carld
Senior Member
I think they are around 350 lbs.
Opened Turnbuckles
- Thread starter Captm
- Start date
kmacafee
Senior Member
I like this approach up to the point that the system has to be tight all the time. These campers weigh anywhere from 800 to 1500+ pounds and on my Tacoma, using FWC's bed mounting plates bolted to the frame, the camper doesn't move side to side much, if any. The biggest risk is movement up and down and. of course, it could slide out the rear of the truck. As you say, if the connection is tight, the only way for the energy to get released is through the truck bed (and in my case composite) or the camper itself which requires expensive repairs.carld said:
I have done a lot of off road driving with my camper using the forged turnbuckles with closed ends. After rough sections, I typically check them and at least one or two are loose. I know the camper is probably not going to slide off the back as the turnbuckles I am using exceed the camper weight at each corner. So, isn't a little slack ok? And using the climbing slings without tightening them might provide more than enough holding power (as a backup) while allowing for a little movement on rough roads to minimize damage to the truck or camper.
ntsqd
Custom User Title
That tool is used in doing the preliminary set-up on vintage road race cars and coil-over suspended off-road vehicles.Wallowa said:
Our camper is a Phoenix, so no FWC turn-buckles or their eye-bolts. When we bought we weren't given any turn-buckles by the PO. Not sure how he held it in his truck. What I am saying is that I don't care how strong or weak the FWC turn-buckles are. Can solve the problem without that bit if info, its superfluous.
I understand the desire for a slightly dynamic mount, but I don't think it a good idea. If those ginormous hard-sided campers were built properly they could be anchored to the truck's frame and not need or use spring loaded "attachments." The truck already has a suspension system, build it to do the job its supposed to do. Anything that can move independent of the chassis is asking for an inertial over-load problem.
With no FWC eye-bolts to anchor to I use the corner jack brackets. At the front I had to build a trussed cross-member to relocate the upper turn-buckle points inboard of the bed rails. Our front turn-buckles are easy to set, I tighten them by hand - no tools, as tight as I can reasonably get them. The rears are harder because they're much smaller and need a wrench to tighten. I take them up to just a little past taking all of the slack out of them and stop well before I start to spring the stake pocket brackets.
ntsqd,
Ok, now I understand your posts...apples to oranges...Phoenix 'no-mounts provided' compared to FWC turnbuckle and eye-bolts provided by FWC. Hence the strength of the FWC components are indeed "superfluous" to you. But not to the rest of us with FWC units.
Oh, I used a commercial scale [vehicle level when weighed] to find the mass at each wheel, front and rear axles and then entire vehicle on my '62 Corvette when I was balancing it out for Green Flag @ Thunderhill and Pony Express events. Plan to do the same for our '05 Tundra and the Hawk. In all honesty I believe the Tundra and Hawk will be just fine even if I don't determine the load and it seems with the thousands of FWC campers mounted with the tie down system they provide indeed works with only an occasional modicum of attention if you pound the rig over rough ground.
Just my take and I could be wrong; but my FWC set up is "good to go" until and unless proven otherwise by my experiences with the tie downs. Hell, I already worry too much about too many things; worrying about this is for me "superfluous".
Phil
Ok, now I understand your posts...apples to oranges...Phoenix 'no-mounts provided' compared to FWC turnbuckle and eye-bolts provided by FWC. Hence the strength of the FWC components are indeed "superfluous" to you. But not to the rest of us with FWC units.
Oh, I used a commercial scale [vehicle level when weighed] to find the mass at each wheel, front and rear axles and then entire vehicle on my '62 Corvette when I was balancing it out for Green Flag @ Thunderhill and Pony Express events. Plan to do the same for our '05 Tundra and the Hawk. In all honesty I believe the Tundra and Hawk will be just fine even if I don't determine the load and it seems with the thousands of FWC campers mounted with the tie down system they provide indeed works with only an occasional modicum of attention if you pound the rig over rough ground.
Just my take and I could be wrong; but my FWC set up is "good to go" until and unless proven otherwise by my experiences with the tie downs. Hell, I already worry too much about too many things; worrying about this is for me "superfluous".
Phil
ntsqd
Custom User Title
No, I disagree. Knowing the FWC turn-buckle strength only tells you what that is. Can't infer anything further numeric from knowing that number. That some pull loose or open up their hooks tells me that they're below the minimum acceptable strength.
ntsqd said:
OK...not my intent to engage in a belly bumping session.... but I still am at a lost to understand how knowing what the strength limits of the FWC components will not be a benefit to the owner in determining if those limits are adequate to retain their FWC camper. It is of course a starting spot; but you need quantification of what you have or it is a total guessing game in your effort to know if your tie down components are going to do the job and not fail.
Pulling hooks straight or loosening or breaking turnbuckles/eye-bolts are obvious issues that must be addressed;however, you need to know the strength of the component that failed to even have a clue why they failed and then plan to prevent future failures.
Failure alone does not mean the eye-bolts or turnbuckles where not strong enough if the real cause of the failure was a loose component or improper mounting and then a large kinetic load delivered at the wrong angle due to the slack or improper mounting angles results in failure. Perhaps your components are strong enough but your system was not tensioned correctly [no slack] or incorrectly installed.
At least If you know the strength of the turnbuckles and eye-bolts you can then add in your best "Kentucky Windage" WAG by increasing the strength of the components 2X or 4X or whatever makes you comfortable. Or if you are a mechanical engineer you can do the math and that will make you comfortable. But without knowing the strength of the components you are working blindfolded. Like in any search you need to know the starting point to be effectual.
I am out of here...only my perspectives and your mileage may vary....
Take Care,
Phil
Stalking Light
Feral Grandpa
If your turnbuckles are stronger that what they attach to then you've just moved the failure point somewhere else. Spare turnbuckles are likely cheaper than fixing your truck bed or camper frame.
craig333
Riley's Human
I was going to upload a photo but it seems photobuckets latest update hosed the service. Anyway I agree with stalking light, I'd rather have a turnbuckle fail than anything else. I carry a spare one just in case.
ntsqd
Custom User Title
Phil, I'm sorry if my posts came across as "belly-bumping", they were not intended to read that way. I simply see no value in knowing the FWC turn-buckle rating because that number does not validate or confirm anything that I either don't already know or can't get in a more direct manner. I'm trying, and failing, to understand your need to know that number. To me, the only thing that the rating would tell me is that it isn't enough, but I already know that because they're not holding up and I have a rough idea of what the strength needs to be to not fail.
If the pre and post camper truck weights are known then you have a pretty good idea of the what the camper weighs. If the FWC turn-buckles are losing their tension for what ever internal reason (i.e. not the bed distorting etc.) then knowing their rating means nothing when you know the camper's loaded weight. Whether or not you know the FWC turn-buckle rating, they either work for you or they don't. If they don't and you have weighed the camper or calculated it then you can use the formula's that I posted earlier to figure out what I consider to be what your minimum turn-buckle strength should be. This approach has worked for me.
Anchors appropriate for those loads need to be designed. It would never be enough to simply bolt through the bed. Formed sheet metal is surprisingly strong, but it does not like highly localized loads. There needs to be an appropriately sized load-spreading plate used with each anchor. Mine are roughly 4" per side & square. All of the corners and edges were carefully radiused to not be sharp.
I'd rather not have anything fail. There is no need for a "fuse" in this system. That isn't to say that it should be over-built, just that everything should be sized with appropriate margins.
If the pre and post camper truck weights are known then you have a pretty good idea of the what the camper weighs. If the FWC turn-buckles are losing their tension for what ever internal reason (i.e. not the bed distorting etc.) then knowing their rating means nothing when you know the camper's loaded weight. Whether or not you know the FWC turn-buckle rating, they either work for you or they don't. If they don't and you have weighed the camper or calculated it then you can use the formula's that I posted earlier to figure out what I consider to be what your minimum turn-buckle strength should be. This approach has worked for me.
Anchors appropriate for those loads need to be designed. It would never be enough to simply bolt through the bed. Formed sheet metal is surprisingly strong, but it does not like highly localized loads. There needs to be an appropriately sized load-spreading plate used with each anchor. Mine are roughly 4" per side & square. All of the corners and edges were carefully radiused to not be sharp.
I'd rather not have anything fail. There is no need for a "fuse" in this system. That isn't to say that it should be over-built, just that everything should be sized with appropriate margins.
daverave
Senior Member
I checked and our recently installed Hawk also has the rubber bumpers that others have referenced so I am now a bit less worried about lateral movement since any tendency for forward movement has been mitigated. Just for S&G I dug out my old adjustable triangle from my hand drafting days and found that all four turnbuckles on my F-150 have been installed at about a 67 degree angle. Certainly not vertical and my seat-of-pants estimate is that that would be an appropriate approach to attachment.daverave said:
I also was at Home Depot yesterday and noticed that the largest turnbuckle that they carry is 3/8" x 8" with an aluminum body and stainless steel eye and hook. It is too small (and cheap!) for this application but was rated at 350 lbs. working load.
I'm planning at this point to procure a couple of turnbuckles for back-up in case of failure but will ride with the set-up that FWC has provided. I am going to assume that they have done their homework on this issue (although I will probably ask some questions this weekend at their campout.) Thanks for all of the discussion.
ETAV8R
Senior Member
I'll chime in with my experiences.
I've got the stable mats between the metal tie-down bars mounted to the bed/frame of the Tacoma. On top of that is the Tacoma bed mat. The turnbuckles I have are the cheaper looking ones from FWC. My camper/truck have done hundreds of miles of off-road travel and the turnbuckles are always loose upon arrival to any given destination. I put wingnuts on top, not the nylock type, and they don't do too much to stop the loosening.
The following turnbuckles have been in my cart for some time but don't state the rating from what I can see.
http://www.amazon.com/5Pcs-Stainless-Steel-Turnbuckle-2-3mm/dp/B00RVVJRC8?ie=UTF8&psc=1&redirect=true&ref_=ox_sc_act_title_1&smid=A9HNRUVYNT2TE
I've got the stable mats between the metal tie-down bars mounted to the bed/frame of the Tacoma. On top of that is the Tacoma bed mat. The turnbuckles I have are the cheaper looking ones from FWC. My camper/truck have done hundreds of miles of off-road travel and the turnbuckles are always loose upon arrival to any given destination. I put wingnuts on top, not the nylock type, and they don't do too much to stop the loosening.
The following turnbuckles have been in my cart for some time but don't state the rating from what I can see.
http://www.amazon.com/5Pcs-Stainless-Steel-Turnbuckle-2-3mm/dp/B00RVVJRC8?ie=UTF8&psc=1&redirect=true&ref_=ox_sc_act_title_1&smid=A9HNRUVYNT2TE
craig333
Riley's Human
Always loose? Mine are rarely loose and I don't have a mat. Do need to check as rarely certainly doesn't mean never and I have lost one (luckily three still hold pretty well).
Ok, I decided after all this talk, to upgrade my turnbuckles to these. I tried to plan ahead knowing it'd be a bit more difficult to get the nut and pin in and it was. I over-thought it. Really not that difficult once you have the eyelets turned a bit towards the camper.
Never mind... I can't remember how to post a picture but I used heavier duty 1/2" drop forged turnbuckles that have a "U" on the end of each with a bolt and cotter pin that keeps the nut from coming off.
BTW, why isn't there just an icon that allows you to add a photo or am I missing it?
Never mind... I can't remember how to post a picture but I used heavier duty 1/2" drop forged turnbuckles that have a "U" on the end of each with a bolt and cotter pin that keeps the nut from coming off.
BTW, why isn't there just an icon that allows you to add a photo or am I missing it?
Hey, guys, I'm a noob here, and this is my first post, but I've been following discussions on WTW over the past several months as I figured out what I want in a camper. Right now I'm waiting on a Hawk which should be delivered sometime next month. I've learned a lot from all of the discussions here.
The posts about using climbing slings to tie down the camper unlocked some old memories. When I was in college, I did a lot of caving (the geology of the area I live in is karst and like swiss cheese). At first, I had to learn how to rig ropes for rapelling into deeper parts of the cave. Often that involved putting a sling around a column or knob, and then hanging the rope from the sling. When a load is put on the rope, it makes the junction between the rope and the sling look like the letter Y (where the two arms at the top of the Y are the sling arms, and the vertical line of the Y is the rope). The older, wiser cavers always taught that the angle between the arms of the Y should never be greater than 120 degrees. Above that, the tension on the arms of the sling will exceed the weight of the caver hanging on the rope.
Shortly after that, I wound up taking a class in statics, where you learn to analyze the force on a structure using trig and vectors. Applying what I learned confirmed what the older cavers taught. In fact, the analysis shows that if the angle between the sling arms is 150 degrees, then the tension on the sling arms is about double that on the rope.
The same principle applies to turnbuckle tie-downs. If the turnbuckles are mostly vertical, then a horizontal force applied to the camper can generate some pretty large tensile forces in the turnbuckle. For example, if some motion results in a horizontal acceleration of 0.1 g of a 1500 lb camper relative to the truck bed, then a lateral force of F=ma = 149 lbf is generated. If the turnbuckle is inclined 30 degrees from the vertical, a tensile force of 149/sin30 = 298 lbf is felt by the turnbuckle - not too far from the 350 lbf rating of the FWC turnbuckle. Seems to me that it wouldn't be hard to see more than 0.1 g acceleration when off-roading.
The turnbuckles won't necessarily take the full acceleration load, though. If the camper is resting against the side of the truck bed in the direction of the acceleration, then the bed side will share some of the force. If there's a rubber bed mat and the camper doesn't slide over it, then some of the force will be taken up by the bed mat.
Anyway, check my numbers and my reasoning. Structural mechanics is not my field.
I tend to agree with the opinion expressed in posts here that you'd rather have the turnbuckle fail than the truck bed. I'll be interested to see how they mount my Hawk to my aluminum bed 2015 F150. When I stand or walk in the bed of that truck, there's a slight amount of give - doesn't feel as solid as a steel bed.
If I find some time after getting my camper, I might put some accelerometers on the truck and camper and some strain gages on the turnbuckles and run those into an Arduino datalogger just to see what kind of forces they see in use.
The posts about using climbing slings to tie down the camper unlocked some old memories. When I was in college, I did a lot of caving (the geology of the area I live in is karst and like swiss cheese). At first, I had to learn how to rig ropes for rapelling into deeper parts of the cave. Often that involved putting a sling around a column or knob, and then hanging the rope from the sling. When a load is put on the rope, it makes the junction between the rope and the sling look like the letter Y (where the two arms at the top of the Y are the sling arms, and the vertical line of the Y is the rope). The older, wiser cavers always taught that the angle between the arms of the Y should never be greater than 120 degrees. Above that, the tension on the arms of the sling will exceed the weight of the caver hanging on the rope.
Shortly after that, I wound up taking a class in statics, where you learn to analyze the force on a structure using trig and vectors. Applying what I learned confirmed what the older cavers taught. In fact, the analysis shows that if the angle between the sling arms is 150 degrees, then the tension on the sling arms is about double that on the rope.
The same principle applies to turnbuckle tie-downs. If the turnbuckles are mostly vertical, then a horizontal force applied to the camper can generate some pretty large tensile forces in the turnbuckle. For example, if some motion results in a horizontal acceleration of 0.1 g of a 1500 lb camper relative to the truck bed, then a lateral force of F=ma = 149 lbf is generated. If the turnbuckle is inclined 30 degrees from the vertical, a tensile force of 149/sin30 = 298 lbf is felt by the turnbuckle - not too far from the 350 lbf rating of the FWC turnbuckle. Seems to me that it wouldn't be hard to see more than 0.1 g acceleration when off-roading.
The turnbuckles won't necessarily take the full acceleration load, though. If the camper is resting against the side of the truck bed in the direction of the acceleration, then the bed side will share some of the force. If there's a rubber bed mat and the camper doesn't slide over it, then some of the force will be taken up by the bed mat.
Anyway, check my numbers and my reasoning. Structural mechanics is not my field.
I tend to agree with the opinion expressed in posts here that you'd rather have the turnbuckle fail than the truck bed. I'll be interested to see how they mount my Hawk to my aluminum bed 2015 F150. When I stand or walk in the bed of that truck, there's a slight amount of give - doesn't feel as solid as a steel bed.
If I find some time after getting my camper, I might put some accelerometers on the truck and camper and some strain gages on the turnbuckles and run those into an Arduino datalogger just to see what kind of forces they see in use.
kmacafee
Senior Member
I have a Tacoma with the Composite bed so tying to that alone was not an option. I have a friend with the new F150 and I would be concerned about bolting a camper down thru that as well. Check and see if FWC is planning mounting plates for the F150 similar to what they have for the Tacoma. The plates bolt directly to the frame and are solid.
I know most of the discussion here has been about the strength of turnbuckles, and I have broken one myself, but I've broken three of the single bolts holding the forged eye bolt on the camper side.
So, after breaking three of these on my 2012 Fleet
I heard about the new stainless steel brackets held by three bolts instead of one (and the same size). So Roy at FWC helped with my order and I installed this weekend.
I also ordered the beefier turnbuckles recommended by Stan to Captn, Forklift S9012, so after I get those installed this upgrade will be complete.
This was the first time I've crawled under my camper since I bought it new in 2012, as it is on full-time. I was really happy with how everything looked, basically like new. I guess it helps to live in southern Calif. I also wondered if the stresses that broke the bolts also stressed the plywood around the eyebolt, but it also looked perfect.
So, after breaking three of these on my 2012 Fleet
I heard about the new stainless steel brackets held by three bolts instead of one (and the same size). So Roy at FWC helped with my order and I installed this weekend.
I also ordered the beefier turnbuckles recommended by Stan to Captn, Forklift S9012, so after I get those installed this upgrade will be complete.
This was the first time I've crawled under my camper since I bought it new in 2012, as it is on full-time. I was really happy with how everything looked, basically like new. I guess it helps to live in southern Calif. I also wondered if the stresses that broke the bolts also stressed the plywood around the eyebolt, but it also looked perfect.
Kodachrome
Senior Member
I have had zero issues with the turnbuckles themselves breaking or failing but have busted 4 elevator bolts on the camper side of the mounting equation over the years. So I not only check torque on the TB's but totally reset them to the proper setting once a month or after arriving at my destination.
In addition to a full set of spare elevator bolts, I also carry two motorcycle tie downs and spare hardware to secure the camper front jack brackets via the tie downs to my rock sliders in case I really need it ( saved my rear in Death Valley ).
To be honest, I think I would rather have an easy to replace elevator bolt fail than any other part of the equation. I think the way these campers attach to the truck bed is very "1980"...both FWC and ATC should be looking at a frame to frame mounted, shock absorbing system that bolts to the frame under the truck bed and uses top notch hardware.
These campers cost between 10-25K depending on make, model and features, it's completely *insane* to me that all that weight is relying on less than $100 in hardware. I admit, these are, thus far, easy field fixes for me, especially since I can now access all 4 elevator bolts ( access holes for left side on cabinets ). But it would be better structurally to consider an approach to mounting these campers to the trucks they are in that reflects the age we are in, 2016...not 1980.
My 2 cents...
In addition to a full set of spare elevator bolts, I also carry two motorcycle tie downs and spare hardware to secure the camper front jack brackets via the tie downs to my rock sliders in case I really need it ( saved my rear in Death Valley ).
To be honest, I think I would rather have an easy to replace elevator bolt fail than any other part of the equation. I think the way these campers attach to the truck bed is very "1980"...both FWC and ATC should be looking at a frame to frame mounted, shock absorbing system that bolts to the frame under the truck bed and uses top notch hardware.
These campers cost between 10-25K depending on make, model and features, it's completely *insane* to me that all that weight is relying on less than $100 in hardware. I admit, these are, thus far, easy field fixes for me, especially since I can now access all 4 elevator bolts ( access holes for left side on cabinets ). But it would be better structurally to consider an approach to mounting these campers to the trucks they are in that reflects the age we are in, 2016...not 1980.
My 2 cents...
craig333
Riley's Human
Looks similar to the fix I did for my failure. If we just stuck to paved roads I'm sure there'd be no problem.
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