TeeELL’s Tank transporter - AIRFIX 1:76

[TeeELL 601]

I have recently received some files allowing me to print a complete resin Scammell TRMU20 tractor and trailer.  It happened along when I was working on parts to enhance the re-released Airfix Scammell TRMU30.  There are a number of areas which the Airfix designers got wrong some of which cannot be rectified easily.  There are areas where some enhancements help to overcome or disguise those shortcomings.  The advent of 3D printing has made ‘scratch building’ easier and parts created reproduce-able.

I am sure that many of you have looked at the builds and improvements done to this venerable old kit by the likes of ‘Neilly’ in Canada and ‘T16S’ here in the UK, perhaps you’ve even stumbled across my efforts.  I have used their work, and my first build, to design enhanced replacement parts for the kit.  I will be building both a ‘parts demo’ model based around a ‘green plastic’ kit and then a proper build using a grey plastic kit.

Firstly, roll back to 2016(ish) and I built ‘MOLLY’; it featured a raised roof line, scratch built rear bed and turntable, improved ‘walking beams’, air-filter and a few other changes.  About a year ago, and new to 3D CAD and printing, I created an improved front axle with much finer mudguards and better detailed ‘walking beams’.  ‘MOLLY’ received those upgrades during periodic servicing and displayed them at SWM last year.

‘MOLLY’ looking a little the worse for wear - I’ve recently found out the correct serial number for this vehicle.  What is probably very obvious is the more robust axle and the much finer mudguards 

 

In this view you can see the additional detail of the ‘5th wheel’ and rear bed.  The air-brake reservoir, vertical sheave, trailer support, robust tow hooks and the access steps (or what remains of them) for the rear cab.

 

 

Edited August 6 by TeeELL
Title

[TeeELL 601]

I started creating a few components to improve the look of a ‘green plastic’ kit by referring to the work I had done on ‘MOLLY’, I designed a bonnet with panel details and handles plus an ‘early style’ air filter.

I discovered that the panel you can see needed to be shorter and the hole for the air filter was too far back.  The advantage of CAD is that it was a matter of moments to correct this.

The front axle is significantly different to the kit offering and sets the wheel track more accurately, the ‘walking beams’ have also been modified to achieve their correct track

 

The walking beams are fixed in place inside the ‘springs’ rather than by sticking a cap on the end of the axle.

 

All these parts were fitted to the ‘mule’.  A printed roof with raised front was also created.  Please note - this is a test piece and will only ever appear thus.

At the back end a few replacement parts were designed, printed and added.  You can see the air brake reservoir, ‘5th wheel’ and vertical sheave.  In this view there is a better detailed fuel tank and crew steps.  The far side benefits from a corrected ‘chain locker’.

whilst one of the ‘gimmicks’ of this kit is the articulation of the axles, I decided that continuing to allow this gave the vehicle the ability to be mounted on an uneven base.  The front axle is also fully articulated - as an aside I also have wheel off set to the left and the right, to add visual interest.  The wheels are 3D printed.

 

So this completed the planned enhancements for this kit ……… or is it?  Next instalment tomorrow.

Edited August 6 by TeeELL

[Gorby 20,039]

Wow that's fantastic work. I assume this is the 1/76 kit?

[TeeELL 601]

56 minutes ago, Gorby said:

Wow that's fantastic work. I assume this is the 1/76 kit?

Gorby this is the 1:76 Airfix kit - if I can, I will change the title for clarification.

[Gorby 20,039]

Even more impressive in that scale.

What 3D design program do you use?

[TeeELL 601]

I want to remind you that what you are seeing just now are the development stages of the kit enhancements I am creating.  
Following SMW last year a few people acquired sets of axles and walking beams for their Airfix models, but the parts undergo refinement as I find out more details.  For instance - the track of the rear wheels is a little too wide, even with the thinner ‘walking beams’ as a consequence, I have revised the inner V support but kept the fixing method.  At the front, I’ve now made the axle/mudguards/perch-bar/track-rod print as a single unit and can be dropped in and pinned after painting.

I am happy that I have achieved all I can at the front of the vehicle, yes I could refine the radiator but there would be no Airfix kit left!  An area that would benefit was the cab sides, apart from the ‘ships rivets’ there are errors of proportion - the panel between the rear and front doors (the center panel with the small window) is too wide, making the driver and co-drivers access doors too small.  It was a straight forward job to create a replacement, mirror it and then add the off-side semaphore signal.

As I’ve said, this process is one of continuous refinement - having designed and printed these I found a video clip which showed the interior shot of the front door, the diagonal brace runs from top front - opposite to my ‘guess’.  It was a moments work on the PC to rotate the bar and the latest file prints things correctly.

 

[TeeELL 601]

6 minutes ago, Gorby said:

Even more impressive in that scale.

What 3D design program do you use?

Gorby,

  I use a program called Fusion360.  I’ve never done any form of CAD before (it wasn’t a required skill for an RAF ‘fast-jet’ pilot), I started learning it early 2022 and have used a variety of personal use projects to improve my skills.  The Scammell front axle and mudguards being an early attempt - as reflected in a build ‘history-line’ that is very long and full of error boxes, but it works, so I’m leaving well alone.

I use an Elegoo Mars2 Pro resin printer with Sunlu U/V cured resin.

[Gorby 20,039]

3 minutes ago, TeeELL said:

I use a program called Fusion360.

Unfortunately that isn't available for Linux at the moment. I might have a look for something suitable as I'd love to try 3D designing.

I was trained as a draughtsman many yeas ago and have had a little experience in 2D CAD. 

Thanks for the information.

Incidentally, @Jag Mate was also a fast jet pilot. 

[TeeELL 601]

Returning to the bed of the tractor, I was unhappy that the raised section and associated ‘bits’ for the 5th wheel.  Some of the 3D printed parts didn’t fit as they should and rather than modify them to fit the kit I decided to replace the whole section and design (or rather incorporate several independent designs) a single replacement.  This is the CAD:

The part is a design for the base with the air reservoir, shock absorber and vertical sheave added from separate drawings.

The printed parts have turned out well although separating them from the print bed is a bit time consuming.  I’ve revised the supports a couple of times in an efforts to make it easier.

I will post images of the actual parts.  The turntable is a good fit and I’ve a ‘C-clip’ printed that fits over the stem and secures the turntable.

I’ve been asked if I could design better head lights, I might take a look at that as well as rather more robust looking tow hooks.
 

 

Edited August 6 by TeeELL
Trxt

[TeeELL 601]

21 minutes ago, Gorby said:

Incidentally, @Jag Mate was also a fast jet pilot. 

Yes, we both served on 29(F) Sqn but different aircraft and eras.

Edited August 6 by TeeELL

[TeeELL 601]

What I have published so far are the development stages in the creation of an improved set of parts for the Airfix kit.  The second ‘green plastic’ kit will incorporate the enhancements and enable me to write the supplementary instructions.  Finally the ‘grey plastic’ kit will be built for my own collection and will feature an entirely new ‘early style’ 30-ton trailer (I model N.Africa campaign AFVs etc so the Airfix trailer is a late 1943 pattern so inappropriate for that period).

 

Edited August 6 by TeeELL

[Jag Mate 1,125]

TeeELL,

I find this fantastic and very serious stuff.  Quite exceptional modelling.  You can stick that comment in your logbook.

Brakes off....

 

[TeeELL 601]

4 hours ago, Jag Mate said:

TeeELL,

I find this fantastic and very serious stuff.  Quite exceptional modelling.  You can stick that comment in your logbook.

Brakes off....

 

Well, if it is worth doing, it is as easy to do as good a job as possible.  When I print the various items and check them, if they are not quite right, it is easy enough to tweak the drawing for re-printing.  For instance, the rear bed is on its 4 correction.

[Mad Steve 23,561]

Very very impressive TeeELL 

[TeeELL 601]

37 minutes ago, Mad Steve said:

Very very impressive TeeELL 

Thanks Steve.

[TeeELL 601]

There are photos showing scammell trailers with spare wheels sitting in the trailer well at the front, as it adds interest I thought I would create a suitable wheel ie unmounted.  I had spent some time designing a diamond pattern ‘sand tyre’ often seen on the trailers so I made an electronic copy before attempting to create the unmounted wheel.  The back was removed along with the ‘attachment bolts’ and the axle cap but the ‘bolts’ holding the split rims together remain.  I’ve not printed this as yet so no idea how or if it will be satisfactory.

Rear view

 

Front view:

[Vaastav 3,123]

An interesting project and great work. I will follow along.. 

[TeeELL 601]

I didn’t wash the resin out of the ‘spare tyre prints’ yesterday, so they lost detail, I will try and do better today.  The other parts I did photograph, so to show you what the finished articles look like:

 

at top is the tractor rear bed, the trailer turn-table (in the photo, the orientation is such that the tractor would be at the top of the page), finally the retaining C-clip

below the trank track guides for the trailer and the ‘walking beams’ (with brake drums) and the U- shape retaining clips.

[TeeELL 601]

I Have taken the ‘green’ Scammell apart!  I decided to recycle it with the latest components rather than sacrifice a ‘new’ model.  I managed to take it apart almost without injury (to me).  This is the state of the thing tonight

Despite everything and working on the ‘measure twice etc’ principle, I still had to do some adjustments to the cab sides which are now being reprinted.

[Gorby 20,039]

Nice work. I'll be interesting to see how it all goes together.

[TeeELL 601]

It is going together well enough, I’ve completely forgotten to post the updates.

The front axle has been fitted temporarily in order to find the position for the perch bar rear pivot.

I’ve fitted the walking beams .  The axle needed shortening to allow the V section to sit inboard of the ‘springs’.

[TeeELL 601]

In this picture the rear perch bar support has been fitted, the front pivot is temporary the whole idea being that this fairly delicate part can be painted separately before being attached.
In addition I’ve temporarily fitted the replacement prop shaft.  The ‘engine sits further forward against the U on the forward cross member, it has also had 1.5mm filed off the rear to allow it to be positioned further into the bonnet.

The rear axle has been fitted and the top of the differential attached and fitted into the forward section of the transmission.  Again, the temporarily pivot has been fitted and it will be replaced when the rest of the construction is complete.

[TeeELL 601]

The rear bed has also been added although I should have fitted this after the differential.  
 

 

For some reason the roof doesn’t fit quite as well so I’ve printed a slightly longer one.  The old roof has been prised off but I will sort out the gap at the top of the windscreen before refitting.

[Gorby 20,039]

It's looking good.

I like the way the front wheels/arches are slightly turned. Always gives the model a little more interest.

[TeeELL 601]

1 hour ago, Gorby said:

It's looking good.

I like the way the front wheels/arches are slightly turned. Always gives the model a little more interest.

Thanks Gorby,  I’ve designed 2 other ‘turned wheels’ sets - to the left.

Last night I looked at other modification I made to my 2016 model ‘MOLLY’.  The front and rear tow hooks were replaced with etched brass model railway parts.  I sat and created replacement items using the more detailed references I have.

I designed ‘blackout’ and standard headlights and added them to the front tow print, it has a hole for them but I suspect it will need reaming out a bit.

A couple of views of the items fitted:

I’ve made a point, rightly or wrongly, to use faulty printed parts rather than well printed items (note the ‘spring’ and the tiny hole in the bonnet).  I am keeping the ‘perfect’ versions for my proper builds.

In addition, I’ve sorted the gap at the top of the windscreen and fitted the slightly extended roof.

 

 

Edited August 11 by TeeELL
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