8mm Forum: How to change a worm gear.

This is topic How to change a worm gear. in forum 16mm Forum at 8mm Forum.

To visit this topic, use this URL:
https://8mmforum.film-tech.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=5;t=000363

Posted by Dan Lail (Member # 18) on October 24, 2008, 02:52 PM:

I am ready to change worm gears in a B&H 2590. What assemblies do I need to remove in order get to the worm gear? [Confused]

I have a Filmosound Service Manuel, but it doesn't tell specifically how to get to it.

Posted by John Whittle (Member # 22) on October 25, 2008, 08:06 PM:

Dan
In the best traditions of Bell & Howell, the way to do this is with the factory jigs to set the timing of the various pieces. Once you tear down to the worm gear, you lose the timing of the cam/claw/shutter.

Some have successfully done this by carefully marking the timing of the parts before disassembly. But it's quite a job to get the worm out and in.

I would suggest that if you have more than one machine, you use a part donor to learn the procedure and sequence (alot of which you'll have to come up with on your own) to get the part out and know how that other pieces need to come back to stay in time.

Good luck. (That's why it's usually easier to just keep buying machines until the break.)

John

Posted by Maurice Leakey (Member # 916) on October 26, 2008, 03:58 PM:

Dan

You'll really need the correct Bell & Howell tools to do the work. I've never attempted such a difficult job. But if you do proceed I wish you luck.

Posted by Georgios Tsakonas (Member # 1326) on October 29, 2008, 05:44 AM:

[Frown]

I did it!!! But i hope not have the need to do it again!
I have 3 B&H and 3 new worm gears.I repaired one of them .
You must loose a lot of the pojectors parts.I spend 2 days of
hard work, but the resolution is not perfect. For some reason
and for some films, the clow jumped and the lower space of the film is desapeared.I was trying to fix the problem . In the BFCC
i got the projectors service manual , and a special tool for controlling the clow.I hope that i will have some good result.
Good luck!

Posted by John Whittle (Member # 22) on October 29, 2008, 09:40 AM:

That tool (if it's the one I think it is) is necessary to set the proper timing of the claw to the two cams. There is an up and down movement and an in and out movement and they must be set properly so that the action of the claw looks square on the top and bottom so it make a clean insertion, pull down, and clean exit.

You loose the loop if the claw retracts before it's come to a dead stop at the bottom or if it starts it's downward movement before it's made a full movement forward.

In some cases you can get it close until a splice comes through and then the slight difference in film exceeds the setting on the claw and you lose the loop.

So it's either a lot of trial and error --or-- you use the B&H jigs to set the timing.

This isn't unusual for B&H BTW, all the Filmo and Eyemo cameras require a couple of fixtures to set the shutter to the claw and cam as well.

John

Posted by Mark Todd (Member # 96) on October 29, 2008, 05:00 PM:

By far the best way to sort out the worm gear in a Bell and Howell for good is to buy an Eiki really !!!!!

Best Mark.

Posted by Chip Gelmini (Member # 44) on October 29, 2008, 08:38 PM:

Dan, try Richard Patchett in Minnesota. He's a member here just look him up. Replacing a worm gear is a big job, the machine has to be really worth saving to do it.

cg

Posted by Richard C Patchett (Member # 974) on November 01, 2008, 10:45 PM:

Worm gear replacement is major overhaul. To change it requires EXTENSIVE dis assembly of the mechanism (once it's removed from the projector of course!). Once you start dissembling the mechanism you lose all the critical adjustments which require the special (expensive) Bell & Howell tools & jigs to readjust/realign. The new gears are colored black to distinguish them from the old style plastic

It takes at least 4 to 6 hours to open / replace that worm gear / and to REASSEMBLE your B&H correctly.

Average cost worm gear replacement job costs around $250 per machine. but it's well worth it because you get a guarantee and the new style worm gears are made of much superior materials that the projector will provide many, many more years of use

One could replace only the cracked worm gear, but it is almost the farthest thing into the projector. Half the labor is expended just accessing it. And, the projector probably wouldn't be happy and might have wow in sound and picture instability, because sprocket spindles may be dry of lubrication, a sprocket gear may be warped, sound head needs attention, shuttle needs adjustment, uneven take up drive, etc., etc.

Oh by the way I'm in Michigan
Thank you Chip for the referral

[ November 02, 2008, 02:35 PM: Message edited by: Richard C Patchett ]

Posted by David Michael Leugers (Member # 166) on November 02, 2008, 07:24 PM:

Lots of people tend to trash the B+H projector line because of this problem. What we are missing it that properly adjusted and maintained, is there a better machine out there for the price that produces the rock solid image and sound, can handle the worst of prints effortlessly (3 tooth claw), is imminently maintainable(lots of spare parts) and is just a great machine? I think that $250 for a tune-up and worm gear replacement is a bargain. With that you get a perfectly running machine ready to outlast you.

Posted by Dan Lail (Member # 18) on November 19, 2008, 09:58 PM:

Thanks, everyone, for the advice. I had disassembled the projector and renoved the mechanism assembly with no problem, but when I dissected the mech.assm. that's where I goofed. I didn't know all the gear positions needed to mark for reassembly. After installing the new worm gear I couldn't get the bottom and top film loops to synchronize. I ended up sending just the mech. assm. to Ken Layton for cleaning up and adjusting my fun time in gear land. His prices are more than reasonable.

Posted by Brad Kimball (Member # 5) on November 21, 2008, 08:20 AM:

Roughly, what do you think he would charge to replace the worm gear and fine tune a 2580 or 2585? I understand we would be discussing mere ballpark figures here and that price would entirely depend on what would need to be done once he got started. Spoke with KMR Electronics and he turned me away. Apparently KMR prefers only to work on the traditional "green" B&H models and not the later "brown-black" models. KMR will not repair slot-loaders either.

Posted by Bill Brandenstein (Member # 892) on November 21, 2008, 03:48 PM:

Oh great! My 2592 has some hours left, I hope, but who knows how many.

Why won't KMR do the later ones? Hey, Dan, you might have a side business pretty soon here!

Posted by Brad Kimball (Member # 5) on December 27, 2008, 10:21 PM:

Richard, I meant no disrespect. I asked about Ken's pricing because I was unsure if in your reply you were emphatically stating that you offer the repair service yourself or if you were simply estimating what it might cost to have someone do it. I know you've been in this hobby an awful long time and I truly respect and enjoy reading what you have to say.

Posted by Dan Lail (Member # 18) on December 28, 2008, 10:40 PM:

Brad, click my name over my pic and send me an email. [Smile]

Posted by Brad Kimball (Member # 5) on December 29, 2008, 11:55 PM:

I called KMR about 18 months ago and the gent on the phone (I'm assuming he was the owner, but I'm not positive) said that he never liked slot-loaders and that he only repairs auto-loaders. He also went on to say that it would be very expensive and that unless there was some special sentimental reason for repairing what I had - it would probably be in my best interest (financially) to simply discard what is no longer functioning properly and seek out another 2nd hand machine. I don't entirely disagree with his assessment. However, truth be told, at what point are you spending more for replacements than what it would cost to fix ole "Belle" (this is what I call my B&H models - I refer to them as "Belle" 1, "Belle" 2, etc.). It's silly, yes, but I believe everything, organic or not, has some kind of personality and it helps to inflate the respect for all things great and small by giving them a name. I prefer slots because in the event of a calamity you can get in there mighty quick and there's less risk of "chewing" up yard after yard of celluloid.

Posted by John Hermes (Member # 1367) on December 30, 2008, 01:43 AM:

The trouble with "another second hand" machine is it will probably have a cracked worm gear as well. The last two B&H projectors I won on eBay had them. A guy I know picked up a lot of one hundred and fifty new 2575 projectors and every one has a cracked worm gear. It really is a plague and a shame. I was able to get a 1585 with a replaced black worm gear. I did some clean up and lubrication on it, and now it's a very nice and quiet projector. Even though there are lots of cheap B&H projectors on eBay, each one is a gamble unless you know the condition of the worm gear.

Posted by Richard C Patchett (Member # 974) on January 01, 2009, 09:55 AM:

Greetings Brad
Brad wrote Richard, I meant no disrespect.
No disrespect here.
Its always good to check out pricing.
As i said, Average cost worm gear replacement job costs around $250 per machine. worm gear only
If i get the whole projector. I go through it And replace other parts as necessary If one of the plastic gears is worn down and or missing a tooth that gear is replaced. I have seen many gears that are worn down not just plastic but even the sprockets that are metal have worn down teeth that chews up film in path
This is were the extra cost comes from.

Posted by Brad Kimball (Member # 5) on January 01, 2009, 02:13 PM:

Thank you so much for replying. I wasn't sure from your original post if you actually hired yourself out for the work or if you were simply just guessing at what it would cost to have someone do it. Nice to know that you're available and that you do perform a thorough inspection of all parts and not just the one worm gear. Thank you again and now everyone here knows that you do perform these services - Terrific News!

UBB.classic^TM 6.3.1.2