Help with Simplex 35 Intermittent Rebuild

[Chris Wehrman]

While I was troubleshooting an image steadiness issue with my Simplex 35 (PR-1014), I discovered that the intermittent assembly has a lot of drag after I disconnected the drive gear and turned the flywheel by hand. So it looks like a rebuild or replacement is in order. I've researched a few forum archives so I know that a successful rebuild takes a lot of finesse and fine tuning and "run-in" time on a bench to get them perfect. Id like to think this is something I could tackle provided I have the right tools and parts but I know I won't be able to do as good of a job as some who has experience in rebuilding them (I would very much like to learn how). I also have a spare XL machine but that intermittent also has drag to it and is not much better.

I need help with the following questions:
Is purchasing a assembly already rebuilt my best option provided one is available?
Is rebuilding the one I have even an option any more(parts available, repair shops, people who are skilled at rebuilds)? If so, Is there anyone that could be able and willing to rebuild it for me?
If my only option is rebuilding it myself, what parts and tools do I need to do it? (there seems to be star and cam shaft parts for sale on e-bay at this time)
Since the part numbers are different, are the star and cam shafts interchangeable between the Simplex 35 and the original XL?
Are the entire intermittent assemblies interchangeable between the 35 and the XL(can I take a XL intermittent and put it in the 35)?

This projector is in my home screening room, so it won't be used all that much. Still, I'm trying to keep the long term picture in mind, keeping my entire film system running long term is my goal.

Any advice is appreciated as always.

Thanks,

Chris Wehrman

[Mark Gulbrandsen]

Several things... One... If the machine was sitting for a long time, the oil may have evaporated anmd all it needs is a good cleaning and reassembly. The problem is... you need a new gasket that goes between the two halves. So you will need to hunt around. Magnatec, Boston Light & Sound and Cardinal sound are a few places you can try. The second thing is the cam shaft or the star shaft may be partially seized up. So when you take it apart inspect the shafts and the bore carefully. But what ever you do don't run it. If you continue to try to run it, you could end up stripping the small fiber gear that's behind the flywheel. When you reassemble it tighten the four cover screws lightly, then back them off a half turn and let the weight of the outer (Sprocket) half set the clearance between the star radius and the cam. Then Re-tighten those 4 screws a little at a time. The net result has to be a free spinning fly wheel...!!

[John Eickhof]

a properly adjusted intermittent should have a very slight almost non-existant drag when in the dwell and when in pulldown hold the flywheel and try and move the intermittent sprocket in its rotation, if it has play the pin is worn flat on the cam or the star has been bent (if theres slack in only one of the four quadrants) if thats the case a new starwheel shaft is required. the other source of unsteadiness is the gate and trap, more so on the curved model than the flat type. is it jumpy or jittery?> or does the film fove side to side on the screen? jitter or jumping may be caused by improper tension on the film, or undercut intermittent sprocket, or improper adjustment of star and cam...by design, the xl intermittent will survive for many years as long as it has oil...I did rebuild an xl from st. louis once that had never been oiled but was lubricated with vaseline like a century...it was actually runningg for over 15 years! however the cam pin was flat the star was worn out of spec and the shafts and case were galded and worn! it rebuilt nicely and is running flawlessly in a home screening room to this day!! I do intermittent work and still have all necessary tools and parts in stock. I am retired so the cost would be reasonable.

[Mark Gulbrandsen]

I just punch the pin out and reverse it. Had very good luck doing that till I got back to the location with a new cam.

[Chris Wehrman]

Thanks Mark and John for the information. I went ahead and took out the intermittent from my XL machine. When in my hand, this unit seems to turn pretty well, better than I thought before. It dose have some minor play between the drive gear and cam shaft gear, but other than that, this movement seems in very good working condition. So I swapped it out with the one in the 35 machine and re-timed the shutter. While running some RP40, at first glance it looks like my image steadiness has improved quite a bit. There is still some minor vertical jitter and weave side to side but nothing like what it was.

I looked at the original intermittent I took out of the 35 and now I see what the problem is. The fly wheel is rubbing against the side of the assembly itself. My guess is some one had dropped it once before? I can't seem to get the fly wheel off and I'm afraid to use any force. I assume the cam drive shaft is bent.

John,
I examined both intermittents as you described by putting it in all 4 mid pulldown positions and checking for any play. Neither intermittent assembly has any play with the sprocket in either the Pulldown, or dwell stages. Id like to have the original intermittent form the 35 repaired and back in service, I know it has less miles on it than the one in the XL. Also the vertical shaft drive gear meshes with the original intermittent a lot better than it dose with the one I puled form the XL.

Again, thanks for all the input.

Chris

[Mark Gulbrandsen]

Chris,
You need an.appropriate sized gear puller to safely remove the flywheel... A little gear play is normal. A thickness of notebook paper is about the normal clearance.... the two gears behind the flywheel are the oil pump that force feeds oil into the intermittent. Once apart you may have trouble getting the cam.out if it really is bent.

[John Eickhof]

just like the E7, the XL flyweel establishes end play in the star shaft, loosen the two fillister head screws slightly and hold the flywheel in your hand, gently tap the shaft with a soft face hamme (brass head or plastic) then see how it feels, if too loose just place a flat blade screwdriver in the slot on the end of the shaft and gently pry the flywheel towards the intermittent case then tighten screws and check the feel.the shaft indeed may be bent if so, it will need an overhaul, let me know how it goes

[Mark Gulbrandsen]

I think John meant Cam Shaft, not star shaft. And if it does not come loose with just a slight tap... then get the gear puller. Auto parts stores rent them.

[John Eickhof]

thanks mark, got my shafts confused! however, i was taught by howard straight on tapping the cam shaft to establish about .001 end play in the shaft / flywheel, slightly loosening the two fillisetr head screws will allow the shaft to move slightly, otherwise there is no other endplay adj on the camshaft or the G-1836 intermediate shaft on the movement. The flywheel does not clamp to the shaft but is held fast by the fillister heads against surfaces machined in the flywheel.

[Mark Gulbrandsen]

thanks mark, got my shafts confused! however, i was taught by howard straight on tapping the cam shaft to establish about .001 end play in the shaft / flywheel, slightly loosening the two fillisetr head screws will allow the shaft to move slightly, otherwise there is no other endplay adj on the camshaft or the G-1836 intermediate shaft on the movement. The flywheel does not clamp to the shaft but is held fast by the fillister heads against surfaces machined in the flywheel.

That's pretty much what I do too. On the intermediate shaft I used a .001 feeler gauge to establish the same clearance as the cam shaft before I put the cam in... But one must do the reassembling in the correct order assuming you took it all the way apart. First you have to place the spacer plate that forms the oil pump between the gear on the flywheel and the fiber intermediate gear.... Do that before any shaft's are secured.