion if the final part is used in a hot or cold environment?
Great question. While I am no engineer I imagine your print would account for this. The dimensions and tolerances would likely be sized according to the anticipated growth or shrinkage of features.
I think the equation can tell you where the part will be if you know the temperature it operates at
U just account for that temperature in the equation, should be on print. With implants we generally have to hold there tolerance in a 97 degree enviorment, so there is no risk of the part shrinking or expanding inside someone.
If it's THAT critical your customer should be willing to tell you the temperature the part is going to be used at. (All together now: "Yeah, RIGHT!")
Good video Travis. His title could be Spatial Accuracy Enforcement officer 😀
Two instances when you really should consider thermal expansion.
1) Very large components that need to be machined to a tight tolerance.
2) Materials that have a high coefficient of thermal expansion and a tight tolerance. (PTFE)
this guy is amazing !
Hi Titans!
Great video! Are you guys also in Hannover at the Emo this year?
don't forget surface temperature might be different than internal temp especially for big parts with no internal surfaces
Great video overall, but especially the explanation of why hole diameters increase with a positive temperature change - I knew that on a practical level, but lacked the intuition you gave about the _circumference length_ increasing.
Dang Officer awesome video!
i think i have a correction on the 10 times to the negative 6 in the example shown there is a missing 0 so its actually 0,0000013 so if we calculate all that again 0,0000013*5,001*(-22)= -0,0001430
so that means 5,001-0,0001430= 5,000857
i mean i could be wrong but i think for metal (i only work with plastics) this is actually way off
That’s Mechanical Engineering 101 for you ❤
Great video
Real knowledge
Kudos
sometimes it can be a good excuse not to run something because it's way too hot, we've had 3-or-so ton rotors that NEEDED to be made done and all I can say while I try and touch it is "can't do, it's so warm I can boil pasta in the roughed pockets'
In that calculation you used degrees Fahrenheit is that equation not in celcius?
The equation can be used for either Fahrenheit or Celsius so long as the CTE you use in the calculation is the correct one for the temperature units used. That is, the same material will have different CTE values based on whether you are calculating for Fahrenheit or Celsius.
Oh yes, imagine a 30m Steel Part of a Bridge, measuring with plastic rulerband and steel rulerband. Huge differences at any temperature, This part cools out in a few days.. :-) Tolerances +- 1mm even similar rulerbands shows differences.. finally use lasermeasurement and tempcalc. Fits finally perfect at the plant.
What's yo video Equipment made out of? So sharp
Have to do this for heated dies
If digital micrometers could adjust for temperature, that would be a game changer
@travisjarrett2355 Great job explaining this, as someone who isn't a machinist or use that kind of math at any given time (or use it period LOL), I was able to understand what you were talking about. Took a moment but it all clicked and I was able to understand totally. Look forward to seeing more videos like this. Keep up the awesome work.
As well as accounting for expansion in the part, do you not also need to account for expansion in the instruments used to measure the part?
Great question my friend. If your instruments were on the floor then yes you would need to account for them too.
Ah sweet! Solid mechanics math-suprise in the middle of dinner 😅
Travis is a G
I assume you need a certain temperature and humidity maintained in the shop....
Gonna show my boss this tomorrow.
I machine In a climate controlled shop but my parts are assembled in a non climate controlled section of our building.
It’s a constant argument of this bore is out of spec.
Honestly never even considered this to be an issue
Would it be interesting to do those videos with Metric numbers somewehere?
Just convert them, it takes 2 seconds.
Inch × 25.4 = MM
MM/25.4 = Inch
@@verakoo6187 Oh yes, I always wan't to do math whenever looking at measurements and tolerances.
Yes, polymers have a high coefficient of thermal expansion
nice video
Great content. The ending killed me
Had to add some Donnie!
@@travisjarrett2355 😆
Put them in the fridge. They will shrink. Put them on your coffee cup. They will get bigger. I specifically run plastics. They can be very frustrating.
There is too little Travis on the channel!
I would like to see a study about how much larger living things get when it’s hot.
🤔
The only thing better than titans is an ak50 update.....😁👍👍👍
I'll tell you hwhat.... when your parts tolerance plus/minus .0005 temperature is very important
This should be video 101! Airbus needed to mate the prototype tail from Spain to the fuselage in Germany, and they didn't fit! (a big L₀ and Spain's hot weather)
Great😊
For all those who are like me and not making important parts ill save you some time:
Heat makes things bigger, cold makes things smaller.
New series idea: Will it Thermally Expand?! Travis measures all the things before and after thermal expansion.
In germany we learn this in school for machinist
Keep a known temperature bucket of water to dunk the parts in....
So to solve expansion, I need to sell my house and use the cash to buy a cmm. My wife is going to so happy to hear my solution.
Plugging in diameters to that formula doesn't work. Like he said before you need to do the circumference. The CTE is linear not diametrical
Get a chiller for your coolant. Keep that at 20 degrees and your part is at 20 degrees. Chiller for the spindle and ball-screws.
Love my Matsuura Hplus300. Precision all day 24/7/365. Non stop machining
Thank you for not doing this video in Celcius, Travis!!!
No Barry, you were the chosen one! You were meant to bring balance to the measurements not leave them in darkness.
😂😂😂
🤣🤣 I would never do that to you Barry!
I work at an hdpe machine shop and thermal expansion is our mortal enemy
Sorry had to laugh when he talked in *imperial* 😂
Great video nonetheless
🤣Thanks man! What can I say...hailing from the USA.
Great video, very informative, but in a nutshell you really looks like cop :)
I love these videos but this one confuses heat and temperature. Brisket takes a lot of heat, but temperature is not!desirable, a weld takes a lot of temperature, but heat is not desirable.
°C - я для тебя какая-то шутка?
😵💫
For a quick and dirty knowledge :
Steel take ~.1mm and aluminum take ~.2mm in expension with heat.
It's not precise AT ALL, but it's a good idea as to how your piece will react.
Machining plastics is not as easy as it sounds if there are tight tolerances. All plastics wether extruded, molded, cast... have internal stresses that are released as the plastic is machined. It may check out great just off the machine but can change the part over time, Even some of the great engineering plastics have these issues. To control tight tolerances on plastic parts we would rough cut the parts, anneal them to relieve the stresses then finish machine. Then there is the issue of moisture absorption; some plastics like nylons can change depending on the humidity. It is important to understand the operating environment of the finished part for temp and humidity and design accordingly. Decades as a machinist, ME and designer...
Who'd have thought a 100k machine is the best way, lol.
Great😊