8mm Forum: LOOP ISSUE

This is topic LOOP ISSUE - RCA 416 in forum 16mm Forum at 8mm Forum.

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Posted by Chris Fries (Member # 2719) on January 24, 2012, 03:09 PM:

Hello all,

I recently brought my RCA 416 out for a thorough cleaning. It had not been used in about 10 years. After I was done, I ran some film through it. It seemed to work fine. Last night I threaded up a new film. It took me 20 min. to get it to play properly. The film would not stay even in the gate and the loop would not hold in place.

Also, I the top loop sometimes goes too high and then the sound is out of sync.

Here is a video of what it is doing.

http://www.youtube.com/watch?v=mlNZwnI4_fE&feature=youtu.be

Eventually I did get it to stay so I could watch the film. So, what is going on? The sprockets are holding the film in place. There is nothing wrong with the rollers, stabilizer or the drum. I watched and felt the claw while the projector ran without film. It seemed to be working fine.

Is it because it hasn't been used for so long? Do I need to adjust or oil anything?

Any help would be greatly appreciated.

Posted by Gerald Santana (Member # 2362) on January 24, 2012, 03:50 PM:

Hi Chris,

One rule of thumb to have before turning on the machine is after threading, turn the thread knob or "inching knob"a few times to make sure your film is passing through without a problem. The knob looks to be right below the supply reel on your machine.

Try turning a few times and if you hear or see anything out of the ordinary, it will be at that point, so you don't have to keep turning on the machine, or mostly to spare you from having to switch on the lamp if it's not threaded correctly.

Posted by Chris Fries (Member # 2719) on January 24, 2012, 04:36 PM:

Hi Gerald,

This machine has no thread knob. What you are seeing is the screw that holds the supply reel arm to the projector.

Is there something else I can do?

Thanks,

Chris

Posted by Jim Schrader (Member # 9) on January 25, 2012, 12:15 PM:

Chris are you making sure there is a loop on the lower half? how about the framer is this an issue? kind of a tough one.

Posted by Gerald Santana (Member # 2362) on January 25, 2012, 12:51 PM:

Hi Chris,

Yes, what Jim said may be an issue as well...

Check your top and bottom loops make sure they are aligned. The top loop usually goes up like that (from your video) when the bottom loop is lost.

Make sure you have a good upper loop, use the edge guides, if you have an loop forming roller for the bottom loop, use it. Close the gate, thread around the sound drum pressure roller or damper roller, and then close the take-up sprocket clamp.

If there is any way to advance the film manually without having to turn it on, give it a few turns. Or turn on the motor drive but don't start the lamp until it sounds smooth to you. If this fails try a different film or clean the one that is giving you a hard time with 91% isopropyl alchol and a couple of drops of mineral oil and run it again.

Posted by Nick Field (Member # 2132) on January 25, 2012, 01:54 PM:

It looks like to me that the guide rollers seem to spin up before the claw starts it's motion, is there a mechanical slippage problem in the drive system like a belt or a shaft?

Posted by Barry Fritz (Member # 1865) on January 26, 2012, 01:26 PM:

Is there any damage to the sprocket holes on the film?

Posted by Chris Fries (Member # 2719) on January 26, 2012, 05:30 PM:

Gerald, there is no way that I know of to advance the film outside of turning the projector on. This machine doesn't even have reverse projection.

Nick, there may be a mechanical slippage problem. I don't know. I will investigate later.

Barry, the sprocket holes are fine.

Thanks guys. I will let you know what is going on with it as soon as I get the time. Very busy right now.

Posted by frank arnstein (Member # 330) on January 28, 2012, 06:28 PM:

Hi chris

Open the gate and check the tip of the claw to see if there is a build up of fluff on it.

Sounds to me like the claw is slipping out of the film holes due to insufficient penetration into the film. You may need to increase the claw stroke depth to ensure it doesn't keep slipping out and loosing the lower loop.

good luck with cleaning the claw and the gate area.

Dogtor frankarnstein

Posted by Chris Fries (Member # 2719) on January 29, 2012, 01:23 PM:

Thank you, Frank.

That is excellent advice. You may have hit the nail on the head with your diagnosis. After 15 min. of trying I finally got film to stay in the gate so I could watch it. Then there was a splice and the film slipped out of the loop. I got it stay until there was another splice.

I will try to clean the claw and the gate later.

Posted by Chris Fries (Member # 2719) on January 29, 2012, 04:40 PM:

Well, I cleaned the dirt and muck out of the claw and gate. The problem is still there. What else can I do?

Posted by Jim Schrader (Member # 9) on January 29, 2012, 09:21 PM:

you might want to check those splices I have had some that looked fine but were crooked that can throw the film off. if you have a 16mm splicer just stick it on the prongs and see if there might be any misalignment. Just a thought.

Posted by Allan Broadfield (Member # 2298) on January 31, 2012, 04:40 PM:

Don't know the exact workings of the RCA, but it looks as if the spring action holding the pressure plate against the gate has slackened whilst in storage, or the stock isn't being held accurately against the bottom sprocket. More likely the first option.

Posted by Jeff Taylor (Member # 442) on February 02, 2012, 03:27 PM:

I never liked the nylon pressure shoes on the 415/416 as well as the old metal ones on the RCA400, but my vote would be the pressure springs behind the shoe being weak. Take them out and give them a slight pull to extend the springs enough to increase pressure and you should solve your problem. Obviously it could be claw protrusion as well, but if it hasn't been monkeyed with that sounds unlikely.

Posted by Chris Fries (Member # 2719) on February 25, 2012, 12:57 AM:

Jeff & Allan,

I wanted to let you know it was the springs. After adjusting them, the projector is working just fine.

Thanks guys,

Chris

[ February 25, 2012, 04:00 AM: Message edited by: Chris Fries ]

Posted by Allan Broadfield (Member # 2298) on February 26, 2012, 06:26 AM:

Great, Chris. I like it when a plan comes together.

Posted by Patrick Flynn (Member # 5615) on November 29, 2016, 12:31 PM:

Bumping this old thread, since it appears we have the same model of projector - I'm having issues with my lamp, I don't have a manual for the projector (Film Tech provides one for the 400 model, not the 416).

How does the bulb get released from its housing, I don't want to force it out. Secondly, if the issue is not the bulb, where do I go from there?

Thanks!

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