Beseler MXT Disassembly

[M Carter]

I have an MXT with a broken tension spring in the bottom tube - looks like someone tried to align it and broke the holding screw, so - no tension, and the motor sounds a little rough. I recently found an MX that's in good shape, and I want to swap the carriage+motor assembly.

Looks like getting the neg and lens stages assembly off is straightforward; but how does the carriage come out? I'm guessing I'd run it all the way down til it's free of the track, and then remove the bolts and cross members from one side of the frame, allowing me to bend the frame away enough to free the carriage? I'm guessing the spring won't unwind in that scenario, since the carriage can be dropped down and re-engaged if it skips a tooth?

Anyone done this that can point me in the right direction? And should anything be lubed while it's all apart? Thanks for any help!

 

[John Koehrer]

Wouldn't be just as easy to drill the broken screw out and re-tension the spring?

Of course I'm assuming that once the carriage is free of the track, the new one is also going to lose tension.
You know what they about assuming things though.

 

[M Carter]

I understand the spring tension is really difficult to repair - someone here mentioned it once, required machine tools and so on. The spring is coiled up inside one of the cross tubes and held in by some sort of machined pin, and has significant (maybe dangerous??) tension.

But one of the steps of aligning the enlarger is to drop the carriage out of the track if it skips a tooth on one side, so removing it doesn't change the tension. No idea how that works. I may email KHB and see if they'd share some know-how.

 

[shutterfinger]

Perhaps the Exploded Parts Diagram will help.
https://www.beselerphoto.com/wp-content/uploads/2018/08/45MXT-Exploded-View-_-Parts-List.pdf

 

[darkroommike]

Call Beseler, 1-800-BESELER (really, that's their number).

 

[M Carter]

Perhaps the Exploded Parts Diagram will help.
https://www.beselerphoto.com/wp-content/uploads/2018/08/45MXT-Exploded-View-_-Parts-List.pdf

Thanks, I have that for the MX and MXT. I play around with the MX first and see how it goes. Did manage to get the neg/lens/bellows assembly from the mount, fairly simple.