Before commencing work, and two barometers:
Hour pipe – simple turning:
Hour bridge, friction spring and rev minute arbor:
Reverse minute wheel and pinion:
Minute wheel and pipe:
The 1/8″ arbor goes all the way through a hole drilled through the centre of a 1/4″ mild steel block. The crutch is 1/16″ steel rod soldered to the block. The slotted plate is milled from 1/16″ mild steel.
I round the inside edges of the slot to stop it snagging on the suspension spring block.
Two pieces of brass angle 3/4″ x 3/4″ x 1/8″
A piece of brass strip 1/2″ x 1/8″ and a piece of 1/4″ brass rod.
Silver soldered together and milled square.
The 1/4″ square piece is riveted on by turning a spigot on the end. Cut a slit in the square rod on the milling machine.
When in position correctly clamp it down and spot through the two 2BA and two register pin holes.
Next I would like to make the pallet arbor crutch. But this can’t be fitted until I cut out the top slot in the back plate. Because once it’s soldered on I won’t be able to get it out unless that slot is cut. But; one of my registering pins is right there in the way, and I need it to help me position and depth the striking train. So the striking train has to be done next all the way up to the fly. Then I can cut out the back plate, so that I can work down towards the pendulum.
To mark out the steel for the anchor I either clamp the scape wheel directly to the high carbon steel sheet or mark it on paper then scribe from that. This Escapement is a square recoil escapement, square because the pallets span 7 1/2 teeth of the scape wheel which has 30 teeth.
So mark (on the paper) the 7 1/2 points (with a dot of your pen)
Coincidentally (and this is not critical) the inner circle of your crossed out wheel is approximately right for finding the degree of angle for the two impulse faces (radius= .71). So scribe/draw a line from your dots and across the inner circle so it just touches it, one across the top from the left pallet and one down the right from the right pallet. Next put in the drop-off face angles; from the centre of the wheel draw a line outwards directly to both dots and past, shade in to make clear this is metal to keep.
Next find the position for the anchor arbor. The distance between the arbors is X.
X divided by the radius = 1.41 ~ so the radius multiplied by 1.41 = X.
In this case 1.15.
Use a compass to scribe this line, it doesn’t matter too much where along the anchor the arbor hole goes. Place it centrally to look good.
Carve all this out of the steel keeping clear of the scribe lines as it can be shaped little by little in the depthing gauge. Hopefully it should jam as you have made it too big and when it is nearly there finish it off by planting it in the clock. When it is nearly there remember to file/polish down the drop-off faces which shortens the pallet instead of taking too much off the impulse faces making it ‘drop’ too far.
Completed barrels and great wheels:
Barrels, end plates, slipwasher and rachet:
For the barrels I used 2″ drawn brass tube. 1 3/8″ long. Faced off nicely in the three jaw chuck.
Wheel, collet, arbor and pinion:
The mounted great wheels:
The screw cut:
Mounting the great wheels and going train:
Division plate and lathe mod for roller filing rest
Here I make pinion wire. All of my pinions are made out of 5/16″ diameter stock on the milling machine. When I have cut all my leaves I can cut off a pinion one at a time at the required length, drill the hole and position on the arbor. A main advantage of fabricating instead of turning the whole arbor & pinion from solid is so that it is much easier to depth the pinions to the wheels using a simple homemade depthing tool. 3 pinions are to have 8 leaves and 4 have 7.
The 3rd and Centre pinions are 8 leaves and both are turned down to the 3/16″ to hold their wheels respectively. The Scape, Fly, Warn, and Pallet are 7 leaves. And the Pin is 8 leaves. Pinions and pivots should be hardened and tempered to prevent wear.