building the Bullet XV

[Saline]

First off, incredible build! You might check into what Sportsmobile uses in their electric lift. I believe they use a screw drive mechanism that has a god amount of torque.

[haven]

I think the ram type lift is a better idea than a screw type electric lift.
The screw type is more sensitive to alignment as the top is being raised.
The sensitivity to misalignment increases as you add actuators. Ram
type actuators, on the other hand, don't seem to jam as easily.

I've seen the screw type lift for a bed in an RV jam easily if the RV is
not level. It would be a pain to have to level the vehicle with ramps
or rocks every time you wanted to pop the top.

[sarconcepts]

mid holiday progress pic
sidewall temporarily mountedwall panels 011.jpg

[adrenaline503]

Looks good!

[sarconcepts]

I know I'm about a month late on this, but i think i found what the sterling sales guy was talking about regarding the engine
(this is for you dzltoy)

"Cleanest.
This engine utilizes a third-generation High Pressure Common Rail (HPCR) fuel system and has pressure capability of up to 1800 bar (26,000 psi). It is a highly flexible system that achieves a total package of lower Noise, Vibration, Harshness (NVH), reduced emissions and improved fuel economy. This engine uses cooled exhaust gas recirculation (EGR) and other air-handling concepts, including Cummins own proprietary sliding-nozzle Variable Geometry Turbocharger to give optimum boost level as a function of engine rpm and load. The multi-injection-capable fuel system is then used to manage in-cylinder conditions to limit emissions. The product also has a particulate filter that reduces particulate matter (PM) level by 90 percent of pre-2007 levels.
Leapfrogging the competition, the 6.7L Turbo Diesel engine met the more stringent 2010 EPA NOx standard a full three years ahead of the requirements. Cummins is the first diesel engine manufacturer to have a product certified to the 2010 EPA heavy-duty engine standards for oxides of nitrogen (NOx) and particulate matter (PM) emissions, making it the cleanest heavy-duty diesel engine available in North America.

Cummins fully supports the development of renewable energy sources. This engine's fuel system has the ability to run with B5 Biodiesel as standard. The engine has also been designed to operate on Ultra-Low Sulfur Diesel Fuel (15-ppm sulfur).
Quietest.
As an added bonus, this engine is 3dBa quieter (~1/2 the engine noise than the 5.9L Turbo Diesel at all points on the engine speed operating range). The 6.7L engine incorporates several features that contribute to a 50 percent quieter engine and significant reduction in cabin sound levels, increasing the vehicle's overall refinement. This provides owners with the quietest engine in the heavy-duty diesel pickup truck market."

& I know this is just one side of the story.

[DT75FLH]

the last tier emissions for diesel in the US was the 2008 standard. Chevy,ford and dodge all have diesel particulate filters which scrubs the visible soot from the tailpipe....

the next tier is 2010 or 2011 and dodge met that with the 6.7 the dodge 3500 also got a 6 speed trans which helped with the fuel mileage a bit.

my 08 f-350 is the nicest riding, nicest towing, and quietest diesel that I've owned....but with the dpf on there it wont pass a gas station.

my neighbor has a 6.7 dually and gets 2-4 mpg more than my truck... you'll be very happy with that setup

[63tlf8]

I think the ram type lift is a better idea than a screw type electric lift. The screw type is more sensitive to alignment as the top is being raised.The sensitivity to misalignment increases as you add actuators. Ram type actuators, on the other hand, don't seem to jam as easily.

I've seen the screw type lift for a bed in an RV jam easily if the RV is
not level. It would be a pain to have to level the vehicle with ramps
or rocks every time you wanted to pop the top.

I suppose it depends on your design. Somewhere on this forum (possibly MOG section) I have posted some initial stuff on my camper build. My lift for the sliding upper section is 800mm and I looked at every system I could find. My choice was acme thread screw lift as it best suits my requirements and budget. With a sliding top it needs to come up square and even the Alaskan has been known to grab at times when not level. Essentially if you throw money at it then any system will work very well. If you need to budget then the choice narrows considerably. Linear actuators, pneumatic or hydraulic all need to be synchronized to raise square and that's where the money comes in. I haven't seen any mention of ram piston diameter yet. Either higher pressure or larger pistons plus the volume requirement of the medium may be needed to cater for the weight of the roof and any accessories. Again no problem with the top shelf units but sticker shock can ruin your day.

My screw lifts are linked by a shaft so they raise square every time. Doesn't take much thought to allow for very minor misalignment. The sliding sections of my camper limit the movement of the top relative to the lower section.

You may need to do some thinking on how things will work for your rig but my only recommendation is to go with what suits you and what you have.

Enjoy

Tony

[sarconcepts]

at this point, I may be still leaning to hydraulic ram type pistons, as the alignment seems to be the issue. I should also say this will be a soft sidewall, which gives me allot more play than a hardside, (nothing to grab).
I'm also thinking of using larger diameter pistons, like 2", and having the base be the full 4' tall even though the stroke will only be 2', this will give much more ability to stay aligned horizontally (or side to side) when the top is raised, as half the piston is still in the base (I know, thus far we're talking about vertical alignment,or lifting alignment (up & down), but the soft side should accomodate some play in that direction too)
I'm also thinking these will be 2 way pistons, or, power up-power down, as this will also hold the roof assembly down when in transit. I'm aware that (4)-2" diameter pistons will raise slower & require more reserve than smaller pistons. let's do some quick math, 1" radius squared x 24" stroke x 4 pistons =301 s.i. =1.3 us gallons, not too big a reserve tank. technically the 2 way pistons just displace fluid from one side of the piston to the other, but still, not a big deal.
I do like the idea of electric actuators, but all this input on alignment is making me nervous about this idea as I don't plan to mechanically connect the 4 actuators together.
the other thing to consider is the speed of the hydraulic pump, as I would like to move 1.3 gallons in about 20 or 30 seconds, I have yet to look into this aspect.
As of right now, I know where the pistons will be located, how they will connect to the top & bottom, & have some ideas on how to limit the 24" stroke (chains or threaded rod, etc.) but those details I know I can figure out later.
I want to get the walls & roof assembly built first, then decide, so I'm still very much open to more feedback.
By the way, I'm assuming the roof assembly will weigh about 300 lbs with solar panels on top, divided by 4 pistons is about 75 lbs per, very little weight for hydraulics.
Money really isn't the issue, as I plan on this lasting into our retirement, & I come from the perspective of doing this once & doing it right the first time, plus, how much would we really be talking anyhow, fifteen hundred to a couple thousand dollars max ?

[kellymoe]

Very cool build. I'll be expecting to see you out in the Saline Valley at some point, I hope

[sarconcepts]

oh yes.. ..you will
wall panels 015.jpg
rear wall on