Film-Tech Forum ARCHIVE: Simplex XL Gate Spring Replacement

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Posted by Jim Cassedy (Member # 4115) on 10-23-2014, 03:56 PM:

Well, this is embarrassing!

I'm having trouble figuring out how to replace the gate spring on a Simplex XL.
In almost 30 years, this is the first time a machine has me 'stumped'.
Heck, I even OWN two XL's. (But I've never had to replace the gate spring.)

Takalook at the picture below of the partly disassembled mechanism.

The problem is that I have to pull out the spring & shaft (S&S)
But they are held on by a retaining clip (#1445 in diagram below)

It would be really easy, if I could just separate the lever assembly from
the slidngthingy that the gate attaches to. But that linkage (L) has
grooves so that the link posts & plates don't come apart from each other.

There is a "plan B" where I think I could get everything out of the
projector by removing the hex nut (HN) and another piece, but that hex
nut seems to be frozen in place & partly stripped. I don't see any way
of getting it out without drilling. I could also remove the entire back
plate ["P"] but that would also require pulling & disassembling the entire
fire-shutter assembely which has far more tiny springs & parts that I want
to deal with.

Geez- - this is a simple (I thought) spring replacement. Am I not s
seeing something? Is there a "trick" to getting to that stupid shaft out?

Here's the exploded parts diagram:

If I could just get to that retaining clip, I could get this job done!

For now, I've re-assembeled everything I pulled apart yesterday and they are
holding the gate closed with a rubber band, which has worked for the past week.

H E L P !

Posted by Steve Guttag (Member # 268) on 10-23-2014, 08:23 PM:

First, remove the gate closer mechanism from the projector (Have to remove the trap first)...the whole shebang is held on the main casting by 4 or so cap screws. It will be TONs easier to work on it off of the projector.

What you are pointing to as "L" is is P-1610 in the drawing. It is held on just by a pair of clips. Don't be thrown by your P-1610 being triangular. That design helps to keep the closer from going too far. The elliptical ones can allow the closer to close too far and actually start going backwards.

Note once you pop the clips, P-1608 will want to start to fall out and jam up on you but you should be able to rotate the shaft to get it clear.

You'll need to drive out P-2960 to remove the lever and remove the P-1445 clip to get to the spring.

Reassemble in reverse order with the spring de-tensioned. You will tension it P-1630 once everything is reassembled. P-2737 engages one of the holes on the outer part of P-1630...using a sturdy dowel (or suitably sized screwdriver) rotate P-1630 one screw hole at a time (tightening/loosening P-2737 to secure/release P-1630) until the tension is what you desire on the gate closer. Be forewarned, there is a fair amount of torque on that spring/collar.

Posted by Jim Cassedy (Member # 4115) on 10-24-2014, 03:01 PM:

quote: Steve Guttag
P-1610 in the drawing. It is held on just by a pair of clips.

See, that's the problem, Steve- - I didn't see any clips holding the little
triangular link-thingy in place. It appeared the link was pivoting on grooves
cut into the small shafts it's attached to. If there were clips, I'd have
popped the thing off & had this fixed two days ago.

HOWEVER- I was working in bad light & up against a time deadline, as
I had spent more time than anticipated on this thing and I had to grab
some grub & get over to a Dolby screening on the other side of town.

Now that I've blown up the image a bit & played with the contrast,
I think I MIGHT see a small retaining clip on the lower pivot in this photo.

I'll go back next week with some better light, my "maginifying work
glasses" and a clip-tool and see if I can get this done. I had everything
else figured out. It's not rocket science. . it's just a friggn' gatespring.

THANKS FOR YOUR HELP!

Posted by Louis Bornwasser (Member # 3063) on 10-28-2014, 10:51 AM:

If you are like me, take your large searchlight. Steve's method is exactly right.

Posted by Mark Gulbrandsen (Member # 72) on 11-13-2014, 10:29 AM:

Anyone have a Super Trooper that Jim can borrow to do this repair? [Wink]

Posted by Jim Cassedy (Member # 4115) on 11-13-2014, 11:40 AM:

quote: Mark Gulbrandsen
Anyone have a Super Trooper that Jim can borrow to do this repair?

Thanks, Mark- - that's probably just what I need.

I'm still able to 'focus' OK, but it seems that my aging eyes are
starting to loose their 'night vision' (or 'booth vision!) qualities.

Actually, I still need to go back & finish up on that job, but I've been
'booked solid' with a steady stream of film festivals plus press and Academy
Screening events that I haven't been able to go back & re-spring their gate.

Fortunately, they don't use the 35mm too often, and for now a heavy
rubber band has worked adequately to hold thier gate closed.

I'm in Phoenix this week, but when I get back to San Francisco, fixing
that gate is one of the first things on my 'to do' list.

I have a wholebuncha screenings at Dolby when I get back, and the
venue with the broken gate is only about mile away from there, so
I'll probably just stop in & fixit some afternoon on my way to work.

. . .and I'll wear one of my "super bright" headlights- - similar to this one:

FYI> To anyone in the SF Bay Area-
I'm scheduled to be doing all the 'tech-stuff' at the November SMPTE
meeting at Dolby Labs the night I return from Phoenix. (Nov 20th)
So if U R there, be sure to stick your head in the booth & say "hi"

>More Info Here<

Posted by Mark Gulbrandsen (Member # 72) on 11-13-2014, 01:49 PM:

I'm in the same boat Jim! I have to get new glasses about every two years now...