LPL 4x5 Variable contrast filters 'sticking'

[beepix]

My LPL enlarger with the variable contrast head gave me some trouble a few months ago when I tried to calibrate my RH Designs enlarging meter. Today I tried to check the condition of the filters and noticed that they are sluggish in moving in response to rotation of the contrast knob. I suspect a bit of CLA is in order.

Would appreciate a pointer or two.
1. Especially need warnings about bear traps if I open the filter housing (the double wall between the bulb and the diffusion chamber), e.g. tension springs that might pop out.
2. Any insight on the life expectancy of the filters?
3. Who sells replacement filters?

Thanks

 

[bdial]

Probably the best place to check would be KHB photografix, http://www.khbphotografix.com

I've never had a reason to go into mine, so I don't know what's involved.

 

[Oren Grad]

The filter mechanism in my LPL4500II color head gummed up about a year ago, so I had it serviced by George Brown ("apogeebee" on eBay). KHB can do it too, but they would have been quite a bit more expensive. That was the first service it's needed in more than 20 years of use, so I couldn't complain.

I doubt you'll need to replace the filters unless you damage them in handling. Most likely, just the mechanism that moves the filters needs a CLA.

If you need parts, KHB would be the first place I'd call.

 

[paul_c5x4]

Most likely, just the mechanism that moves the filters needs a CLA.

Agreed - The CLS450 head on my Durst was being "uncooperative", so I opened up the casing to give it a clean. Found quite a bit of dust & dried up lubricants on the control rods and pivot points. Cleaned as much as I could with the use of cotton buds & alcohol, then gave it a very light lubrication with a sewing machine oil.

 

[beepix]

Thank you all! I will have at it with confidence, knowing there is backup if needed

 

[beepix]

There is joy in Mudville tonight! A bit of alcohol on a Q-tip and everything slides freely. Took care to spread lube on the cam surfaces again and other moving joints (white light linkage). Back to work now.

 

[paul_c5x4]

If the 745x enlarger heads are anything like the C7700 ones, they are of pretty simple construction. All it takes a little nerve to open it up.. Pleased to hear that you got yours sorted.

I don't suppose you took any photos while you had the covers off ?
That sort of information would help someone else contemplating a similar task.