I recently got a hold of some second hand wooden Venetian blinds that were too big to fit the windows I had intended to use them on. After some careful restructuring of them I was left with a load of cut off sections and kept them for some future project. Yes, I'm a hoarder!
It eventually turned out that they were ideal for a Nixie Clock project I had in mind so I have put them to use for it here.
If you don't know what a Nixie Tube is, you can visit Wikipedia Nixie Tube and also read this article from the IEEE SPECTRUM magazine both of which give excellent explanations about Nixie Tubes. They are still being made today by Dalibor Farny in Czechoslovakia and his video gives an insight into the making of these amazing glowing displays.
So on with the Instructable.
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Step 1: Tooling and Materials
Although I have a reasonably equipped small workshop this clock can be built with minimum wood working skills and a little knowledge of soldering and the use of a multimeter.
A bundle of cut offs from a wooden Venetian blind - my wife is eyeing up the rest of them for diorama boxes!
Wood glue - I use Evo Stik brand but any good one will do
Abrasive paper in a few fine grades
1/3rd sheet Orbital Sander
Fine toothed files, normal and small
Fine toothed saw - preferably a draw saw - I used an old style Olfa craft knife with an 18 mm SWB-1 blade
Clamps - I have those pistol type ones from Irwin
4 mm Securing bolts, washers and nuts for the bulk work
Wood Stain and Gloss Spray on Lacquer
Brass disks - I made all my own from 14 mm round brass bar drilled with a 4 mm hole and cut to 3 mm
4 mm x 1.5 mm Brass washers made from 10 mm round Brass rod
4 mm Threaded Brass rod
4 mm Brass Dome Nuts
4 mm tap
3.2 mm drill bit
4 mm drill bit
3 mm T-Nuts
3 mm Brass Screws
3 mm Brass nuts
Spacers for the circuit board
7 mm Spanner to tighten the Dome Nuts
A CNC machined top plate with mirror finishing
IN-8 Nixie tubes - available on Fleabay at various extortionate prices
A PV Electronics 'Elite Class' Nixie Clock kit or similar - you can get them for a lot of different Nixies
A 240 VAC to 12 VDC wall wart
Digital Multimeter to check voltages on the clock board during construction
Hobby milling machine, a small pedestal drill or a battery drill
Hobby Lathe for the metal parts or get online from good fastener stockists
Home made disk sander attachment for the lathe
Thanks to the following
Peter Virica of PV Electronics for producing excellent clock kits
Paul Parry of Bad Dog Designs for support and idea bashing at any hour
Andy & Mandy of Engraving UK for putting up with my design changes over the years
Step 2: Some Wood Work, Sanding and a Prototype Followed by More Sanding!
To make the case I had in mind I needed plates about 9 cm wide and over 18 cm long so I had to join 2 of the slats together. They had rounded edges so I had to get rid of them first. I cut the slats to approximate length in a mitre saw and then clamped them in a vice on my milling machine where the rounded edges were removed from one side.
Once this was done I had to glue them together but having only 6 clamps this took a couple of days to do as I had to allow the glue to dry thoroughly. I held them in place against metal plates to ensure as even a join as possible.
The finish I had in mind was satin Antique Pine and I had to remove the existing finish with a 15 year old 1/3rd sheet orbital sander using fine grades of abrasive to keep the plates as thick as possible as they were starting out at just over 3 mm. That sander has been brought back from the dead more times than the Merc with the mouth! This done I used the worst looking plate as a prototype.
I marked out the required area needed for the electronics and drilled holes in the corners. A handy sized varnish tin provided the arc for the end curve and the excess was cut off and the curve finished by filing and sanding. Once this was done I used a fret saw to cut out the cavity and finished that off by filing and sanding.
A check against the circuit board of the clock and a small adjustment gave me the correct dimensions to make the rest.
The top and bottom plates are doubled up by gluing 2 plates together to give a stronger platform for the case. then I bolted the rest of the plates together with them along the glue line and squared them off by milling away any variations on both sides.
Extra holes were added that would be used later in the assembly and I was good to go with shaping the ends. I got technical with this and used a set of compasses to get the curves perfect. I cut of the excess on the corners and next was to sand the curve on the plates. I had a circle of MDF from a previous project and I superglued fine abrasive to it's face and bolted it in my little lathe. It just cleared the bed by about 5 mm, perfect! Another plate of MDF across the bed of the lathe and I was good to go with shaping the curves. A dust mask was essential for this as it gave off huge clouds of dust! It only took a matter of minutes before both ends were sanded to the arcs on the plates. I split the plates to remove the top and bottom double thickness ones as they would be getting a different treatment The next step was to 'pecker' drill the cavity in the rest of the plates with a 20 mm Forstner bit with a backing piece under the plates to avoid tear out. It is not essential to have a milling machine to do this but it makes the task a lot easier. The same result can be done with a small pedestal drill and very carefully with a battery drill, make sure the bundle of plates is well secured before drilling After this was a clean up with an end mill before cutting the inside corners square with a draw saw. Draw saws work the opposite way from your normal saw in that you pull the cut instead of pushing it. I used a fine draw saw blade in an Olfa knife to do this and finished off with filing and a light sanding to complete the cavity.
More Sanding and Staining.
More sanding of the plates to get the wood as light as possible for staining and remove any surface deviations.
Staining the wood proved to be a real PIA as using the stain straight from the tin with a brush did not give an even coat no matter how I tried to remove the brush marking. If I lived near a large DIY store I would have gone and bought some spray wood stain but I am out in the country and it would involve a lot of time. I had a cheap airbrush and compressor so I diluted the stain with thinners and sprayed a couple of them to see if it would work. I was able to build up the depth of staining to a reasonable level and even though it was time consuming it was working fine! After several coats, a final couple of coats of acrylic varnish was sprayed on to give a gloss finish to the wood. I originally planned to have a satin finish but on receipt of the brass top plate I thought it need a deep gloss finish to set it off.
A note on spray on finishes. Although the makers of most of these will say 'touch dry' in 30 mins, 1 hour etc it is best to leave them at least 24 hours as they are still in their 'green' state which means they are easily damaged as they have not cured fully. Makers times are based on ideal conditions for the application of their product and most of us hobbyists do not have those so err on the side of caution and leave them to cure for as long as possible. The lower the temperature they cure at, the longer they take to cure fully.
This also applies to two part epoxy glues. I have steered away from the syringe types and I use the type that come in separate tubes as they have better adhesion properties and also more economical to use. These I give at least 48 hours to fully harden as in their 'green' state they can have the excess easily removed with a sharp craft knife from places you do not want them.
Step 3: The Brasswork Parts.
Every Nixie Clock I have made has featured some Brass parts in it somewhere and this one is no different.
I wanted to have a 'stacked' look to this clock and decided to make brass spacers to go between the wooden plates. Originally I had thought of full brass layers but this would have been costly as they would have to be made from 3 mm brass plate and machined to the same dimensions as the wooden plates. I did however work out a way of doing this from flat brass bar and soldering to minimise the cost of 'full' brass layers (see the last page of the instructable). So not having any flat bar to hand I used a piece of 14 mm round Brass rod that proved to be the ideal size for the spacers and setting it up in the lathe with a parting tool it was a simple task to polish the brass and bore the 4 mm centre hole and part off the spacers, all 56 of them!
Not wanting to have screw heads showing the only choice was to use Brass Dome Nuts with brass washers to secure the case together. The last layer of the spacers I made with 3 mm holes and tapped these out to 4 mm which enabled me to have the case as a box with a lid that could be removed by undoing the top dome nuts and allow the electronics to be lifted out if required. These needed to have the machining marks removed as they would be visible on disassembly so they were roughed off by fixing them to a 4 mm screw in the mill and run against 2 fine grades of emery paper before being mounted on a battery drill and polished up against a buffing wheel. I 'Loctited' the bottom dome nuts to the threaded brass rod to prevent them undoing if the case top was removed.
The top 2 layers at the rear of the box were cut to allow access to the controls of the clock and the bottom layers got some of the brass securing parts added.
The dome nuts also formed the feet of the clock which was a bonus.
Step 4: The Clock Kit Part
I have used PV Electronics Nixie Clock Kits for a few years now and have found them to be totally dependable. Peter Virica, the owner, is extremely helpful to anyone buying his kits and has excellent support for anyone getting into difficulty with the build.
The 'Elite Class' nixie clock kit is is a relatively new kit which is basically a scaled down version of the 'Spectrum' kit and has a few extra features in it. You can visit PV Electronics to see details for yourself.
The photo above shows the difference in size between the two kits The Brass and Oak clock behind the Elite kit is called 'SARA' because of the typewriter type setting buttons I made on it's rear so this clock is actually SARA's Little Sister
There are other Nixie Clock kit providers out there and already built clocks can be found in Fleabay if you are not electronically minded.
This kit uses IN-8 Nixie tubes from the Soviet era and recently prices have been rising for Nixies due to the popularity of Nixie Clocks. It is that warm glow that attracts people to them!
Building the kit is straight forwards if you have some soldering skills and should present no difficulty. Pete Virica supplies excellent build manuals on his site. (I should try reading them fully sometime!)
Once built I had to make the cut outs on the top deck of the case for the nixies and neons. The simplest way to do this was to cut a slot and then fit a face plate over it. The face plate for this clock required a lot of accuracy and my attempt to make it myself was close but no cigar as there was a little misalignment caused by the size of the cutter I used. Initially I used a series of step drills and then a 19 mm end mill for the tube holes but the end mill over cut and tore into the neon tube holes on the plate. (I found out later that I had neglected to tighten the milling cutter in the collet head and this was the cause. Doh!)
I get some engraving done for clock name plates in the UK and the company was able to make a perfect face plate with accurate holes for me rescuing the finished look I wanted. Thanks, Andy Blackett!!
Fixing the circuit board to the top deck was done with 3 mm T-Nuts. If I had thought about it earlier I could have put them between the top layers before gluing but this would have caused issues with sanding the inside face. I mounted them with spacers to the circuit board and then epoxied them to the top layer after positioning the clock board.This will be more than enough to hold them in position.
To get 100% accuracy on the placement of the brass plate I had the circuit board and tubes mounted to the underside of the top deck and put some double sided tape along each side of the tubes before slipping the plate over the tunes. The clearance I had for this was 0.5mm so it had to be exactly spot on. I removed the circuit board and tube and then drilled 3 mm holes into the top deck through the brass plate where the fixing screws with the dome nuts.would be fitted. Tapping these out and then dripping superglue into them to strengthen them.
There is an addition that can be added to this clock in the form of a remote station kit that captures a GPS time signal and also supplies external temperature data to be displayed on the clock.
Step 5: Case Build Up.
Now that I had most of the case components to hand, a dry build was needed to see the overall look of the case. I was originally going to have 8 layers excluding the top and bottom deck plates but settled on 6 and this gave a nice balanced look to the case
Next was to secure the T-Nuts as I described earlier and after centring the clock board on the top deck I applied the epoxy and a weight was added to secure it during curing.
The arrival of the Brass top plate just need it to be placed over the nixie tubes and neons. This is fixed in place by drilling 3 mm holes and then tapping the holes to 4 mm and strengthening them with a few drops of super glue on the wooden thread.(Deja Vu?) Short pieces of 4 mm screwed brass rod were cut and fitted to the dome nuts that secure this plate and just needed polished before screwing into the top plate to complete the build of the clock. I also polished the rest of the Dome Nuts for effect.
Step 6: Wrapping Up the Build.
All in all, some scraps from the wooden blinds made a great case for a Nixie Clock that is not 'run of the mill' looking and is overall quite a good looking construction. This clock could easily be made from clear or coloured acrylic, plywood or even hardboard. With acrylic you would have to polish up the edges and take care not to mark the surfaces but would result in an excellent looking clock. You could even have the parts laser cut to suit what kit you use and just assemble them.
It may seem that I go to lengths to make cases for my clocks and for them to be transformed from the ordinary into something artistic but great results can be achieved from much simpler ideas. Take a look here at Bad Dog Designs DIY showcase page where Paul Parry, the owner of Bad Dog Designs, posts photographs of Nixie clocks from hobbyist builders from all over the world. There are some stunning designs along with some very simple but effective designs. (OK, I'll be honest, I have a few in there too!).
Imagination is the main ingredient in making something different and everybody has that so get your ideas out of your head and into reality, let everybody see what you can do no matter how simple it may be.
The Instructables site was created just for that.
Brass Costs Saving Tip
Here is a tip that would save on the cost of the brass component for your design. Referring to the sketch above, 'A' is the wood layer of your design and you also want to make a Brass copy of it for the sandwiching. 'B' is the brass layer made up of flat bar instead of plate brass. Using 3 mm plate brass would be more expensive and a lot more cutting involved to make it. 'C' shows a soldering trick to get a good bond on the joints. Drill holes about 3 mm diameter centred on the joins and solder at these points only with the parts clamped together. Fill the holes until they form domes above the brass surface. The solder will not protrude at the edges and on shaping the joint will be nearly invisible. To solder this, get a flat piece of vermiculite insulation material and use this as backing. Once the joints have cooled you can flatten the solder 'blobs' with abrasive paper, files or a Dremel.
Step 7: Thanks for Looking!
If anyone finds this of use then my thanks to them.
This is not beyond basic skill levels so just take your time and work your way through a build.
What to make next?
A Victoriana styled clock called 'Nixies Under Glass' with ZM1040s.