Strong Super 80 / Century JJ Alignment

[Ryan Gallagher]

Alignment update:

Today we successfully align-o-tron'd our No.1 JJ (non-turret) Super80 lamphouse, both centering and back-reflecting with a mirror, got the field set and happy for 70mm testing (next opportunity). Major improvements to field and brightness were had.

Opted to stick with the beam spreaders for now, not cutting down snoods just yet for the sake of experimenting without the spreader. Working distance was set to 34in (it was pretty close).

However, less successful on No.2 (dual lens turret). According to laser the reflector center is high (about 1/4in at the reflector insert), BUT that pedestal has no more "down" adjustment on it's lamp house mounting plate screws. At a bit of a loss as to where to look for what I might be able to blame for this misalignment. Perhaps something related to the turret, but we did check that the laser is centered on 70mm RP91 in the gate. The co-planar relationship of the gate to lens holder perhaps, but I'm not aware of "easy" adjustments to change that relationship. No.2 working distance is a bit over 34in, but the snood impedes moving it to match (for now).

No.2 was our "better" of the two field/alignment wise prior, so we buttoned her back up and re-did the best we could with the XYZ and field with existing alignment.

I don't think we are revisiting until after Summer Films, but curious for any thoughts.

[John Eickhof]

post a picture of the pedestal, RCA enclosed base and Brenkert HD base were precast with no lamp table adjustments, the soundhead hangar bracket as designed to do x-y djustments with slotted and keyed mounting of the hangar against the lamp table, horizontal and vertical jacking screws are provided to shift the soundhead / projector into position. This applies to both the hangars that fit the large pattern 9030/9050 series as well as the narrow pattern 1040/1050, simplex, and century soundheads. I always liked that way of adjustment, you could easily dial things right in

[Ryan Gallagher]

post a picture of the pedestal, RCA enclosed base and Brenkert HD base were precast with no lamp table adjustments, the soundhead hangar bracket as designed to do x-y djustments with slotted and keyed mounting of the hangar against the lamp table, horizontal and vertical jacking screws are provided to shift the soundhead / projector into position. This applies to both the hangars that fit the large pattern 9030/9050 series as well as the narrow pattern 1040/1050, simplex, and century soundheads. I always liked that way of adjustment, you could easily dial things right in

Thanks John, I'll do some more looking and share some pictures of the soundhead mount and pedastal soon. Cheers!

Also, on our working distance. It appears the prior installers measured back of reflector to the upper face of the v-block where the gate would mount. My feeling is that is also slightly off, as the gate/film itself is a bit further towards the lens. Did not prevent us from getting a good field, but if we were to "get our hands dirty" again....

[John Eickhof]

generally speaking the wd specified by manufacturer is plus or minus 1/2" or so for a good field. always measure glass reflectors from the silvered surface and metal reflectors from the front surface unless specified different by mfgr.

[Ryan Gallagher]

Here is the pedastal in question, It has the lamp table adjustments, but do not appear to have much in the way of soundhead mount adjustment. This one in particular appears to have had custom holes drilled in the soundhead hanger to accommodate the JJ hole pattern.

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And here you can see we are at the lowering limits on the lamp house table:

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Amusingly, it's partner, the one we were able to calibrate, had a different model hanger with correct hole pattern, the idiosyncrasies between these two projectors keeps multiplying!

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And it's house is within the adjustment limits

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[Ryan Gallagher]

The "horizontal and vertical jacking screws" at the soundhead mount that John mentioned is something I have not been able to spot in our configuration, if they even exist.

[Mark Gulbrandsen]

Ryan, Not all pedestals have that feature... perhaps it was an option during purchase, or something a certain theater supply co in the past offered, I've never been able to determine. Among all the locations that I've ever serviced, I'd say less than 1 in 20 pedestals had that feature.

[Gordon McLeod]

The bullnose on one pedestal is for a RCA soundhead and has had new holes drilled for the Century bolt pattern

[John Eickhof]

Gordon and Mark are right on, you have two different era pedestals, the one not redrilled is for narrow pattern soundheads like century, simplex and early RCS 1040-1050 you will note it is not slotted for the bolts to drop in,, making the bolts that attach the bracket to the pivot the adjustable type that is keyed and adjusts axis x and y the bracket that has been redrilled is originally a RCA 9030-9050 pattern and is not drilled to the correct point, my recommendation is the remove the bracket and have the holes slotted vertically at a machine shop this will allow you to raise or lower the projector to get the spot centered only need to slot the holes 1/4 top and bottom but the on the lower set and slot straight up on the top set, this will make it easier to mount the projector back on by sliding the top bolts into the slots then start the bottom bolts if I read your note correctly, the spot is high on the aperture so you will be able to raise the projector up to get the spot in line, of its too low then all four holes need to be slotted to the bottom 1/4 to 3/8" once in position, tighten them down, also on at least the upper bolts, install flat washers to equalize support against the casting. I may have a correct narrow pattern hangar in stock if you are interested, it would solve your issue. pm me

[Ryan Gallagher]

Gordon and Mark are right on, you have two different era pedestals, the one not redrilled is for narrow pattern soundheads like century, simplex and early RCS 1040-1050 you will note it is not slotted for the bolts to drop in,, making the bolts that attach the bracket to the pivot the adjustable type that is keyed and adjusts axis x and y the bracket that has been redrilled is originally a RCA 9030-9050 pattern and is not drilled to the correct point, my recommendation is the remove the bracket and have the holes slotted vertically at a machine shop this will allow you to raise or lower the projector to get the spot centered only need to slot the holes 1/4 top and bottom but the on the lower set and slot straight up on the top set, this will make it easier to mount the projector back on by sliding the top bolts into the slots then start the bottom bolts if I read your note correctly, the spot is high on the aperture so you will be able to raise the projector up to get the spot in line, of its too low then all four holes need to be slotted to the bottom 1/4 to 3/8" once in position, tighten them down, also on at least the upper bolts, install flat washers to equalize support against the casting. I may have a correct narrow pattern hangar in stock if you are interested, it would solve your issue. pm me

Thanks John. Yeah the three options (using existing equipment) that I could imagine were:
1. machine the adjustment slots into the hole pattern.
2. Seek the proper hanger (like the other one).
3. install a spacer between the soundhead and the projector to make up that 1/4in, but would impact bottom loop size etc.

I prefer 2 or 1, as I think in order to get the lamp table back towards the center of it's adjustment range that spacer would actually want to be closer to 1/2in or more.

Either way this is a lot of disassembly that will probably have to wait for a rainy week beyond this season of film bookings.

[Jack Ondracek]

Here is the pedastal in question

Wow! I trained on a pair of those with Brenkert heads and Ashcraft Core-Lites on them... ummm... 58 years ago? True beasts!

[Ryan Gallagher]

Wow! I trained on a pair of those with Brenkert heads and Ashcraft Core-Lites on them... ummm... 58 years ago? True beasts!

I'll have to take some nostalgia photos for ya from the museum piece downstairs. Brenkert 80 "Supreme" with all the art-deco housing flourishes mounted on the same style ped. Paramount booth had two of them at one point in the RCA era. We re-purchased one for the history aspect and eventual lobby display in the smaller art-deco theatre after it's scheduled remodel. Kept one of our original spotlights from the same era too, the other went to the Harry Ransom Center Museum collection eons ago.

[Jack Ondracek]

I'll have to take some nostalgia photos for ya from the museum piece downstairs

Would appreciate that. Thanks.

[Mark Gulbrandsen]

I only knew of one other Brenkert Supreme and that was in a short lived cinema museum in Chicago.