3D Printed Memorial Clock for my Gt. Uncle Trooper Cyril Arthur Brindley & the men of the 24th Lancers who died while serving their country in WW2

Sherman_Tank_Clock

The tank clock uses two stepper motors, one to drive the tank body on a turntable to display the hours and the other to drive the clock turret to display the minutes.

The clock is controllrd by a ESP32 WROOM 32D Microprocessor and has a JQ6500 sound module to play the clock chimes.

Designed around a 1:35 scale M4 Sherman Tank this clock should work on any similar sized tank with a central turret.

Features & Functions

3D printed case on an Oak base with a Perspex display dome.

The large 300mm case is designed to be printed on a 230mm x 230mm printer bed.

Displays the time using a 1:35 scale Sherman Tank model. The tank body displays the hours and the turrent the minutes.

Time is auto set from the internet via the ESP32 WROOM32D micropocessor.

The clock has full quarter chimming and hours as well as a 2min silence completion chime for 11:00am every 11th November.

Chimes can be set to 24/7, daytime only or off and the volumn can be adjusted.

Daylight saving time is controlled by a single switch.

Telling The Time

The hours are simply read off the hour ring as it passes the 24th Lancers badge. The hour ring revolves with the tank body and increments once an hour.

The minutes are read off the tank turret/gun barrel. The turret increments once a minute.

The time indicated below is 1:04.

Animation showing the clock hours advancing from 2 o'clock to 3 o'clock

Animation showing the clock mins and hours advancing from 1 o'clock to 2 o'clock

Video showing how to read the time from the clock.

Video showing how hours are displayed on the clock note how the clock jumps from 12o'clock to 1o'clock

Model Sherman Tank

The clock uses a 1:35 scale Early Production Sherman Tank Model from Tamiya.

There are many Sherman Tank versions and after studying actual WW2 images and videos of the 24th Lancers at that time I chose this model as it contained various Sherman Tank versions in the kit.

I have attempted to base it on a 24th Lancer C Squadron Tank as my Gt Uncle Cyril Brindley was in C Squadron.

24th Lancers C squadron markings on the completed model.

From videos of the C Squadron tanks being entrained the Markings were higher up on the front of the tanks above the wooden load board.

In this position the markings would have been hidden behind the jerry cans of water & other bits and pieces carreid on the tanks.

24th Lancers identification

The bridge load marking as seen on the entraining video can be seen painted on the hull casting of the antenna mount.

There is a further C Squadron roundel on the front left of the differential cover again behind the jerry cans.

C Squadron did not all have the same Sherman Tank versions as can be seen here. Note the vision slits on the driver and gunner positions.

In action these slits were found to allow fragment to enter the inside of the tank.

Armour plates would have been welded over these slits prob at the south coast.

C Squadron en-route to the South Coast note the lead tank has a 3 part differential cover showing yet another differnet tank model within C Squadron

Tanks would often be named for example C squadron with a name beginning with C ( the 24th Lancers used this convention confirmed by Tomalin, Roy Ernest William (Oral history)).

 Example below B Squadron from the same video useing B to start their tank names.

I have used poetic license and named my tank after Cyril Brindley after my Gt. Uncle.

From the video the Tank serial numbers were on the side of the tanks. I have used an actual C Squadron serial number from the video.

Photograph of the 24th Lancers in action in Normandy showing the plank of wood mounted across the differential cover rucksacs on the turret

and the unusual (for British Tanks) .50 caliber machine gun on the turret roof.

The model used in the clock has odds and ends added randomly about the tank most of which are included with the model kit.

I could not see applique armor on the left side of the tanks in the video but I think this extra armor wold have been added once the tanks arrived at the south coast before the tanks left for France.

I could not see any pictures of the track covers fixed to the tanks in Normandy so I presume these would have been removed once the tanks were readied for invation at the souh coast.

C Squadron (9 tanks) en-route to the South in preparation for the Normqndy landings. Looks like the men travelled in a carridge just behind the engines.

View from the rear of the train.

Operating the Clock

Setup

Before use set the following in code.

timezone line 117

Wifi SSID line 127

Wifi password line 128

The clock is very simple to use with minimum intervention from the user.

On power up the clock will aquire time from the internet.

Once the time has been obtained the clock will auto set to the home positions- 1 hour and 0 seconds.

On pressing "Start Clock" the clock turns the tank body and turret to indicate the exact time.

Time is now updated every 1 minute indicated by the turret with the tank body moving every hour to indicate the hours.

Chimes are set as required on 24/7, daytime only or off.

In summer the "DST On" button is pressed followed by the "Start Clock" button to advance the clock by an hour.

In winter the "DST On" button is released followed by pressing "Start Clock" to retard the clock 1 hour.

Clock Controls & Indicators

The control panel has 8 switches 3 locking and 5 non locking as well as 5 panel mount LEDs.

Switches Latching

Chime On - When on chimes are enabled.

Chime 24/7- when on and Chime On is also on allows the chimes to sound 24/7.

Chime 24/7- when off and Chime On is also on allows the chimes to sound only during the preset times in the Arduino code.

DST On- When activated the clock will show DST (summer timw) & when off the clock will dsiplay winter time.

Note press "Start Clock" to set the clock to the new time.

Switches Non- Latching

Chime Vol + Increases the chime volume to max of 30.

Chime Vol - decreases the chime volume down to 0.

Start Clock after power on and the clock has stopped at the home location 1h 0m pressing this button sets the clock to the correct time.

Reset Clock Pressing this button resets the clock.

Step Hour this button rotates the hour hand by 1 hour and is used for setting up the clock.

LED Indicators

End Stop Hours this LED lights when the Hour endstop sensor is activated.

Note End Stop Hours LED will flash(and the clock is stopped) if the end stop is not reached in a preset number of steps.

WIFI Seach This LED flashes while the clock searches and logs into a WIFI Network.

WIFI OK This LED illuminates when WIFI is succesfully logged in.

WIFI FAIL This LED illuminates while there is no succesful WIFI login,

End Stop Minutes this LED lights when the Minute endstop sensor is activated.

Note End Stop Minutes LED will flash(and the clock is stopped) if the end stop is not reached in a preset number of steps.

Control Panel LED Indicators

On Power on the WIFI fail indicator lights to show WIFI is not connected.

The WIFI Search Indicator will now flash as the clock finds and gets the time from the NTP set in code.

Once NTP time is obtained the WIFI OK indicator lights to confirm.

After a short delay the tank body rotates to it's home position at 1hr.

When this position is reached the End Stop Hour indicator illuminates to indicate hour home is reached.

Once End Stop Hour is reached the tank turret starts to rotate to the End Stop Minutes position (o mins).

The End Stop Minutes indicator lights when the tank turret points to 0 minutes .

The clock now stops and waits for the Start Clock button to be pressed.

Full startup animation

End Stop Fail

If the clock at any time fails to find the hour or minutes end stop the tank body or turret could spin forever.

The clock detects if too many rotations have taken place it will stop the clock and flash the End Stop Hour or End Stop Minutes indicators.

End Stop Hour not found

End Stop Min not found

24th Lancers Cap Badge

A replica silver cap badge was purchased from Ebay.

I painted the badge matt black then rubbed the high areas back to give an aged effect to the badge.

The badge was then painted and then glued to the 3D printed badge mount.

The top centre of the badge indicates the hours

Clock Build/3D Printed Parts

Apart from the Oak base & the Perspex Dome the clock is 3D printed.

The clock turntable and drive gear were downloaded from https://www.printables.com/model/127726

The instructable is here https://www.instructables.com/3D-Printable-Timelapse3D-Scanning-Turntable/?utm_source=YT

Turntable viewed from below showing the gear teeth.

Below the turntable is modified by cutting out the large center spindle.

Spigot - glued over the hole in the turntable above the spindle from the minutes stepper passes through this part.

Completed Turntable lower side showing spigot glued to the modified turntable. The upper turntable has 6 M2 self tappers and washer fixing it to the hour dial.

Turntablecentertool - used to center the spigot in the turntable while the fixing glue dries.

Hi-Gear-56-Teeth this gear is attached to the hour motor and drives the Turntable above.

base11- mounting for the veroboards/modules, turntable and stepper motors

Control Panel

A hole will need to be cut in the back of the control panel for the wiring

Control Panel Fixing

Fixed inside the control panel with 2 off M2 self tappers through the top of the control panel into the wooden base below.

M3 holes are dilled through the fixing and control panel.

Control Panel Screw Washer

This washer allows the fixing screw for the control panel to fit square against  the angled control panel.

Switch Spacer

Spaces the switch Vero board away from the control panel.

2 off M2 bolts,nuts and washers fix the Vero board and spacer to the control panel.

Below- completed control panel.

Turntable

This is the upper turntable where the hours dial is fixed to. The Tank body sits on here.

The turntable is fixed from below via the lower geared turntable.

Base

The circular base is constructed with 4 baseouter parts.

These 4 parts are fixed with glue and M3 nuts and bolts.

Base bolted and glued together. 

The completed base below is painted white and decorated with the 24th Lancers roll of honour.

Base Fixings

4 off baseouterfixings are required and are fixed to the wooden base with M2 self tappers 2 off per fixing.

Once the fixings are in place an 4 off M2.5 holes are drilled through the completed base above to match the locations of the base fixings.

Pilot holes are then drilled through these holes into the baseouterfixings to accept M2 self tappers.

This allows the base to be reomoved for maintenance.

Brackets in place on the base.

Dial Bezel

The dial bezel is printed in 4 parts and has a grove for the Perspex dome to sit in and also provides the location for the minutes dial decal.

The bezel is screwed through the recessed hole into the completed base and is also glued to the base.

The size of this part may need to be adjusted including the groove width depending on the Perspex dome size as these are not produce to ery procise dimentions.

Dial bezel in place on the base with minutes decal applied.

LED Holder for thin 4mm LED strips

The Optional LED Holder (LED_RingThin135_01) is fixed by 2 off M2 self tappers to the dial bezel.

The thin 4mm LED strip is just fixed using the self adhesive backing on the LED strip.

The power wire goes through a small hole drilled through thr dial bezel and base.

The LED_RingThin135_01 can be seen in position on the dial bezel at the front of the clock.

Centralizing/Fixing Bracket

The bracket is made of 4 seperate parts below.

3 off all parts are required.

minuteringbracket

The minuteringbracket is fixed to the base11 part with M3 nuts and bolts. M3.5 holes need to be drilled in base11 legs to match.

The bracket is fixed to the wooden base through the central hole and a washer to allow some adjustment to ensure the base is central to the turntable.

The minuteringouterbracket is fixed to the slots of the minuteringbracket with M3 bolts.

minuteringouterbracket 

turntablebracket

The turntablebracket  is fixed to the top of the minuteringouterbracket with a single M2 self tapper.

Washer

Used to adjust the position of the clock on the base to ensure the turntable is central.

The 3 completed brackets in place.

BearingMountCenter 3 off

The 3 off bearing holder holds a standard 3D printer bearing. These bearings stabilise the turntable

The mount fixes to the three fixing legs slots of the base11 with M3 bolts and nuts.

The three black 3D printer bearings can be seen above the slots of the base11.

Bearings

Bearingmounthour

Mount for the hours bearing. The slots allows adjustment of the gears that drive the hour/turntable.

hallsensorcovermins 

HallSensorCoverMinsSpacer

Spaces the HallSensorCoverMinsSpacer to the correct height.

magnetmountmins

The hall sensor magnet is glued onto the mount and the mount is glued onto the rear spindle of the minute stepper.

hallsensormountmin

Mounting bracket for the hall sensor that detects the position of the minute stepper.

hallsensormounthours

Mounting bracket for the hall sensor that detects the position of thehours stepper.

Speakercover

Covers the hole in the base cut for the speaker

Speakerstand

The chime speaker is mounted in here with M2 nuts and bolts. The stand is fixed to the wooden base with M2 self tappers

Verowasher

Used to space the various boards & modules off the base11.

badgemount

Cap badge mount rear.

Front view with badge mounted.

Turret Fixing

The turretfixing fits into the base of the turret with glue.

The spigot faces down and into the spindle connctor

Below the turretfixing fits into the base of the turret and is a friction fit but cn be glued if required.

Spindle Connector

spindleconnector

The round opening faces up and takes the spigot from the turret fixing depth set and fixed by an M2 bolt.

The "D" shaped opening faces down and the spindle from the minute stepper fits into it.

Mounting the tank in the clock

Image below shows the Clock with spindle connector attached to the minute stepper spindle.

If use a M2 bolt in the lower hole to fix in place.

A large hole is drilled in the base of the tank hull so the spindle connector can pass through.

Remove the engine hatch from the model to access the spindle connector

With the turret removed place the tank body onto the turntable and position it as required.

I position it so the front of the tank is between 1o'clock and 12'oclock.

Replace the turret on the tank so the spigot on the turret fits into the spindle connector and tighten the M2 bolt on the spidle connctor to lock it in place.

With the clock powered on wait until the turret stops turning and the "End Stop Min" indicator is lit.

Losen the M2 bolt so the turret is free to rotate without moving the stepper motor.

 Move the turret to the 0 minute position and tighten the bolt.

Reset the clock and check the turret points to the 0 minute when the endstop is reached.

Replace the engine hatch and press the "Start Clock" button and the clock will now tell the time.

Constructing the Wooden Base

Place the completed base and control panel on your chosen piece of timber.

Draw around the base leaving whatever overlap is required.

Cut out the base with a jigsaw.

Clean up the cut edges.

Using a router add a bevelled edge

Paint or varnish the timber base as required then fix all the clock parts to the base.

Stepper Motors & Turntable in place

Tank in place

Completed Base

Front

Left showing HQ and B Squaron Roll of Honour

Rear- Speaker & LED Brightness Control

Left- C & A Squadron Roll of Honour

LED Strip Illumination

The 12v LED strip is controlled by a LED controller.

The control board is removed from the case has a variable resistor on the reverse side which is mounted on the case by drilling a suitable sized hole.

The 12v input connector is left in place and the output is removed and connected to 12v.

The output is wired to the LED strip on top of the base.

The plug and socket on the 12v feed and input allow the base to be removed for maintenance.

The LED control board is fixed to the case via the variable resistor mount.

Turntable and Clock Construction

The steppers motors, electronics and 3D parts of the clock internal are shown below..

All the parts are built off the 3D printed "base11" shown below flipped upside down.

Bottom view of Base11

Mount the 3 off "bearingmountcenter" on the three legs as shown below.

Loosely fix in position with 6 off M3 Bolts, 12 off M3 Washers and 6 off Nyloc nuts.

Glue center 22mm x 7mm x 7mm bearing in place flush with the rear of the round plate not the square stepper motor plate so it sits out from the other side of the plate a few mm.

Insert the 3 black printer bearings onto the 3 "bearingmountcenter" and secure with M2 self tappers and M2 washers.

Below bearing fitted flush to base not the sqaure stepper mount.

Black 3D printer bearing.

22x7x7mm center bearing.

Fix the "Bearingmounthour" loosely in place to the "base11" with 4 off M3 bolts, nyloc nuts and 8 washers.

Once the geared turntable in in place the hour stepper motor is adjusted so it meshes correctly with the turntable gears.

The 3D printed part "Hi-Gear-56-Teeth" is pushed onto the hour stepper shaft below the bracket once the hour stepper has been mounted.

Mount the hour stepper motor on top of the "Bearingmounthour" and fit the "Hi-Gear-56-Teeth" onto the motor spindle.

Mount the minutes stepper motor in place in the center of the clock.

Glue a neodymium manget wih super glue to the "MagnetMountMins" then super glue the "MagnetMountMins" to the rear shaft of the minute stepper.

Fit the hall sensors to the  "HallSensorMountHour" and "HallSensorMountMin" brackets with M2 Nyloc nuts, bolts and washer.

Fit the "HallSensorMountMin" bracket in place with M2 self tappers close to the minute sensor magnet so the hall sensor is triggered when the "MagnetMountMins" attached to the stepper shaft rotates.

Note there are no holes printed fo the backets so mark and pre-drill holes as required.

There is a bit of adjustment built into both brackets.

The "MagnetMountMins" attachemennt to the stepper shaft is very fragile so I have designed a protective cover that just slots over the rear of the minute stepper.

"HallSensorCoverMins" in place over the minutes stepper motor and sensor mount.

The Vero Boards, and modules are mounted on 5mm 3D printed "verspacers".

The spacers accept 2mm self tappers and holes for these will need to be drilled as required.

Vero Boards and modules fixed in place with self 2mm self tappers.

Three support/fixing brackets are made up from  these parts 1 off "MinuteRingBracket", 1 off "MinuteRingOuterBracket" and 1 off "turntableBracket".

See picture below for location and fixing details. Fixings with M3 Bolts, Nyloc nuts and washers. The only exception is the "turntableBracket" is fixed with a single M2 self tapper.

Brackets in place ready to fix to the base/clock surround.

Turntable Build

The "hourring" below is fitted to the top of the turntable with 6 off 2mm self tappers.

Turntable fixed through the back to the "hourring" with M2 self tappers.

The Geared turntable is fixed to the turntable with self tapping screws. Ensure the geared turntable is fitted in the exact center of the turntable as this is a rotating part.

Note the spigot glued to the middle of the geared turntable.

Picture of complete turntable. Washers under the M2 self tapper are there to prevent the selftappers from showing throught the hour ring.

Depending on the length of M2 self tappers you have available these mat not be required.

The main clock body loacted in place inside the geared turntable.

Note the hour gears meshing and the center bearing located over the spigot. This bearing and the three black bearings take the weight of the geared turntable, turntable and tank body.

Completed turntable fitted to the clock movement (from below). This is now ready to mount into the clock surround.

Final Clock Build

The case is fixed to the wooden base and movement.

The case fits into 4 off "baseouterfixings" which are fixed to the wooden base with 2 off M2 selftappers each.

Mount the clock movement onto the base losely at first.

Case fixing.

Line up the badge with the middle of the control panel and fix the clock case in place.

If you have fitted LED lighting plug the LEDs into the controller before putting the case on.

Top view showing the case in place.

The upper fixings of 3 x M2 self tappers locate into the turntablebrackets as

4 x M2 bolts hold the case to the "baseouterfixings" via drilled holes.

Once the case is fixed in place lower the completed turntable onto the geared turntable ensring that the gears are engaged.

Ensure that there is an even gap all round the turntable then remove the turntable and tighten the screws on the "baseouterfixings".

Replace the turntable.

Fit the "spindle connector in place on the minute bearing spindle and ensure when the spindle turns it stays centered.

Spindle connector in place. 

Remove the turret and engine cover from the model.

Locate the tank body over the spindle through the hole cut in the tank body floor.

Turn the tank body to half way between 12 and 1 on the hour ring.

Align the turret to 0 on the minutes ring and tighten the lock screw.

Test every thing is fine by reseting the clock and checking the tank turret points to zero minutes and the tank body/hour ring stops at 1 hour.

Vero Board Layouts (click to view full size board layouts)

Note Vero Board will need to be trimmed around 3D printed part "base11".

Layouts without modules in place

Layouts with modules in place

Rear Veiw

Schematic

Click to view full size

Decals

Decals were printed on white inkjet transfer paper.

Decals supplied with kits varies but the only decal I could use was the star for the turret top.

Tank Serial number (taken from a C Squadron tank from 1944.

Fitted to both side of the hull.

I printed this decal white inkjet transfer papaer with the background the same colour as the tank.

Bridge Weight Indicator

C Squadron Marking

24th Lancers Regiment

8th Army

24th Lancers Cap Badge

Poppies used on this clock  Image by macrovector on Freepik

I have compiled a list in Excel under seperate tabs containing various date.

You can compile your own lists in any order as required by using my sheet.

24th Lancers Roll of Honour Decal by Squadron

Control Panel

Minute Ring

Minute Ring Label

Hour Ring

Hour decal fitting instructions

With the hour ring attached to the turntable and the turntable in place on the clock.

Turn on the clock and let it move to the home positions with both the End Stop LEDs illuminated.

Apply the hours decal making sure the 1 lines up with the center of the badge on the front of the clock.

Code & 3D Parts

Code

3D Parts

Includes "hi-gear-56-teeth" & "turntable_top_v1_1" which are were part of a Turntable design.

Desktop Image