JJ Lower Pad Roller Assembly (removal for a stuck one)

[Ryan Gallagher]

Any veteran tips for getting the lower pad roller assembly out of a turret model Century JJ when it appears to be somewhat seized in place?

I can't get any movement out of it with the set screw removed. I didn't go ham on it yet, but reasonable force was not doing anything.

Would it be better to rotate it first to free the seize, then pull? Tap on it? Heat it? Freeze Spray it?

Those are the only two pad roller shafts I have not serviced yet, and it's needed now because the 35mm one will "stick" in place if you are not paying attention and intentionally nudge it to break whatever dirt/goup bond is causing it to stick to it's shaft when it is idle.

There didn't seem to be anything on the drive shaft side related to that mount that would help access/free it.

Thanks.

[Ryan Gallagher]

It seems too aggressive, but maybe a slide hammer with a head sized for the shaft below the knurling of the assembly handle? Or invent some way to mount/use a gear puller on the same handle?

Would it be safe to douse that area in some penetrating lubricant such as WD40 before the next attempt?

[Randy Stankey]

I'd try a little percussive maintenance first. Just a gentle tappy-tap-tap. Pull and twist as you go. Stop if you don't get any movement after a couple of tries.

Fail that, can you take the whole assembly out? It might be better if you can put the whole assembly on your workbench and, maybe, put it in a vise or something.

[Ryan Gallagher]

I'd try a little percussive maintenance first. Just a gentle tappy-tap-tap. Pull and twist as you go. Stop if you don't get any movement after a couple of tries.

Fail that, can you take the whole assembly out? It might be better if you can put the whole assembly on your workbench and, maybe, put it in a vise or something.

The lower assembly does have to come out as a unit to access the plate to remove the lower pad rollers. Getting the assembly out of it's bushing is the stuck bit right now.

Though maybe you mean remove the whole bushing with it? Those retaining screws appear to be obstructed by the assembly when in place (unless i'm confusing alignment vs retaining screws). Not sure how the bushing itself is mounted.

[Ryan Gallagher]

Although, re-reading, maybe I missed something. Perhaps it only pulls out when clocked in the closed position. In my couple attempts on this unit I may have missed that step. On the other JJ I was following the manual more intimately.

It seems a bit counter intuitive cause in 70mm closed, the roller would impact the drive sprocket when pulling the assembly out. Maybe clocking it between 35&70mm or removing the drive sprocket first is the way to go.

Lower Pad Roller Servicing.png

[Mark Gulbrandsen]

Be sure to keep track of which pad roller came from where, and which the sides of the pad rollers were in case you are going to re-use them. They do not always wear evenly and you need them back in the same places for re-use. You could also measure the OD of the actual pad roller wheels with a dial caliper.

AND, OH MY HECK! (As they say in Utah) THROW THAT DAM CAN OF WD-40 IN THE TRASH.... IT HAS ABSOLUTELY NO PLACE IN THE BOOTH, PERIOD! It was designed to protect the outer skin of Atlas rockets. Well, throw it away unless you are keeping Atlas rockets in your booth... It was also used as a moisture displacement on the electrical connectors in those rockets to keep them from going up, turning over in mid flight and coming back to the launch pad....

[Ryan Gallagher]

Haha. It’s and old can that has been here a while, this is the first time I’ve considered using it.

[Randy Stankey]

WD-40 is good for something... Removing adhesive from tape, stickers or other kinds of sticky crap.

It's cheaper than Goo-Gone.

[Mark Gulbrandsen]

It works good sitting in a garbage can...!!

[Randy Stankey]

When you're out in the garage, sneaking a cigarette, when your wife walks in. You shoot a spritz of WD-40 up in the air to cover the smell of smoke.

[Mark Gulbrandsen]

Am not a smoker... Can't even begin to tell you how many service calls I made over 40+ years because some dufus used it in the booth, often on stuck pad rollers or platter rollers. Synco lube is ok to use though... made by the company that makes Superlube.
When I was a tech at Canon, we got in cameras that people had sprayed WD-40 in. AE-1's sometimes developed a squeeking sound when you'd take a pic. It was just the mirror governor that made the noise, and was only a Class B repair. Instead, Canon gave the WD-40 customers a new camera at the class D service rate.

Anyway, enough about old gummy in a spray can...

[Ryan Gallagher]

Synco Lube and SuperLube appear to be the same product just different regional naming.

The custom keyboard community is big fans of the Krytox grease (GPL 205 especially), but probably just because they cost a lot. $$ translates to value with those folks.

https://www.krytox.com/en/-/media/fi...t-overview.pdf

https://www.krytox.com/en/-/media/fi...ose-grades.pdf

https://www.krytox.com/en/-/media/fi...06-216-226.pdf

(GPL 205 is a chemically resistant bearing grease).

[Randy Stankey]

I wasn't supposed to be smoking, either!

Makes a good deodorant, though! That and some Hoppes No. 9 for cologne and you're all set for a night out on the town!

[Brad Miller]

THROW THAT DAM CAN OF WD-40 IN THE TRASH.... IT HAS ABSOLUTELY NO PLACE IN THE BOOTH, PERIOD!

You sure about that? I heard it was great for getting DTS drives working again.


wd40.jpg

[Mark Gulbrandsen]

LOL!!! Good one Brad... I can only tell you it ruined all the optics in any Canon A Series body. Thankfully, it seems as though most people sprayed it in through tje lens mount.