

17. Assembling of the enclosure

It is necessary to note that we will mount the NixieTherm Mk II enclosure not only „from the top to the bottom“, but also upside down. Therefore it is necessary to secure the thermometer’s scale e.g. with a small vice. But before you clamp the scale please cover the jaws with any kind of protective material so as not to scratch the scale’s Plexiglas.



Start with peeling off the protective film from the scale. Now apply carefully both tube clamps into the scale’s notches.



Note: The clamp itself has also a small notch on its back side so fit them in that way that this notch is located on the „rear“ of the scale.



Now fit this “scale-tube-combination” to your vice in such a way, that the „Mr.Nixie logo“ is readable upside down and located near to the jaws.

Pay extra attention that the tube doesn’t drop out during mounting and do not tighten the jaws too tightly.



Now fit the top cover to the scale. Remember again, we are working „upside down“ so the milling „NixieTherm“ must be readable mirrored. Futhermore these words must be located at the front of the scale – this is the direction from which you are normally looking at the thermometer. Have a close look at the pictures on left, which will help you to find the correct fitting position.



At this stage it is time to check the alignment of the bargraph tube. If the tube is dropped in the right way round you will see the anode mesh when looking at the scale from the front (non-mirrored digits). When looking from the back you should see a metallic surface in the tube with the print of type and manufacturing date. If not, simply rotate the tube by 180°.



Now take both LED covers and remove the protective films from the mirrored side. Both covers have a deep milling grove for the tube and a slight wider milling grove for the space of the resistor R5, which is located near the LEDs at the position of the back cover. Both deep milling groves must facing “downwards” to the tube.

Have a close look again at the picture on the left for assistance. The mirrored face of the LED covers must face to the scale on both sides as it will reflect the LED lighting.



For mounting the PCB holder pick up two mounting brackets, two M3x16 screws and four washers and assemble as shown in the picture. Now slide this combination though the drilling holes of the LED covers and the scale.



At the threaded end now fit again a mounting bracket and a dome nut and tighten them slightly only by hand.

Now adjust all four brackets for orientation upwards and parallel to the top cover. Now tighten the screws again, but only such that the mounting brackets can slightly adjusted by pushing them.



Now pick the four flat hat M3x8 screws and the M3x12 metal spacers and stick them „from bottom to top“ through the drill holes of the top cover. Only tighten them slightly by hand. Pick up both thicker (8 mm) Plexiglas frame halves and peel off the films. Slide them gently over two distances.

Pick up now the „fully“ Plexiglas frame with the „chamber“ cut-out and bend them carefully over the four distances; pay attention to the orientation of this „thermic chamber“ and the cutout for the USB connector. The picture gives you assistance in this assembly stage.



• Now fit the electronic board. Pay attention at the three tube’s leads. They must be threaded through the milling groove in the middle of the board. Also these leads may not cross match.

Attach the shaft to trimmer TR2 through the solder side’s drilling hole and press it to its mechanical end.



• Pick up the four Philips screws M3x6 and tighten them softly within the tapped holes of the mounting brackets. Maybe the screws must be bend a little bit if the holes of the bracket will not fit to the holes of the board. Now fasten the four screws with your screwdriver in a crosswise fashion.



• Pick up the supplied tube and cut them in the middle. Thread both halves through the outer leads of the tube, the milling groove of the PCB and push them as close as possible to the tube’s glass body. Now cut the leads as they must be soldered to the pads A, K and K1. Pay attention not to stick the leads too far through the drilling holes of these pads as they may produce a short circuit with the parts located on the assembly side.



• Now an additional jumper must be set between the solder pads X1 and Y1.



• Finally pick up the smaller (4 mm) Plexiglas frame halves, remove the films and attach them to the enclosure.



• Now thread the remaining four Philips M3x16 screws through the holes of the four rubber feeds.



• Pick up the black bottom cover, remove the protective films and attach them to the case. If all is well, both bent leads from the tube should a little press on the bottom. This will fix the tube in its final scale position and is intentional.



• Pay attention to correct orientation of the bottom cover. The louvres are now located at the front side, so you should see the soldering pads mentioned before when looking through the louvres. Also only the left potentiometer TR2 may be accessible through the drilled hole. Have a look at the picture on the following side for assistance.



• Now assemble the four rubber feet to the bottom cover. Please don’t over tighten the screws.



• Finally fit the supplied label, unclamp your NixieTherm from the vice and place it down on its feet.



• After tightening the four pan head screws with an appropriate screwdriver we have finished or work.



