I have a GC4 that I need to relocate. I'm thinking about trying to set it up myself, I have plenty of time to kill.
If I buy a Starrett level should I get a 6, 8, or 12 inch level?
Thanks
6 is good, 8 is better, 12 is very expensive, but more accurate.
A 6 or 8 used on a beam, like a good carpenter level for better span is good.
6 is good, 8 is better, 12 is very expensive, but more accurate.
A 6 or 8 used on a beam, like a good carpenter level for better span is good.
Don't trust a carpenters level to be dead flat or as flat as a Starrett 98, you can use a carpenters level with a machinist level on top to level the frame but I do not suggest it on top of the slate and my reason why is this > I've found that most carpenters levels even with a machined edge are no where near as flat as the bottom of a Starrett 98 level. I've put two different quality/name brand carpenters levels on Starrett true stones and put my Starrett level on top with a piece of notebook paper in between to slide the Starrett level from end to end on the carpenters level on both foot print side.. The smaller the level I put on top the more void I found.
the carpenters levels can not maintain dead flat from end to end...those aluminum levels can really move with climate and use conditions.
SO, be careful my friends' and level responsibly
Rob.M
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That's exactly what this means Rob,,,,,"A 6 or 8 used on a beam, like a good carpenter level for better span is good"
That said, nothing like slow rolling balls for fine tuning if needed.
I think what Rob was saying was that the frames on a carpenter level are not as square as the measuring surface on the Starrett. I can put my Starrett 98-12 on different carpenter levels and get different readings on each level, I can also rotate the carpenter level 180 degrees and get a different reading. The carpenter levels are just nowhere near accurate enough for a machinists level, even just using as a straight edge. To make a short machinists level longer you need a precision straight edge, preferably ground. If you get lucky and test enough different carpenter levels you may get lucky and find a good one. All you need is a flat surface and your machinists level to test them. Put the carpenter level on a flat surface, then put machinists level on top of that, take a reading, rotate carpenter level only 180 degrees and see if you get the same reading on the machinists level. The test will only be as good as your set up accuracy.
OK, then just use a beam of some sort with exactly parallel sides,,, if you can find one. I stated a level as a pretty good beam that is readily available.
Note that a precision level can easily be calibrated to whatever BEAM you choose to use, it just needs to stay fixed after calibrating.
Have anyone try to leveling with optical levelling
If I buy a Starrett level should I get a 6, 8, or 12 inch level?
There are Starrett levels, and then there are Starrett levels.
Can't advise on length but you probably want the 98-series, which have ground vials and .005" /ft accuracy (per division)
The 97 series looks the same, but has bent glass vials like a carpenter level, and about the same accuracy; variously reported (on machinist sites) as around .015"/ft/division.
Point being, be careful not to pay 98 prices for a mere 97 someone is trying to palm off.
If you want to drive yourself nuts, get the Starrett 199. No, not really. Good for rescraping machine ways (in concert with a scraped straight edge & surface plate). But the .0005" (1/2 thousandth)/ft /division accuracy means it moves if you breath on it, or walk around the table to the other side, and it is off the scale most of the time, so really difficult to work with outside of machine rebuilding. :smile:
smt