Quote Originally Posted by EHM2 View Post
The negative holder and the lensboard stage on the Beseler are castings that slide relative to each other up and down an accurately machined and ground bar of steel. If the castings were beefy enough this would be an ideal design. They are not beefy enough as they are made of rather thin aluminum or pot metal, but they are usually good enough. Once you put the adjustable lenboard on, you can quickly adjust the two planes to be parallel and they will remain so. This presupposes that the stages are in good working order with their bearing surfaces (brass and later plastic) properly tightened with those little screws. As discussed above, this is the critical part of alignment and Beseler did a good job of handling this issue. Less well handled is keeping this whole fixture parallel to the base as the motor whirs the whole assembly up and down. Suffice it to say that the engineering on this aspect is not very good, depending on a fairly flexible frame work of thin steel frame and struts. But this is less critical as the depth of focus at the paper can be half an inch. The laser doesn't know which measurement is more critical and will scare you unnecessarily as you watch the red dot wander around. So before you haul your 45M away or put a sheet over it in disgust, get the adjustable lensboard and relax.

Hypocrite alert: I mentioned before that I have both a 45M and a Saunders. In my darkroom, currently set up, is the Saunders, but if I had more room they would be side by side. However, I bought the Saunders (at many times the expense of my $50 45M from the '50's) for the convenience of the VCCE head and the fine focus + extension - before I bought the Versalab and got hypnotized by red dots.
Until the struts are properly set, you will be realigning the beseler enlarger everytime you change the height of the head. In reading this thread again it's apparent that this is underappreciated if not totally misunderstood so much so I now suspect that 99% of the alignment problems that vex beseler mx owners could be traced back to this misunderstanding. Instead of clamoring about alignment tools and adjustable lens boards this dorky debate should really be about the relative merits and shortcomings of a protractor vs. an angle finder.

The Versalab is a convenient albeit pricey tool to measure the parallelism of the three planes. But the degree of accuracy it provides is really only necessary to printers who need or who prefer to expose with their lenses wide open and who are using glass carriers. A piece of safety glass and a bubble level will suffice for instances of enlargement under 20x or for folks who prefer to stop down a stop or more.

In the case of the 150mm apo componon f4, parallelism at the lens stage is accomplished by adjusting the three spring-loaded thumb-screws that retain the lens stage plate to the camera. These adjustments should only be in the order of fractions of a millimeter. If you find that you need more adjustment at the lens stage then you have something set up incorrectly.