Omega 4550 XLG focus knob won't stay in place

[Chuck_4x5]

The title says it all, are there any other users of this enlarger that have had this issue and how can I fix it. I don't currently see a set screw of any sort that I may be able to tighten. Thanks.

[anphotoart]

I've had a similar issue with an older enlarger, and in my case, the focus knob kept slipping because of some wear. If there’s no visible set screw, it might be a press-fit knob, so you could try gently prying it off to check underneath. Sometimes, debris or old grease can cause it to slip, so cleaning and applying a bit of graphite lubricant helped me. If nothing seems to work, it might be worth checking if the internal mechanism is worn out or if any parts need replacing.

[Chuck_4x5]

Thanks for the info.......I have since posted the same question on Photrio as well and a fellow told me about the screws directly behind the focus knob on the right side. Of coarse I saw those screws but they all looked like just structural in nature with basic phillips heads. But it was the very bottom screw that was actually the one that adjusts the friction on the focus knob. So I was relieved......but thanks.