Introduction: The Sprintronic - Clock With Laser Cut Case

Picture of The Sprintronic - Clock With Laser Cut Case


If you have read Sky Mall magazine on a plane, then you have seen the inspiration for the Sprintronic clock.

This is a very easy, inexpensive, and quick project. The clock's movement is a standard battery powered quartz movement from an arts and crafts store. Its case is made of inexpensive 5 mm (0.2 inch) plywood. The face lens is a small piece of Plexiglas.

The case and lens patterns were cut on a laser cutter, however neither are too complicated to fabricate using a scroll saw and drill. The face lettering can be transferred using the toner transfer method when cut with a scroll saw.

A complete kit for this clock is now available at http://www.dougparadis.com/products-page/clock-kits/sprintronic-clock-kit/

Step 1: Materials and Tools

Picture of Materials and Tools

Materials:
     1  -   Battery Powered Quartz Clock Movement. I have used movements
              sold under the labels "The Clock Shoppe" and "ArtMinds". The
              movement shaft should be sized for either 1/4 or 3/8 inch face thickness
              (you may need to adjust spacing slightly with washers).

     2  -  11 inch by 12 inch pieces of 5 mm (0.2 inch) plywood
     1  -  3 inch by 4 inch piece of Plexiglas or clear plastic
                   (I used 1/8 inch thick Plexiglas)
     2  -  Popsicle craft sticks
     1  -  Sheet of 110 weight (lb) card stock.

     1  -  #4 - 1/2 inch (3 mm x 12 mm) screw
     2  -  #4 washers
     1  -  #4 lock washer
     1  -  #4 nut

     1  -  Credit card size cold laminating pouch


TOOLS:
     Scissors
     Ruler
     Craft knife
     Glue (wood and super)
     2 small Clamps
     Sand paper
     Block of wood
     Access to laser cutter or scroll saw and drill

     Optional:
      3/32 and 3/16 inch hole punches
      Stain
      Finish (varnish or other)
      Mallet

Step 2: Cutting the Case

Picture of Cutting the Case

The patterns for the clock's case are attached below. The files with .svg extensions can be opened in Inkscape, a free vector drawing program that is available for all major operating systems. The files with .pdf extensions can be opened in Adobe Reader which is also free.

Note: If you use material of a different thickness (i.e., not 0.2 inches or 5 mm) you will have to adjust the height of the tenons and and the width of the mortises (grooves).

Step 3: Staining and Finishing the Case

Picture of Staining and Finishing the Case

If you have laser cut your case pieces they will most likely have some areas where smoke from the cutting process has left a stain on the wood. The way I addressed this was to lightly sand the wood to minimize the smoke stains. I then stained and finished the wood with a wipe-on varnish. The stain camouflages any remaining smoke stain and enhances the beauty of the wood.

Staining and finishing the case is an optional step. It slows the project down, since you have to wait for them both to dry, however the results are in my opinion well worth it. 

STEPS:
     Sand
     Stain
     Wait for stain to dry
     Buff with soft cloth
     Wipe on the varnish
     Wait for the varnish to dry
     Repeat with 2nd coat of varnish
     Buff with soft cloth

Step 4: Making the Clock Faces

Picture of Making the Clock Faces

The file for the clock faces is attached below. After printing out the clock faces on card stock, use scissors to cut them out. Work slowly and you should not have any issue making nice round faces.

I have added a second option for the clock faces where the minute dial is made of a transparent material. In this clock face option the minute dial will be on the outside ring and the hour hand will be on the inside ring.  The hour hand should still be printed on card stock. This option was suggested by many people in the comments. See the 2nd .pdf file below.

The second picture shows the holes that you want to make in the center of the faces (assuming you used the recommended clock movements). These holes can be cut with a small pair of scissors, however an easier way is to use hole punches. It turns out that 3/32 and 3/16 inch hole punches work perfectly.

Punching the round hole in the hour face is easy. The shape that is in the center of the minute hand can be achieved by using the 3/32 inch punch in two overlapping punches that stay within the red border marked on the minute face center. The third picture shows the first punch being made on the minute hand. If you look closely, you can see that there is still a area of paper not punched within the red border in the center of the face.

Step 5: Mounting the Clock Movement

Picture of Mounting the Clock Movement

To mount the clock movement select the three pieces of the movement mount and assemble them as shown in the second picture. The hole for the movement's shaft may appear centered, but it is actually shifted a little towards one of the end pieces. The end piece that the shaft hole is closest to will be towards the top of the clock.

The fourth picture shows the movement being mounted. If the movement has a hook built into the case, remove it. You may need to adjust the amount that the shaft sticks out the front. When the hour hand is attached it should just clear the edge of the end pieces. After the depth of the movement is correct, tighten the retaining nut.

The minute hand shaft should be positioned so that the flat part of the shaft shape is perpendicular to the 12 O'clock position. See the last picture. The hour hand should then be placed on the movement, with its position so that it points at 12 O'clock.

Make sure that any temporary protective plastic covering the hour hand has been removed, then carefully place super glue on the front of the hour hand. Make sure that you do not glue the movement so that it can't turn. Next, place the hour face dial over the hour hand with the 12 O'clock position corresponding to the hour hand position. Hold the face dial in position with your fingers for 20 seconds. Wait 15 minutes before putting on the minute hand.

The minute hand face should just slip on to the minute shaft, being held in place by the oblong shape of the shaft and the punched hole in the minute hand face. After you have the minute hand in place, screw on the nut that comes with the hands set onto the shaft.  

If you did everything right, the 12 O'clock position on the hour hand face should line up with 60 minute position on the minute hand face.

Step 6: Attaching the Lens

Picture of Attaching the Lens

The first step of attaching the lens to the clock case, is to make sure the lens fits in the lens hole.

Next prepare the cold laminating pouch by removing the side that has no adhesive and discarding that piece. Using the side with adhesive, carefully peel the protective cover off.

Remove the protective cover from the backside of the lens, and wash that side thoroughly with window cleaner. Do not skip this step.

What we are going to do is attach the piece of the laminating pouch plastic that has adhesive to the backside of the lens. The part that overlaps the lens will be stuck to the backside of the case front. This step is a bit fussy. We want to make sure that all the air bubbles are removed from where the plastic film contacts the lens. Do not be surprised if you are not successful the first time. The trick is to touch the back of the lens with the laminating material only in the center of the lens, then use the tip of your thumb to slowly smooth and attach more of the plastic to the lens. When you get one half done, do the same for the other side. I got it right on my second try.

Now carefully insert the lens into the back of the front piece of the case and smooth the overlapping adhesive covered plastic film firmly onto the case. Turn the clock front over and remove the protective covering from the front of the lens.

Originally I tried to use clear packing tape for this purpose. What I found was that the packing tape isn't as clear as you want, so even if you get out all the air bubbles, it will not look as good as the laminating pouches.

When you are done you should not be able to tell that the laminating film is there.

Step 7: Assembling the Case

Picture of Assembling the Case

Assemble the front and back of the case to one of the side pieces. Then slide the movement and its supports into the notches that are cut into the side piece. Make sure that the 12 O'clock position is correctly orientated.

Next place the clock on its side and carefully position the second side piece. You may need to adjust the position of pieces to make sure everything lines up. Use the palm of your hand to gently tap the second side into place.

After the sides, front, back, and movement mount are all attached, place the clock on its feet and align the top. Again use your palm to gently guide the pieces together. All the pieces should fit together snugly. No glue should be needed for the case.

Step 8: Assembling the Battery Door

Picture of Assembling the Battery Door

The picture shows the back of the clock and the battery door. Take one of the Popsicle sticks and cut it in half. Sand the cut ends so that they are smooth. Glue each of the half sticks about 3/4 inch from each end of the back of the battery cover door. The two pieces should both be centered on the door so that there is equal overlap of the door edge (See pictures). I used wood glue for this purpose. If you have clamps, place them on the pieces for about an hour.

Next take the other Popsicle stick and cut off about a fourth of its length. Round the end of the long piece so that it matches the non-cut end. Drill a 1/8 inch (3 mm) hole into the center of the stick. Place a washer on a #4x1/2 inch screw and insert the screw into the Popsicle stick. Insert the end of the screw through the door. Finally, place another washer, then a lock washer, then a nut on the screw and tighten. The door should look like the last picture when you are finished.

The door is installed by pushing the door into the clock and holding the clock overhead on its back. Shift the clock until the door falls into position. Finally lock the door by moving the outside stick across the door.


Step 9: Fine Tuning the Clock Disks

Picture of Fine Tuning the Clock Disks

You can slightly adjust the relationship between the hour face and the minute face by moving the body of the clock movement as indicated in the picture. After shifting the movement body, reset the minute face with the adjustment dial on the back of the movement.

Before installing the battery and closing the battery door, turn the movement time adjust knob around several times to make sure that there is no binding in the two dial faces. If everything looks good, install the battery, set the time, and lock down the door.

Now sit back and enjoy your new clock!

Step 10: Conclusion and FAQ

Picture of Conclusion and FAQ

I have found this project to be so easy, quick, and inexpensive that I have actually made two. I plan to make a few more as gifts for family and friends. It makes a great desk or shelf clock.


FAQ:

Q:  What is the one thing that you would do differently?
A:   The wood I used was very inexpensive, I would like to build one
       using a better grade of wood.

Q:   What type of wood did you use?
A:    I used a scrap piece of luan underlay plywood bought at a local
        home improvement store.

Q:  What are the fussy parts?
A:   There are two parts that are a little fussy. Sticking the laminating
       pouch plastic to the back of the lens, and getting the hour/minute
       hands just right.

Q:  Why is it named "Sprintronic"?
A:  The watch that it is emulating is called the "Dashtronic". So keeping
      with the idea of "dash", I chose "sprint".

Q:  Do you have access to a laser cutter and if so how?
A:   I do have access to a laser cutter through membership in the
      Dallas Maker Space. If you are in the Dallas area, come by and visit.
      See www.dallasmakerspace.org for location and meeting times.

Comments

Doug Paradis (author)2011-08-28


I have added a clock face dial set that assumes the minute dial is made of a transparent material to step 4.

With this new dial set you could have the minute dial on the outside ring and the hour dial on the inside ring.

The hour dial should still be made on card stock. Both dials will be the same diameter.

I have updated step 4 to explain this option and attached the .pdf file for the altered clock dials.

My one concern is shadows. We'll just have to see how it goes.

Thank you to the many people who suggested this idea both here and on Hack-a-Day.

Alcyon (author)2012-09-01

Well blow me down, nice clock.
I made one with a old key from a typewriter to use also the seconds.

Doug Paradis (author)Alcyon2012-09-01

Cool clock!  You have added the second hand in a very inventive way that doesn't distract from the overall design. The brass outline of the old typewriter key finishes it off nicely.

DesignMakeLearn (author)2011-08-31

I created a clock like this concept last year and thought I came up with such an original idea! Noooo!! Ha ha!
I like the customization you did on the dials and box! Nice job! Well, I guess I won't enter mine in the contest since it's so close to yours, and you did a much nicer job!
My idea was to read the time from the left side with the numbers in line with the "pointer" as the time (8:45 in the picture).
Great job!

Like it ! bit of a steam punk look too.   It seems 
A surplus  ,used Bike gear would work too.  Or most any gear over 12 teeth

Thanks for the kind words.

laserline (author)2011-08-30

I just added it to my favorites. I guess that definitely means it deserves (and got) my vote.

Doug Paradis (author)laserline2011-08-31

Thank you!

pahosler (author)2011-08-28

making the mins on the outside should be fairly easy... make a clear plastic disk with the mins on the edge, the hours will be on a disk behind them showing through the gap.

couldn't you reverse the movement by rotating the clock movement 180 degrees (put it in upside down) instead of trying to disassemble the thing and flipping the stator motor?

Doug Paradis (author)pahosler2011-08-28

Flipping the stator is extremely easy (a few screws and keeping track of the parts). Rotating the clock 180 degrees will not change the direction.

The clear plastic disk idea would work. I am going to give that a try to see how it looks on my next copy.

Keep the ideas coming...

pahosler (author)Doug Paradis2011-08-28

doh! you are right, not sure wtf I was thinking!

You were thinking correctly, just not on the right axis. :) If the movement is mounted to the front of the clock ("backwards", not "upside-down" - 180 degrees on vertical axis), then you're right, it will reverse the apparent rotation direction.

The disadvantage is the amount of space between the front of the housing and the dials is larger. Nothing one can't design around, though.... and then you could put a time adjustment knob right on the front!

Kaelessin (author)pahosler2011-08-29

With a bit of finagling you could manage to put the movement in backwards (requiring larger dials) to reverse direction.

javajunkie1976 (author)2011-08-29

Have you ever thought about putting a small lightbulb on the bottom of the arc so that the face can be read at night?

Good idea. Since it is battery powered, I would use a LED and button switch.

If you wanted to be really clever you could use a eBay PIR switch without the Frenel lens (to keep the look simple).

This would complicate things, but might be worth it. There is room in the case for sure.

simplebeep (author)2011-08-28

This is really cool, especially the fact that you can build it with a standard clock motor.

It'd be interesting to figure out a way to have the minutes dial show on the outer ring, rather than the inner, in order to make the clock more precise. It would also be interesting to reverse the direction, as per this instructable, to make it seem like the hand in the display window was moving forward rather than backward.

Anyhow, just a thought. This is pretty damn sweet as it is!

Doug Paradis (author)simplebeep2011-08-28

I considered changing the direction of the movement and dial faces. I may still do that on one of these clocks to see if I like it better. It is easy to do with these movements. You just pull the stator of the motor, reverse, and re-insert it. Which direction the movement should move was a subject of debate with friends before building the clock. I chose the simpler way and left the direction unchanged, which by the way, is the same direction as the original watch.

Moving the minute dial to the outside ring is more problematic. I haven't found a movement setup that way. I believe that you would have to craft something to get that effect. I have not looked into the gearing of the movement and do not know what is possible.

The preciseness of the minute dial is very good due to the thin line on the lens. It does take a little interpretation to tell time at the hour, however I am not sure exchanging the rings the hour / minute dials were on would help much with this. 

Thank you for your very thoughtful comment and kind words.

jelmore1 (author)Doug Paradis2011-08-28

How about using overhead transparency sheets for the minute dial. Then it could overlap the hour dial all the way to the edge.

simplebeep (author)jelmore12011-08-29

Oops! sorry, I hadn't read your comment before I posted mine above.

Doug Paradis (author)jelmore12011-08-28

WOW!
That is an excellent idea! Thanks for sharing.

simplebeep (author)Doug Paradis2011-08-29

Indeed. My thoughts were a "maybe someday" sort of musing. I've worked with these clock motors and I understand how difficult it would be to get the minutes on the outside ring. Unless you used a transparency sheet...

handy157 (author)Doug Paradis2011-08-28

Moving the minutes to the outside of the wheel next to the hour would be easy but make it much more difficult to read the time. You wouldn't use the current minutes disc at all, but just use the disc that is mounted to the hour shaft. You would just have to make 60 little lines or dots between each hour and you'd probably want to mark the 5 minute increments to be less confusing. The size would make it very hard to read anyway, unless you made the entire clock much bigger. Then you would have a wall clock instead of a desk clock.

dimtick (author)2011-08-29

I really like the idea of this but not really the final outcome. I think there is a freedom and power that a laser cutter gives you. it would be cool to see something that really took advantage of the advantages the laser has over convential methods.
I've attached an image of a cardboard chair just to illustrate what i'm talking about. that is "out of the box" thinking. can you image trying to create that using conventional tools?

zerobitjack (author)dimtick2011-08-29

That chair would be quite easy to make with a scroll saw.

dimtick (author)zerobitjack2011-08-29

I think my post came out harsher than I intended.
I've done my share of scroll saw work and cringe, thinking about what it would take to cut about 50 identical pieces with those curves. It would take forever and I'd go batty before I got halfway. a laser cutter doesn't care if it's cutting a curve or a straight line or if it's on piece 1 or 50.
the chair photo is simply one example of looking at a problem differently and thinking about the oppertunities that a laser cutter brings.

debefree (author)2011-08-29

Thank You for such a fine project and clear instructions

I "saw" the "dashtronic" influence at once.

This is going on my clock to do list..

stienut (author)2011-08-28

do you have parts and pieces for sale? I'm all over this!

Jim

skylerskinner (author)2011-08-28

So cool man, I have a steel watch made by Stauer that looks just like this... in fact, I'm sure you know that Stauer uses that signature fancy "S" that you have in the middle of your clock face.

RedBinary (author)2011-08-28

Having the end grains showing on front is a bit of a downer, but otherwise that enclosure is damn sexie!

Doug Paradis (author)RedBinary2011-08-28

Actually if the pieces are laser cut, the edges are charred to a interesting dark brown/black edge that hides the ply boundaries.

If you are using a scroll saw to cut the pieces, I would imitate this effect (black edge) by sanding and painting the edges with a thick black epoxy paint. The effect can also be accomplished by sanding the edge, using some filler on the edge, sanding flush, and painting with regular black paint, but that is a little more work.

RedBinary (author)Doug Paradis2011-08-28

I was basing my comment on the pictures, though I think I might like the black epoxy, too! I will *definitely* have to try that on a bent-wood project that I am working on about now.

biloyp (author)2011-08-28

Very nice job! Gonna have to try this one.

Exocetid (author)2011-08-28

Very nice design.

Dream Dragon (author)2011-08-27

Excellent project. Nicely documented. Thank you for sharing.

javajunkie1976 (author)2011-08-27

Very classy look. I've always been in love with the design ever since I saw a similar wrist watch in a National Geographic magazine.

fleirvik (author)2011-08-27

Love it! I have had a similar idea to this for long and combined with the need of a clock at work, I now seem to have found what I was looking for! Thanks a lot!

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