The OpenBuilds PartStore says that V-Slot is available in 500mm, 1000mm, and 1500mm lengths. When they state those lengths, is there a tolerance specified for those measurements? Like +0.1 / -0 mm, or something? Being slightly over the length is OK, you can always cut trim it short... not so much if a piece is under length by 0.5mm or something.
You should get the length you ordered at minimum. It's that way with metal stock. I've ordered a lot of it over the years and most of time it's between 1/8 and 1/4 inch over if it's saw cut. The idea is you get what you ordered. Don't take my word for it. Inquire with the store.
How does one inquire with the store? I can't seem to find even a "contact us" e-mail link or something.
You can either email http://support.openbuilds.com/support/home or use the contact form on the about us page (or both).
Though my 'recent' experience, the V-slot seem to be close to 'standard' tolerance for extrusion, as seen with a few nearby extruders who referred to 'standard tolerance' as (from memory) "+3.25/-0". Precision cut to within +0.01mm is possible from some extruders ... at a cost. The V-slot I have received to date, have been as much as about 4 mm longer. Most were close to the +3.25mm. Not that I had that many lengths (to date). I started building myOX with as many full length as possible to avoid having to do precision cuts, especially with the three X lengths. It turned out to be my worst nightmare. Always measure twice, pre-cut (factory) or not (you cut them).
I plan on taking mine into work to mill myself, but have a back-up plan with a machine shop around the corner if this isn't cool with the boss. They'll face to equal lengths for dirt cheap. I don't know why there is a whole huge thread about cutting these things to length with less precise miter saws and boxes when it is light work for a machine shop to do on a milling machine. $20 for all lengths is well worth my time. They'll even tap the ends for a couple bucks more! It's all on how you talk to them. Basically, I need this one and this one the same length and so on. If your 1500mm pieces of stock both turn out 1499mm..so what. They're the same length. If you request them to 1500mm +/- some tolerance then you screwed yourself. just my 2c.