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dmoore
Sat 03 May 2008, 17:05
On drawing 10 10 300 W A, in the upper right corner it says "This dimension tightly controlled during welding" then below it says "CRITICAL". Is the critical reference more for making sure that the distance between the outside edges is even and consistent throughout the length of the two beams or is it refering to the Y+430mm (17") distance.

The reason is that I am .5" under the Y+17" dimension but it's spot on across the entire lenth of the two beams. I'm assuming I already need to make up for this on the gantry so everything will line up - correct? Anything else?

Thanks,
david
Gerald D
Sat 03 May 2008, 21:52
The reason that you are a consistent 0.5" under is probably because you took the cross-supports (1010302S) as giving the width of the table. The cross-supports are 1/4" short on each end to give space for a decent weld.

Personally, I would not adjust the other dimensions to suit. Execute drawing step 10 10 300 D as per drawing. The 2.5" wide angle iron rails can live happily with the extra 1/4" overhang.

Why did I mark that dimension as CRITICAL? Well, I had hoped that folk would not take the cross-supports as the finished width. I had to say something to make them stop and think. ;)
dmoore
Sat 03 May 2008, 22:34
The reason that you are a consistent 0.5" under is probably because you took the cross-supports (1010302S) as giving the width of the table. The cross-supports are 1/4" short on each end to give space for a decent weld.

That would be the case - I lined up the ends of the cross supports to the edge of the main beam. I suspect they also look better set back from the rails the way you have them. :( I bolted my table so the extra space wasn't neccessary.

Why did I mark that dimension as CRITICAL? Well, I had hoped that folk would not take the cross-supports as the finished width. I had to say something to make them stop and think. ;)

That red color comes out as light grey when I print in black and white... it was that or that I just didn't pay attention. On my second MechMate, I'll do it properly. :)

Thanks,
david