vibration in durst enlarger ventilation fan

[Herb Cunningham]

If anybody has the Durst 184 laborador with dichroic head, here's a new question:
do you know if the version that has the ventilation fans inside the diffusion box below
the dichroic head gives problems with vibration?
I have to get new fans, as mine did not come with fans, and I see in Durst's manuals
that they have two versions, one with the fans in a box remote from the enlarger, and
connected by hoses, and one with the fans integral to the "lacobox" which is the big
diffusion glass holder below the light source.

I thought it wise to ask. Jens is not around anymore, and the folks at Durst were most
likely children when my enlarger was built. I have sent Glenn Evans (Glennview) this
same question, but it is always a good idea to ask the forum.

Many thanks

[resummerfield]

Which colorhead do you have--the CLS 300 or 301? Or do you have the CLS1840 which also fits?
The fan on the CLS1840 turns at a pretty high RPM, but I don't notice any vibration. I think any quality fan could be carefully tuned and balanced to eliminate almost all vibration.

[Herb Cunningham]

It is the cls 300.

[resummerfield]

After thinking about this, I think an external fan would likely give less chance of vibrations. Also, with an external fan, you could assemble something cheaply, and maybe better, from non-Durst parts. But remember, I have no experience with the CLS300; only the CLS1840.

[Michael Rosenberg]

Try giving the folks at Jensen Optical a call. They are very knowledgable and have good service.

Mike

[allen curtis]

You can buy two squirrel cage fans from granger to blow into the head, using the bottom hose connects. The top two are the exhausts. Hose is hard to find. Mount the fans on a wall. I built a relay box so that the fans are switched on for the exposure and focusing and then shut off afterward between 20 sec and three minutes later. One set-up I have has the fans, switched on 220, mounted in a filter box. The other switches on 110 and is a tandum fan, two blowers on one motor, and has filters over each intake.

Jensen is still around. He called me yesterday about a contract issue that I thought had been settled last year. It's not for public forum yet, but getting close.

If I can help, let me. The relay box is also so that I can switch the 220 head circuit on using a 110 timer.

[Juergen Sattler]

Allen, do you have a schematic of the relay box you built? I just bought a used Durst with the 184 Dichroid head - it's not hooked up yet because I need to get an electrician first to install a 220 line to the enlarger. I was wondring already how I would solve the problem of the timer being 110 and the head being 220 - seems you figured that out. You can also email me at sattler123@yahoo.com. Thanks: Juergen

[Herb Cunningham]

Allen: I would be overjoyed at some details about the relay hookup. Since I wrote this post, Jens got in touch
and sent me a custom made box with two fans that hook up to the 220v controls on the power supply.
I am mounting the box this weekend, but I still need to get an axial fan to pull the discharge from the two fans
to the outside, so Jens tells me.

I am an engineer with enough electrical knowledge to hook up stuff, but I am not relay savvy.

My email is tgyatso@earthlink.net

Thanks