Film-Tech Forum ARCHIVE: Simplex XL Upper Pad Roller Assembly

This is topic Simplex XL Upper Pad Roller Assembly in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Thomas Moore (Member # 3427) on 08-22-2009, 06:28 PM:

Im in a bind here. I have a replacement pad roller assembly I need to put on the XL there is a sping and a spring guide that requires alot of tension to depress to replace. Can someone please tell me the quickest and simplest way to replace the spring to replace the pas roller assembly. Thanks

Posted by Tim Reed (Member # 137) on 08-22-2009, 06:33 PM:

There is a small hole in one side of the fork that the spring fits over. Compress the spring with its cap in place, and stick a small paperclip in the hole to hold the spring in place. Install, and then remove the paperclip. It takes a little practice to get the clip in there, however, and you may want to use channel locks to compress the spring so you can set the clip (taking care that it doesn't go flying across the room if you slip).

Posted by Thomas Moore (Member # 3427) on 08-22-2009, 06:41 PM:

oh damn anyone in st louis want to come help me with this!

Posted by Louis Bornwasser (Member # 3063) on 08-22-2009, 08:51 PM:

Thanks, Tim, I never knew that; I've been doing it the HARD way. Louis

Posted by Steve Guttag (Member # 268) on 08-22-2009, 08:57 PM:

Wait....you Louis...didn't know about the little hole? You've got to be kidding...that isn't even a real secret! At the shop, we leave them pre-loaded and ready to go.

Steve

Posted by Monte L Fullmer (Member # 2797) on 08-22-2009, 09:04 PM:

...the "grenade pin" - pull the pin and everything goes anywhere.

Posted by Louis Bornwasser (Member # 3063) on 08-22-2009, 09:12 PM:

OK, we don't have many Simplexes, even fewer that had the problem. (I like the grenade pin analogy!) LOuis

Posted by Thomas Moore (Member # 3427) on 08-22-2009, 09:19 PM:

ok really is there an easier way to put this spring on...i can even reach behind the assembly to place the spring..much less see it to release the pin.

Posted by Steve Guttag (Member # 268) on 08-22-2009, 09:33 PM:

No no...preload the spring with the paper clip. Take the screw out that the arm pivots on. Pull the arm. Place the preloaded spring assembly on the arm and as you slide the arm back on its pivot swing it and the fork up to its associated groove (the fork will be at an angle until you get the arm slid all of the way on. Once all is set and you get the screw back on the arm pivot stud, pull the paper clip and that is about it...pretty unexciting really.

Normally, it is the lower arm that dies since the P-1447 stud is not only the part the fork rides on but also is the pad roller arm stop. The grove acts like a score line to break the stud off by just the action of opening the arm.

BTW...truth be told...I often pull the whole sprocket assembly when I put these on in controlled circumstances. When I have the assembly off, I set the pad rollers perfectly too and ensure everything is just right (and change the gasket if petrified...as they almost always are)...and then set gear lash as I reinstall. Much easier than doing everything on the projector. Just make sure you have the gasket BEFORE you pull the assembly.

Steve

Posted by Monte L Fullmer (Member # 2797) on 08-22-2009, 10:45 PM:

And the P-1447 stud isn't that much to replace if you have at your location an arbor press ($34.00 from Harbor Freight) and a bunch of these studs.

(The terminology of "grenade pin" comes from my fellow auto mechanics who do timing belts and some motors require a hydraulic adjuster on the belt tensioner pulley. When one replaces this adjuster, the hydraulic ramrod is held down in place by a locking pin, being so nicknamed, "the gerenade pin". For if this pin comes out before installation that hydraulic ramrod, which the one end is under great pressure, suddenly comes out fully extended where it can actually damage the assembly requiring a new adjuster.)

-Monte

Posted by Joe Redifer (Member # 3) on 08-22-2009, 11:22 PM:

Just wait until the time comes when you need to tighten the spring tension on the gate closure. Loads of fun!

Posted by Steve Guttag (Member # 268) on 08-23-2009, 08:49 AM:

Really? That is pretty easy too...if you have allen keys handy...put one in an available hole before you loosen the screw...the gate will keep it from unwinding...use the allen key as a handle to advance the tensioner one position at a time.....next.

Posted by Joe Redifer (Member # 3) on 08-23-2009, 12:47 PM:

Yes, in theory it should be pretty easy, but instead it is mostly annoying. I use two allen keys so I can pull one out once the rotation has gone so far to the point where the holes have to be changed. Then getting a flathead screwdriver under there to re-engage the locking pin while holding the allen is a pain. Slotted screws should be illegal in most cases as they are extremely difficult to grip with the screwdriver. Still not tight enough? Damn. Loosen the locking screw and have at it again. Mess it up and the spring tension comes all the way loose and you have to start from square zero. Make sure to remove the lens first as the assembly that holds it stops it from rotating (not the gate).

Posted by Eric Robinson (Member # 2966) on 08-25-2009, 01:48 AM:

The older Simplex machines didn't have a little hole in the spring fork. Sure is handy though, once you learn about it and use it.

I recently took a pad roller arm out of an SH1000. The arm uses a completely different design to hold the arm in the closed position. This arm had a recessed spring loaded ball bearing on the inboard surface of the arm which contacts the projector casting. Anyone know why this design was abandoned for the ever problematic fork and spring?

Posted by Tim Reed (Member # 137) on 08-25-2009, 09:27 AM:

AFAIK, all SH-1000s had that style of pad roller. I never saw one that didn't.

Posted by Mark Gulbrandsen (Member # 72) on 08-25-2009, 10:13 AM:

Eric,

Wait till you get an SH-1000 pad roller arm with a spring that has taken a bad set to it. Then the pad roller won't stay closed. You can get the ball and spring out of there but it's pretty tricky to do so. Spring has to be replaced... stratching it out is only a temporary fix.

Mark

Posted by Eric Robinson (Member # 2966) on 08-25-2009, 01:59 PM:

What I meant earlier is why didn't the SH1000 pad roller arm design get carried forward into the Simplexes so as to alleviate the monotony of servicing the spring and fork design.

Thanks for your insight Mark. I guess there is always a pitfall in any design.

Posted by Tim Reed (Member # 137) on 08-26-2009, 03:02 PM:

That was just part of the design of the Simplex XL, which was introduced around 1950. The whole projector was quite a departure from the norms of the day. I actually liked the SH-1000 style arms. They were very easy to set pad roller clearances with.

Posted by Steve Guttag (Member # 268) on 08-26-2009, 11:29 PM:

Yeah, but the SH-1000 arms often become weak.

Steve

Posted by Louis Bornwasser (Member # 3063) on 08-27-2009, 10:13 AM:

I'm with Tim, the SH-1000 pad arms were great. No doubt the exposed, pitiful mechanism on the XL was a good bit faster/cheaper. Louis

Posted by Mark Gulbrandsen (Member # 72) on 08-27-2009, 11:06 AM:

Don't no Louis but they had to have dies to stamp out the forked slider and dies cost lots of money. The SH-1000 arms are simplicity in themselves and the springs in the arms can be replaced when they take a set and become weak.

Mark

Posted by John Walsh (Member # 168) on 08-27-2009, 04:38 PM:

Can't say I care for those SH1000 pad roller arms myself ... the ball indent hasn't been strong enough to prevent the arm (the upper) from getting thrown open when a thicker splice passes through. I've had trouble fitting replacements, too - after installing the roller, it doesn't line up with the sprocket. Another one would stop about a 0.1" away from the sprocket when closed; it looked like that pin was in the wrong place. Also, it looks like the spring (for the ball) can't be replaced on all of them; on the lower arm there's no hole in the back to get at the spring. I admit I worked on very few, but so far I'm only impressed with the quality of the manufacturing, not the design.