8mm Forum: Bell & Howell worm gear.

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Posted by Tom Photiou (Member # 130) on February 03, 2004, 02:35 PM:

I know this is an 8mm forum but please read on.
I was informed today of the passing of the gentleman who was sound and screen services, he was also a B & H specialist and the main outlet for spares, i was told by a well known repair chap in Stoke on trent that his son has no knolage or inclin on the cine buisness and when a worm gear was requested a picture of one had to be sent so he knew what he was looking for [Eek!]

As i understand it there are two types of gear, animated and non- animated. The main ones in use,(i think)are Animated, (for use with still frame) These gears are the main problems with these otherwise bullet proof machines and it was suggested that i try to get some made as without them the machine is finished if new ones dry up which looks like they are. These worm gears have been used in these machines for the last 40 years from the 640 right up to the TQ1, TQ2 and TQ3 all models in these series.
You boys out there are in the know, would that be an excercise worthy of me persueing? I am happy to have a go if there is demand, maybe i could get the cost of an all metal one. [Wink]

Posted by Tim Christian (Member # 48) on February 03, 2004, 03:13 PM:

Tom,
CHC were selling them - have they still got any?

What's up with this one - is it split or worn?

Posted by John Whittle (Member # 22) on February 03, 2004, 06:06 PM:

Replacements are still available in the US and I though that someone in the UK had a "brass" version.

The problem isn't the worm gear (since you can get those) but installing it is no simple matter. Ideally you need the Bell & Howell jigs although there are some who have done this without them. You have to be careful or you'll lose all the adjustments of the shuttle when you do the replacement.

Ultimately, it's cheaper to find a "working" machine.

John

Posted by Kevin Faulkner (Member # 6) on February 04, 2004, 07:48 AM:

I think as John was saying there are a load of these worm gears about and certainly several sources in the UK. I thought the animate (still frame etc) one was the least common. Having said that I dont know how long that will be the case.
I have managed to do 3 B&H TQ's without setup jigs. I have not been able to see why there should be a problem doing these yourself. What may happen is that when you put it all together there could be a + or - one frame shift in the upper or lower loops. I have written down the number of frames there should be and feed some film into the mechanism before final assembly to make sure the required number of frames is correct. It's worked for me each time. The rest of it just seems common sense to me.

Kev.

Posted by Tom Photiou (Member # 130) on February 04, 2004, 12:33 PM:

Thanks boy's, thats a bit of a relief for me as i would like to concentrate on the Elmo drives for a while longer,i.m still getting enquries and hope the review in the next FFTC may get me enough new requests to do another run + the 18 fps unit,
cheers chaps, [Wink]

Posted by Mikael Sundstrom (Member # 150) on February 04, 2004, 02:43 PM:

Speaking of worm gears and in the context of registration... Was there ever a projector in the Super 8 format featuring any of the sort ?

Posted by Ian John (Member # 26) on February 07, 2004, 08:34 PM:

Hi Tom,

You can still get the "Worm Gears" from Classic Home Cinema, and I think they are made of brass. They are made for the Non-Animation Bell and Howell's, but you can fit them into the projectors that have the animation facillity, but you must dissconect the "Animation" function so it cannot be used, but the Worm Gear will fit both types of machine.

The only difference between the two gears is, the "Animation" worm has a "Clutch" and the other worm dosn't, but as John W. said above, it can be a pig of a job to do your self.

The other place I think sell's "Worm Gears" is "Edric Audio Visual" London.

Hope that helps.

Ian. UK.

Posted by Kevin Faulkner (Member # 6) on February 08, 2004, 03:04 PM:

Mikael,
Actually all the Elmo super 8 machines have a worm gear. Have a look in the back the next time you get a chance. It's the easiest way for a projector manufacturer to get drive from the main shaft to the sprockets so many other machines will have them.
What no one has ever told me is what happens on a B&H if this so called timing is out of kinker.

Kev.

Posted by David Park (Member # 123) on February 09, 2004, 04:46 AM:

Tom in response to your orginal post and the gentleman who had B&H spares who died and his son not having them.
The spares are with "Steve Rouse" whos e-mail is spr@streb.co.uk
I bought some spare belts from him at the end of last year, I also know he has worm gears as he was selling some on E-bay. Found him helpfull and quick with del'y.

Posted by John Whittle (Member # 22) on February 09, 2004, 09:59 PM:

Kevin,

The most common problem of "timing" is the position of the sprockets to the shuttle such that the loop isn't set properly in autothread. It's critical and one of the reasons that these autothreaders are often called "autoshreaders" in the states.

Bell & Howell made a bunch of tools and jigs to use on these machines to set sprocket position, adjust sound head position, check solar cell pick up etc etc.

With the gear out it's possible to turn one of these shafts and throw off the timing. Of course if the gear is broken, then the timing is probably shot before you start your project. Just another reason service manuals come in handy.

John

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