Linear Actuators on Trailer

[[email protected]]

Has anyone used 12v electro-mechanical/12v electro-hydraulic/manual hydraulic linear actuators on a clam shell/alligator type trailer top. I have bent 4 (SUSPA) gas springs in the past 4 months. Ordered what was on the trailer when purchased. Ordered a pair of Bansbach Easylift gas springs, but waiting for the SUSPA gas springs currently on the trailer to fail before I put the new ones on.
If you have done any type of linear actuators and it is working, can you forward photos? If tried and it is a futile effort on my part let me know, I would prefer to spend my funds on other glider stuff.

r/Jim
N9XL/H201B

[Steve Leonard[_2_]]

Are they bending when extended or retracted? Check on the mechanism to make sure you aren't getting something nearly on center when open. If you go there, loads go out of sight high, and you can bend things when you try to move it back the other way.

Steve Leonard

[[email protected]]

On Wednesday, November 27, 2013 2:05:09 PM UTC-5, Steve Leonard wrote:
> Are they bending when extended or retracted? Check on the mechanism to make sure you aren't getting something nearly on center when open. If you go there, loads go out of sight high, and you can bend things when you try to move it back the other way.
>
>
>
> Steve Leonard

They bend when bringing the top down. They bend to the back of the trailer.
The trailer weighs in at 1200lbs. sq tube truss construction covered in aluminum sheeting. suspect from the size of the top it weighs in at a good 600lbs+.

[Dan Marotta]

I'm not a mechanical engineer, but I've seen lift struts encased in square
tubing. There are two square tubes, sized to slide into each other. They
are attached to the pivots on the top and bottom of the trailer using the
same bolts that attach the gas strut to the trailer.

It would appear that the square tubing would support the gas struts and
prevent or reduce the tendency to bend.

But, then again, I'm not a mechanical engineer.

> wrote in message
...
> On Wednesday, November 27, 2013 2:05:09 PM UTC-5, Steve Leonard wrote:
>> Are they bending when extended or retracted? Check on the mechanism to
>> make sure you aren't getting something nearly on center when open. If
>> you go there, loads go out of sight high, and you can bend things when
>> you try to move it back the other way.
>>
>>
>>
>> Steve Leonard
>
> They bend when bringing the top down. They bend to the back of the
> trailer.
> The trailer weighs in at 1200lbs. sq tube truss construction covered in
> aluminum sheeting. suspect from the size of the top it weighs in at a
> good 600lbs+.

[Dan Marotta]

Something like this?
http://www.servocity.com/html/560_lbs__thrust_linear_actuato.html

Don't know your stroke length requirement, but these guys may be able to
custom build what you're looking for. PS - They ain't cheap!

> wrote in message
...
Has anyone used 12v electro-mechanical/12v electro-hydraulic/manual
hydraulic linear actuators on a clam shell/alligator type trailer top. I
have bent 4 (SUSPA) gas springs in the past 4 months. Ordered what was on
the trailer when purchased. Ordered a pair of Bansbach Easylift gas
springs, but waiting for the SUSPA gas springs currently on the trailer to
fail before I put the new ones on.
If you have done any type of linear actuators and it is working, can you
forward photos? If tried and it is a futile effort on my part let me know,
I would prefer to spend my funds on other glider stuff.

r/Jim
N9XL/H201B

[GM]

On Wednesday, November 27, 2013 12:46:41 PM UTC-5, wrote:
> Has anyone used 12v electro-mechanical/12v electro-hydraulic/manual hydraulic linear actuators on a clam shell/alligator type trailer top. I have bent 4 (SUSPA) gas springs in the past 4 months. Ordered what was on the trailer when purchased. Ordered a pair of Bansbach Easylift gas springs, but waiting for the SUSPA gas springs currently on the trailer to fail before I put the new ones on.
>
> If you have done any type of linear actuators and it is working, can you forward photos? If tried and it is a futile effort on my part let me know, I would prefer to spend my funds on other glider stuff.
>
>
>
> r/Jim
>
> N9XL/H201B

Jim,
when a long slender member like a cylinder or gas spring bends or buckles, it is a clear indication of side-loading. There are several ways of introducing side loading, such as the member's own weight (not likely in your case), the member interfering with something during its operation (you would have seen that already) or due to torque introduced into the pivot points. Please check if both rod ends are free to swivel, i.e. have either a straight bushing or better yet a spherical eye end. The bolt or pin going through said bearing must not bind the rod or body end of the gas spring.
The nesting square tubing Dan M. mentioned are more for protection and guidance of the shell and they may limit the sway of the shell as it moves up and down. Are you seeing this damage on an Eberle trailer which many Std.Libelles came in?
Uli

[Dave Nadler]

Jim - Take some photos of the trailer top lift
mechanism in the closed and open positions and
post them, otherwise we're all guessing here.
Forget about linear actuators!
Happy Thanksgiving,
Best Regards, Dave "YO electric"

[Dan Marotta]

Yah, but wouldn't it be great to push a button, take a sip of your beer, and
watch the lid open/close? The tail gate on my car does that (by wireless!)
and it's very nice!


"Dave Nadler" > wrote in message
...
> Jim - Take some photos of the trailer top lift
> mechanism in the closed and open positions and
> post them, otherwise we're all guessing here.
> Forget about linear actuators!
> Happy Thanksgiving,
> Best Regards, Dave "YO electric"

[Dave Nadler]

On Thursday, November 28, 2013 10:56:25 AM UTC-5, Dan Marotta wrote:
> Yah, but wouldn't it be great to push a button, take a sip of your beer,
> and watch the lid open/close?

Sure, until only one side operates.
Then again, I'm still frightened by my new car...

Much simpler to fix the original mechanical problem,
though no doubt less entertaining.

[Dan Marotta]

A second beer will alleviate worries about single-sided failures...


"Dave Nadler" > wrote in message
...
> On Thursday, November 28, 2013 10:56:25 AM UTC-5, Dan Marotta wrote:
>> Yah, but wouldn't it be great to push a button, take a sip of your beer,
>> and watch the lid open/close?
>
> Sure, until only one side operates.
> Then again, I'm still frightened by my new car...
>
> Much simpler to fix the original mechanical problem,
> though no doubt less entertaining.

[[email protected]]

I'll be darned. I used to own N9XL from 1986 to late 1992. I really can't make a reasonable answer to your trailer problem. I've not had problems with gas springs. In fact I'm curious about how you can bend one without bottoming out the
piston. Maybe the piston rod got bent sometime while extended. Not by the linear loads, because that would have let the piston work, but by something putting an external load across the rod while extended. This assumes that the ball ends are in use and free.

[[email protected]]

On Friday, November 29, 2013 8:30:50 PM UTC-5, wrote:
> I'll be darned. I used to own N9XL from 1986 to late 1992. I really can't make a reasonable answer to your trailer problem. I've not had problems with gas springs. In fact I'm curious about how you can bend one without bottoming out the
>
> piston. Maybe the piston rod got bent sometime while extended. Not by the linear loads, because that would have let the piston work, but by something putting an external load across the rod while extended. This assumes that the ball ends are in use and free.

So, if you owned 9XL from 86-92 do you have any of the missing logbook(s)?
Just boggles my mind that logbooks disappear.

Not sure what trailer you had with 9XL, Tim Mara told me he reworked/rebuilt this trailer. It is a front hinged clamshell/alligator type. And the top is bloody heavy! The gas springs have all bent when trying to close the top. as the top goes down, they bend to the back of the trailer. The gas springs appear to be fully extended when the top is open. gas springs are 250lbs. each. Ball ends are free.

A friend of mine (and several club members) suggested I use electro-mechanical struts to lift/lower the top. the control would have 2 switches, one to control both struts and the other to disable one side so if they were out of sync, the remaining active strut could be positioned with the other to complete the transition. He said it would work similar to a boat lift. all of the mechanism is internal and IMO I don't like the arrangement, it should be external.

[son_of_flubber]

On Friday, November 29, 2013 9:44:29 PM UTC-5, wrote:

>The gas springs appear to be fully extended when the top is open.<

When the trailer is fully open, how close to vertical are the struts? (Use a level or plumb bob to define the vertical.) Are they tilted to the rear or front of the trailer?

Does the strut bend at the junction of the rod and the tube? Assuming that it is the rod that bends, does it bend at the very end of the rod where it enters the tube and is the rod fully extended?

Did the first pair of struts fail by buckling? If they did fail by buckling, how many times (approximate) did you open and close the trailer before they failed? (I'm wondering if the trailer ever worked properly or if it was always on the edge of failure.)

When the struts fail, do they both fail at the same time? If not, is the first failure always on the same side? When you say four struts failed, do you mean four pair (eight struts) or two pair?

I only see three possibilities:

1)the trailer always had a latent problem with geometry or strut selection.

2)the trailer developed a problem with geometry or misalignment.

3)The new struts are defective (even though they have the same Part Number, they may be manufactured differently and have different properties. Have you talked to the supplier or manufacturer of the struts?