Bell & Howell 16mm Film Projectors: Failing Worm Gears and Belts 

You're very welcome. BTW, those videos on replacing the worm gear don't discuss how to properly time the upper and lower sprocket so the film feeds properly after gear is replaced. I did make a video on doing that manually here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ilrn5polPMo.html There's also a link in the comments to the 16mm Film Talk forum discussing that topic...lots of info on that site. Good luck!

Larry and his tech will help you troubleshoot this. In the meantime, do check that the film is snug where it goes around the sound drum. The sound flywheel (inside) maintains a constant film speed at this point, with two spring-loaded guide rollers (outside, top and bottom) maintaining a light pressure on the film around the sound drum. If the rollers stick, that can cause wow or flutter in your sound. Without film loaded, manually try moving the guides apart and up and down by hand to see if they are sticking; if you pull them apart, they should snap back together. I've had to clean/lube the pivot point inside to get them freed up if they stick. This is not easy to do, since the pivot is inside the sound housing and behind the flywheel. Work with Larry on this. Here's a link to illustrate where the sound drum and rollers are: drive.google.com/file/d/1BekulMNqzxB8ZvB6I6CdWwPRT90kqypU/view?usp=drive_link

@@mp5802 thank you for your response. I'll check that. I do know that Larry checked the projector and made sure it is maintained. He's great. And everything seems to be now running correctly, on the same films that started having the issues. I remember one of them had some bad sprockets which caused the automatic loop restore have to kick in. When I ran it again, the projector then handled that same section with no issues. Although I think the problem of the running of the film was from the beginning to end with the wobbly uneven speed when I first started having issues. I'll keep testing it, I still have some time with Larry's guarantee.

I'm sorry, that topic is just too complex to summarize in a comment. Look around on RU-vid, and you'll find a few decent videos about it. Good luck.

Sorry but I've never worked on one of those models, although they're probably similar to the 1500 and 2500 series. If you can hear a small hum (motor) from inside the case when you turn the switch on, then it might be as simple as the belt slipped off. At least, take the back off the machine, turn it on and see if the electric motor is spinning. Otherwise you just have to get your voltmeter out and track down the problem.

Actually, there is no set screw that holds the worm gear on the shaft on a still- function machine (the ones with the clutch). The gear on those freewheels unless the clutch is engaged. They are kept from moving laterally with a circlip that goes around the shaft on both sides. I don't have a video to show you about that.

@@mp5802 if you can make a video to show me ill venmo you 30 bucks. Im completely stuck until i get some help.

Sorry, no, but there are several good videos on this topic on RU-vid. The procedure to replace the worm gear in the 1500 and 2500 series are all very similar.

Send a photo of the springs to mp5802@gmail.com

It is very old. I will try to find out what year it was made.

I've never worked on that earlier Bell & Howell series, so I can't say. Looking at photos of that model, it's an entirely different design than the 500 thru 2500 models that my video relates to. Perhaps, you can browse some of the film forums and ask your question. Try 16mmFilmtalk.com

Nope, not that I've ever heard of

@@mp5802 do you still do the repair? I just acquired a 1580C. I haven't checked the worm gear yet but I just wanted to ask and see where you are located.

@@mcqproductions7803 I haven't repaired one of those worm gears for about a year. I have several in inventory awaiting repair if I ever get around to them. .. kind of lost interest I guess. I'm retired and living in Rancho Cordova California

@@mp5802 No problem I understand.