April 4, 2017: Posted mechanical part shop drawings and STEP files
April 4, 2017: PMT Shutters Modification
See Partslist page for information about adding PMT Shutters for experiments where imaging is needed quickly after 1p photostimulation, and where it is impossible to block bright light from reaching the PMTs with chromatic filters.
February 16, 2017: Additional mounting hardware for Motorized Mirror Cover assembly
The magnets which were included with the original design of the motorized mirror cover assembly have insufficient strength to hold the assembly together. Additional latches were added to the design to perform this function. An updated parts list and DWF model are posted (in both cases, the main parts list and model have not been modified–look for the updated file for this specific assembly). The threaded holes necessary to use these should already be present in the custom cover pieces that were received. Note that the long #10-24 screw/washers/nut shown replaces a standard #10-24 screw which was used to fix the Big detection lens holder to the main optical table. The washers/nut allow the screw to be fixed in position and still support the Big detection lens holder, while also extending out to be used to support the motorized mirror cover assembly. The custom 3d printed latch may have already been sent out to each lab that participated in the 2p-RAM workshop (if not, then please email or comment). For the side latches, it may work easier if they are inverted from what is shown, with the small, button strikes on the top cover piece. In the way shown, when the bottom cover is removed, the latches swing down into the assembly, potentially touching the dichoic/mirror, and generally getting in the way.
February 16, 2017: Entrance Beam Expander position
We found that if the Entrance Beam Expander were positioned as shown in the models then part of the beam could clip/reflect off of the Resonant mirror chamber. We solved this by moving the beam expander completely downstream of the resonant mirror chamber, as shown below. Also, we changed the magnification of this expander to 3x (using Thorlabs f = -50 mm and f = 150 mm -B achromat lenses), after more carefully adjusting the colimation of the beam out of the 2x expander that comes before the prism pair compressor (which made the beam larger after propagation to the microscope). In general, it is probably optimal to make the beam as large as possible going into the remote focus objective, such that the maximum power that can be transmitted to the sample (100% power in ScanImage) is as large as you think you'd ever want to use. This was around 200 mW for us (See Podgorski, Ranganathan, J. Neurophys 2016.) For reference, I think that we could get at least 50% more power with our Chameleon at 970 nm if we didn't overfill the remote focus objective as much.
October 18, 2016: Accessory optics system: Coverglass alignment system alignment issue
It's possible that the spot that the coverglass alignment system should project onto the camera for this system does not hit the camera, due to small misalignments of several optics, even when the coverglass is perfectly aligned with the imaging objective. There are few degrees of freedom to fix this, as the assembly is currently modeled. We fixed this by separating the LED and pinhole from the accessory optical systems main body, and attaching it to the main microscope vertical breadboard, allowing it to move in x and y relative to the rest of the system. See picture below.
October 13, 2016: Accessory optics system: 1p photostimulation galvo issue
The design of the standard electrical connector for the 6210H galvo changed at some point in the past, and the accessory optical system design only works with the old connectors, while the galvos purchased for the accessory optical system (XY 6210H galvos w/ 3mm aperture mirror set) have the new connector. As such, the y-axis galvo will NOT FIT into the 2p-RAM system (it's connector hits PupilRelay3). The easiest way to fix this problem is to purchase a replacement 6210H galvo with the old style connector, which is still available. Gary Tillman <Gary.Tillman@cambridgetechnology.com> created system part # 6SD11390 ($677) for this, and it should contain the proper galvo, a y-axis mirror (attached to the galvo), and the proper wire to connect the galvo to the driver. He thought that it would not be necessary to send your driver in to be retuned to the new galvo. (It would be best to confirm all of this with Gary when you place the order.) There IS a 10-12 week lead time to receive the galvo, however.
If a fix is needed in less than 10-12 weeks, then there is an alternate, 2-step solution (see photo below).
- Take the y-axis 6210H galvo, remove the electrical connector that is soldered to it (cut it off, and then desolder the pins one at a time), and then remove the connector on the cable that goes with the galvo and solder each wire directly to the galvo PCB board.
- Modify the accessory optics system main housing: the pocket that accomodates the y-axis galvo PCB board needs to be widened and made more deep, as this PCB is itself different on the newer galvo design. The pocket should be widened to have a 39mm diameter, and should have its depth increased by 1mm. The hole that the galvo itself goes through need not be changed.
From left to right: The old style connector. The new style connector. A galvo with the new-style connector that was made to fit into the old design through soldering the wire directly, and modifying the accessory optics main body part.
October 12, 2016: Resonant mirror angle alignment issue
Issues with alignment were found when using the original resonant mirror angle alignment procedure. A new, in situ procedure was developed, which does require modifying the resonant mirror chamber part from the original design.
September 2016 and previous
NEW- Custom condensor lens from IRD
The custom condensor lens (to be attached to the PMT) is not ideal. IRD was not able to manufacture the lens without a chamfer on the stem of the mushroom, which prevents the lens to fit entirely into the PMT opening. However, the gap between condensor lens and the PMT housing is sufficiently small so that we do not consider this a problem. You may have to press the lens into the PMT opening.
We were offered a 25% discount on this order, due to this issue. Please check that this discount is applied on your invoice.
Dowel pins update
(MCMASTER-CARR 90145A567 Dowel Pins are BAD)
Gary Zera from Zera Development will be reaching out to all of you regarding modifying two additional parts (three in total).
Alternatively, you can have your shop fix the pieces.
The surface that needs to be fixed is marked with the Diameter 3.055 dimension (zone C1). The center of this curve has to be located using the dimension 2.820 (it currently is located using the dimension 2.835).
H10770PA-40 SEL - GaAsP without shuttering
H11706P-40 SEL - GaAsP with shuttering