MB 1120 Coming to America!

VerMonsterRV

Traveler
Yup, you will need to be on the bed to open the cabinets. We are sort of used to that as we have lived on a boat for the last 20 years. Sort of a trade off, but one we are willing to make for more storage. Under the bed is the "gear garage", space for folding bikes, inflatable kayak and backpacking gear. The bed is a queen size east/west in the rear of the habitat. Below is an early floor plan, I made a few changes during the build, one being the dry bath. You can see in the lower left where the "headboard cabinets" are.

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Another piece of advice perhaps too late....
With only 50L black water tank it’s good for over a week when I am by myself. But what fun is that? With daughter and significant other only 3 days. Get the biggest possible black water tank. Gray water is easy to dump.
 

VerMonsterRV

Traveler
Another piece of advice perhaps too late....
With only 50L black water tank it’s good for over a week when I am by myself. But what fun is that? With daughter and significant other only 3 days. Get the biggest possible black water tank. Gray water is easy to dump.
We skipped the black water tank and installed an AirHead (more compact than the Natures Head) composting head. It is in place now with only PVC cement for hoses and a bit of wiring for the vent fan left. I am planning once the cabinet work is complete then the wiring/plumbing will start. The plan for this truck is to head outside of North America so a black water tank was out, the only other option would have been the cassette toilets and we chose composting in hopes it will be less labor intensive (note I used "hope", never used one before). I'll post a current picture of the bathroom tomorrow.
 

DiploStrat

Expedition Leader
Since I can never resist a plug for composing toilets! o_O

We hauled out the smelly cassette and installed a C-Head. (http://c-head.com) Chosen because it is smaller than the Nature's Head. Initial three weeks have been great. Following Sandy Graves's advice, we change once a week.

The bucket based system is MUCH easier to dump than the Nature's Head.

Shower sealing is less than perfect, but most of the leakage goes into the toilet box, not the feces bucket and the toilet has been completely odorless.

Quick and dirty install pictures here: https://diplostrat.org/2019/06/16/why-we-love-the-loneliest-road-or-back-on-route-50-again/

We are running a combo of pet bedding with a bit of peat moss. The pet bedding is readily available at Target/Walmart/Petco, etc.
 

VerMonsterRV

Traveler
Thanks DiploStrat for the composting medium pointer. We are not yet at the point of using the toilet but when we do I will look into it. Ours shipped with a compressed brick of coconut fiber to start us going.

Thanks Andreas for the compliment. Been a lot of work but we are starting to get excited as things are coming together.

The last couple of days has been work on the exterior corners (the 45's which added a bunch of time to the Total Composites box, I am guessing well over twice the amount of work as otherwise the box goes together pretty quickly). By the end of tomorrow they will be ready to paint. Also met up with a interesting guy who owns a shop that does waterjet cutting. Ends up he has a PhD in mechanical engineering, along with a couple of masters in material science. And the best part is he even gave me a quote for parts and says he can get to them in about a week! Finally a bit of progress on the metal front. So now I need to pour some serious time into designing the tire/motorcycle lift. Here is a CAD diagram of the arms and the lower plate for the lift. There will be 2 on each side hinged right below the chassis. When up they will put the motorbike at the top of the 45 panel at the rear of the truck. Am thinking of mounting the spare underneath the bottom arms. This will keep weight lower and allow the motorbike to be tight against the rear wall making the truck a bit shorter. The arms will be made of A513 2"x5" 3/16" steel.
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Ozrockrat

Expedition Leader
Just for something to consider with the spare. It is much better to have the spare when loading or unloading to be vertical. Not sure what tire combination you have but mine weigh about 450# at the moment (bloody runflat inserts). And I’m no 100# weakling but they kick my arse if I have to get them from horizontal to vertical. It is much easier to have them standing up and rolling them into place.
 

VerMonsterRV

Traveler
Just for something to consider with the spare. It is much better to have the spare when loading or unloading to be vertical. Not sure what tire combination you have but mine weigh about 450# at the moment (bloody runflat inserts). And I’m no 100# weakling but they kick my arse if I have to get them from horizontal to vertical. It is much easier to have them standing up and rolling them into place.
Good advice, weight wise our tire/rims are way lighter than yours. We have single piece 22.5" steel rims with 385/65R22.5" tires. Have not weighed them but I am guessing around half the weight? Even with that I will try and work a way to have them vertical by the time they hit the ground.
 

VerMonsterRV

Traveler
Hey all, did some more CAD (this time cardboard aided design) to try and get the geometry and lengths right. Found that the arms need to be a bit shorter than I had hoped. With the design below, in the full down position it is still about 10" above ground. To try and keep ground clearance I did it like this. This will require a small flip up ramp on the end of the platform so we can roll the motorcycle/tire off the platform. The cardboard platform is 30" wide in this picture, just got back home where the motorbike is and now think I can trim the platform down to 24". The tire/tires (still not decided on 1 or 2 spares) will load first with the motorbike aft.
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In this mock-up the arms will be made out of 2"x4" 3/16" wall rectangular A513 steel. I am thinking that the pivot points that the arms fit into will be 3" wide 3/8" wall rectangular tube with a face cut off. This should allow some washers to fit and have a little play. I am also thinking 1" shoulder bolts for the arms. The triangular holes would be water jet cut locally. Not sure if it is worth the expense but would save a bit of weight.
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So, now I need to work out the lifting mechanism. One plan, and the one fairly easy to figure out would be a fixed frame in between the chassis rails that goes up the back of the habitat. The fix a hoisting winch (bi-directional) with blocks to raise and lower. The other one that I have not figured out the needed geometry would be a hydraulic ram. I am guessing it is way simpler to do the winch.
 

VerMonsterRV

Traveler
Nice design! Any thought about how to lock it in place while traveling? I could probably even "borrow" your design and add in a platform for the tire/motorbike to sit on. Any thoughts though on the amount of stress on the lower pivot point? Not being an engineer designing something like this is a bit tricky. The guy that might do the water jet cutting could design the entire thing, even doing finite element analysis, all at a cost of course.

One problem I might see is the ram connection for us. The bottom of my pivots is already as low as I want to go. Actually the platform is also a bit lower but have not worked out a way to address that. Also, the ram would go through our gray water tank.
 

VerMonsterRV

Traveler
If you can post up basic dimensioned drawings and weights, I can do a quick and dirty FEA in solidworks.

A small electric winch could be a good option for lifting.
Thanks for the generous offer. From what the water jet guy told me SolidWorks does not take a Sketchup File (which is what I am most familiar with), any chance you know of a good conversion? I ended up importing the sketchup into Autodesk 360, convert to stl (tried the dfx but the 360 dxf would not open in SolidWorks), then he converted it into an igs in order to feed it into water jet estimator.

By the way, know of any small winches the have both power up and down? Can be either 12v or 24v.
 

Ozrockrat

Expedition Leader
By the way, know of any small winches the have both power up and down? Can be either 12v or 24v.
Harbor Freight. Go 1 size over what you need. I swapped out a Warn and put a Hated Freight one on just for the wireless remote and since they are so cheap I grabbed a spare (carry the spare remote and control box).

I have lifted my R1200RT, K1200LT and the old 1963 R60 BMW with a Ural sidecar. It does make some awful noises but it has not given me any trouble in the last 4 years.

Also stick with the steel cable. The synthetic crushes on the drum too much.
 
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