Bell & Howell 483A Tire Replacement

[John Meyer]

I am working on a second Bell & Howell projector. This is the one I've owned since we got it new in 1961. It is a single format, Super 8 only. I finally got around to fixing the gears in the rewind reel arm but then found out that, when I got it all back together, it wouldn't run very fast. This slow speed has nothing to do with the arm that I fixed.

So, I replaced the drive belt.

For those who might come across this post, the belt I purchased is 3.40 mm (i.e., 0.133" or 1/8") diameter and somewhere between 9.0 and 9.5 inches inside circumference, depending on how far I stretch it on my PRB belt measurement tool.

To get the belt on, I removed the lamp housing and loosened the cardboard fan shroud. I was then able to stretch the belt and get it through the two gaps shown in the picture. That turned out to be pretty easy (I thought it was going to be harder, after all the old posts I read). I had to change the "forward-pause-reverse" lever to get the gaps to their widest. It was a different setting for each gap.

However ...

When I put it back together, it did run a little faster, but still not anywhere near full speed.

It is now clear that the two "drive tires", which I've shown in the picture below, also need to be replaced. I tried rubber rejuvenator, but it just didn't give them enough grip.

Question: does anyone know a source for these parts or, lacking that, some specifications?

[John Meyer]

I found the parts and they are on their way. The bigger problem will be installing them. The main drive roller (B&H apparently doesn't use the term "tire") makes contact on the inside of the shutter wheel and I don't see any way to get that off without disassembling a huge part of the projector.

Has anyone replaced the drive rollers on a series 400 Bell & Howell projector?

[John Meyer]

This is turning into a conversation with myself, but just for those who might read this in the future ...

I was able to replace both the forward and reverse drive rollers without disassembling anything. The forward drive roller, which is located inside the shutter wheel took about an hour of horsing around with various tools I have for prying things open (like iPods and iPhones). I did manage to dislodge two of the three shutter blade springs, but fortunately they were more or less intact and I was able to reattach them. There is just enough space between the end of the roller mechanism and the shutter housing to work the roller in and around the mount.

The good news is that the new rollers grip more strongly.

The bad news is that once the film is threaded, the projector still runs slowly.

Since I just fixed a dual 8 B&H of the same vintage, and since the claw on that was totally misadjusted, I'm going to get out my calipers tomorrow and check the claw on this projector. The reason I suspect that it might be the same thing is that as the felt pad ages (this is the pad that pushes the claw back and forth into the gate), it doesn't push the claw far enough forward and therefore the claw arm has to be bent forward to get to the correct "intrusion" into the gate. The other reason I suspect the claw is that when running in forward, the picture loses sync, even though the loop is just fine.

So, if I do fix it, I'll come back here one last time, just because I enjoy talking to myself.

BTW, I wish I'd set up the video camera to show people how to get the belt on without any disassembly. I guess if I figured it out, probably everyone else can as well, but it did take a little nerve to stretch the belt, to make it a little skinnier, and then work it through those to gaps shown in the picture above. I did get a new belt for the 456 that I fixed last week, so maybe I'll do the video on that one.

[Steve Klare]

Sorry John,

We're really not ignoring you! I think you should paste the link for this thread into "Index of Technical Topics - Please Contribute!"

https://8mmforum.film-tech.com/vbb/f...ase-contribute

-so it will be there when someone needs it. Discussion forums have kind of a horizon and it's a shame when a useful contribution slips over the edge and is not gone, but still forgotten.

This reminds me of a conversation from years ago:

https://8mmforum.film-tech.com/cgi-b...c;f=3;t=001734

Is this the same part?

[John Meyer]

Steve, thanks for replying. It was getting lonely here. 😀

I'll wait to add the link in the index of technical topics until I have finished my work.

As for that other thread, the OP was asking about the load tire that is found on the B&H dual format projectors. I've seen quite a few videos and posts across the Internet about that part because it must be made of a different type of rubber that is prone to degrading into a sticky mess. That roller/tire is found on the outside of the projector and grips the film and feeds it into the loop and down into the gate. As soon as the gate claw grabs the film, you are supposed to let go of the lever which engages the tire so the two don't "fight" over how fast to advance the film.

As for the tires that I'm talking about, you can see one of them clearly in the photo I posted in my first post above. It is the one at the top (the other tire turned out to only be used during slow motion and is therefore of no concern to me). The big metal wheel you see under the word "Tires" is the shutter wheel. The other drive roller/tire (which is the one used to drive the film forward and therefore is the most important) is mounted inside the shutter wheel. You can just barely see the black rubber from that wheel under the letter "S" in the word TIRES. I was able to pry off the tire from its hub, moving it to the left in the photo. There is just enough clearance between the end of the roller hub and the semi-enclosed portion of the shutter wheel to get the tire off and then work it out the back. As I stated above, if I had to do this again, I would pay a LOT more attention to the springs that operate the slow motion shutter blades (I assume they double the number of light "on/off" pulses to reduce flicker at the slower speed. I feel pretty lucky that I didn't completely destroy them. It took about 15 minutes to get them fixed and reattached.

Finally, since I am now doing this post more for other people who might some day need answers, the two tires in my 483 projector are identical and look exactly like a plumbing washer. I have the old ones sitting next to me, along with my calipers. Here are the measurements, averaged out between the two samples. I am posting in millimeters because I get more precision.

Outside diameter: 26.84 mm
Inside diameter: 18.43 mm
Thickness [should be (out - in)/2, but I measured this independently so there is a slight discrepancy]: 4.22 mm
Width (side-to-side): 4.50 mm (one was closer to 4.40 mm)

I bought these on eBay from a seller named isellprojectorbelts. He has over 14,000 transactions and a 100% feedback rating. My experience with him is that he (Mark) is even better than those phenomenal numbers would indicate, if that is possible. He implied in one of our emails that the two drive tires for other 400-series Bell & Howell projectors might be different size than these (for my 483), so anyone reading this may have to do their own research for their model.

Here is a link to the listing from where you can buy the "generic" 400 series tires (i.e., these should work for other people who do not have the 483):

Bell & Howell 400-Series Film Feed Tires, TWO PIECES

I paid quite a bit more for mine because he said the sizes were somewhat different ("higher"). What he sold me was exactly the right size.

[Steve Klare]

I know Mark well!

(He's kept me in the Movie Business for something like 15 years now.)

[John Meyer]

I put the new belt on the 456 and videotaped the process. If the video looks good, I'll post it.

I adjusted the claw on the 483 (the subject of this thread), but the picture jumps unless I set the frame adjustment to one extreme, putting a big part of the frame on the bottom of the screen. I clearly screwed something up because when I move the frame adjustment to the other extreme, the excess frame is still on the bottom. Obviously, if properly adjusted, it should give me an equal amount of frame on the top and the bottom as I move it from one extreme to the other. The service guide doesn't provide much help.

I'll poke around tomorrow and see what I can find.