engineering a power slide out on bunk end.

Discussion in 'Slide-Outs / Bunkends' started by ill.plainsman, Sep 24, 2014.

  1. ill.plainsman

    ill.plainsman happy, happy

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    I on a wish to myself and not taking it seriously in another part of this forum I said I would be camping till after the grand kids are grown. but i was just thinking has anyone ever tried to put an electric motor on a couple of bunk ends? my DW can't open or close our bunk end cause she is only 5' tall and can't reach the ends. yeah they stick out way up there. it is all i can do to reach the canvas and spread it out or tuck it in. i have to use a grabber, one of those things used by trash men to pick things up, just to tuck in the corners. it sure would be nice if someone had some ideas on how to motorize such an animal. it couldn't stick out much if at all, it needs to push and pull probably about 35 pounds, don't think it weighs more than that, and it can't hang up on the canvas or bed sheets.
    i probably won't get anyone who has done this but i would pay to see some ideas. respectfully IllPlainsman. [2C]
     
  2. swordfish

    swordfish Well-Known Member

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    I have never heard or seen motorized slide out bunks.
    I am doing a mod to simulate Flagstaff's system. The supports are set up before the bunk is pulled. Not sure that would help your wife. I would just make that your job. There are plenty of other things she can do.
    [​IMG]
    free upload image
     
  3. jrclocks

    jrclocks Member

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    You can push/pull the bunkends from inside the camper all but the last foot or so on the one end.

    Saw this camper on CL. It has it from the factory, roof, slide-out and bunkends. Perhaps you could learn from how Coleman did it.

    http://stlouis.craigslist.org/rvs/4647401084.html
     
  4. tfischer

    tfischer Well-Known Member

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    Maybe a small stepladder would be a lot easier to engineer ;)
     
  5. tfischer

    tfischer Well-Known Member

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    Holy cow that thing was $14,300 when new. Who would pay that for a pop-up? No wonder Coleman lost their way and went out of business.
     
  6. ill.plainsman

    ill.plainsman happy, happy

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    problem there, the bunks rest on a roller on each corresponding side of the kitchen slide. don't want to climb over the kitchen slide to push it out.or pull it in.
     
  7. generok

    generok Well-Known Member

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    Hmmm. You'd have to go electromechanical, since electricity is available and fairly light. The problem is, they slide out harder than you really think they do. So, you're going to have to go with mechanical advantage versus brute force.

    My first thought is a garage door opener. It has plenty of power, has upper and lower limits, and fairly compact. The problem I have is I want to do a center pull on the bunkend, but that places the tracks and power unit in the middle of the PUP floor, which is not typically a strong selling point with marketing.

    So, I need to run twin screw rods on the box sides, and have dual and synchronized motors. Ugh, not unheard of, but flap motors from a light single engine aircraft could work... they have limits and they have a built in syncro sensor. Well, maybe a rack and pinion setup on the front and back wall under the slideout... yeah that eliminates the syncro issues.

    Bottom line, yeah, I could do it, but I can already see it being expensive to retro. It would be much easier to integrate it during the build in the front and back wall.
     
  8. jrclocks

    jrclocks Member

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    There is a length of gear rack centered on the underside of the bunkends and a motorized pinion mounted into the front and back walls. You can see the motor housings in the photos. Similar configuration under the slideout as well.
     
  9. ill.plainsman

    ill.plainsman happy, happy

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    thanks Generok & jrclocks for taking this seriously. after i saw this i thought how about like you said a garage door screw on each side mounted under and on the bottom of the bunk a little gear on each of the screws with a matching 12 volt motor on each. wire it into a switch and there is one end. do the same to the other end on a different switch and wallaaa [LOL] . only thing i think i really need is to find a place that manufactures like aluminum screws and a corresponding gear box to mount under the beds. aluminum so I save some weight . those screw bars would be very heavy. maybe a 1/2" or 3/4" rod. i would have to put some kind of cable on there so i could tell when both sides are taught [full extension]. aircraft thoughts out. very expensive. where else can i find a long screw like that? what other trade or outfit would have something like that? [?] [NTBK] [?] [?]
     
  10. zorak

    zorak Member

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    What you would be looking for is a rod with an acme thread. This is the same kind used in c clamps and vices , its designed to handle more force than standard threads. You could look at Mcmaster Carr. They are an industrial supply compan and carry a lot of stuff like that.
     
  11. skeetercampsintexas

    skeetercampsintexas Active Member

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    Plainsman, we have the same pup. I know you have a power roof lift. Imagine your pup, lid down, bunks in. Now imagine a cable/strap/pulley attached at the center of the lower lip of the roof and anchored, headed towards a caged pulley that is set center on the bunk, then headed directly under the bed slide to another removable anchor point in the center of the upper lip of the box.....now here comes the magic!! Think of this....as you raise the roof with your power lift this cable will obviously pull tight, as it does so this will force the bunk ends outward to their respective positions. Seeing as one anchor point is removable, i.e. with a caribiner (spelling?), you go inside take the cable down and you're good to go!!

    I know this doesn't solve putting them away, nor the canvas issue, but it's a thought for one problem at least. For the canvas issue, I usually carry a step stool for mine. Although I realize for some this may not be possible due to some ailments.
     
  12. ill.plainsman

    ill.plainsman happy, happy

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    thanks zorak and skeeter. i'll check on this acme thread at mcmaster carr. skeeter i don't know. cables get mighty dirty and they would be all over the end when getting started. afraid there would be black marks all over each end. nice try friend [;)]
     
  13. generok

    generok Well-Known Member

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    If we weren't in the middle of a huge policy and guidance review, I'd throw it out to the gang at work. Nothing like a team of 6 engineers working on an issue to come up with at least 12 designs to thoroughly confuse the issue. We have more time in the winter for exercises though, we're still pretty buried with the summer season.

    Personally, I think the rack and pinion version is less complex than twin screws (per end).

    Is the problem also RETRACTING the bunk ends or JUST EXTENDING??? If it is just extending, perhaps hydraulic (air spring) door openers would open (or greatly assist) the bunkends, but would actually make restoring them slightly harder.

    We really need to define the design objectives before we look at component selection... if I've learned anything from our line of work.

    From a design point of view, there's no sweeter words than "I want to do this on principle". Oh yeah, let the billable hours fly! But, in the end, wouldn't a travel trailer really suit your needs without the design and modification work, time and funds?
     
  14. jrclocks

    jrclocks Member

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    Agreed! Much lighter & simpler. Limit switch location would be on the motor assembly. Drive mechanism is out of the way. Gear rack is out of sight and won't get grease on anything. Will be able move bunkend both in and out.

    Only other thought would be to use a length of chain in place of the gear rack and then you could use a chain drive garage door opener as the drive system. You wouldn't have to design the gear drive system for the pinion. The opener has built in limit switches. Would require 120VAC to operate.
     
  15. ill.plainsman

    ill.plainsman happy, happy

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    well generok if you need or want some time for your team to ponder this be my guest. in no hurry [SNZ] . i'll keep checking in to see if you come up with something. really if it can be done i would like to try. maybe i need to talk to the flagstaff manufacture to see if they have put something like this on a unit like mine [?] . no reason to reinvent the wheel if it has been done before. thanks all , i like the problem solving that goes into this kind of exercise. [RTM] only real limitations will be expensive plans out. hundreds is to much, other thing , has to be light weight. no 100pound bars hanging off the bottom of the bunk. and last but not least, no mess to the rest of camper or bedding. i'll keep researching this and post back when i find an answer. thanks all. :)
     
  16. qwed94

    qwed94 New Member

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    You could basically set up a motor and gearbox assembly. The very same system that they use for slideouts.

    I would think you could mount the "slideout" motor/gearbox assembly in the center of the bed area. (Mount it to the camper box itself).
    Then run the shafts to the outer edges of the bed area. Then run the tracks under the bed itself, right where the gears from the shaft will meet.

    The hardest part might be building a removable cover for this motor and shaft that will remain in the same place, inside the camper. (Basically, find a TT with a "Lippert" brand slideout). Then use those parts for yours.
     
  17. ill.plainsman

    ill.plainsman happy, happy

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    That sounds like a good idea. I think they may be kind of expensive. I'll have to check. They used to be hundreds of dollars each. Thanks.
     
  18. arthuruscg

    arthuruscg Active Member

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    What about changing the suspension? If you have the space in the wheel wells, Dexter makes a axle that uses air bags instead of springs. This would let you raise the camper for travel and then drop it to the ground when camping.
     
  19. tfischer

    tfischer Well-Known Member

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    I don't personally see how you're going to do his for less than "hundreds", especially if you have to do both sides.

    Are you willing to set up the support poles manually, or does that need to be automated too?
     
  20. Novarich

    Novarich Active Member

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    Can you push the bed out a foot or so without climbing over your dinet? Perhaps you could make a handle that pivots down to pull and push the bed out and in from a lower point. It could clip up to the bottom of the bed when it is pushed in. Something that locks the handle like the legs on a folding table?
     

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