Full Wall slide dependability

dougrainer wrote:
As an RV Tech for 38 years, I would NOT want a FULL wall slide. I have seen too many problems with them. BUT, there are exceptions. It all depends on the TYPE/BRAND of the slide mechanism. I would have NOTHING designed by LCI/Schwintek. I would want NOTHING that has the tracks mounted on the outside sidewalls. Doug

My thoughts exactly and even without 38yrs in the business.
I mean that's one big hole in the side without any uprights for reinforcing. Then there's gotta be more than one motor on the electrics and for being in sync.

Hikerdogs wrote:

dougrainer wrote:
As an RV Tech for 38 years, I would NOT want a FULL wall slide. I have seen too many problems with them. BUT, there are exceptions. It all depends on the TYPE/BRAND of the slide mechanism. I would have NOTHING designed by LCI/Schwintek. I would want NOTHING that has the tracks mounted on the outside sidewalls. Doug

I would agree. We have a 2013 Winnebago adventurer with the original configuration Schwintec 29' full wall slide. It's been repaired 3 times and will be going in for the 4th time when we get finished with our current trip.

The last time it was repaired in December of 2015 at the Winnebago factory in Forest City. The repair lasted until last week. The first day we were on the road the slide refused to work properly. The back would extend but not the front. We'll be on the road for another 7 weeks without the use of the slide.

The motorhome has just over 37,000 miles on the odometer which equates to about 6,000 miles per year. We certainly wouldn't have considered a full wall slide if we had known it would need to be repaired every 9,000 miles.

Sorry to read this. Your experience is EXACTLY what I'm talking about in my previous post. Without seeing it, my bet would be that the whole wall/slide/roof/floor/frame of your RV needs to be taken apart and reinforced so that it is much more rigid. At the age of your RV, it's out of warranty and probably not something the manufacturer wants to admit or even attempt to tackle fully on their dime.

Chum lee

Adding to my other post and having a full slide for over 10 years, there are a couple of rules for my full slide MH. Always level the coach before engaging the full slide, and when you engage it you extend it all the way out or all the way in and don't leave it half in or half out. ;)

dougrainer wrote:
As an RV Tech for 38 years, I would NOT want a FULL wall slide. I have seen too many problems with them. BUT, there are exceptions. It all depends on the TYPE/BRAND of the slide mechanism. I would have NOTHING designed by LCI/Schwintek. I would want NOTHING that has the tracks mounted on the outside sidewalls. Doug

I would agree. We have a 2013 Winnebago adventurer with the original configuration Schwintec 29' full wall slide. It's been repaired 3 times and will be going in for the 4th time when we get finished with our current trip.

The last time it was repaired in December of 2015 at the Winnebago factory in Forest City. The repair lasted until last week. The first day we were on the road the slide refused to work properly. The back would extend but not the front. We'll be on the road for another 7 weeks without the use of the slide.

The motorhome has just over 37,000 miles on the odometer which equates to about 6,000 miles per year. We certainly wouldn't have considered a full wall slide if we had known it would need to be repaired every 9,000 miles.

Ductape wrote:
We've had two Newmars with FWS, zero problems.

Yeah, but you didn’t work for a helicopter company.

RRTom wrote:
Thinking about getting back into rv'ing. Have they now got full wall slides that are dependable and trouble free? I know it might depend on which brand. We are looking at Holiday Rambler 30' and Coachmen Mirada 29'.

Hopefully this information can help. Consider the following equation:

5wL^4/384EI = deflection in inches at the center of the span

The above is a structural engineering equation that engineers use to determine vertical deflection of a beam. (greatly simplified)

This is for a simply supported uniformly loaded beam of constant cross section. Don't run just yet because of the math. I'll try to explain why it's important without using much math.

w = weight in lbs. per lineal inch of span (usually determined by the roof loads)
L = length of span in inches (notice that it is raised to the forth power)
E = Modulus of Elasticity of beam (for steel its about 30,000,000)
I = Moment of inertia of beam (important, but you can disregard)

So, why is this so important? Imagine a hole in the side of a Class A motor home that measures 12 feet wide by 7 feet high. This hole will be what the slide eventually fits into. Now, suppose I told you that after a thorough structural analysis, the deflection of the main beam that spans the 12 feet at the top of the hole deflects 1/8 of an inch at center span. How much would the beam deflect if the hole was framed the same way but spanned twice the distance? (24 feet instead of 12) (look at the equation) You might guess, hummmmm, twice as wide so twice the deflection. But no. WAY OFF! Because the length of the beam is raised to the 4th power, the beam would now deflect 16 times as much as the smaller span. In this example, that's 2 inches not 1/4 inch. That's waaaaaaayyyyyy too much. You must drastically improve the structural strength if you enlarge the hole.

That's the problem when you cut large holes in surfaces. Does that mean that you can't put a large slide in a motor home? NO! It doesn't. What it means is that you have to design the framing around the hole very carefully so that you don't get excessive deflection. This is clearly a job for the most experienced structural engineers, not the new guy on the shop floor in Elkhart, Indiana. Unfortunately it's the latter that often gets the job. So, don't be too quick to blame the slide hardware, gear drives, and other slide components. Often they are mounted to structure that acts like jello, especially under the dynamic loading in a large motor home. Things flex far more than you think. On the other hand, the hardware can also be pieces of cr*p too, just like the structure!

Anyway, the bigger the slide, the more attention to detail is required to minimize slide problems (deflections) down the road. Best bet: If you want a full length slide, do your homework and check the record of the specific manufacturer for the specific year/model you are interested in buying. IME, somebody's always trying to save a buck at your expense.

Chum lee

My Discovery is 11 years old and has a full slide with 3 Power Gear motors. So far no problems. Would be on my bucket list if I was buying a different coach.

We have a 2011 Georgetown with full wall slide. The slide is hydraulic with 2 rams. It has given us no problems. The hydraulic lines however are junk and I will complete their replacement this winter with real hydraulic hoses.

We've had two Newmars with FWS, zero problems.

Having worked for a Helicopter company for 30 years I can tell you every door, window, access panel or cutout weakens the structure. This all has to be designed for by adding structure around the cutout area which adds weight to the aircraft. Large tapered pins could be added to the slide out that would fit into Al or steel fittings that would stabilize and support that large cutout while traveling. I have not seen this in any of the MH's that I have looked at. I would not doubt that hitting potholes would add many more G forces than an air craft would ever see in flight modes