Daylight Savings Clock

At first glance this looks like a normal clock that is missing a minute hand, but it has been designed to make it easy to adjust for daylight savings time. To set the clock an hour forwards you simply tilt it to the right and to set it back an hour you tilt it to the left, simple as that. It is a re-make of the design I found here

The clock has markings for hours, quarter hours and half hours so as you can see in the picture the time is about 8:25.

The reason the minute hand is omitted is because when the clock is adjusted as well as changing the hours by one hour it would also change the minutes by five minutes. I left the second hand on because although it will also be changed by 5 seconds when the clock is adjusted this is such an insignificant amount of time that it really makes little difference.

Tools:
Stanley Knife / Box Cutter
Pair of Compasses
Ruler
Protractor
File
Drill
Pliers or snips
Glue Gun
Lathe or other means of cutting a circle

Materials:
Clear 3mm  Perspex
Quartz Clock Movement & Hands
Cardboard
CD Jewel Case
Plantpot tray or similar thin plastic
White Spray Paint
Glossy Photo Paper & Printer

The first step was to make a prototype out of card to ensure that the 2 bases were in the correct position and the clock was the right size for the length of hands I was using on the clock.

I decided on a diameter of 15cm and cut out a disc from the card. I used the protractor to mark out the 12 hour markers and the 12 half hour markers, there should be 15 degrees between each marker.

I then marked out the 2 bases to be cut off, they should be at right angles to the 5 o'clock and 6 o'clock markers and should intersect at the 5:30 marker.

I have made many clocks in the past so have a box of various clock hands, the first one I pulled out which was the right sort of length looked a bit too 1970s for my liking so I eventually decided on a basic straight hand.

The front of the clock is a 15cm disc of 3mm clear perspex. My Dad had several pieces he was throwing away because they were "too small to do anything with", I decided to prove him wrong and managed to find a piece that was just big enough for the clock.

I am lucky enough to have access to a woodturning lathe so was able to use that to cut the disc, although you could also use an adjustable hole cutter that attaches to a normal power drill if you don't have a lathe.

I attached the persex to a piece of plywood, mounted it on the lathe, marked the centre point and used a pair of dividers (you could just use a ruler if you don't have them) to mark the diameter to cut out on the perspex and then used a standard woodturning parting tool to cut the disc out.

I then used the file to remove any rough edges from the perspex.

To finish off the front, I glued a piece of paper to the perspex and marked out the clock and the pieces to cut off in the same way as the cardboard prototype. I then scored the 2 base lines on both sees of the perspex, then positioned the scored line on the edge of a piece of wood with the steel ruler on top and while applying pressure to the ruler carefully snapped off the unwanted pieces.

It is important to score the line on bothe sides of the perspex in order to get a clean break, if you have any jagged pieces remaining they can be removed with a pair of snips or just filed off.

I then printed the face out on a piece of glossy photo paper and using the plastic front as a template cut it out to the correct shape making sure that the intersection of the 2 bases was at the 5:30 mark on the face.

I then removed the paper I had glued to the front and cleaned off any excess glue with methylated spirit (any alcohol based solvent would also work).

Then drill the hole in the middle of the face making sure is it the same size as the diameter of the clock shaft you have.

The next step is to make the stand for the clock so it can stand up on its own. I cut this out of an old CD jewel case, these are made of quite thin plastic and are easy to cut using the knife and a ruler.

Because the clock will be fairly back heavy due to the clock movement and battery I made the stand 5cm deep to prevent it topping over.  You can see it in the pictures temporarily attached to the front with Blu-Tack

Finding suitable materials for the back was the most difficult part for me, I needed something fairly thin but rigid enough to hold the paper face firmly against the front. I originally wanted to use a CD jewel case again but they were too small. In the end I found a plantpot tray in a local hardware store, it was big enough and was made of a soft plastic that was easy to cut with the knife, I drilled a hole in the middle, then used the plastic front as a template to cut around.

Unfortunately although the plastic is very easy to cut it is also quite flexible, so in order to stiffen it up I then cut out a smaller disc from a CD jewel case and glued this to the back of the back using heavy duty spraymount glue. This worked out better than I expected and made the back completely rigid.

Finally the stand you made in step 5 is glued to the back you made in step 6 with the glue gun, I then spray painted the whole of the back white, but you could chose to leave the stand transparent if you wanted.

The face is sandwiched between the front and the back and the whole thing is held in place by the spindle nut on the quartz clock movement, I then glued the movement in place to prevent it moving and therefore telling an incorrect time.

I painted the second hand red so it shows up more on the white face and added markings to the stand so I know which side is GMT (Greewich Mean Time) and which side is BST (British Summer Time).