Hi All,
Thank you all for posting and threads. Is a good resource. Wish I would have found this place sooner. Anywho, I’m squaring the XY on my machine build. Is the low profile vise base square enough to do this with? I have some 1-2-3 blocks but was hoping to use something bigger without delaying my build to far.
Thanks,
Nic
Do it correctly. Buy yourself a 2-4-6 block, or I will let you borrow one. Let me know, and I will ship it to you. By the way Welcome to the jungle… 
I’ll buy a 2-4-6 block or see if I can borrow one from work. I was just asking to see if anyone had confirmed how square the vise base was. Would be a pretty accurate way to square the machine since it’s quite long.
It’s not only for squaring but for dialing in CutControl calibration.
I don’t see a reason for the vise to be made square like a 2-4-6 block. Precision costs money.
Just get the right tool and do it correctly the first time.
Keep i mind that 1-2-3 and 2-4-6 blocks are not necessarily square. The 1.000" or 2.000" dimension will be really accurate, but not actually square to one another.
I had used a 1-2-3 when assembling my machine, after having some squareness issues in parts I checked the perpendicularity of the blocks I was using. There was around .0015" across the 3" length. Taking into account the 24 or so inches between ball screws (adjusting points) and it introduced a LOT of perpendicularity into the machine.
You can get a really accurate machinist square thats ground within .0005" over 4 inches for a reasonable price, and it’s well worth it in my opinion. When it comes to getting your X/Y or X/Z square, you want to be as close as possible for all future operations. It shows really bad when drilling holes over an inch deep when one side of the drill starts rubbing. Or when you’ve milled a “square” corner on a part only to find that it doesn’t quite assemble right.
All depends how accurate you want or need your machine to be. Sorry for the word salad.
Maybe this is true if you are using some bootleg 1-2-3 blocks. Squareness is a basic requirement of acceptable 1-2-3 blocks.
My Fowler 2-4-6 set (52-439-246-0) is square to under .0003" per inch (.0002" max deviation according to my calibration cert)
Editing to say - I take your point that a good square is more square, and I agree that’s important if you are milling wide parts and need great accuracy over a distance. I’m skeptical that it would matter for parts that would fit in a single vise station, or that you could reach with a jobber, if you square the machine with an acceptable 2-4-6 block.
The set I used during setup were a pair of Brown & Sharpe blocks that have been in service since the 80s or 90s. (Maybe I need new blocks 
) Their tolerance on the 1-2-3 dimensions is within .0002" but the squareness is not. Just putting my experience out there as something to keep in mind.
To each their own, just make sure your square surface is square enough for what you’re making.