Home Made Key for M.O.W. Padlock

[GWiens2001]

Making a key for my Ministry Of Works (M.O.W.) lock. It took a bit of figuring out, but it works!



First, made a high tech measuring tool from a bobby pin.



Slide the hook end down into the keyway. The measurements needed are the full depth of the keyway, the top and bottom of the slot at 9 o'clock and at 6 o'clock. When the hook gets to those measurement points, use tape level with the top of the keyway to mark the measurement.





Then use a micrometer to measure it. If measuring the top of the groove, measure to the inside of the angle of the hook. If measuring to the bottom of the keyway or bottom of the groove, measure to the outside end of the hook.



These are the measurements...



These are the primary components of the key. The shaft of the key is made of aluminum because that is the widest diameter tubing I had in my collection. And the inside of the shaft is brass tubing, because it needed to be stronger. Used epoxy to hold the inner and outer tubing together. The movable part of the key is made from windshield wiper spring. Drilled it with a diamond bit dremel bit to slightly over 1/16". The pivot pin is brass. Drill holes through the tubing for the pivot pin. Cut the slot in the tubing with a dremel tool, clean up the edges with a needle file.



Trial fit the parts, and make sure that the movable part swivels completely freely. If it binds up inside the lock, you are screwed! So be sure it moves freely. When it moves freely, epoxy the pivot pin in place.

Do not hammer the pivot pin with a small hammer like a rivet - it will bend, and you will have to drill it out and make another pivot pin. This is experience speaking.

Before the epoxy dries, again make sure the moving part moves freely. This key moving element is gravity operated. Did not think it would work, but the patent drawings don't lie. So make sure it pivots easily.





Once the epoxy (I used JB Weld) was dried and hardened, used a dremel with a cutoff wheel to cut the pivot pin off on both sides. Then used a needle file to clean up the sides. Then it should look like this...



With the moving element inside the tubing... (fgarci03, get your mind out of the gutter!)





Sizing some aluminum stock for a bow.



And marking for drilling to insert the key into the bow.



Drilled the hole - 1/16" for a pilot hole, then worked up to 3/16".



Shaped the bow, rounded the edges. Roughened the sides of the key shaft where it will be glued into the bow.



Used JB Weld epoxy to bond the bow to the shaft. Let it set overnight to cure the epoxy fully.

The resulting key and lock!



Gordon

[keysman]

NICE WORK !
Have you seen a picture of a working key before you started this project ?


Once again .. NICE WORK !

[GWiens2001]

Thank you, Keysman.

No, had not seen even a picture of a working key. Looked at the patent drawings, though.

Also, I better post this picture, too.



Gordon

[Squelchtone]

I'm lost. Can you explain how the swiveling bit comes out of the key once you insert the key all the way into the lock? and how does it retract back into the key blade once you are ready to remove the key from the lock?

Thanks,
Squelchtone

[GWiens2001]

I'm lost. Can you explain how the swiveling bit comes out of the key once you insert the key all the way into the lock? and how does it retract back into the key blade once you are ready to remove the key from the lock?

Thanks,
Squelchtone

Good questions. The swiveling part opens by gravity, and falls out the bottom of the key into a taller slot at the bottom of the keyway. The narrower neck on the swiveling part allows the key to be turned in the thinner slot which goes all the way around the keyway.

Once the lock is removed, turn the key so the swiveling arm is at the bottom of the keyway again, and flip the key/lock so that the key is pointing straight up. Gravity then pulls the arm back into the key shaft, allowing the key to be removed.

The lock is not key retaining, nor does it require the key for relocking.

Now it can be seen why I emphasized the need for that arm to pivot freely. If it binds in the lock, there are problems.

Here is a picture down where the shackle locks. The brass lever/locking dog is angled, and also attached to the other side of the shackle. As you close the shackle, you can see that lever retracting until the moment the shackle is fully closed, when it releases and locks with a stout SNAP. The spring is surprisingly strong.



Gordon

[MacGyver101]

That's fantastic: thank you! I've got a locked one of those, and making a key has been on my "to do" list for a long time... those measurements help a lot!

[GWiens2001]

Per request by PM, here are the materials used in making this key:

Key Bow
* 3/4"x1/4" (19,07mm x 6,37mm) Aluminum bar stock
* Cut to length and desired shape

Key Shaft
* Outer 3/16" (4,76mm) Aluminum tubing
* Inner 5/32" (3,92mm) Brass tubing

Pivot Pin
* 1/16" (1,57mm) Brass rod

Moving Arm
* .125" x .032" (3,16mm x 0,76mm) Spring Steel (wiper insert)


Clear Epoxy
* Bonding Inner and Outer Key Shafts

JB Weld (Metal Epoxy)
* Bonding Pivot Pin ends into Key Shaft
* Bonding Key Bow onto Key Shaft
* Filling keyways to prevent damage to pins while shipping to ARF-GEF


As MrWizard pointed out, now that we know that there are no moving parts in the key aside from that arm, if I were to make one of these again, it would be easier to make the key shaft from solid 3/16" (4,76mm) brass stock, and dremel out a groove long enough for the moving arm to fit.

Gordon

[kerti]

Exellent work !

[kilae]

Wow, nice! Thanks.
This is now on my list.
So many projects on my list, but only so little free time to do it!

[GWiens2001]

Wow, nice! Thanks.
This is now on my list.
So many projects on my list, but only so little free time to do it!

Same here, kilae. That is one of the hazards of browsing here. Keep finding more locks I want, more projects to attempt, but can't seem to find more time to do them all.

Gordon

[GWiens2001]

Updated MOW padlock key.

Have finished trying various things and finally come up with a 'final version' of key for the Ministry Of Works padlock.



The first key I made for this thread - an aluminum, steel and brass key used tubes and whatnot due to my trying out various ideas to make a key. Now that I understand how the key is supposed to work, the final key is much simpler.

The shaft of the key is 3/16" (about 4,5mm) diameter solid brass stock. The key bow is made from 5/16"x1" (8x26mm) rectangular solid brass stock. The pivot pin is 1/16" (1,5mm) diameter brass rod and the flag is a wiper insert.

First measure for the location of the hole in the key bow.



Use a center punch to make a divot so your drill bit will not wander when starting to drill.





Use tape to mark the depth of hole.





Now start to drill the hole. Use your smallest drill bit at the start - unless you have a drill press, the drill bit will want to grab and pull the soft brass, throwing off your hole and distorting your metal. Drill the hole only about 3/16" (4,5mm) deep to start...

Now put in a drill bit the same size as the hole you are drilling. This is how you check that the hole is straight. You don't want to drill and get to the last size drill bit and find yourself drilling out the side of the key bow. If it is a little off, it is easy to fix at this stage.



Use the length of your metal stock to check how straight the hole is, too.



Perfect! Now drill until you reach the tape using the smallest drill bit:



Work your way through all the sizes of drill bits until you reach the final diameter.

Now check the fit and straightness of the hole using the key shaft stock.



Both ways...



Draw your key bow shape and start to cut it out with a hacksaw.







Use a file to clean up the shape and bevel the edges. NOTE: Do not use a file to bevel the edge directly around the hole for the key shaft. That will be taken care of later.





Now for the sandpaper. This is used for final shaping, rounding edges, and yes, polishing. I used 220, 320, 400 and 600 grit sandpaper.



Work on sanding the edges and corners first. It helps to place a pad or piece of cloth under the sandpaper to help make smoother curvature on the edges.



Sand in the same direction with a single grade of sandpaper. Change sanding direction with each change in sandpaper grit because it will make all the previous sanding marks stand out until they are entirely gone.



After the corners and edges are done for each grit, sand the flat edges. Then you are ready for the next grit.



Remember to change sanding directions with each grit change.





Each side on either side of the hole are sanded with a different grade, and you can see the different directions.



Ended with 600 grit sandpaper, but looks fairly decent.



Let us change the angle so you can see one of the sky lights in the shop.



Use the same methods to make the flag from wiper insets same as the first key.

The case the key is in is not really that fancy. But not bad for cardboard and electrical tape, with paper towel lining to keep the key from being scratched.

The measurements are in standard, not metric measurements, and too tired now to convert. Or even to type them out.



Gordon

[fgarci03]

Gordon,

Thank you for posting this!
I really enjoy reading yout tutorials and the advice they generate. Your tips about using a cloth to sand, or the tape on the drill bits is very ingenious!

Now check the fit and straightness of the hole

Do I need to say anything??