If you’re looking for some measuring callipers, there’s an overwhelming number of options. Do you go for dial, vernier, or digital? Do some perform better than expected, while others are overpriced for what you get? Which ones do I keep for myself, and which do I giveaway to people I don’t really like? To work all this out, I spent my own money buying 20 different callipers off AliExpress ranging from 76p up to £34 and I tested them to find out which are worth spending your money on. So today I’m going to share the results of my experiments, give out some fun awards, and share my favourite measuring callipers tested.
My goal in this article is to help you, a 3D printing hobbyist, find the right callipers for doing jobs like printer calibration and reverse engineering. Of course price will be a driving factor in our testing today but I’ll also be recording a number of other factors that could be important to your decision such as the measuring error, smoothness, readout responsiveness, and packaging. The full testing results will be available for youtube and patreon members, or directly via my website.
With all that cleared up, in no particular order, lets greet all of today’s competitors
Callipers Tested
| Number | Nickname | Model | Total Price (£) | Weight (g) |
|---|---|---|---|---|
| 1 | Carbon Fiber | SL150 | 2.56 | 55 |
| 2 | Mitutoyo Hulk Edition | 500-196-20 | 34.10 | 155 |
| 3 | Fantastic Plastic | F40(14)-02-07 | 3.15 | 16 |
| 4 | MituNoNo Greasy Boys | 530-122 | 20.58 | 149 |
| 5 | Blue Shae | 5110-150 | 25.81 | 167 |
| 6 | Off White Shae | 5000-150 | 25.81 | 167 |
| 7 | Notitoyo | KC33 | 18.19 | 160 |
| 8 | Hobbit Long Pockets | 150mm | 14.00 | 162 |
| 9 | Little Digits | 5112-150 | 19.58 | 155 |
| 10 | Pure Imperial Plastic | Imperial | 6.09 | 49 |
| 11 | Micro Plastic | G | 1.13 | 6 |
| 12 | Silver Slider | C | 4.07 | 50 |
| 13 | The Dark Blight | A | 4.07 | 46 |
| 14 | Moody Blues | CAM010 | 15.36 | 202 |
| 15 | Green Thumb | ET50 | 11.19 | 162 |
| 16 | My Eyes are Fine | FRDM730002 | 20.13 | 198 |
| 17 | Daily Drivers | MW110-15DBL | 26.50 | 161 |
| 18 | Always Measure Rong | NR350501 | 7.92 | 151 |
| 19 | Grandpa | 150 | 8.53 | 161 |
| 20 | Definitely Not German | 150 | 8.99 | 161 |
Calliper Testing Method
There are only really two full objective measurements in the testing. Those are weight and accuracy. For accuracy, I’m going to be measuring all three dimensions of a metric 123 block, that’s 25mm, 50mm and 75mm. I’ll wipe the tips and block and then take the readings. There is some bias in calliper usage since the applied hand pressure can change the reading, but I numbered the callipers to avoid recognising brands too often, and left weeks between measuring and purchasing so that I’d forgotten how much I paid for each of them. Hopefully that would reduce my chance of biasing my result based on which I thought would be better
For weight im using some precision scales. I just placed them on, let it settle, and recorded the number.
Moving on to more subjective tests. For testing the smoothness of the slide I tried to gently glide from one end to the other, and back again. I made notes on how it felt in terms of the mount of force and the consistency of the friction and then once I tested them all I graded them.
For the readout speed I made the judgement based on if the numbers would jump over large amounts at a time when I moved the slide. Large jumps means low refresh, small jumps means high refresh. While this doesn’t change the final reading, I think faster updating is preferable.
For the wheel, some had one, some didn’t. It’s useful for fine adjustments and one-handed use but not essential. I just checked if they had one or not.
For all of these tests I set out scoring too, so I could add the points at the end for overall winners, and filter different values to make decisions in different situations and thus award for different categories. The scoring distribution looks like this. As I consider them more important, price and accuracy are worth more points than the other metrics.
Results
Starting with slide performance, only 45% of the callipers tested had a smooth sliding motion. Of the callipers that were not smooth, most struggled due to manufacturing tolerance rather than dirt or lack of lubrication.
Moving on to the readout, half of them had a fast readout that didn’t lag significantly behind the motion of the slide which helps quick work when taking a lot of readings. As it takes some time to read I marked all the vernier scales as no here, even though they obviously don’t need to digitally update.
Although, vernier scales only accounted for 20% of the calipers tested, while digital made up 75%.
Of the 20 units tested we ended up with 12 stainless steel, and these often took the top spots in other categories with our 6 plastic units always finding their way to the bottom of the pack. This obviously cuts up our weight graph too with the 12 heaviest being our stainless steel options, and the 6 lightest being plastic.
When it comes to protecting your valued purchase, 12 of the 20 callipers had some form of protective case. You might expect a minimum price point to receive this but I even got a case with a £6 pair so at seems you could get this at any price point. Some of the more expensive options had really nice cases like those from SHAHE, but the MituNoNo Greasy Boys that were over £20 didn’t come with a hard case, just this plastic onea.
One quarter of the units tested didn’t use any batteries, while SR44/LR44 was the most common battery type, followed by CR2032.
Moving on to some real stats, this is the average error taken at 25,50 and 75mm.
At the bad end of the scale we have some of our plastic callipers and these were barely better than a ruler with an average error over 200microns for the “Fantastic Plastic” and “MicroPlastic” with the “Dark Blight”, “silver slider”, “pure imperial plastic” and “carbon fibre” coming in fractionally better with an error between 100 and 200 microns.
At the good end we had some quite impressive results from the “Notituyo” and my “Daily Drivers” with an average error of 7 microns, with a good selection in the acceptable range up to around 20 microns including the “Hobbit Long Pockets”, the “Definitely Not German, VonHaus” and a couple of similar tools from “SHAHE”.
If we now compare the reading error to their declared accuracy we find that 70% Pass and 10% fail with 20% not declaring anything. If we ignore those, its an 87% pass rate.
Moving on to the pricing. Unsurprisingly, the worst 5 competitors on accuracy also hold the 5 cheapest spots on the board, all coming in at less than £5. The Notitoyo are placed well given they had the best accuracy results too. Very much in contrast to the Mitutoyo hulk edition that failed on accuracy and are also the most expensive.
If we combine all our factors together using my scoring system out of 33, with the weightings distributed like this, we can get an idea of how they all stack up against one another. In this system the higher the score the better the result so the winner according to the scoring system is the Notitoyo. They were a great all rounder at a reasonable price as well as topping the charts for accuracy. Clearly not all Mitutoyo clones are made equally though, as the MituNoNo Greasy Boys took last place scoring only 4.69 points.
Awards
| Award | Judged on | Winner | Reasoning |
|---|---|---|---|
| Best to use in an MRI Scanner | Best all plastic | Pure Imperial Plastic | Fairly poor performance but 100% plastic (I think) |
| Marking Tool | Cheapest steel | Always Measure Rong (AMR) | Cheap and made of steel |
| Buyers Remorse | Most overpriced, worst value | Mitutoyo Hulk Edition | Green, poor performance, low quality, high price. |
| Pesimism | Best deliver vs. quoted figures | Silver Slider | Pretty terrible, but the manufacturer knew it and sold them anyway. |
| Smooth Operator | Best slide action | SHAHE Brand (all) | Well made, smooth action, consistent results |
| Best for Measuing Around Corners | Most Bendy | Fantastic Plastic | Nothing bends like these do |
| Best for Bad Eyesigght | Biggest Display | My Eyes are Fine | Fiddly to use, but the digits are huge compared to all others. |
| Best for Children (not actually) | Fewer sharp edges, cheap | Micro Plastics | They’re actually just bad in every way |
| Best Underdog | Underdog | Green Thumb | Low price and pretty good performance overall |
Calliper Conclusions
- Don’t buy anything less than £10/$13
- Don’t buy anything more than £30/£40
- Never buy plastic callipers for measuring
- In this price range, digital were preferable to vernier or dial.
- Buy a good battery separately, the included ones weren’t good.
Links
| Name | Total Score | Award | Link |
|---|---|---|---|
| Notitoyo | 27.34 | Best Overall | Link |
| Hobbit Long Pockets | 25.95 | Link | |
| Green Thumb | 25.72 | Underdog | Link |
| Little Digits | 24.19 | Smooth Operator | Link |
| Blue Shae | 23.19 | Smooth Operator | Link |
| Off White Shae | 23.19 | Smooth Operator | Link |
| My Eyes are Fine | 22.74 | Best for poor eyesight | |
| Moody Blues | 22.58 | Link | |
| Definitely Not German | 22.55 | ||
| Daily Drivers | 20.07 | ||
| Grandpa | 19.44 | ||
| Mitutoyo Hulk Edition | 17.62 | Buyers Remorse | Link |
| Silver Slider | 17.20 | Pesimism Award | Link |
| The Dark Blight | 17.20 | Link | |
| Always Measure Rong | 16.07 | Marking Tool | Link |
| Pure Imperial Plastic | 14.65 | Best to use in an MRI scanner | Link |
| Carbon Fiber | 14.61 | Link | |
| Micro Plastic | 10.00 | Link | |
| Fantastic Plastic | 9.45 | Measuring Around Corners | Link |
| MituNoNo Greasy Boys | 4.69 | Link |