Chinon 6100 too fast and a bit unsteady

[Chad Shumaker]

Hello All,

Just picked up a Chinon 6100 for a song. Put a new belt on, removed old gummy grease and regreased gears. Gave it a run and...

Picture is nice and bright, sound is pretty good, but it seems to play a bit fast. The sound is definitely higher pitched than it should be. Also having a hard time keeping the picture steady. It wants to move up and down ever so slightly. Any suggestions here?

[Brian Harrington]

I'm having a similar problem regarding steadiness with a NOS 7500. You may want to piggy back onto my thread to discuss, since they are similar machines: https://8mmforum.film-tech.com/vbb/f...00-help-please


Regarding the speed issue, running too fast is better than running too slow. At least you know it's well lubed and there is no drag. I don't believe the 6100 has the slight speed adjustment knob above the 18/24 switch. In that case, you may need to adjust the potentiometers on the PCB, since a new, tight belt can (but not always) cause any machine to run a bit fast. The location of the potentiometers varies from model to model, but there should be at least 2, and possibly 3. One for 18fps, one for 24fps, and sometimes one for rewind. They are not always marked clearly, but if you're lucky, you will see an 18 and 24 marked. If not, you just have to do a trial and error, as I had to do with one of my Sankyos, which also buried them in a hard-to-get place. I've never mucked with them on my Chinon 7500, though, nor have I had to use the slight speed adjustment knob -- I keep it set at "neutral."

[Brian Harrington]

Another thing I might add--

After you use the machine for a few hours, you might find that it starts to run at the correct speed. I recall slowing down a machine with a new belt, only to later have to speed it up again after the belt settled in and stretched a bit. Really depends on how big a deal it is to adjust the potentiometers. You need to use a non-conducting screwdriver if you adjust them with the machine running, for safety purposes.

The adjustment usually needs to be very, very slight to get it to a speed that sounds right to you. The other thing is that you need to hook up an external speaker to make it easier, since with the back cover off, which holds the speaker, you can't hear anything! I find that I need to play a film I know well and use my ear to judge if the pitch is right. A tad slow is better than a tad fast in terms of a margin of error, since the ear is more sensitive to recognizing the pitch being too high than too low. But everyone's tastes are different.

Don't sweat it to get exactly 24fps, because these motors that vary in speed depending on voltage will speed up or slow down anyway due to fluctuations in your mains voltage -- but rarely enough for the average person to notice.

Which brings up another point -- is that a multi-voltage model? Chinon usually added the MV designation if so, but not always. If MV than you can change the mains voltage setting. Sometimes there's a knob to turn, sometimes you have to connect the wire to a different terminal on the transformer. The factory setting is usually 117 volts in the U.S. Setting it lower, to 110, will increase the voltage to your motor, since the transformer thinks it is only getting 110 volts, so it has to up it to match you mains. In your case, you probably want to try increasing the setting to 125 if it is set at 117. Or to 117 if it is set at 110.

Lowering the voltage setting also will make your lamp brighter, with the downside of it lasting for a shorter amount of time. But in your case, you will notice the lamp is dimmer if you increase the voltage setting on the transformer.

Make these setting changes with the projector unplugged!

Good luck and let us know how it goes!

[Chad Shumaker]

Brian- Thanks for the advice! One problem solved!

I found the proper pots and adjusted ever so slightly to tweak the speed. Got the right one on the first try and a very slight turned gave me the perfect speed.

Now as far as the unsteady frame, I'm stumped.

[Brian Harrington]

Glad u fixed speed issue.
Have u read my post I linked to regarding my Chinon? It is NOS and has unsteady image on certain prints. I go over all the checkpoints in that post. Since it is NOS, the only conclusion I can come to is that it is finicky with prints. Lubing may help problem prints but I havent tested any yet. The issue is the fixed width gate that I assume yours has too. Every other projector I have has one side of the gate spring pressured to allow for small variations in film width.

The research I did before buying a Chinon claimed only the 330 model had this gate but that info was flat out wrong.

I avoided Chinons for years since I read they scratch and eat film. Mine does neither. They are popular on auction sites and sell very well in all conditions. An unsteady image is a deal breaker for me, and I know from many years experience that if u need to lube a film to get it to run steady, the projector is the problem.

One film that runs rock steady in my Chinon I bought new 50 years ago. I have never cleaned nor lubed it. It is b&w acetate which is the thickest and least smooth compared to color stock and anything on polyester.

[Chad Shumaker]

So- some new developments...

I took the Chinon apart today and blew out as much dirt as I could from between moving parts. The claw mechanism was pretty dirty as were the areas behind posts that the reels mount on. I added just a few drops of oil to those super dirty areas. I thoroughly re-cleaned the entire film path. I also used the tape from a VHS wet cleaning tape and ran it through the sound heads.

I ran a test reel and the sound was super crisp, played at the proper speed and pitch, but still had the slightly unsteady picture. I was sitting there watching the film play and then got an idea. I turned the sound very low to listen to the projector. The take up reel was giving a slight squeak that coincided with the unsteadiness of the picture. When the film was done, I got a different take up reel and popped it on. It was not an automatic as the previous one had been. It was also a 600 instead of a 400. I also put the new belt back on (I had put the original back in place) and made sure it was seated properly.

I loaded my test reel and everything was much smoother. A bit of lift now and again but nowhere near as bad as it was!

[Brian Harrington]

Well, good news that you're making progress.

Did you know that if you press down where the arrow is in this picture of the 6100 I found online, you get full access to the sound heads? The film path is identical to my 7500. I didn't know that at first, but now it is so easy to clean the heads.

Cleaning the machine, especially the claw, and lubricating everything is a must for used projectors that may have sat around awhile, or have been used but haven't been maintained.

When the lower loop is too small on these machines, you will hear the flutter in the sound, so since you said it sounded fine, we know your loop is being set properly. I've barely ever heard flutter on my other machines, but it shows up right away on my Chinon when the loop is off. That's when I engage the loop former quickly and put it back in play. That's what the user manual says to do and it usually works, but doesn't always fix the unsteadiness.

Interesting about the take-up reel. That squeak is probably the film rubbing up against the flanges. Any plastic reel has the tendency to get out of shape if the plastic gets warped, usually because it was stored empty and something might have been pressing on it for a long time. I'm using a 600 foot take-up reel, but not the one that came with the Chinon, since that one is pristine with styrophoam on the inside to keep it from getting bent/warped. I have plenty of take-up reels, and the one I'm using is exactly the same, and came with one of my Yamawa machines.

If your reel was squeezing the film too hard at one point during the rotation, it will jerk the film once per rotation. I could see that being an issue for a sprocketless machine, or one that has a feed sprocket only, since that "jerk" will be felt all the way to the gate. You would hear it in the soundtrack as well. You also have the added protection of the pinch roller after the soundhead. But you say you are still getting a "lift" occasionally. As I pointed out in my other thread, the unsteadiness is inconsistent from film to film, with some having no problems at all. Do you keep using the same film to test?

It seems that there is no coincidence in your issue and mine being similar. Mine is NOS, and yours is used. I've read other people having issues like this with Chinons. After all is said and done, the common solution seems to be to lube problem films and the image will be steady, assuming you've fixed any potential problem areas in the machine.

Some of my problem films have a nearly constant up and down jitter, while others exhibit the occasional one as you describe. Is it like you are moving the framer slightly where you will see a frame line intermittently? Mine looks like someone moving the framer about once or twice per second. And to emphasize again, I have some prints that run what I call "rock steady" with no issues at all.

Hopefully someone else with chime in with their experience.

My other nitpick with my Chinon is that it is hard to get the lens in and out! Never had a projector that made it so difficult.