Tiger Ausf E “F01” Gruppe Fehrmann

[Adrian Harris]

I'd certainly like to see an engine build thread please

Adrian.

[Vince Cutajar]

Me too. If you have the time.

Vince

[AlastairCooke]

Hi All,
Update: 8 Jun 20
Not much to report on this thread as I spent much of the last couple of weeks getting the basic engine completed (see HL230 engine build thread). However, the first item was a dry fit of my custom-made idler adjustment capture plates.

Then a test fit of a design of the front mounting plate for the engine, this was printed by Shapeways as I wanted it to be tough and durable.

With this installed I could position the engine carcass and think about how to secure the firewall at the bottom.

That’s all for now.
Alastair

[AlastairCooke]

Hi All,
Update 19 Jun 20
I designed a replacement tow hitch and also got it printed by Shapeways in Nylon 12 (Versatile Plastic) as I wanted it to be tough and durable. This will be the material of choice for any non-structural external detail. If we get into structural parts (perhaps with the new resilient wheel hubs that are designed for the KT and need to change for the Tiger 1) then MJF Nylon 12 possibly with glass beads may be chosen. Anyway the Versatile Plastic parts are covered in Mr Surface 1000 to act as an primer and filler since the plastic is porous.

revised tow hitch
The next job was to shape the internal floor that is being ‘constructed’ from the surplus belly plate:

Note that the plate has been cut to allow its removal without disturbing the drive motors.

Here we see holes drilled so that plate can be secured to the front ‘stiffening’ bar. I will probably use cap screws here for ease of access for removal. I am trying to design all the internal features so that it is possible to access the torsion bars without disturbing the basic hull. This idea is demonstrated with the firewall:
The top is screwed to the radiator inlet grill supports...

...and attached to the internal floor using some of the roof support brackets that are now surplus:

front view

rear view
The plan (at the moment) will be to attach the engine front support plate to the firewall at the top only so that if required the firewall can pulled out vertically and the internal floor removed with disturbing the engine. Likewise, using a scheme yet to be devised , I plan to be able to remove the engine without disturbing the firewall or any items attached to the belly plate.
Because of all this design work and the desire to minimise any requirement to drill/tap holes in situ I am still some way off etch prime and red oxide priming the hull. In addition, I am only partially successful at thinking 10 steps ahead . So far there have been only a few “aw shucks” moments . I will show how close my proto-typical front roof support is to the drive motors when it is completed... the fit is very tight!

I hope this amount of detail is of interest?

Alastair

[Christoffer Ahlfors]

You bet!

[Stephen White]

Just when you think there are no more photos of FO1 out there, another one pops up. This one was posted on the 3RTR Facebook page today. 3 RTR knocked out FO1 on the Aller Crossing recounted elsewhere. (Photo via Adam Hermitage)

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There are six images in the Tank Museum Archive:

And I was aware of three others, now this one makes four:

[AlastairCooke]

Hi Stephen
Many thanks for the 'heads up'. Looks like this image was taken a little later when it had been pushed off the track? The available views now give the full driver's side... pity no one stood the other side! I suspect that was too difficult given the trees, the ground conditions and 'natural' view for passers by.

Alastair

[AlastairCooke]

Hi All,
Update 16 Jul 20
Let’s start at the front.

Proto-typical front roof support. Grey resin web is my 3D print, which will eventually be attached by M2 screws to the aluminium plate. Weld detail will be added later.

As promised...clearance for drive motor! Good job the electrical terminals face forward!
Front support plate added (3mm aluminium sheet) to provide space for electronics and bow MG servo etc.

Moving on to the sponsons and engine decking...

sponson side supports, drilled and tapped to accept securing bolts for radiator inlet grills.

grills and radiator cover attached, will use square head bolts eventually.

Milling the extension floor plate for the fan, radiator, and upper fuel tank space. The angle is added so that it fits against the rear hull plate.

Marking out the support block for the extension floor plates. Note I am using longer versions of the sponsor securing bolts.

Extension plate in position. It will need to be reduced in width. This will be measured up later when the engine space side plates are fitted. Material had to be removed from the custom designed cross brace due to the position of the firewall ‘pocket’ that houses the ventilator fan.

rear cross brace milled to accept front of engine and firewall ‘pocket’ plate

Some imaginative use of the mill to drill securing holes for the firewall ‘pocket’ attachment system, shown below.

Custom designed attachment fixture. This will locate and secure M3 nuts so that the plate can be fixed and removed by means of bolts from the other side. The fixture has been designed so that it can accommodate some of the electronic and switch detail found on the engine side of the firewall. The web (which is not proto-typical) will be hidden by cables etc. Note also the support block for the rear of the engine. This will make a platform on which to sit the engine block and a means of securing the rear support bracket.
Final picture for today...

The engine space starting to come together. You can see the oversize sponson floor extensions. The width needs reducing by about 1 cm or so. Also note the non proto-typical bracket for the engine cover support frame. This uses the original holes for the rear plate angle brackets and provides a means to secure the frame at the back. This part will not be visible unless the central cover is removed.
Alastair

[Martin Hofmann]

Hi Alastair,
i had send you a pm about the cooling vents.

[AlastairCooke]

Hi All,
Update 18 Aug 20
It is about a year since I got the kit from Stephen and I am still not ready to assemble the basic hull ! Whilst waiting for some fasteners to help with the engine deck I decided to make a start on the road wheels.
The late pattern Tiger 1 resilient road wheels were constructed partly from two circular plates that were held together with M20 bolts. These bolts had a 30mm A/F nut and so the standard M2.5 nut at 5mm A/F is just right. The inner hub consisted of three tapered sections that bolted through to another set on the other side. One set had a tongue that locked into a groove on the axle. The bolts securing these were M14 on the King Tiger and started as M10 on the Tiger, upgraded to M12 later. Knupfer Modell-und Feinwerktechnik market M2.5 bolts and nuts which are 3.5mm A/F which is 21mm A/F at 1/6 scale this is close enough, for me, to the scale 19mm A/F used with a M12 bolt.
After much consideration and design work in Fusion 360 I have decided to stick with the kit supplied solid rendition of the resilient wheels. The main reason being that the new versions are thinner at the hub and this would have involved replacing the spacing tube for the more widely separated (outer) sets of wheels. Simply using spacers to make up the difference was not viable as this would change the position of the bearings relative to the hull sides and result in a requirement to replace the axles.
The different hub bolt arrangement on F01 when compared to that in the kit has been resolved by custom 3D printed nylon hubs. I reckoned that all 15 M2.5 bolts were not required for strength purposes, especially considering that the Early Tiger 1 kit only used 6, and that I could just use the 9 that matched up replacing the other six with heads glued into the hubs. The hole for these ‘faux’ bolts were made deliberately undersize so that a positive ‘push/screw’ fit could be achieved.

Front view of original hubs – Armortek Stock Configuration.

Front view with revised (3D printed) hubs with standard M2.5 nuts. Note etch primer on wheels.

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Inner set with inner faces primed using basic Halford’s Red Primer. Will be assembling this unit prior to spaying base colour (Dunklegelb) as I assume this mimics the production process. Not too worried about true colour match here to RAL 3009 as it will be hidden. In fact, I plan to use this primer for all surfaces that will be oversprayed with the base colour.

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Spacer in place. I will probably use adhesive to help secure wheels to hubs as well as the bearings.

Rear face of inner wheel set. I have added hex bolts in the holes to mimic those required for securing the actual wheel plates together. I have also added a hub for improved detailing and to shield the bearing from debris etc.

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Rear face of outer wheel set, again note hub.

Front face of outer wheel set. Note the 3d printed replacement hub. I have not added the faux bolt heads yet as I want to check the utility of the printed internal thread for the hubcap. The smaller nuts really disguise the fact that the bolts are the same diameter.

Outer wheel set showing nut retention plates and standard bolt head size used on the spacer (You will not see these) so I get the benefit of a greater surface area for the fastener. I will probably still use some adhesive here.

Front view of both sets (checking clearance of bolts etc.).

Rear view of both sets. Design update: thread for hub cap was too fine to work in this material so have increased it to M20 x 2.5. May need to increase fit tolerance too, we shall see.
Alastair

[AlastairCooke]

Hi All,
Update 09 Sep 20
With the arrival of some low profile M3 x 4.0 A/F nuts (from Knupfer) the engine cover support frame is complete.

Top view of frame.

Top view of frame in situ (The frame is made from an aluminium sheet and 3D printed ‘bearers’ with locking tabs).

Side view showing how the sheet aluminium part fits with the 3D printed plastic elements.
With the frame sorted, I can now secure the engine bay side plates: this was done with 3/8” ABS angle.

Left side plate attached to frame with 10BA C/S bolts. These will be cut to size after final fitting.

ABS angle attached to side plate.

ABS angle attached to side plate and sponson floor (Gap at rear will be hidden by rear plate doubler and weld detail)

Right side plate with sponson floor cut to size.

Empty engine bay waiting to be fitted out!
Thoughts now turn to the rear plate and hull sides. I want to plan and mark out all the changes required before stripping the hull down so that the next assembly can be the last.

Alastair

[AlastairCooke]

Hi All,
Update 23 Sep 20

Following up a previous post on the Forum that discussed ways to avoid project stall I offer the following.

For me the secret to keeping interested is twofold, one: treat each step as project in its own right and try to avoid looking too far ahead as you may get discouraged with the ‘distance’ still left to travel. The other is to think about what features you could add and research the possibilities, knowledge, and skills required.

As a result of the changes I have made to the rear I will not be able to use Ivano’s or John’s aftermarket fan and radiator units but still intend to have some animation.

I am probably going to delve into the use of Arduino or Raspberry Pi micro-controllers and so here is my ‘wish’ list:

• Single stick steering

• Two start sound sequences (electric and manual)

• RC controlled ‘clutch’ switch so that the engine can be revved without the sprockets rotating when desired.

• RC controlled smoker switch with fan speed proportional to throttle position. This will allow smoker to be switched off remotely to simulate a warm engine. Probably separately powered.

• Radiator fans controlled so that they are synchronised with each other and the speed is a function of throttle position. Probably separately powered.

• Servo controlled Bow MG with sound, light, and motion triggered by RC switch. The gun will follow a programmed set of manoeuvres

• RC switch to trigger co-axial MG sound and light

• Wireless communication to turret. Turret will have its own power supply for main gun firing sequence, MG and commander animatronics.

• RC switch to start four servo controlled commander figure. The figure will follow a programmed set of movements with sound.

• RC switch to trigger main gun sequence that will include verbal commands, sound, recoil, smoke and light.

Whist I appreciate that some of these functions are available ‘out-of-the-box’, others will need me to acquire some new skills.

Alastair

[Adrian Harris]

A very good wish list, and all of them achievable.

The RC clutch is part of what we're looking at with the OpenTX transmitter system, along with gear changes and gear proportional steering. Engine speed proportional turret turning is also possible.

The fan speed etc is something I have been doing for some time but currently relies on the Benedini sound board. If you're going with Beier or Shockwave sound boards then they may do something similar internally or you'll have to listen to the throttle RC channel and react to that.

With the MGs, etc you can either use an Arduino to drive them directly or use a Pololu servo board and control that from the Arduino. They have a very good serial control protocol. I thrashed out a mulitplexing system for the M3 where a three position switch on the transmitter allowed you to control either the 75mm, 37mm or commanders cupola from the left stick on the transmitter. Now all I need to do is to build the tank

I have also looked at wireless or IR communication between the hull and the turret and decided that it was much easier to just bind two receivers to the transmitter, with one in the hull doing hull based tasks and the other in the turret. Two separate sound systems also means the engine sounds won't be dipped when other sounds are played, which can sound quite false.

I love tinkering with the electrics in these models, so I look forward to seeing how you tackle them

Adrian.

[AlastairCooke]

Hi All
Update 25 Sep 20
Received a package from Australia: 30 tracks links from Liam! They certainly live up to expectations. The budget did not stretch to a full set and so I decided to compromise and order enough for the front and the turret. I reckon the standard Armortek links will suffice for the running gear.

Liam's links placed in position.
Moving onto to the rear plate
First the armoured exhaust covers. The M3 fixings provided in the kit are too small to my eye especially considering that the same size is used to affix the heat shields. So I decided to open the holes out to accept M5 as well as milling out the drainage ‘holes’, holes for the lift studs and slots for the securing nuts. I have yet to round off the corners and put on a coat of cast texture.

Current state of the exhaust covers.
Next, some test prints of items to go in and around the engine bay.

Here we have exhaust pipe flanges, fan drive seals, mounting plates for lower water pipes, union to connect left radiator piping to oil cooler, part of the deep wading conduit, sponson air valve and air pipe mounting plates and the backing plate for the electrics.
Finally, for now, is a mounting plate for the smoker. I plan to have a dual system and am considering mounting them either side of the engine where the lower fuel tanks would be. This will release space under the turret and fill a void as I am not going to fit copies of the fuel tanks. Before finalising the position of the smokers I would be interested in any information about their operating temperature and whether the heat is likely to damage Ivano’s resin engine model.

Alastair

[Adrian Harris]

The smokers get quite hot to the touch, especially when the fan isn't running, but I don't know if it would be hot enough to affect resin.

Adrian.