Does Temperature Change Affect Accuracy in a Home Workshop

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  • Опубликовано: 2 ноя 2024

Комментарии • 71

  • @Martyn-ey9lw
    @Martyn-ey9lw Год назад +1

    Hi Jon, Why would you have a negative change on one axis (Y) and a positive change on the other axis (X), with a round bar I would have thought the expansion/contraction would have been the same on both axis ?

    • @jonsworkshop
      @jonsworkshop  Год назад +3

      Hi Martyn, thanks for the comment and the excellent question. I am in danger of writing a thesis here lol. This is a hugely complex topic but in summary, I am dealing with a metal Airfix kit where between the table and the spindle there are 10's of interfaces all with their own inaccuracies (out of squareness, parallel etc) and a mix of materials with different coefficients. The final movement at the spindle nose will depend on the combination of all of these variables and basically 'which inaccurate interface wins the fight'. I hope that makes sense as a summary, very very complex which is why I kept this video at a really high level otherwise it would have run for hours🤣🤣🤣. I will pin your comment as it really is an excellent question and your inquisitiveness pleases me, I thought it was only me sad enough to get excited about this stuff!

    • @MaXpeedingRods_Coop
      @MaXpeedingRods_Coop Год назад

      how could we have a talk? /. hope to sponsor ,@@jonsworkshop

    • @jonsworkshop
      @jonsworkshop  Год назад

      @@MaXpeedingRods_Coop Hi, thanks very much for reaching out. At the moment I don't really want to go down the sponsorship route, as I believe that will detract from the purpose of the channel. If I change my thinking in the future, I will be in touch. Cheers, Jon

    • @MaXpeedingRods_Coop
      @MaXpeedingRods_Coop Год назад

      @@jonsworkshop thanks Jon , how i could keep in touch with you on ig or fb ?

  • @markrainford1219
    @markrainford1219 Год назад +1

    That's dedication; making a video on a Friday night while the pub's open. Cheers.

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Mark, thanks for the comment. Lol, the bar was well and truly open, just out of shot. Cheers, Jon

  • @TheRecreationalMachinist
    @TheRecreationalMachinist Год назад +1

    That was brilliant. Thanks Jon 👍 🇬🇧

  • @richardlamb5771
    @richardlamb5771 Год назад +1

    Thanks for sharing your expertise, even though we may not understand it as well as you do, doesn't mean we don't enjoy getting into the numbers.

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Richard, thanks for the comment. Lol, I just worry lots of people will just switch off 😂😂😂. Glad you enjoyed it. Cheers, Jon

  • @terrycannon570
    @terrycannon570 Год назад +1

    Great demo Jon. Thanks for bringing us along

    • @jonsworkshop
      @jonsworkshop  Год назад

      Thanks Terry, much appreciated mate. Cheers, Jon

  • @907jl
    @907jl Год назад +1

    Great info Jon. As a former metrologist, I really enjoy, and appreciate this sort of content!

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Jeff, thanks for the comment, glad you enjoyed it. Cheers, Jon

  • @wibblywobblyidiotvision
    @wibblywobblyidiotvision Год назад +5

    Interesting video Jon. A more common way to get bitten on this is workpiece heating due to cutting, particularly on lathes where you might experience 50 to 70 degree deltas. In terms of lathe work, most people know about diametric changes, but tend to ignore the associated length changes, this can blow axial dimensions quite easily.
    Guilty as charged :)

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Wibbly wobbly, thanks for the comment. Yup, bang on. I should have mentioned this in the video. I have covered this in previous tips videos etc, but I wanted to split the two things out otherwise it becomes a monster of a topic to try and cover. Cheers, Jon

    • @Xynudu
      @Xynudu Год назад +2

      @@jonsworkshop Hi Jon. This was my thought as well. A good case for flood coolant, but most small hobby lathes don't have that. A very complex subject as you have said. Cheers rob

    • @jonsworkshop
      @jonsworkshop  Год назад

      @@Xynudu Thanks Rob. Cheers, Jon

  • @AlmostMachining
    @AlmostMachining Год назад +2

    Heck yeah it does. Great Video Jon! Hard to get a change in your shop as you said. For me I get 0c at the min in the winter and then 47++c during the summer with over night lows changing I guess 15c or so. 115 and then 88 or so bananas early in the morning in the summer. If you needed me to make you a precise part in the summer I would have to offset the dims for it to be on size at your shop. Another thing can be when you were clocking the part in the machine, both the part and the machine change size..so as the machine contracts so does the part. the scales have some wiggle room in the stability of the glass being glued in with a silicone adhesive so it doesn't rip the glass apart when the holder changes size.

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi, thanks for the comment. 100% on everything you say! Our range is -18C to +30 at worst so similar. I could bang on for ages on this topic, soak times, thermal gradients etc etc but I think I would bore people lol. Cheers, Jon

    • @glennwright9747
      @glennwright9747 Год назад

      I was also curious about the glass scales and their thermal coefficient. Is the glass more stable and helps compensate?
      I wonder if your machine and workk piece with same thermal coefficient if using mechanical scales and screws etc would cancel each other out?

  • @carlwilson1772
    @carlwilson1772 Год назад +1

    That was very good Jon. You know how much I like the calcs. My workshop is actually part of my house, so I am very lucky because the temperature in there is uniform, pretty much, year round. It is something that I am very glad about.
    Like others have already said, I think the biggest issue for a lot of us is the very large deltaT's that can be had by heating due to machining. That is how dimensions can easily be blown, and yes I have done it.
    As an addendum, another interesting use of the expansion formula you showed is to design shrink fits in components. I did exactly that when I dimensioned my bronze acme nut and continuous cast iron nut housing for my Harrison milling machine.
    Thanks for a great film.

  • @nobbysworkshop
    @nobbysworkshop Год назад +1

    Thank you Jon. A very interesting subject. I've learnt to let parts cool down after machining before making final measurements. Using cutting oil to reduce heat. Stefan Gotteswinter did a recent video on the subject using a test inducator to measure metal expansion. More tips like this Jon are so useful to me. Cheers Nobby

  • @swanvalleymachineshop
    @swanvalleymachineshop Год назад +1

    Mate , you are giving away all our secrets ! Now they know , when we give the finished parts back in the warm afternoon they will think we made it undersize ! Same goes for bores on a cold morning ! Cheers . 👍

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Max, lol, I know. I have actually seen something similar done in the past for the 'customers eyes' lol. Cheers, Jon

  • @TrPrecisionMachining
    @TrPrecisionMachining Год назад +1

    good video Jon..thanks for your time

  • @PeckhamHall
    @PeckhamHall Год назад +4

    You could have put a long length of aluminium in an oven at 100°C and measured the length and temperature at the same time, then done it again when it had cooled down because machining can make something pretty hot. I think this is something that the home machinists need to worry about more than the night and day temperature difference, as most probably use blunter tooling with no cooling methods. One experiment that would show more of a result to get your point across maybe, just an idea, these measurement experiments I find interesting. I liked it when you get into the mathematics of engineering.

    • @jonsworkshop
      @jonsworkshop  Год назад +2

      Hi James, thanks for the comment. You are correct. I have covered this in previous tips videos on coolant and balanced cuts etc. I wanted to cover the ambient temperature aspect in isolation otherwise it gets really complex trying to explain the joint effects of both etc. Hope this makes sense. Cheers, Jon

  • @kevinwillis3390
    @kevinwillis3390 Год назад +2

    Nice one Jon
    Well temperature change certainly affects my accuracy in the midst of winter, when I'm dithering and shaking whilst using a micrometer 😂🤣👍🍺
    See you next time
    Regards
    Kev

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Kev, thanks for the comment. Lol, I never thought of that variable 🤣🤣🤣🤣. Cheers, Jon

  • @bostedtap8399
    @bostedtap8399 Год назад

    Nice subject Jon, yes, many think it needs 100°C delta to impact accuracy and tolerance.
    Clockmakers knew this, hence the pendulums are manufactured from two complementary materials to reduce length change.
    My apprenticeship machining was on copper and bronze alloys for resistance welding equipment, what fun.
    Excellent video.
    Thanks for sharing

  • @MattysWorkshop
    @MattysWorkshop Год назад +2

    Gday Jon, that was very interesting and I’d like to see this revisited on the winter there, I know it gets bloody cold where you live, great video mate, cheers

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Matty, thanks for the comment and feedback mate, much appreciated. I will revisit this as I am sure the results will open a few eyes! Hope you're coping buddy, still firmly in my thoughts! Cheers, Jon

  • @NellsMechanicalManCave
    @NellsMechanicalManCave Год назад +1

    In 1989 I was a steel fabricator. I was working outside in mid summer on new 1.5m high, 27 m long castellated beams. The inspector checked my work at the end of shift and said I was 5mm over tolerance and I needed to remove an end plate and shorten the beam before welding. 10am next day it was within tolerance without me touching it 😂

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Neil, thanks for the comment. Lol, you clearly knew better than your inspector 🤣🤣🤣. And you know fine well if you followed his instructions and next morning it was undersize, it would all have been your fault. Cheers, Jon

  • @ollysworkshop
    @ollysworkshop Год назад +2

    Hi Jon, the varying emissivity of the surfaces affects the reading from non-contact IR thermometers. To get a consistent reading you need matt black. Get a roll of black (or blue isn't too much different) masking tape and stick it to what you want to measure. Excellent topic for us amateurs, whilst I could have worked this out I didn't (because I try to engage brain as little as possible in down time), so I had to learn this the hard way!

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Olly, thanks for the comment and tips on the IR thermometer. I will get myself some, I guess sharpie on normal masking tape may work, will give it a go. Cheers, Jon

    • @ollysworkshop
      @ollysworkshop Год назад

      @@jonsworkshop Sharpie on masking tape will also work, I've done that myself.

  • @houseofbrokendobbsthings5537
    @houseofbrokendobbsthings5537 Год назад +1

    Very good Jon.
    Great topic for “how the heck did that happen to my parts dimension”

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Thanks Dan, hope you're well mate. Cheers, Jon

  • @GHA_1620
    @GHA_1620 Год назад +1

    Good video thanks Jon. I think this also links in to your video on coolant. When machining bearing diameters on the lathe coolant is a must because the CTE increases the diameter during cutting and then when the part cools it is undersize. I also had this issue on my surface grinder when grinding dry. So I always use flood coolant now when trying to hold tight tolerances.

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi, thanks for the comment. Yes, you are correct, definitely linked. I wanted to split ambient from generated heat as trying to cover both in one video would have been difficult and probably confusing etc. I only scratched the surface here as well, this topic is massive (measuring temp gradient from floor to ceiling etc etc). Cheers, Jon

  • @dreamsteam8272
    @dreamsteam8272 Год назад +1

    Hey Jon m, nice video!
    I once worked temporarily on a hardening furnace for sintered parts. gears for diesel pumps for VW were manufactured there. the dimensional tolerances were CPK +/- 3.2 müy We had special measuring rooms in which the temperature and humidity had to be maintained. and when entering the measured values, the component temperature and room temperature also had to be recorded. a difference of 5 degrees celsius resulted in a measured value difference of 15 müy ... that's about 1/6 of a human hair. that was interesting work.
    Have a nice weekend!

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Chris, thanks for the comment. Sounds very similar to the work I did in Rolls-Royce, we were splitting microns as well. 😊. Cheers, and I hope you are well. Cheers, Jon

  • @tonypewton5821
    @tonypewton5821 Год назад +1

    Hi Jon, enjoyed the video! 👍
    Regards Tony

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Tony, thanks for the comment and feedback, much appreciated. Cheers, Jon

  • @stevechambers9166
    @stevechambers9166 Год назад +1

    Good video Jon 👍👍👍

  • @stephenbrown1143
    @stephenbrown1143 Год назад +1

    Good morning Jon. I was watching you take multiple temperature readings with the associated bleeps..... Mrs B from the hall, " you better come and have a look at this, I think we've got a problem with the burglar alarm." 😂

  • @alasdairhamilton1574
    @alasdairhamilton1574 Год назад +1

    Jon, have you seen rail tracks buckling under the summer heat? (Not here in Scotland😅) It petty incredible the amount of distortion. 👍🏴󠁧󠁢󠁳󠁣󠁴󠁿

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Alasdair, thanks for the comment. Yep, it's phenomenal. With global warming, maybe making rail is a good business idea🤔. Cheers, Jon

  • @daveticehurst4191
    @daveticehurst4191 Год назад +2

    Good points there Jon. 13 Metre plates, what machine can you fit those on and get a 1 thou tollerance ? Regards from Australia.

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Dave, thanks for the comment. Lol, I think you should soon get a look, won't hold a thou though despite what they tell you over there😂😂😂😂😂. Cheers, Jon

  • @willemvantsant5105
    @willemvantsant5105 Год назад +1

    Hi Jon, my DRO has glass scales mounted in Aluminium housings, they are held in with rubber inserts so free to float with unequal expansion, yes the housing will bend hoping the error will be reduced.
    Have no idea how much the glass scale will expand with 10 degree Celsius temp change.

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Willem, thanks for the comment. If its normal glass, it will be similar to steel in terms of expansion, if it is Pyrex glass it will be almost identical to cast iron, and if its quartz it will be almost zero. Glass is very stable below 1000C, which is why it is used in machine scales. Rubber mounts on the more expensive scales mitigate the effects. Cheers, Jon

  • @opieshomeshop
    @opieshomeshop Год назад

    I keep my shop at 65 to 70 bananas all year round. 65 bananas in the summer and 70 bananas in the winter. If I know I'm not going to be in the shop a few days, I'll turn the AC off in the summer or down to 45 bananas in the winter until the day before I'm going back in the shop, so everything has 24 hours to get to temp. People who visit asked why I do this, and I explained this to them, and they are always amazed by it. The winters where I live (Pacific Northwest USA) are long and average 5 to 10 bananas and sometimes goes into minus bananas.

  • @thehobbymachinistnz
    @thehobbymachinistnz Год назад

    Hi Jon, this is quite interesting. I did not know that 10 degrees temp difference can make that much of a difference in size. Thanks for sharing.

  • @TheKnacklersWorkshop
    @TheKnacklersWorkshop Год назад

    Hello Jon,
    Sorry for being on the missing list, back now... interesting stuff, I remember learning this stuff in my apprenticeship... see you next time.
    Take care
    Paul,,

  • @624Dudley
    @624Dudley Год назад

    Hello Jon, this is exactly why I went to the trouble of schlepping tons of machinery down into the basement. With a modest energy input, the space realizes a near-constant temperature (and dew point) all year - so blown tolerances are all down to the operator. 🤨

  • @paulrayner4514
    @paulrayner4514 Год назад +1

    Stop trying to frighten me John😱 I'm not building a spaceship! It takes me all my time to be 0.01mm repeatability on a couple of parts without you throwing a spanner in the works😁

  • @improviseddiy
    @improviseddiy Год назад

    I have seen 0.03mm difference in diameter on a bearing on a 25-degree delta. It can influence a press fit. I measure the bearings at temperature before I do my final cuts.

  • @billdoodson4232
    @billdoodson4232 Год назад +1

    It always surprised me how much difference in temperature reading you could get when checking different surfaces with an infra-red thermometer, due to the different emittance from those surfaces, even though you totally knew they were all the same

    • @jonsworkshop
      @jonsworkshop  Год назад +1

      Hi Bill, thanks for the comment. Yeah, just getting used to mine as its a new toy. Going to get some matt black tape which I am told improves the variability. Cheers, Jon

    • @billdoodson4232
      @billdoodson4232 Год назад

      @@jonsworkshop I got one from Aldi, from the middle Isle, an impromptu purchase if you like. It would have been 5 or 6 years ago, then a couple of years later I went to use it for the first time. The rubber outer had sort of perished and gone all sticky and semi liquid, absolutely revolting. It still worked, but it went in the bin.

  • @improviseddiy
    @improviseddiy Год назад

    Aluminium drives me nuts when you clamp it on an inside bore. The one minute you are cutting and the next you're ducking. You have to either cool it or constantly tighten your chuck.

  • @j.f.christ8421
    @j.f.christ8421 11 месяцев назад

    On the Z-axis, won't most of that get negated by the column lengthening as well? Why not clamp the rod in the middle and put indicators on both ends? (Ok, your base is going to expand as well, feels like Archimedes looking for somewhere solid to put his lever.)

  • @chrisstephens6673
    @chrisstephens6673 Год назад

    Digging around in the dark recesses of my memory banks, not something someone should do if they are of a sensitive nature, i recall that they found railway tracks only expanded at the ends of the rails which is counter intuitive. That was why traditionally they had short ish lengths and expansion joints, but found they could have long welded tracks and far fewer joints, making for smoothrr and quieter trains. Mind you as that snippet came from my recesses it could well be complete phooey, or should that be utter bollocks?
    Interesting subject all the same but how many of us have temp controlled environments outside of a metrology lab, if only i had the dosh! Maybe in my next life?😗

  • @brucegriffiths8861
    @brucegriffiths8861 Год назад

    Youve used the thermal expansion coefficient for cast iron per degree Fahreneight. Your value for the thermal expansion coefficient of aluminium seems rather high. Typical aluminium aloys have a coefficient of thermal expansion of around 24 ppm/C near room temperature. It may be somewhat higher for temperatures significantly above ambient, The thermal exapnsion coefficient of most metals approaches zero as the temperature drops to absolute zero.

  • @TERRYB0688
    @TERRYB0688 Год назад +1

    Umm, thinking !!

    • @jonsworkshop
      @jonsworkshop  Год назад

      Thanks Terry. Don't think too hard, it hurts. Cheers, Jon

  • @howardosborne8647
    @howardosborne8647 Год назад +1

    Global warming will surely make this a problem of the past as there will be no more cold places left on the planet.....you can see I'm really observing the physics here🤣

    • @jonsworkshop
      @jonsworkshop  Год назад

      Hi Howard, lol, it will still be pi$$ing with rain here no matter what happens. 🌧️🌧️🌧️🤣🤣