building the Bullet XV

[ersatzknarf]

Hi Steve,
From reading your site, if I understand correctly, there are two sets of Maylines, one on each side, running front to rear ?
Just curious if it would be possible to have another set of two for the side to side balancing or would that be counterproductive/impossible to align ?
The solution you have found is really impressive.

My cable hydraulic equalizing system is now in & works perfectly.The cables hide behind the lifting pipes & wall cap, one more major step accomplished. now onto the ceiling & softwalls.

http://bulletxv.wordpress.com

 

[sarconcepts]

Yes frank you are correct, I have built two pulley systems (or maylines) one on the left, one on the right. This has proven to be absolutely perfect at aligning the two connected cylinders, it has to be, as it is geometrically impossible not to be, unless you break a cable. Now I do get a little deviation from side to side, but I chose not to connect them side to side only because doing so, in my particular case, is a little tough. Typical with all 'Steve' designs, I design everything with about 1/32 " clearance, and in this case, I've got so many things in such a small area, adding yet another pulley gets tough, not impossible, but tough. The easier connection would be to run a system across the front wall, connecting the two sides together across the basement floor, but I've got wires, cylinder mounting brackets, & hydraulic lines all crammed together, because in my case, this is where all the equipment is. The rear two cylinders are technically a little easier, as there's no stuff in the way, but to do this I would either have to run a cable in the thickness of the floor plywood (which isn't in yet, or below the structural floorboards. Now, I would never normally penetrate the floorboards, opening up the potential for water infiltration, but in my particular case, as this was once a u haul, the floorboards are shaped with a specific enclosed chamber every 10" across the width of the floor, & yes, I'd feel fine running a cable through it. In my case, the side to side differential lift wasn't enough to bother me, (about 1" difference over the 24" of lift) so I didn't foray into the side to side. I would however start a design with this in mind, & make it a little easier on myself to do by the time I got here. Think about it, by this time, you've already got the cable mounts on the bearing blocks, it's just a couple more 1/16" cables & pulleys, no big deal at all.
Overall, I'm comfortable with just doing the sides, but connecting all four would be amazing.
you know frank, i might just keep connecting the rear two through the thickness of the floor plywood an option, let's see how things work over the next few weeks.
Steve
(here's the cross section of the u haul floorboards, 1" tall, 10" wide, & yes, I measured & drew in auto cad every part before I began!)

 

[ersatzknarf]

Hi Steve,

Thanks for confirming that
I am glad to know that the idea could be applied side to side, in addition to front/back.
Good that you'll keep it as an option. You've gone this far with it...

I wonder if the mayline idea could be applied to air struts or electric linear actuators...?

Regardless, the more I look at what you're doing and have accomplished, the more impressed I am. This is a great job !

 

[sarconcepts]

Yes, this system certainly could be applied to air struts, assuming there's a central manifold to share pressure between the individual struts, but not with electric actuators, as they each have independent motors, & this set up is for equalizing pressure between cylinders. similarly, this wouldn't work if you had four hydraulic cylinders with four independent pumps, at that point, the cylinder lifting the fastest would be taking all the weight of the other three, & you'd need bigger cables & much stronger pulleys.

 

[ersatzknarf]

I see. Thanks. That makes sense about the electric actuators. I am interested in the air strut idea (no oil), but guess that those need to be locked into (the up) position more so than the hydraulics...

 

[sarconcepts]

finished framing the lower ceiling this past weekend, ready for upholstery

 

[HMR]

Wow! Ceiling looks great.

 

[sarconcepts]

I am glad to know that the idea could be applied side to side, in addition to front/back.
Good that you'll keep it as an option. You've gone this far with it...

thanks for poking me in the butt, ERSATZKNARF, I've decided to, & figured out how to, run my cable system across the front wall. Instead of running it across the floor of the basement with all the utilities, or across the rear cylinders in the thickness of the plywood floor, I'm going to run it across the top of the front wall, just below the cabover (just under the bed) where I've got a straight shot. yesterday I picked up 12 more 1" pulleys & square tube to make the double pulley bases needed to finagle the cables to where I need them. This will then connect all four cylinders together, getting them all to lift & lower at exactly the same speed, with no deviation at all, side to side.
You were right, I've gone this far with it, why allow even the 1" of deviation side to side I was getting.
& no, there won't be any complications adjusting them as the cables will be run in exactly the same layout with turnbuckles on each run, to allow for minute adjustments.

 

[ersatzknarf]

Hi Steve,

Well, there was absolutely no intention of doing that, especially there, but very glad to hear that the solution will be taken to its ultimate conclusion

<snip>You were right, I've gone this far with it, why allow even the 1" of deviation side to side I was getting.<snip>

It's really impressive that the mayline solution can be run in a variety of manners and still accomplish the same result.

Now, I am very interested to hear more about the ceiling and that figure 8 shape, please - very intriguing ! ! !

 

[sarconcepts]

I just finished installing the pressure equalizing cables across the top of the front wall,connecting all four cylinders together. Although the space in behind the lifting pipes was tight for all the pulleys & cables (as I came up with this concept after the lifting pipes & cylinders were put together), I got it all in, & am so glad I did as now all four lifting pipes go up exactly together, I mean 'exactly', & will always, they have to, even if I load the roof on 1 side

There's nothing magical about the figure eight shape, in-an-of itself, I really want the interior to be playful & a challenge to build, so I've designed the cabinets & ceiling to be more curvaceous or yacht like. In plan view you can see the way the ceiling curves will play with the curves of the cabinets below.
it's also somewhat reminiscent of a limousine ceiling (without the mirrors, stripper pole & strippers)!
http://www.bulletxv.wordpress.com

let me add(now that i look at the drawing) that I have added more curves to my cabinet plan than what's shown here, I just noticed that this was an older cabinet layout

 

[chrismc]

Have you tested out the lift in various "bad" situations to make sure it works reliably? I.e., with the truck significantly off-level and/or with varying weights on the roof? Those situations could significantly change the physics involved. In an altered physics situation, the forces involved could easy be transferred or concentrated somewhere where you wouldn't expect it after thorough testing in the "standard" orientation. What is the weakest link in your system? If things go wrong, is the weak link easily serviceable? It would be unfortunate to have something fail in a bad way when you're miles in the backcountry, so it would be nice to identify any problems while its still easy to remedy. This is fabulous work, though, and I'm really enjoying your thorough documentation both on ExPo and on your blog (each has details that the other doesn't so its always an interesting read). The end result is going to be amazing!

 

[ersatzknarf]

Hi Steve,

Congrats on finishing the second set of maylines ! Brilliant solution !

Ah, hah ! Now it's more clear about the interior. Great idea to make it more like a yacht interior. Having all that 'interest' inside will keep it fresh for a long time.

 

[sarconcepts]

you know CHRISMC, as of now, I've just gotten the whole lifting system put together & adjusted, & the roof is not even on it, so no, I have not tested it in abnormal situations. I live on an extremely steep hill though, & I plan to start working on the interior cabinets out of my home shop, so I will have plenty of chances over the next several months to test, re-test, adjust & fix any problems that show themselves. I am also pre-thinking in my cabinet design, how to construct them in a manor that can be disassembled for access to various utilities, your thinking is right on, as far as the weakest link, right now my paranoia is about the hydraulic seals, with no good reason, but things need to earn my trust.

 

[ersatzknarf]

Bump for a great camper build !

 

[sarconcepts]

yeahhh.. ..sorry frank,
as much as I planned to start moving on the interior, the ceiling's still being upholstered, (they may be done today) the delay was not with the upholsterers, but with an inordinately long time to get the right led 'love' lights. the company I ordered through got the wrong color first (cold white not warm white, & I hate the cold blue color) so we re-ordered, & it took forever to get the warm white through customs (they came from china). The upholsterers did the upper center ceiling, then had to wait for me to get & install the lighting before they could do the lower perimeter ceiling.
This, in addition to the fact that Bethany & I went camping three out of four weekends in July, went to a blues fest along the water, did a bike tour, went to a wedding, & saw the scorpions live.
At this point i'm trying to remember just what the Bullet XV is!
& who are all you people!
I actually did make a little progress in between all that, mounting the lower storage compartment doors, right now I'm doing a little 'body work' on them.
plus pulled apart the cab interior to get the air compressor pressure gage & switch in just the right spot, & run air lines & wires back to the compressor.
not very exciting or picturesque, but progress.. ..