Bulb stuck in old movie projector

Wayne · Dec 17, 2020

I've got an old Ampro Precision 16 mm movie projector, and the damn bulb won't come out. I'm sure its a push-down-and-turn type bulb, and I push down and turn but it still doesn't come out. I can't get near the base because there is a metal housing around it that you can't remove if the bulb is in. At first the bulb didn't move much at all but with a couple drops of wd-40 and wiggling it back and forth every day for over a week, it is plenty loose and mobile and should come out. But it doesn't.

I called a projector guru and he suggested breaking the bulb and removing the base with pliers. Well that's my last resort but hoping for a better idea.

awty · Dec 17, 2020

Does the bulb still works ?
A bit of heat might help.
You'll need to wipe away the wd40 off the glass.
Can you turn the projector so the bulb is facing downwards, gravity may help. Any way if you have to break it best to have the glass not falling back into the projector.
Coincidently I just picked up an old 16mm Bell and Howell 601 and 622 yesterday, have the 601 working, the 622 needs a bit more work.

AgX · Dec 17, 2020

Wayne said:
I called a projector guru and he suggested breaking the bulb and removing the base with pliers. Well that's my last resort but hoping for a better idea.

That would have been my approach too, actually did so myself. Unless one could loosen the fixture and thus take out the whole shebang.

shutterfinger · Dec 17, 2020

Well instead of going for the WD40, something that should never be used in camera equipment, you could have searched for an instruction manual. I found this one http://www.paulivester.com/films/projector/Ampro_Stylist.pdf
Even if its not the model you have companies have a tendency to use similar mechanics across their line of products.

or go get a bigger hammer and smash away.

Wayne · Dec 17, 2020

shutterfinger said:
Well instead of going for the WD40, something that should never be used in camera equipment, you could have searched for an instruction manual. I found this one http://www.paulivester.com/films/projector/Ampro_Stylist.pdf
Even if its not the model you have companies have a tendency to use similar mechanics across their line of products.
.

I already have the original manual for my model, which is perfectly useless. I also looked at that Stylist manual a couple weeks ago, but it doesn't provide anything useful either except for "push down and turn 90 degrees". I'm not too worried about a couple drops of wd-40, I was very judicious and I will clean it up when I finally get the bulb out. But thank you. It wasn't going to budge at all without it.

shutterfinger · Dec 17, 2020

Can you post pictures of the bulb base, socket top side and bottom side.
Every bulb I've encountered was a very tight fit.
Using an ink refil syrenge or similar apply cider vinigar to each pin of the bulb from the bottom of the socket. Cider vinigar dissolves rust on steel and corrision on magnesium. It might dissolve magnesium so rinse off after 30 to 45 seconds.

Wayne · Dec 17, 2020

shutterfinger said:
Can you post pictures of the bulb base, socket top side and bottom side.
Every bulb I've encountered was a very tight fit.
Using an ink refil syrenge or similar apply cider vinigar to each pin of the bulb from the bottom of the socket. Cider vinigar dissolves rust on steel and corrision on magnesium. It might dissolve magnesium so rinse off after 30 to 45 seconds.

No, I can't show a picture. As stated above I can't even see the bulb's base or the top of the socket because of the housing it sits in that can't be removed with the bulb in place. All I can see is the top of the bulb, just enough to grab.

I think I would break the bulb before I do what needs to be done to access the bottom of the socket. That's not my preferred route, but I do think it would be simpler. Then I could take the housing off and gain easy access to the socket

btaylor · Dec 17, 2020

Sometimes over time I have seen bulb bases distort, resulting in a case like yours- pliers to the rescue. IMO, 16mm projectors are pretty rugged, WD40 and a pair of pliers aren’t going to ruin anything if you are reasonably careful.

shutterfinger · Dec 17, 2020

Wayne said:
As stated above I can't even see the bulb's base or the top of the socket because of the housing it sits in

That's a heat shield that disapates heat from the bulb.
Appearently you cannot push the bulb down far enough for the bulb to turn. Heat distorted parts can be aiding the problem.
Warm it up with a hair dryer and try again.
I'm not convinced breaking the bulb will help.

Wayne said:
No, I can't show a picture.

So you din't have a electronic recording sensor camera of any type, or are you just convinced its not possible for a picture to be of any help?

mshchem · Dec 18, 2020

It could be the last user installed the bulb wrong. Some of these push and turn bulbs have slightly different flanges etc. Could be off by 180°

Any lubricant you can get in there will help. There's probably some corrosion. These things can be tricky, some you can push in too far.

I have a penetrating oil called "Rust Bomb" an old machinist sold me a can, that stuff is amazing.

If you break the bulb, you're committed. Using pliers you could damage the socket. Should be a simple 90° counter clockwise turn then pull straight out.

Wayne · Dec 18, 2020

shutterfinger said:
That's a heat shield that disapates heat from the bulb.
Appearently you cannot push the bulb down far enough for the bulb to turn. Heat distorted parts can be aiding the problem.
Warm it up with a hair dryer and try again.
I'm not convinced breaking the bulb will help.

So you din't have a electronic recording sensor camera of any type, or are you just convinced its not possible for a picture to be of any help?

As I said I can't even see the base of the bulb so there is no way for me to photograph it. It is all hidden inside the condenser housing. All I can see is the top, and a short way down the side of the tall bulb.

I will post a pic later, but it won't show anything but the bulb sticking out the top of the housing.

BAC1967 · Dec 18, 2020

Does the bulb come to a stop when you turn it 90 degrees. If it’s not lining up properly with the release point you may need to try doing very slight rotation until you find where it releases.

Wayne · Dec 18, 2020

I've discovered a new thing, and I can't get a picture of it either. These old projectors have basically cylindrical bulbs. But the rear side of this bulb, (the rear when its screwed in all the way), seems to have a bulge on it. Weird. Its only on the back side. But it seems like that bulge is hitting the condenser housing once I turn it about 45 degrees, so that's as far as I can turn it. And once again the housing can't be removed unless the bulb is removed first, the manual is clear on that.

It doesn't make any sense and there is undoubtedly some really simple solution.

BAC1967 · Dec 18, 2020

There is often a mirror in the bulb to reflect more light forward. Maybe that mirror heats up the glass enough to distort it. If you are turning it before it hits the reflector it may have been put in wrong in the first place. If that bulge is from the mirror in the bulb it should have been toward the back. Breaking it may be your only option if you can’t force it past the mirror.

AgX · Dec 18, 2020

I too got such sample with a bulge. That is not normal, but an indicator for the bulb once having been overheated. Either by not having orientated the lamp correctly or by orientating the whole projector wrongly. (Many high efficiency lamps got restrictions on their orientation in space.)

If there is a mirror in such system, a classic incandescant lamp must be orientated in such a way that the primary and the mirrored image of the filament, as to be caught in front of the projection lens, are located on top of ach other.
Such projectors got at least a primitve means to orientate the lamp by moving its fixture.

Wayne · Dec 18, 2020

I considered that it may have overheated causing the bulge but decided that would be impossible. But if it has happened to others it definitely seems possible now lol

In that case it seems I have little choice but to break it...

AgX · Dec 18, 2020

I kept such sample as exhibition piece, but it still should be usable.

Concerning such old-style lamps I found it cheaper to buy a complete projector locally than such lamp on the net.

Sirius Glass · Dec 18, 2020

Uneven cooling caused projector bulbs to blow out one side with a bulge.

AgX · Dec 18, 2020

Of course one can bring such always back on lacking cooling. But I must admit an overheated filament would have degraded and blackened the bulb.

shutterfinger · Dec 18, 2020

I would try to slip something solid between the bulb and heat shield and pry the heat shield outward in the direction of the bulb turn until enough space is created for the bulb to turn in. The shield can be reformed once the bulb is removed.
I realize space is tight in projectors.

Kino · Dec 18, 2020

This is pretty common with these projectors. You will have to break the bulb to remove it. Usually the bottom of the lamp house screws off and has a brass plate for a contact that is riveted to the Bakelite collar. The lamp socket should fall straight out of the bottom. Some bayoneted in from the top. Can't remember on the Ampro...

This sometimes happens when the projector is run at a slow speed with a vent partially blocked or in "still" mode on a single frame. Can't remember if the Ampro has the "still" function, but it drops a screen or heat absorbing glass in behind the film gate which (in theory) protects the film frame, but does nothing to dissipate the heat in the projector lamp.

awty · Dec 18, 2020

I had a google search of that type of projector, they look really cool. Does yours have an amplifier?

mshchem · Dec 18, 2020

It's time to crap or get off the pot. Break the bulb get in there and grab it with some quality needle nose pliers and apply some muscle. Lube it up and get it done. If the socket isn't holding it back it should come out freely.

Sirius Glass · Dec 18, 2020

mshchem said:
It's time to crap or get off the pot. Break the bulb get in there and grab it with some quality needle nose pliers and apply some muscle. Lube it up and get it done. If the socket isn't holding it back it should come out freely.

If the lamp base does not come out, use the needle nose pliers to grab the edge and give it a hard twist, grab an edge near that spot and repeat. Repeat around the base until it comes out.

mshchem · Dec 18, 2020

Sirius Glass said:
If the lamp base does not come out, use the needle nose pliers to grab the edge and give it a hard twist, grab an edge near that spot and repeat. Repeat around the base until it comes out.

+1!

Bulb stuck in old movie projector

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