Gas Struts

[rickst29]

In this photo of Shanes' mostly dismantled "salvage" 2619 (from a few years before mine), there seems to be a 1" x 1" wood "bottom edge" in the street side lower box wall. (The end of that wood piece is underneath the magic marker written "26").

If that 1'x1" wood edge is still present in the lower box walls of my own TM, my L bar attachments to outside edges of the floor can add some smaller-gauge wood screws through the inner corner of my L-bars, going straight up and that wood for a bit of additional strength.

Those screws should help to prevent the the outside edges of the floor from becoming bent down, pulling away from the street-side and curb-side walls.(Pressure from the struts tries to push the L bars and the overlaying floor DOWN along the outside edge. The frame is a few inches inside from the L-bars, so the downward force at the edge creates torque on the floor.

The horizontal strength of the lower box wall (across its full height) resists a 1-foot long portion from being bent down, The issue would be the strength of the 1"x1" and the actual wood threads holding the screws in place.

I've got a few dozen 2-1/2" Deckmate screws lying around (they're 9-gauge). If I don't countersink the L-bar pilot holes, about 1/8" of head will remain sticking out the L bar. The lower portion through the floor will be un-threaded, that's a slight disadvantage in using these screws. (I'll get no "bite" from the outside floor aluminum sheet.) But the inside layer of aluminum floor will be against threads, and the entire 1"x1" wooden sidewall edge will be engaged by screw threads. Above that, the tip of the screw will exit the 1"x1" and go into the foam by just a bit. The length is perfect, only the lack of threads in the lower portion of the shank is a slight issue.
- - -
Into the actual floor, I'm using several bigger screws (1/4" x 20 threads, stainless) with fender washers on the TM interior, spreading the load from each of the nuts over a larger area. These screws should handle nearly all or the most of the horizontal and vertical loading into the floor - the deckmate screws only keep edge of the floor attached to the sidewalls.

[Shane826]

Yep the bottom box is still fully framed in wood. 1x1 around the walls, maybe a standard 2x4 around the floor.

[rickst29]

Originally Posted by Shane826

Yep the bottom box is still fully framed in wood. 1x1 around the walls, maybe a standard 2x4 around the floor.

Thanks Shane, for confirming that.

My "100 lbs each" initial guess is possibly a little bit too weak (for the initial assistance provided) But they're also possibly too strong, making the final pull down for lift bar locking hooks to hard. (Even when assisted by the foot stirrups and my ever-increasing body weight .

I hope that they turn out be just slightly too strong. In that situation, I can take some lifting power from the still-installed torsion bars by twisting their adjustment screws out from the "all-the-way in, maximum twist power" position which I currently use.

I also also have the option of re-buying just the strut assemblies, with more or less power than these "100 lb" struts, at fairly low cost. The project parts have added up over $150, but the struts themselves for only $27 for the pair. Bigger money went into cut-to-size angle bar segments, and especially into the "countertop support brackets, which were only sold in quantity 4. (I'
m using only two of those).

[Wavery]

Originally Posted by rickst29

In this photo of Shanes' mostly dismantled "salvage" 2619 (from a few years before mine), there seems to be a 1" x 1" wood "bottom edge" in the street side lower box wall. (The end of that wood piece is underneath the magic marker written "26").

If that 1'x1" wood edge is still present in the lower box walls of my own TM, my L bar attachments to outside edges of the floor can add some smaller-gauge wood screws through the inner corner of my L-bars, going straight up and that wood for a bit of additional strength.

Those screws should help to prevent the the outside edges of the floor from becoming bent down, pulling away from the street-side and curb-side walls.(Pressure from the struts tries to push the L bars and the overlaying floor DOWN along the outside edge. The frame is a few inches inside from the L-bars, so the downward force at the edge creates torque on the floor.

The horizontal strength of the lower box wall (across its full height) resists a 1-foot long portion from being bent down, The issue would be the strength of the 1"x1" and the actual wood threads holding the screws in place.

I've got a few dozen 2-1/2" Deckmate screws lying around (they're 9-gauge). If I don't countersink the L-bar pilot holes, about 1/8" of head will remain sticking out the L bar. The lower portion through the floor will be un-threaded, that's a slight disadvantage in using these screws. (I'll get no "bite" from the outside floor aluminum sheet.) But the inside layer of aluminum floor will be against threads, and the entire 1"x1" wooden sidewall edge will be engaged by screw threads. Above that, the tip of the screw will exit the 1"x1" and go into the foam by just a bit. The length is perfect, only the lack of threads in the lower portion of the shank is a slight issue.
- - -
Into the actual floor, I'm using several bigger screws (1/4" x 20 threads, stainless) with fender washers on the TM interior, spreading the load from each of the nuts over a larger area. These screws should handle nearly all or the most of the horizontal and vertical loading into the floor - the deckmate screws only keep edge of the floor attached to the sidewalls.

If/when I do this, I would not count on those deckmate screws into that 1x1 wall framing. They may do the job in the short term but I think that (after opening and closing a few times) they may strip out of that soft wood. The sheet metal has almost zero holding power. If you do use those 2.5" deckmate screws, you might want to add another piece of 1x1 hardwood (with pre-drilled pilot holes) on the inside of the wall for those screws to grab onto (acting like a nut). That would also spread the load. You could also run your 1/4-20 floor screws up through that (added) 1x1. That would take care of all of the twisting (and downward) force on the wall.

I think that I would use 1/4" bolts & nuts through the wall frame. I'd use Blue Locktite on all fasteners.

[Wavery]

Originally Posted by Shane826

Yep the bottom box is still fully framed in wood. 1x1 around the walls, maybe a standard 2x4 around the floor.

Isn't the floor is 3" thick".

I wonder if they took 4x4s (which are actually 3.5x3.5) and cut them down to make the 3" thickness.

[rickst29]

This photo shows the curb side L-bar with holes drilled and mounting screws inserted. The photo is viewing from underneath the the final placement, with screws going up and into the TM side wall and floor.

9 deck screws (brownish-yellow) go into the middle of the 1" x 1" wood base "edge" of the curbside wall. These are not the primary connecting mechanism, they only help to keep the the floor edge firmly attached to the wall. "Lifting Forces" from the gas strut are trying to push this edge of the floor (which is "outside" from the supporting box frame downwards and away from the wall. These screws will help to the floor edge up against the wall, although they are only held by threads within the 1"x 1" wood edging of the wall.

8 1/4" machine bolts (stainless steel), in contrast, go through the floor alone, a bit away from the wall. In my 2619, although I haven't opened it to look yet), these should come up far enough away from the edge to provide for some fairly large fender washers on the inside floor, spreading the downward force from each nut over a wider area.

With 8 bolts and large washers, think that thls will do a good job. A slight variation in hole distances from the edge should help the outer-most deck screws in the job of resisting torque forces on the bar.

An alternative which I considered was fewer of the machine bolts, going through a metal plate on the TM interior floor. Compared to my fender washers, the metal plate would have done an equal or better job of spreading force from the nuts. But I've got washers lying around, while the metal plate or bar would have been an additional purchase.
- - -
On the street side, I have much less "width" from the wall for washers and nuts, before being blocked by the water tank. (I haven't opened it up to see how much room there is). I have cut holes for the same bolts at less distance, but might need to make a run to the "big box store" for some narrow bar or sheet stock - switching the "meta plate" method on that side, if the room for circular washers is too small.

Does anyone have a TM open, to measure the distance of a 40-gallon water tank from the side wall?

[rickst29]

Originally Posted by Wavery

If/when I do this, I would not count on those deckmate screws into that 1x1 wall framing. They may do the job in the short term but I think that (after opening and closing a few times) they may strip out of that soft wood. The sheet metal has almost zero holding power. If you do use those 2.5" deckmate screws, you might want to add another piece of 1x1 hardwood (with pre-drilled pilot holes) on the inside of the wall for those screws to grab onto (acting like a nut). That would also spread the load. You could also run your 1/4-20 floor screws up through that (added) 1x1. That would take care of all of the twisting (and downward) force on the wall.

I think that I would use 1/4" bolts & nuts through the wall frame. I'd use Blue Locktite on all fasteners.

Your method can work, but I'd recommend something "better" along the in inside corner of the the wall and floor. (Perhaps 1x1" metal square tube). I also feel that the deck screws are too weak against bending fores, and would need to replaced by screws or bolts of a larger gauge.

In my case, the main bolts (through the floor) are torqued much tighter than the deck screws, they will handle nearly all the load. I am using Locktite Blue on all connecting nuts

[Wavery]

Originally Posted by rickst29

This photo shows the curb side L-bar with holes drilled and mounting screws inserted. The photo is viewing from underneath the the final placement, with screws going up and into the TM side wall and floor.

9 deck screws (brownish-yellow) go into the middle of the 1" x 1" wood base "edge" of the curbside wall. These are not the primary connecting mechanism, they only help to keep the the floor edge firmly attached to the wall. "Lifting Forces" from the gas strut are trying to push this edge of the floor (which is "outside" from the supporting box frame downwards and away from the wall. These screws will help to the floor edge up against the wall, although they are only held by threads within the 1"x 1" wood edging of the wall.

8 1/4" machine bolts (stainless steel), in contrast, go through the floor alone, a bit away from the wall. In my 2619, although I haven't opened it to look yet), these should come up far enough away from the edge to provide for some fairly large fender washers on the inside floor, spreading the downward force from each nut over a wider area.

With 8 bolts and large washers, think that thls will do a good job. A slight variation in hole distances from the edge should help the outer-most deck screws in the job of resisting torque forces on the bar.

An alternative which I considered was fewer of the machine bolts, going through a metal plate on the TM interior floor. Compared to my fender washers, the metal plate would have done an equal or better job of spreading force from the nuts. But I've got washers lying around, while the metal plate or bar would have been an additional purchase.
- - -
On the street side, I have much less "width" from the wall for washers and nuts, before being blocked by the water tank. (I haven't opened it up to see how much room there is). I have cut holes for the same bolts at less distance, but might need to make a run to the "big box store" for some narrow bar or sheet stock - switching the "meta plate" method on that side, if the room for circular washers is too small.

Does anyone have a TM open, to measure the distance of a 40-gallon water tank from the side wall?

Holy Cow!! That's a lot of screws. Are you disconnecting your torsion bars?

I think that I envisioned your L-bar going the other way around (the inside of the "L" facing the wall & floor).

Sorry, I've been super busy this week and haven't been able to follow this thread completely. I'll go back and study it further.

[rickst29]

Originally Posted by Wavery

Holy Cow!! That's a lot of screws. Are you disconnecting your torsion bars?

I think that I envisioned your L-bar going the other way around (the inside of the "L" facing the wall & floor).

I am not disconnecting the torsion bars. This all depends on the current lift bars and their fulcrum of rotation. That is provided in all 8 cases by the 90-degree angle within the torsion bars themselves (the outside "corners" with radius about 2" before going "up" into the lift bars).

Your "up along the bottom of the side" idea is an interesting one, but it has a likely issue with the rear shell inner wall getting dirty during travel:
Your arrangement would have 1/4" of L-bar and a some screw heads (if not countersunk) sticking out from the bottom box at the base. For about 2" of that length, the 3/8" thick countertop support is set on the outside of the L-bar, with its attachment bolt heads (which again, could be/should be countersunk, but only if you switch from hex head to #3 philips head bolts.)

I think that the rear shell would #1 resist being closed across these bump-outs, and #2 would be leaving a pretty big gap around the bag seal near the L-bar ends, and more gaps at the countertop support. If not sealed (painter tape) for each trip, these allow road dirt and grime to fly up, on to the walls. of the inner shell.
- - - -

If I switched to your mounting scheme, I would not use mere 1" x1" wood strips along the inner corner between floor and sidewall. The first inch of height is taken by floor thickness, but provides almost 2" above (along the side wall) for additional mounting screws, coming in sideways from the vertical side of the L-bar. (Although rather than deck screws into added wood, I'd use a several machine bolts into nuts with 2 or 3" tall metal spreading plate.)

The 3/16 holes in my current L-bars would need to be re-cut for your scheme, but my SWAG is that the new bolts from the vertical side make those weak "into-the bottom-inch of wood alone" desk screws unnecessary. I' would keep some or all of the current "up-though-the floor" 1/4" stainless bolt holes in use.

The 1/4" screws holes for the main through-the-floor supports might probably be OK at their current distances from the corner, so I maybe wouldn't have to re-cut those.

(Cutting with holes with hand drill was a bit slow, but not "overwhelming". Both my 1/4 and 3/16 bits probably still has adequate life to add new holes. Yes, I go slow - with oil.)
- - -
The angle of my fixed countertop support would be more sharply down, but I have no concern about that. It doesn't affect the angle between the strut and the lift bar.

However, - two connecting bolts (from the countertop support "long side" into the L bar vertical side) and all the new horizontal support bolts coming into the interior plate will need to bolted with nuts from the interior of the wall (through that metal plate). On the street side, it will be very awkward for me to tighten down those nuts - I'll need a very long wrench handle, due to the presence of the water tank. A "squeezed in' piece of wood would not have that issue with supporting deck screws, but the countertop support bolts have no alternative.

There is probably insufficient room for a socket with any kind of socket handle going sideways, between that street side wall and the water tank. (I have a very long car repair socket handle with less than 3/16" handle thickness, but that thickness plus the socket and the bolt head is probably too much.)

In contrast, bolting the "countertop supports" into descending faces of the L-bars can be done in free air - and I'll probably be doing that before I attach the L-bars to the TM. The strength of that attachment with short bolts (I've got some 5/16" SS bolts for this) is limited only by my willingness to push hard on the long socket wrench arms, the threads of the bolt and and nut (and by stripping the hex sides and corners, and by the tensile strength of the bolts themselves.) I have absolutely zero interest in testing those limits.

[rickst29]

Here are photos from the assembly YESTERDAY, which required a bit less than 2 hours of drilling and assembly with screws of slightly the wrong size (1/4" width, 1-1/4" length, rather than 1" long).

I had to cut the middle screw for the strut attachment ball post assembly down to only 7/8" of bolt length under the hex head. The hole for this centered mounting screw lies directly underneath the ball mount post. If the "countertop support" angle bar was thinner (it's 3/8" thick), then a screw could possibly fit with the head inside the angle - but my 7/8" bolt length (required to go through all the sheet metal, two washers, and still thread the nut completely) was too long to fit. One way or another, you need to limit the inside height above the mount corner plate to just the bolt head OR the nut, with a helping washer.

A 1-inch bolt, if I had one, would have been slightly too long here (again mounted reverse, with the nut on the "top" and inside the strut ball mount. But, with a 1" screw, I could have simply add a couple more flat washer on the outside (under the bolt head) to prevent the "nut" end of the bolt from sticking too far into the inside of the ball mount post assembly.

Yesterday I connected the 12" long, angled countertop support bar to the middle of the L-bar face with two more 1-1/4 SS bolts. using an existing hole in the countertop support and then drilling another to correct angle of descent for the countertop support. In the photo, the end hole of the countertop support went through the middle of the 12" long L-bar face.

But, when I went out to the Trailer, that caused the end of the L-bar mount (against the TM floor) to unfortunately run into the last of the floor mount screws for the original (and still required) TM 4" high L-bar (thinner metal, with the torsion bar guide hole going through it).

I chose to drill new holes in my L-bar for the "countertop support bar" connection screws, each moved about 1" towards the "rear" of my L-bar. The L bar is moved further from the front of the TM box backwards, but the strut mount remains in about the same place. Load on the floor mount screws becomes less balanced, with even more downward pulling forces on the screws closer to the Lift arm - but I'm hoping it will still hold together well enough.