Tiger Ausf E “F01” Gruppe Fehrmann

[AlastairCooke]

Hi All,
Update 21 Oct 2024
Curved support…

Support in use drilling locating holes for the track hanger pins…

Note use of shaped bases for G clamps.

Track links for turret sides have been drilled and tapped for M3 so that a fixing can be used from the inside. The hole will be hidden by spare track pins.

One link was drilled from the tread side to align the hole and the others were drilled from the rear as they could be held more firmly in a vice in that orientation.

Turret front plate
I have now reached a stage that I has had me concerned for some considerable time: reshaping the front turret plate ends and including weld detail. I wanted to ensure that the Milliput welds had reasonable purchase around these details. It was not possible to cut slots into the turret wall before assembly as the piece far exceeded the capacity of my mill. I decided to use a Dremel with a router bit and attack the aluminium by hand.

The ends of the bar were filed flush with the turret sides then drilled to accept a capping piece that will be epoxied in place after the turret has been etch primed.

The steel trunnion boss was used as a guide for the circular slot. As you can see, some additional shaping of the slots is required.

Zimmerit
As work progresses on the external details for the turret sides, thoughts turn towards Zimmerit. At this stage I am more concerned with where rather than how. Having established that the turret was taken from a vehicle that was delivered in late May 43, it is safe to assume that it arrived at Pz.Ers.Abt. 500 painted in Dunkelgelb but without a coat of Zimmerit. This means that the Zimmerit was applied at the School’s workshop after the general order was issued in Aug 43.

Careful study of images taken subsequent to the demise of F01, in Apr 45, highlights some interesting issues with the application of the Zimmerit paste. On both sides the paste was not applied forward of the lift lug and did not reach the roof on the left side as evidenced by the sharp ‘demarcation’ lines that suggest intent rather that wear. In addition, the pattern changes just aft of the vision port indicating a different batch of paste or a different hand. The pistol port appears to have had the paste applied when removed from the turret, as the ridge pattern does not align with the surrounding area. As the vehicle was based at the Training School it is possible that the application of the coating was a training exercise or done piecemeal when the opportunity arose.

When the time comes I will do my best to mimic this haphazard application.

That's all for now...

[AlastairCooke]

Hi All,
Update 10 Nov 24
The stock trunnion pins were turned down so that the bosses could be permanently installed on the turret sides and have weld detail added. The heads were also reduced to a diameter of 14mm to match the head on the rear boss.

Bosses and front plate ends epoxied in position…

Note the addition of a part that represents the torch cut remnant of the smoke grenade launcher system

Turret vision ports
The stock parts were replaced with a more accurate design that allows for some internal detail.

vision port-small.jpg (28.85 KiB) Viewed 630 times

20241110_115303-doc.jpg (79.7 KiB) Viewed 630 times

Pistol port
As with the vision ports I decided to replace the stock part. First, however the securing bolts need some attention to better replicate the coned taper bolts used on the prototype. The hex heads were turned down and will be ‘let into’ the outer plate.

Pistol Port front.jpg (41.25 KiB) Viewed 630 times

Not sure yet whether to use moulded pins or the M3 cone head bolts to secure the outer plate. It depends on the ease with which the cone bolts can be turned before applying thread lock. I will be tapping the holes anyway for studs on the inside to mimic the through bolts.

Turret electrics
I have started to layout the components for the electrical circuit in the turret. Note that mine is completely separate from the chassis circuits and so I need another battery, relay, switch, charging socket, 12V/5V buck converter, receiver, elevation motor driver, microcomputer, and a fuse box.

20241102_084753-doc.jpg (91.62 KiB) Viewed 630 times

The item at the front of the plate is the mounting for some ‘piggy-back’ shocks that will be fitted without springs to act as dampers to minimise ‘barrel bounce’.

That's all for now.

[Christoffer Ahlfors]

Reducing barrel bounce! That will be exciting!

[AlastairCooke]

Yes, Christoffer. Time will tell if my plan works... I am fitting a pair of Gmade XD shocks.

[AlastairCooke]

Hi All,
Update 26 Nov 24
Turret side weld detail

Turret Electrics
Started to wire up the electrics.

Note the relay rating: 70A! I am aware that this is seriously overkill but wanted to use the same style of fuse/relay module as the chassis and the only one available had provision for a maxi relay. I am currently designing some boxes for the elevation motor driver and the microcomputer.

Pistol port
Drilling holes for attachment bolts using my ‘bespoke’ rig…

Drilling guide in use to position holes and as a flat surface for the tapping guide…

Note use of countersink bit as a ‘key’ for the end of the tap to help ensure the thread is straight and true. The drill chuck on this micro-mill is too small for my usual spring-loaded tap guide.

All six holes drilled and tapped.

That's all for now.

[Tim Carr]

Very nice drill tap setup!

Lots of nice detail and wiring!

Later Tim

[AlastairCooke]

Hi Tim,
Thanks. I am glad you think so. Right from the outset I was not looking forward to adding the extra holes into the top and sides of the turret wrap. Hanging the turret off a portable workbench with a fixture to keep it rigid has worked out really well. My micro mill/drill with a head that can rotate a full 360 degrees has been a godsend.

Alastair

[AlastairCooke]

Hi, Probably the last update of 2024 and so Seasons Greetings to all.
Update 9 Dec 24
Next job, attaching the spare track link hangers and drilling holes in the wrap for securing screws.

Hanger pegs epoxied in place (weld detail will be added later).

Through hole drilled for M3 fastener. This will be almost invisible when spare track pins are inserted.

Left side finished, just need to fit the clips on the top edge of the wrap.

(Note there is an error in the location of the vision slot: it is approximately 10mm too far aft. I became aware of this discrepancy when drilling holes for the track hangers. The issue has been exacerbated by moving the hangers a few millimetres forward to allow removal of the roof. I think that the furthest aft clip is welded over the cupola ring weld on the full size vehicle. I have decided to ignore the error, as I do not have the tooling required to reposition the hole and the problem is only evident when the model is compared with a side view of F01.)


Revised outer part of the pistol port trial fitted…

20241207_082144-doc1.jpg (62.61 KiB) Viewed 99 times

Escape Hatch
I have revised the hinge block as images of the full-sized Tiger 1 show that was made from two pieces. A plate, with predrilled and tapped holes, was welded to the turret wrap onto which the hinge block was bolted. I have replicated this with a shaped part which will be epoxied to the wrap. The hinge block will be through bolted at a later stage.

hinge-1-small.jpg (14.91 KiB) Viewed 99 times

hinge-2-small.jpg (19.25 KiB) Viewed 99 times

Revised escape hatch hinge trial fitted…

20241209_104049-doc1.jpg (66.83 KiB) Viewed 99 times

Front turret roof support and splash guard
Upper splash guard epoxied in place and central roof support dry fitted…

Electronics
Positioning the rest of the turret electronics (enclosures and 12V/5V buck converter)…

20241207_092432-doc.jpg (98.3 KiB) Viewed 99 times

Elevation speed controller fitted in enclosure.

Mantlet casting number
Research using ‘D.W. to Tiger 1’ indicates that candidates for the turret were part of the original contract given to Dortmund Hoerder Huttenverein (code: amp). However, it is possible that the replacement mantlet came from 250445, 250447, or 250456, which would have had armour produced by Friedrich Krupp AG, Essen (code: bwn). This might explain the neater Zimmerit coating on it as these vehicles were produced in Aug 43 just at the time that factory application started. What little evidence for mantle casting numbers that still exists is rather confusing with late production turrets having DHH markings. A quick look through the ‘Tigers in Combat’ series suggests that many mantlets did not have visible numbers and so the safest option is probably not to bother.

That's all for now...