Another noob with questions - Mendel Prusa frame mis-alignment

Hi! I am another first-timer, building a Mendel Prusa (metric). I will upload photos of my progress here:
[www.dropbox.com]

[EDIT: I have decided to create a blog to record the progress of the build, rather than just relying on some photos. See the blog here if you are interested: [julianh72.blogspot.com] ]

Sorry if my question has been asked before (a hundred times!) - I did a search of the Forum, but couldn't find anything relevant.

I have assembled the main frame, and have been pretty careful about the accuracy of all of the dimensions, but I'm not sure if I have been careful enough. When on a level surface, the frame stands on only three of its four feet (the fourth foot sits about 5 mm high), and the front and rear bars between the two end A-Frames are not quite parallel. I think the reason is that the threaded rods between the two A-Frames do not go quite perpendicular through the holes in the printed corner vertices (which I bought on-line). Each of the two A-Frames sat nice and flat on the ground before I assembled them together, and they overlaid on top of each perfectly, so I think the problem is with the rods connecting the two A-Frames, rather than with the A-Frames themselves.

My question is this:

Is this amount of mis-alignment normal,or do I need to something to rectify the alignment now before I proceed further with the build?

And what techniques should I use to improve the overall alignment - e.g. easing various nuts in and out, or start all over being more careful this time?

Thanks in advance for any advice!

Edited 2 time(s). Last edit at 08/19/2011 10:43PM by julianh72.

You need to get the base of the machine flat, otherwise the Y axis will bind because its two rods wont be parallel. Try loosening the nuts on the horizontal rods, press it flat so all feet touch the ground, and then tighten them again.

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[www.hydraraptor.blogspot.com]

OK - I thought that might be the case. I'll have a go tonight, backing off all the nuts on all the horizontal threaded rods a bit, then load up the frame with some weight and checking for level before I re-tighten everything. I'll report back with my progress.

Thanks!

OK - all sorted (I think!)

With a judicious bit of winding a nut in 1/2 a turn here and winding a nut out 1/4 of a turn there, I have the got the main frame sitting straight and plumb.

Thanks for the advice - probably saved me a whole heap of trouble down the track!

Update: I have decided to create a blog to record the progress of the build, rather than just relying on some photos. I will record my trials and tribulations, as well as solutions, for the benefits of others who may want to try their hand at building a Prusa RepRap.

See the blog here if you are interested: [julianh72.blogspot.com]