LPL 4550XL Lens Stage Alignment?

[natelfo]

I just bought an LPL 4550XL enlarger (off the bay) and noticed the lens stage alignment is off. There is roughly 2mm (about 1/2 degree) difference between the left and right when compared to the negative stage, and about 4mm (about 1 degree) difference from front to back. This is definitely a lens stage alignment issue, as it is noticeable when the bellows are fully retracted, you can see it just by looking at the enlarger. The difference remains consistent as the bellows are extended.
Looking at the enlarger, I can not see any obvious way of adjusting the alignment. I tried loosening the set-screws that hold the lens stage onto the two rods, holding it square, then tightening the screws, but that made minimal difference.
Can anyone offer any suggestions on how to achieve proper alignment of the lens stage for this enlarger? Any help would be greatly appreciated.

Thank you,
Nathan

[Jon Shiu]

The usual way would be to shim the lensboard with tape, but yours is off by a huge amount. As you may know, the negative stage is removable, perhaps it is out of place?

Jon

[Oren Grad]

The LPL 4500 series uses small mounting rings, not square lensboards, so it's difficult to shim at the lens stage.

I have the masking attachment accessory in my 4500II. I shimmed my enlarger head by inserting little bits of card stock underneath the corners of the masking attachment.

[Keith Pitman]

Sounds like your lens stage is pretty far out, but this is what I found worked for minor adjustments: To align the lens stage, turn the lensboard until it comes into alignment, then tighten the holding screw until it starts to move the lensboard out of position, then back off just enough so it is firmly held and in alignment. At least some of the lensboards must be somewhat eccentric.

[natelfo]

One rod drives the focus, and it appears that the other is just for support. Is there any way to adjust the position of the rod itself?

[natelfo]

Does anyone know if there is a way to reposition/align the focus drive rod (the one closest to the filter module) by adjusting the focus mechanism (the part the focus and fine focus knobs are attached to and the rod goes through)?

[Jerzy Pawlowski]

I am not sure it will help but to get to rods first you must dismantle the lamp house. Place the head assembly upside down and then undo four screws. May be this will give better access to rods.

I understand your frustration very well. Two years ago I bought 4500 locally. Looked great at that time and I got all necessery accessories. Few days ago (just completed my darkroom) I wanted to start using it and what a mess. Now I am fighting column, you don't need laser, carpenter square is enough to tell that it was wrong. Base board is bent because of badly mounted column. I made a new base board from 1" good table top, looks stronger than original. Now I am trying to shim column properly. I did not get to the negative and lens board stages yet, but by initial trying with laser I can see it does not look very bad.

[natelfo]

I noticed that if you remove the lower stop (the screw with rubber grommet) from the lower side of the column, you can get the lamp house close enough to use a small engineer's square and check it that way. My negative stage seems just so slightly angled up at the front, side to side is perfect. I extended the bellows so that the lens would touch the baseboard, and can see it is angled up much more from front to back, and slightly toward the right. I think I will dismantle the lamphouse and see what I can see. I just got this enlarger to replace my CB7, and I want this thing to be as perfect as it can be so I can concentrate on much more important things, like printing!

[sepiareverb]

There are three screws at the lensboard that can be adjusted. Also, tightening the head to the column can help with alignment issues- check with KHB for their instruction book which gives great instructions for tweaking this enlarger which "never needs alignment".