Cheap or expensive digital capliers?
A friend and I have a printrbot plus on the way. Should we get an inexpensive $15 tool from Sparkfun or spring for a higher end set from Mitutoyo or better? In the comments some users have verified the +/-0.001" accuracy. Is 6" enough for a printer with 8"x8"x8" build area?
https://www.sparkfun.com/products/10997?
I did the build of my #Printrbot without callipers, they’re not strictly necessary. Admittedly for final calibration they’re useful, so get the cheap one…
Calipers are used in my studio nearly everyday Im working on something. More than just useful for your printer. I haven’t had good luck with the tools at SparkFun in general but I bet those would be just fine.
I’m with Jeff on this one. Sometimes you can get their $15.99 6 inch calipers on sale for $9.99.
I work in aerospace manufacturing and personally own a set of starrets (expensive) and cheap $8 set from amazon… Both measure nearly identical. I start to see a .001 discrepancy between the two above 4 inches. My recommendation is go cheap.
Cheap is the way to go, for sure.
Go cheap. Buy four for the price of a good one. You’ll never notice the difference – because you’re using a micrometer for when you really need precision, right?
It’s absolutely imperative that you own a set of digital calipers. You can clearly tell the people who don’t by the results of their prints.
Cheap. They rely on a printed/etched pattern of capacitors that work like an electronic vernier: http://www.flickr.com/photos/50241702@N04/5227386500/in/photostream/ It is hard to manufacture them unreliably. You’ll lose more accuracy by not controlling the temperatures during measurement than in the quality of the calipers.
A digital tyre depth gauge has the same vernier mechanism, even cheaper.
I got my cheap calipers from ebay and their great.
I have one of these, and just last night was comparing it against a 1", 2", and 4" guage blocks. It was spot on, as were the Harbor Freight 0-1", 1-2", and 2-3" mics I bought. They are not Starrett but they will do in a pinch. I know folks who use the cheap ones around hard surfaces where they
might drop them. Better to drop a cheap pair than your “reference” tools.
I have at least half a dozen different pairs, and this is by far my favorite: http://www.amazon.com/o/ASIN/B000UCIGCW/?tag=dp-us-20 I have several cheap ones, and some are perfectly usable, while some are noticeably deficient. The Harbor Freight ones are OK. If you want to be able to measure fractional inches, definitely go for the ones linked above. All the other brands I’ve tried with that feature are at the bottom of my list.
Heck, HFT has their 4" or 6" perpetually on sale. Perfectly fine for the purpose. If you don’t have a way to make stuff to 0.01 mm tolerance, no point fretting about the accuracy of the last 0.01 mm…
The key difference between high-end calipers and the econo-calipers is that the high-end calipers know their absolute position, which the econo-calipers keep track of their position, but will lose their place if the power goes out. (See http://www.robotroom.com/Caliper-Digital-Data-Port.html - under Caliper Power Source)
And, correspondingly, the lower priced calipers will eventually eat through their battery from just sitting there.
I actually bought mine on Amazon for $9.99 and it looks to be pretty much identical to the sparkfun one. It was SUPER helpful when I assembled my printrbot (classic ABS kickstarter version). It has been even more helpful as I have moved on to trying to fine tune the calibration. My cheap-o little calipers never let me down!
I have a cheap digital one and a 25 year old Mitutoyo mechanical. Both work just fine and i use them many times a day. I wouldn’t know what to do without them.
That a chinese model you can get for $6 (cheaper, digital ones for $2.99). You can trust it to 0.05mm but not really more even as it displays 0.01mm increments.
It should be 150mm instead of 6".
I have beautiful Brown and Sharp calipers