Elmo st600 does not auto thread film - Office Equipment & Supplies

The bulb you need is this one:
100W MR16 12V GZ6.35 BASE 64627 HLX OSRAM

You can try to buy it from here:
http://www.atlantalightbulbs.com/ecart/10Expand.asp?ProductCode=ELMO-VPD100ST600ST800#page=description

Is your film super 8mm? If yes, then the red sprocket above the lens should be pushed in, and the bottom black sprocket will stick out. If you have regular 8mm, then the black bottom sprocket should be pushed in. If the sprockets are not in the correct position, push the green lever forward (towards the screen) then open the two orange tabs, then push in the correct sprocket. Once you have the correct sprockets aligned, close the orange tabs. How to tell if you have 8mm or super 8mm film: Look carefully at the film image. If the sprocket hole is next to the middle of the image, it's super 8mm. If the sprocket hole is between images, it's 8mm.

Is your film super 8mm? If yes, then the red sprocket above the lens should be pushed in, and the bottom black sprocket will stick out. If you have regular 8mm, then the black bottom sprocket should be pushed in. If the sprockets are not in the correct position, push the green lever forward (towards the screen) then open the two orange tabs, then push in the correct sprocket. Once you have the correct sprockets aligned, close the orange tabs. How to tell if you have 8mm or super 8mm film: Look carefully at the film image. If the sprocket hole is next to the middle of the image, it's super 8mm. If the sprocket hole is between images, it's 8mm. If your green lever is stuck in the forward position, that's because the film is not threaded. Once your film threads correctly, the green lever will spring back.

There is not any in camera developing. This is not a digital camera it is a film camera wherein we put a film cartridge with a specified number of shots into the camera then thread the film leader to the takeup spool, close the camera advance the film a few frames, then we are ready to shoot. After the specified number of shots, 24 or 36, film is rewound into the canister, camera back opened film canister removed then taken to the lab for processing.

I have a elmo K-100 8mm projector I wish to get a drive belt .Where would I try

The drive belt on the porjector maybe broken. They tend to be made of rubber like an elastic band and tend to get hard and break easily. If this is the case, you may be able to substitute a large elastic band to replace the origional part.

the resolution might not match from presenter to projector. are you using rgb, composite or s-video? the signal might not match. there might be an auto adjust on the projector to read and match the elmo's resolution. if not, the elmo may have an issue sending a powerful enough signal to the projector, and need a new main board.

There are 3 round knobs and 1 Autostart switch on the control panel. The key to rewinding this machine is by pushing the gray button down, while turning the Motor Knob to the "Run" position. Of course you'll need to start the original film back on its reel, directly. (Do not thread the film as you would normally.) BTW, you can show your films in reverse by using the Reverse button on the motor switch while its running. Hope this helps. Now, if I can find someone who can guide me in re-assembling my Elmo projector's lens, which I dis-assembled in order to clean the crud off the multi-lenses in the main lens unit itiself.