Film-Tech Forum ARCHIVE: Intermitttent Problem Question

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Posted by Joe Woodall (Member # 2410) on 07-24-2007, 11:30 PM:

HI everyone ,

Sorry to ask for your help right off the bat, but were in a real mess. I looked through the postings and could not find any answers to my projector problem.

I'm new to your forum ; we operate a D/I in NE GA and have 3 screens using about 1934 year model regular simplex projectors.

Sunday night I noticed a slight undercut during rewinding 1 of the films and choose to make a quick change of the sprocket on the intermitttent movement. I've done it before without any problems, so I took it apart looked into my supplies and but didn't have the same sprocket to interchange (screw in the middle type) - but we have several old intermittents from my former circuit days and so I used one & put a new sprocket on its shaft. Its the 2 pin type. It wobbled so bad you couldn't hardly see the picture. No adjustment of the gate or springs would fix it and Clearly to my eye had a bent shaft I thought. Don't think I did it but who knows. On to 2nd Movement building.

I tried another intermittent, also VERY careful this time not to bend anything; put on the new sprocket and the films still is jumping on the screen. Its better than the first movement , no clear bent star drive shaft, but you can't show a movie this way.

We've gotta have all 3 screens back by Fri. night, So Could Someone Please Tell Me How To Fix This ?
Thank you very much.
Joe Woodall

Posted by Monte L Fullmer (Member # 2797) on 07-25-2007, 05:29 AM:

Hello and welcome to Film-Tech. My experiences with the film bouncing up and down on the screen that gunk gets built up inbetween the teeth of the sprocket causing this bouncing problem.

I don't believe that a sprocket that uses those pins (called taper pins - for the STANDARD, Super and E-7 Simplex machines) can be used, what it seems that you have are XL's since your description of the center screw mounted sprocket to the shaft.

Of course, are you aligning the sprocket, when replacing it, esp. with the rebuilds that you've done, with the rest of the sprockets on the machine? An out of align sprocket could cause some side pull within the sprockethole which could be causing the bouncing ..

Course, wonder if reversing the sprocket would help some..

..just helping out since we don't know the exact model of your projectors..please update with what you have, or even picts would help also.

thx - Monte

Is this ailment on all three screens, or just the one?

Posted by Darryl Spicer (Member # 711) on 07-25-2007, 07:55 AM:

I would go back and replace the current intermittent with the intermittent you originally had in the machine. Then I would remove the sprocket from that one and reverse it so that you are pulling the film down with the other side of the teeth.

Posted by Louis Bornwasser (Member # 3063) on 07-25-2007, 10:05 AM:

Careful, I'm sure you know that most parts for Simplex regular are not easily available.

Suggest that it is high time to install a Century SA if light is valued at this drive in. Louis

Posted by Joe Woodall (Member # 2410) on 07-25-2007, 10:15 AM:

Hi Guys,
1st they are all three regular Simplex machines, some of the family jewels, but over the years parts and the movements were swaped about with whatever was available. The turning of the sprocket is something I thought of when I first saw the undercut Sunday, but that sprocket has already been turned by the previous owner.

I'm having this problem with the 1 projector that I tore into Sunday night , but it is a problem that manifest itself very slightly on 1 other machine. It too had a sprocket change, about a year ago and it has a slight tick, up & down, but nothing like what's going on with this one.

Guess I'm going to have to try to reinstall the original sprocket and order a new one with hopes it will arrive in time & then will work properly. Very confused why this happened though. A Cousin once told me that when installing a sprocket in the intermittent, you have to adjust it and run it in, a several hour process sometimes. I though, I had done so, but this one's sure got me over the barrel.

Thanks for trying to help me.
Joe

Posted by Eric Robinson (Member # 2966) on 07-25-2007, 12:34 PM:

What do you mean by?

quote: Joe Woodall
It wobbled so bad ...

Have you tried turning the motor by hand while checking to see if the intermittent sprocket teeth are possibly rubbing on the shoes?

Posted by Monte L Fullmer (Member # 2797) on 07-25-2007, 01:26 PM:

On a side note: When one disassembles and reassembles an assembly to do whatever, that the cam and starwheel must be in exact proportion so the cam pin enters into the starwheel at the exact place it need to be...and this is accomplished by "tuning" the two halves of the case til the "sweet spot" is achieved for both units.

..just something to ask about... good luck-Monte

Posted by Joe Woodall (Member # 2410) on 07-25-2007, 01:27 PM:

Yes Sir I Did Check But Their Not Rubbing and didn't have any problems with the shoes prior either. Everything is in great shape just got the wobble on the screen when the new sprocket was installed in 2 movements.
Do you know what if any, adjustments are to be made when installing new sprockets ?

Monte do you mean I should rotate the star inside, before assembly, to a veriable position and I can achieve a lesser wobble thereby effecting an adjustment ?

Thanks
Joe

Posted by Louis Bornwasser (Member # 3063) on 07-25-2007, 01:50 PM:

The taper pin installation is not for anyone who does not have the reamer and pin press. If the pin is merely forced into the hole and not properly reamed you will have very severe verical jump. Louis

Posted by Joe Woodall (Member # 2410) on 07-25-2007, 01:58 PM:

Louis,
I understand the need for the right equipment. I did not have the reamer and pin setter but the holes were wide open and the pins just droped right into the holes, no problem there. The shaft is straight and I personally can not see a jump of the sprocket with the naked eye when turning the projector by hand or when running the projector, yet it is jumpy , or giggly on the screen. I going back to re-install the original sprocket & try it & order a new screw pin sprocket too.
Thanks for your help.
Joe

Posted by Ken McFall (Member # 845) on 07-25-2007, 02:12 PM:

There are some jobs that must be done with the correct tools. Louis has it right. You cannot compromise when you consider the size of the frame to that on screen. This in one job that MUST be done correctly.

If you don't have the correct replacement parts then leave well alone. Get someone in that has the tools and the experience to do it right. In the long term it pays. If you f*** up imagin how much a reconditiond unit will cost you.

The other consideration is the damage to your business reputation while you take time to experiment.

Get it done once, get it done right.

Regards Ken.

Posted by Eric Robinson (Member # 2966) on 07-25-2007, 02:14 PM:

Sometimes a physical force placed in the intermittent assembly can bend the intermittent framing cam retainer clip.

If the retainer clip is bent, the framing cam assembly could be out of alignment causing a misalignment between the sprocket teeth and the sprocket shoes. Or, the whole intermittent assembly and framing cam could be moving up and down very slightly while the machine is in operation.

Is there any way to use a pin depth gauge on the edge of a sprocket to detect a mechanical variation while the sprocket is in operation?

Posted by Tim Reed (Member # 137) on 07-25-2007, 04:15 PM:

When the movement is in the locked position, can you move the sprocket circumferentially by hand? If so, either the taper pins aren't properly fit, and/or there is too much clearance between the star and cam in that movement.

I suppose the sprocket itself could be asymmetrical... remote possibility.

Btw, since we're talking Regular Simplexes... these aren't single-bearing movements by any chance, are they?

Posted by Joe Woodall (Member # 2410) on 07-25-2007, 04:25 PM:

Hello Again,

Found a sprocket on another movement that had the screw , it was turned around , installed and the picture is great. Booth tested at least, until tonight, but the picture on cardboard in a dark booth look fine.

Now on to making the other movements that I have bench ready. Where does one purchase the right tools and what does one ask for when asking ?

Thanks
Joe

Posted by Gordon McLeod (Member # 33) on 07-25-2007, 05:48 PM:

Lavezzi sells the reamers amd punvh and a v block

Posted by Mark Gulbrandsen (Member # 72) on 07-25-2007, 06:17 PM:

quote: Gordon McLeod
Lavezzi sells the reamers amd punvh and a v block

Last I looked LaVezzi was out of the Regular and Super Simplex parts biz all together allthough both they and Wolk have a few things laying around. They have no blocks but it is possible that they might have a reamer or two laying around. Taper pins can be had at McMaster-Carr and other machine tool supply houses. We stock the taper pin sprockets new... we also have LOTS of used simplex mvements that are in good shape. In fact LaVezzi doesn't even have the reamers to do SA intermittents any longer.... you don't really need it anyway if you line bore them. They have just released all the parts and tools to do Ultramittents though... I have not had one fail now in over 5 years.

Mark

Posted by Joe Woodall (Member # 2410) on 07-25-2007, 06:43 PM:

Thanks Fellows,
I buy from Wolk often and will check with them in the Morn.
What is LaVezzi's telephone number please ?
Joe

Posted by Mark Gulbrandsen (Member # 72) on 07-25-2007, 06:52 PM:

Just do a Google for LaVezzi Precision.. they also have an on-line projector parts catalog there. If its not listed still gove them a call... they do only sell thorugh dealers though.

www.lavezzi.com

I'm actually with Louis on this one except for the brand. To me someone thats still running this stuff in a Drive In can't be very serious about the buisness he's in. You may well have the very last Regulars running in the entire world on a Regular basis(pun intended)! I still have a couple dozen Super Simplex's("The first modern projector ever made") and one E-7 that I service but they're very different machines.

Mark