The history of that sound head was it was sitting on a basement floor for almost 10 years. That's about it.

There was a rusty spot on the drum itself. that was polished off, and a new cushion roller was replaced in the lateral guide. Seems to me if there is a flat spot on the drum, this could be detected by bringing the drum up to speed and let the cushion roller ride on the drum, and see if there is any bobbing of the lateral guide roller assembly. A flat spot on the scanner will also give a pulsating feeling if touched with the finger.

The scanner shaft bearings are new. The inner seal of the bearing should be removed and disgarded. The bearings should be flushed out with cleaning solvent, and if I understand correctly, Simplex recommends the bearings be lubricated with a couple of drops of SAE 40 Non-Detergent oil before assembly. Two drops every six months thereafter is the lube schedule (but nobody does that).

The rotary stabilizer should be looked at, also. Give it a big hefty spin, and snatch ahold of it for about 1/2 a second to bring it to a dead stop, and immediately release it. It should start spinning again. If it does not, chances are the oil has leaked out through the years, and the big bearing and its race may not be working. Disassembly is now necessary, parts thouroughly cleaned, and filled with mineral oil. How much, I don't know. I would presume it should be filled totally, allowing just enough air space to allow for oil expansion as temperature changes.

These are some ideas that were conveyed to me by another technician. Is there any other things I should know in case I have to perform the same operation on a future SH-1000? Thanks for your input.

Paul

Take a piece of film and get the drum up to speed, when the film runs out, open the pinch roller see if the drum takes over a minute to spin down to verify it isn't a bearing or lubrication problem. (BTW shoot some SH oil into the channel that separates the drum bearings so it is in an oil environment). Note, you said to remove the seal on the inner side of the bearings, hopefully you meant sheild since only shielded bearings should be used, not sealed.

The pinch roller is a bit of a trick most are not assembled well. There should be 9 Oz. of downward force on the pinch roller (+/- 1 Oz) and it must hit the drum square...if you push down on the pinch roller the film should NOT move laterally...if it does, it is hitting at an angle (this little tid bit can really affect digital quality). Make sure the drum roller is spinning freely and that the later guides are operating properly. The felt rollers really do work better than the rubber ones.

Next look over at the feed sprocket right after the drum, is it orbiting?

One real handy too for checking out speed irregularities is a good strobe light...with the strobe, look and see just what the film and the sprockets are doing to cause the problem.

Steve

 |  IP: Logged

 |  IP: Logged

I just got off the phone with Josh, and he mentioned that there may be a possibility of some skewing. I recommended he perform the tests you have cited in your post. Also, he detected some rough bearing feelings and noises in the lateral guide roller.

Mark, he has new VKF sprockets in that soundhead, and the bronze gears are in good condition. The sprocket shafts and pinion shaft bearings are new. As far as I know, the shafts run true and straight. I didn't think of asking him that question.

Barry, I have un-latched a couple SH100* guide rollers only to have a handful of peanuts in my hand when they fell apart. They do crack and break off very easily. I would suspect that most of that is caused by people who don't release them easy or just let them flop open, or they slam them shut with the force that one might expect could bust a cast iron engine block. You are right....and those hairline cracks will eventually give the operator a handful of peanuts - like they did to me.

Paul

 |  IP: Logged

 |  IP: Logged

 |  IP: Logged

To see if the sound drum is running true, painting the drum w/ Prussian Blue can reveal irregularities.

Also, a competitent machine shop can test shafts for straightness and this will only take a few minutes: surface table, v-block, dial test indicator.

Steve G. you said that the felt rollers work better than the rubber ones. Everyone who I have dealt with has always said the opposite. I am interested in hearing about your opinion.

About measuring the 9 oz on the pinch roller. Is there a special tool specifically used for soundheads, or will a standard scale work? I do not remember this being discussed in the tech. manuals.

Interesting info about the brackets cracking. I believe they are die cast zinc. Anyhow, it may be interesting to use a new bracket as a pattern for investment casting in brass, especially since no shrink mold materiials and pattern waxes are now available....I might give it a try?

 |  IP: Logged

There are a couple of rubber rollers out there now (G-1985), Wolk uses a harder roller than Strong. I have had more Simplex rollers crack over the years than the Wolk ones.

The 9Oz figure actually is listed in an early 5-star spec sheet.

Through actual experimentation, I have found it to be a good figure.

As Mark said, there isn't a special tool...just a spring scale.