Mk ?? Conversion in 1/35th scale;
16.5 ton LHS - experimental offering from Oshkosh -
8x8 full time all wheel drive with six wheel steering:





I am starting a conversion project using the popular Trumpeter USMC & Navy Mk23, 7 ton, 3-axle MTVR truck kit. I intend to use multiple kits to produce the 16.5 ton 8x8 variant with Load Handling System (LHS).

Given the modular style construction of the Oshkosh TAK-4 suspension units employed by the Mk 23 this conversion should be fairly straight forward with the necessary frame extensions being the most challenging aspect.


Oshkosh Defense/Pierce Fire Equipment: Independent Front & Rear Suspension:



The 16.5 ton LHS vehicle employs a full time eight wheel drive with three of the four axles steering.

The original MK 23 kit from Trumpeter:

. . . . . . . . . . . . . . . . . . . . . . . . . .

Interestingly the towed weapon that appears on the box art is not included.

Something that may be of additional interest: - The construction of the cab and forward axle is the same for both the stock 7 ton MK23 and for my converted 16.5 ton LHS so my early work shown in this thread will apply to ALL versions of the Mark.

Michael, I am watching this one closely as the Mk.23 is on my list. I used to see these parked and in use around Camp Pendleton when I would go there for medical appointments. Many of them had the up-armored cab and cargo area.

Regards,

Eric

Right off the bat let me say the design engineering, fit, detail and quality of this kit is almost beyond description. It is truly a 21st century work of the model manufacturer's art!

You will be immediately struck with the fine execution and level of detail that has been put into this kit.

I very much like that the Oshkosh badge appears wherever it is appropriate on the truck. The company logo is included on the hood, mud flaps and even on the head cover castings of the differentials. Likewise the tires appear to have all the correct raised lettering including the Michelin X logo.

If I were to have any criticism of the kit it would be that for a model so intensely detailed why no engine? The hood could have easily been made workable to show off what I assume would have been a highly detailed engine. An engine and workable hood would have also made for many more diorama possibilities. I suspect we can leave the matter of an engine for the MK23 to the after market boys.

While on the subject of the model lacking an engine; a closely related complaint of mine is the inclusion of what I will call the low profile "splash pan" or "oil pan engine". This is where the model manufacture simply encloses the bottom of the engine area with a flat undetailed plate , I guess using the idea "who will notice anyway"?

Whether you are building the 7 ton or the 16.5 ton version of this truck, right away I knew I would have to do away with the "splash pan engine"!



As you can see I cut out the "pan" but still left six "engine mount" attachment points.

Anyone who knows me would easily say I am someone who just "cannot leave it alone"!

I have a habit with my models that even when I don't build a full engine I will build a "low profile" silhouette engine to increase the depth of the visual affect when the vehicle is viewed from below.



I admit these changes are completely freelanced and not based on any actual research but I do feel it enhances the 3D affect of the engine area when compared to the "flat pan" treatment of the original model.

A similar example of my low profile engine treatment, this time on the HobbyBoss White Motors 666 Cargo Truck:



Lower portion of engine, starter, generator and main crank pulley added to the model.

Michael, you truly do not disappoint! You dive right in and do more in a single day than I do in a month! Fantastic work sir.

Regards,

Eric

Eric (It's all about being retired!) but Thanks!

Good job on the engine. I did similar with an old truck engine, resin bits, and plastic tubing to fill the void under the hood and lack of anything when viewed from the side. You can check out my full review here. It shows how to properly turn the front wheels too.

This is going to be awesome. I'll be following this one also.

Current status of profile engine/transmission:



Shame that someone still has not come out with a resin engine, in that the big engine bonnet on this model could easily be posed in the open position.

Front drive steering/suspension unit completed:

Loadbox side support boards removed from the frame rails.

Stock Mk 23 6x6: (Drawing by Oshkosh Defense)



16.5 ton LHS 8x8: (Drawing by Blueprints.com - Unfortunately without dimensions)



Red arrow indicates landmark perforation in frame rail that will be used to compute frame extension length.

(OSHKOSH Drawings reproduced here for discussion purposes ONLY.)

Again red arrows indicate landmark perforations also present in the model frame.

. . . . . . . . . . . . . .

Another great project! I'm glad you started first, mine wont begin until after Christmas.

Michael, I'll send you two Mk. 23 kits.. Make the appropriate modifications without gluing any of it together.. Send it back to me and I'll build one as well!

Hopefully Dustin if my plan for the conversion works, this thread will give you all the info you need to complete the build.

A little more progress this evening:

Lots of detail added: air filter and intake stack. On the other side, the battery box.





(Didn't realize such a modern truck was steam powered - or maybe it's a wood and coal gas cooker?)

Drawing of powered front, #1 steering and drive axle:





_______________________________________________________________________________________________

Drawing of rear three axles:
All powered with the last two axles set up to steer.

(Please note: The drawing below is MY artistic combination of two Pierce Catalog drawings, The front non-steering axle is one drawing and the two rear steering axles is a second Pierce drawing.)


In the TAK-4 suspension design EVERY axle is set up with what looks like a steering spindle at the wheel hub. However some axles are set up to steer while the others (in this case the #2 axle is locked down so as NOT to steer.