MACK DM600, 5-th wheel dumper

[truckabilly]

I thought I had introduced this model here already but I cannot find it. So, I probably never had.

I first came across the fifth wheel dumper concept right here on this forum. I´ve never seen it before and I´ve never seen it on any European truck. I assume they are used only in the US.

 

These are the two designes that I was able to find on the net.

Even though the one in the upper picture looks better to me, I decided to build the other one as it looks like a simpler thing to build.

 

The truck that I chose as a platform for the 5-th wheel lifter is a reissued  Mack DM600. The kit has some shortcomings that need to be addressed. Like the wrong position of the rear cab suppport, the rear wheels sticking out too much tyres, that don´t fit the rims very well, tabs that don´t match, etc.

I started out with the engine as usual. I added the fuel pipes with injectors and the alternator holder.

In order to accomodate the the 5-th wheel lifter I extended the chassis. A bit too long maybe but it doesn´t matter that much. With the longer frame a need for anther cross member arose. So, I scratch built one. It was easier than repositioning the existing cross member.

 

 

 

I cut out the 5-th wheel lifter main parts out of some plastic sheets and assembled them.

Here is the assembly and the cab resting on the  frame.

I think that´s enough for the introduction. I will add more details next time.

 

 

 

 

 

 

 

 

 

 

 

[Mopar - D]

Cool truck and excellent scratch building. What are you going to use for your trailer?

[Rusty92]

That looks terrific. I have never seen one of these setups either.

[CRUSADER2]

First time I have seen this system too, I wonder what the benefits were, it looks like it wouldn't help towards the payload with all that extra fabrication, I suppose it was more stable when tipping?  interesting subject to model though, the scratch building looks top notch, really like the alternator support bracket, inspiring work!! 

[bigred63]

Hello Jaroslav, I like what you have done so far. I will be following this build.

[Warren D]

18 hours ago, CRUSADER2 said:

First time I have seen this system too, I wonder what the benefits were, it looks like it wouldn't help towards the payload with all that extra fabrication, I suppose it was more stable when tipping?  interesting subject to model though, the scratch building looks top notch, really like the alternator support bracket, inspiring work!! 

My guess is that you could have one hoist on the truck and not need dump trailers.  Probably cheaper and there aren't any hydraulic lines to hook to the trailer, less chance of leaks?

[truckabilly]

19 hours ago, CRUSADER2 said:

I wonder what the benefits were, it looks like it wouldn't help towards the payload with all that extra fabrication, I suppose it was more stable when tipping?  

 

Here is some info on the system and its advantages compared to some others.

http://www.callahantipper.com/

 

 

[truckabilly]

On ‎22‎.‎07‎.‎2018 at 6:03 PM, Mopar - D said:

What are you going to use for your trailer?

I wish I knew. Right now I cannot think of any suitable trailer produced by any mainstream kit manufacturer. I guess I will end up scratch building again. My idea is something like this:

 

[DrKerry]

Hmmm looks very kool Jaroslav!!! I’ll be watching this one!!

[CRUSADER2]

Hi Jaroslav

  Thanks for posting that info, I had a good look through the site, interesting, you live and learn, still looks strange though, but that's a great reason to model something like this, something different!!   Looking forward to the next photo's 

[DRIPTROIT 71]

Very interesting subject choice. Looking great so far!! Looking forward to more!!

[truckabilly]

Thank you all for your interest. As I had no real dimension of the mechanism, I had to experiment with geometry a bit. The hardest part was the telescopic cylinders. Eyeballing is everything but a precise method and I must have done something not quite right. My 5-th wheel lifter doesn´t hoist as high as the real one does. But I think it´s okay for a model.

 

 

 

I said earlier that the tyres don´t fit the rims very well. I added a stripe of plastic around the rim and now the tyre sits on the rim much tighter.

 

My plan is to make the model of a beaten up rig, sort of yard dog that had seen better days. This makes a great opportunity for me to try the hair spray method. I´ve never tried it on something this big. Here is the basic rust layer on the engine and frame.

 

 

 

As you can see I´ve added one more air tank, an air dryer and replaced the brake chambers. These come from a Peterbilt kit and are more detailed. 

 

 

 

 

 

 

Edited July 29, 2018 by truckabilly

[gotnitro?]

Excellent work looking forward to your weathered treatment!  I've used it several times on armor it's fun to scrape and scratch the paint away.  

 

[Detroit Dave]

Wow very cool - I've never seen anything like this either - Watching and good luck.

[PettyKW43]

I really like this build, as a suggestion for the trailer, look at the AMT exterior post Fruehauf, while not exactly what you have pictured it can easily be cut and modified to get something reasonably close to as pictured without scratching it totally.

[truckabilly]

Thanks for the tip, Richard. I sure will consider that. 

Using the HS method I rubbed the colour off  and this is the tesult on the engine.

It still needs to add more life in it. I´ll see what I can do. I painted the frame black over rust and rubbed it too. For the cab I used an aluminium metalizer as a base and ligt grey for the hood, as it should represent the fiberglass.

 

 

Since I´ve had extended the frame a bit too much, I added a hydraulic  tank behind the cab. I have never painted any of my truck  models green. This was a nice occasion to try  one.  

The front wheels are the kit originals. The drives come from a resin set with no lettering on the sides. The original wheels and tires were sticking out too much, making the model look too wide. I think these look better even without the lettering. 

 

 

 

[gotnitro?]

Nice job !! Like the work effects on the frame and engine really gives it a work horse appearance. Really like the wheels too, always thought the tires have an unusually wide appearance 

Mine didn't wear away as planned  kept coming off in bigger spots than I liked. I cleaned it off and redoing the layers.  I used tamiya acrylics for top coat..next time back to testors enamel..always been happy w wear