Schwintek Madness

[rudyhehn]

Yes, we always do that. Makes no difference, front motor still stalls once during slide out.

[Chuck and Mary Ann]

We went catastrophic as well last week -our slide went totally out of sync and we had to use the override process to get it to retract. There is little worse that watching the slide start in and the bottom on the full wall front go in 4 inches more than the top and the rear be going in normally and them wham, the slide body squares up and resets but chews up the rail teeth! the full wall needs to be reset so an appointment at the Thor factory is inevitable for us. B slide has always worked well for us.

[Scubawise]

See post on Vroom Slide Systems if needed

[Judge]

Originally Posted by Chuck and Mary Ann

We went catastrophic as well last week -our slide went totally out of sync and we had to use the override process to get it to retract. There is little worse that watching the slide start in and the bottom on the full wall front go in 4 inches more than the top and the rear be going in normally and them wham, the slide body squares up and resets but chews up the rail teeth! the full wall needs to be reset so an appointment at the Thor factory is inevitable for us. B slide has always worked well for us.

Read my post...... you would be a good candidate for the Vroom Slide System. If you are out of warranty, I would go the Vroom route versus spending $1500 - $2000 on repairing the Schwintek Mechanism... that could likely fail again.


https://www.thorforums.com/forums/f2...v34-28659.html

[Jimbo56]

I agree with Judge. Also an opportunity for an Arizona road trip!

[Vibeman]

I have a 2020 Hurricane 29m with a full wall slide and the Schwintek system. I am not an apologist for Schwintek, but I think at least some (and maybe even most) of the problems folks have are not really a Schwintek problem, at least not initially. People write something like "one end of the slide did not keep up with the other end while retracting/extending but we were able to push/pull it and get it to go in. We had to do this often and then after a while the cheap junk Schwintek motor/gear/bearing/rack/etc failed" Well, that scenario sounds to me like the very first time it happened something was binding, but the Schwintek was able to overcome it so the root cause, the binding, was not corrected, thereby overloading the Schwintek every time it was used, causing increased wear/damage and eventual catastrophic failure. If the slide did not bind when new, but started binding some time later, then the obvious conclusion is that something changed. It is possible the Schwintek system itself started binding, but I think it is much more likely that in most cases the THOR slide itself starts binding somewhere, causing the eventual Schwintek failure.
So far my slide operates smoothly and consistently every time I use it. I inspect it regularly and maintain it according to the mfg's recommendations. If I ever saw/heard/felt/or smelled anything unusual during inspection or during movement, even one time, I would try to identify the root cause and correct it ASAP. This requires paying close attention to everything, every time the slide moves. Installing a stronger, more robust (and more expensive) mechanism would allow the system to work at a higher load for a longer time, and that is a valid option, but does not really address the root cause, which is an increased load caused by binding somewhere in the system. Finding and fixing the root cause returns the system to it's normal load, which the original mechanism is designed to handle.
The OP wrote: "I find that the rear motor had sheared off the motor retention screw. The screw stops the motor from rising out of the bearing block" I am familiar with the screw and it's purpose and what the OP says is true. That little screw is not designed to take a heavy load and should never have to. The fact that it "sheared off" is only a symptom, not a cause of failure. It is indicative of another problem causing an unintended load on the screw.

Preventive maintenance prevents problems and the damage caused by them.
Reactive maintenance only corrects damage that has already occurred but does not address the root cause of the damage so it can happen again, and again.

[Pete'sMH]

Originally Posted by Vibeman

I have a 2020 Hurricane 29m with a full wall slide and the Schwintek system. I am not an apologist for Schwintek, but I think at least some (and maybe even most) of the problems folks have are not really a Schwintek problem, at least not initially. People write something like "one end of the slide did not keep up with the other end while retracting/extending but we were able to push/pull it and get it to go in. We had to do this often and then after a while the cheap junk Schwintek motor/gear/bearing/rack/etc failed" Well, that scenario sounds to me like the very first time it happened something was binding, but the Schwintek was able to overcome it so the root cause, the binding, was not corrected, thereby overloading the Schwintek every time it was used, causing increased wear/damage and eventual catastrophic failure. If the slide did not bind when new, but started binding some time later, then the obvious conclusion is that something changed. It is possible the Schwintek system itself started binding, but I think it is much more likely that in most cases the THOR slide itself starts binding somewhere, causing the eventual Schwintek failure.

So far my slide operates smoothly and consistently every time I use it. I inspect it regularly and maintain it according to the mfg's recommendations. If I ever saw/heard/felt/or smelled anything unusual during inspection or during movement, even one time, I would try to identify the root cause and correct it ASAP. This requires paying close attention to everything, every time the slide moves. Installing a stronger, more robust (and more expensive) mechanism would allow the system to work at a higher load for a longer time, and that is a valid option, but does not really address the root cause, which is an increased load caused by binding somewhere in the system. Finding and fixing the root cause returns the system to it's normal load, which the original mechanism is designed to handle.

The OP wrote: "I find that the rear motor had sheared off the motor retention screw. The screw stops the motor from rising out of the bearing block" I am familiar with the screw and it's purpose and what the OP says is true. That little screw is not designed to take a heavy load and should never have to. The fact that it "sheared off" is only a symptom, not a cause of failure. It is indicative of another problem causing an unintended load on the screw.



Preventive maintenance prevents problems and the damage caused by them.

Reactive maintenance only corrects damage that has already occurred but does not address the root cause of the damage so it can happen again, and again.

TOTALLY agree. And I’d add that too many folks claim “junk batteries” when they don’t maintain the electrolyte level or keep them charged. Or “crap tires” when they overload them or don’t keep them inflated properly. Fact is that RVs are WAY more maintenance intensive than cars or houses and dealers don’t tell buyers about most of it. And then it takes a while and some unfortunate experiences to get up the learning curve.

[EA37TS]

Originally Posted by Pete'sMH

TOTALLY agree. And I’d add that too many folks claim “junk batteries” when they don’t maintain the electrolyte level or keep them charged. Or “crap tires” when they overload them or don’t keep them inflated properly. Fact is that RVs are WAY more maintenance intensive than cars or houses and dealers don’t tell buyers about most of it. And then it takes a while and some unfortunate experiences to get up the learning curve.

[EA37TS]

Interesting article

https://lifeonroute.com/how-rv-slide-outs-work/

and video

https://m.youtube.com/watch?v=nYDBvuWnHrs

[Judge]

Originally Posted by Vibeman

I have a 2020 Hurricane 29m with a full wall slide and the Schwintek system. I am not an apologist for Schwintek, but I think at least some (and maybe even most) of the problems folks have are not really a Schwintek problem, at least not initially. People write something like "one end of the slide did not keep up with the other end while retracting/extending but we were able to push/pull it and get it to go in. We had to do this often and then after a while the cheap junk Schwintek motor/gear/bearing/rack/etc failed" Well, that scenario sounds to me like the very first time it happened something was binding, but the Schwintek was able to overcome it so the root cause, the binding, was not corrected, thereby overloading the Schwintek every time it was used, causing increased wear/damage and eventual catastrophic failure. If the slide did not bind when new, but started binding some time later, then the obvious conclusion is that something changed. It is possible the Schwintek system itself started binding, but I think it is much more likely that in most cases the THOR slide itself starts binding somewhere, causing the eventual Schwintek failure.
So far my slide operates smoothly and consistently every time I use it. I inspect it regularly and maintain it according to the mfg's recommendations. If I ever saw/heard/felt/or smelled anything unusual during inspection or during movement, even one time, I would try to identify the root cause and correct it ASAP. This requires paying close attention to everything, every time the slide moves. Installing a stronger, more robust (and more expensive) mechanism would allow the system to work at a higher load for a longer time, and that is a valid option, but does not really address the root cause, which is an increased load caused by binding somewhere in the system. Finding and fixing the root cause returns the system to it's normal load, which the original mechanism is designed to handle.
The OP wrote: "I find that the rear motor had sheared off the motor retention screw. The screw stops the motor from rising out of the bearing block" I am familiar with the screw and it's purpose and what the OP says is true. That little screw is not designed to take a heavy load and should never have to. The fact that it "sheared off" is only a symptom, not a cause of failure. It is indicative of another problem causing an unintended load on the screw.

Preventive maintenance prevents problems and the damage caused by them.
Reactive maintenance only corrects damage that has already occurred but does not address the root cause of the damage so it can happen again, and again.

I will agree with some of your points but respectfully disagree with other points.

I’m very meticulous when it comes to maintenace, inspection and watching how things are performing.

If you look at the higher-end coaches with large and heavy full wall slides, they use a hydraulic slide mechanismsp or in some cases a cable system that pulls from all four-corners to keep the force applied to the top and bottom of slide as equal as possible during movement.

In my case, my 23’ slide with probably over 1000 lbs of items installed on it (residential fridge, recliners, full kitchen, bedroom wardrobe, TV, cabinets) and even heavier when loaded puts an excessive amount of strain on the motor mounting mechanism.

With my slide moving evenly and without binding, I could peel the inside bulb seals back and watch the motors moving from the extreme torque during retraction. It is inevitable that the force placed on the 1/8” retaining screw will cause it to eventually shear off or begin to bend the aluminum plate it screws through over time until the screw pulls away from the motor.

So while I agree that issues with the retaining screw are a symptom of a problem, the problem is the Schwintek system is fine for smaller lighter slides but big/ heavy slides are a problem for the mechanism over time.

When I compare the design of the Schwintek mechanism to the Vroom mechanism and also watch how much smoother and quieter the motors are when the slide is operated, I’m convinced it is superior in design and materials and far more robust for a large and heavy slide.

Will some people be lucky and never experience an issue? Of course they will….. my slide held up for almost two seasons of regular use.

But when the time comes that it does fail as it does in many cases, spending $2K on the same Schwintek mechanism and hoping for better longevity and reliability is the definition of insanity.

[wrapped]

After traveling I run the slides out 6 inches then back in and hold for 6 seconds in case the have moved from traveling.

[Judge]

Originally Posted by wrapped

After traveling I run the slides out 6 inches then back in and hold for 6 seconds in case the have moved from traveling.

Slide locks will eliminate the need to do that and take stress off the H-Column during tight turns (exit ramps, etc.).

Most motors becoming out of sync are due to not holding the Extend / Retractbutton for 3 - 5 seconds once the motors stop.

[Chateau_Nomad]

If I understand correctly, Schwintek engineers and manufactures the slide components, but Thor employees install those components? If that's the case, I'm sure Schwintek has developed EXACT install criteria based on weight and loading.

It seems that many slides perform exactly as designed (mine included, so far) but others have problems from day one. Tracks being installed out of parallel, or "keystoning" of the slide room itself could greatly affect proper operation of components. These faults are NOT a Schwintek issue, but could cause severe wear or failure of the Schwintek components.

My point is that maybe the problems stem from improper installation and/or loading... similarly you can't blame a tire for wearing abnormally because of poor alignment and/or inflation.

JMHO... something to think about.

[Judge]

Originally Posted by Chateau_Nomad

If I understand correctly, Schwintek engineers and manufactures the slide components, but Thor employees install those components? If that's the case, I'm sure Schwintek has developed EXACT install criteria based on weight and loading.

It seems that many slides perform exactly as designed (mine included, so far) but others have problems from day one. Tracks being installed out of parallel, or "keystoning" of the slide room itself could greatly affect proper operation of components. These faults are NOT a Schwintek issue, but could cause severe wear or failure of the Schwintek components.

My point is that maybe the problems stem from improper installation and/or loading... similarly you can't blame a tire for wearing abnormally because of poor alignment and/or inflation.

JMHO... something to think about.

For what its worth….

I inspected my tracks regularly and there was no abnormal wear. The tracks on my SV34 were painted black so it made it very easy to spot any abnormal wear.

And some other food for thought…..

Tiffin is now sending some of its customers to Vroom Slide Systems to replace Schwintek Systems that have been problematic. That certainly makes an interesting statement.

[Chateau_Nomad]

Originally Posted by Judge

For what its worth….

I inspected my tracks regularly and there was no abnormal wear. The tracks on my SV34 were painted black so it made it very easy to spot any abnormal wear.

And some other food for thought…..

Tiffin is now sending some of its customers to Vroom Slide Systems to replace Schwintek Systems that have been problematic. That certainly makes an interesting statement.

Consider the build pressures (read: rushed) at Thor... are the slide boxes being built true and square? Are the techs rushing to slap the tracks on... are they really parallel?

Conversely, an aftermarket outfit who is not (currently) under the gun to push "good enough" out the door has an incentive (and advantage) to take the time to "do it right".

Maybe old fashioned competition here could see Thor (Tiffin) award a contract to the Vroom slide manufacturer? The other side of that is... who would then install the systems - Thor or Vroom?

[EA37TS]

Schwintek is good for small slides with little weight. Schwintek is not good for full wall slides or slides loaded with heavy furniture or appliances. All my Schwintek slides have been under 13 feet and never had a problem.

[Vibeman]

Originally Posted by Judge

I will agree with some of your points but respectfully disagree with other points.

I’m very meticulous when it comes to maintenace, inspection and watching how things are performing.

If you look at the higher-end coaches with large and heavy full wall slides, they use a hydraulic slide mechanismsp or in some cases a cable system that pulls from all four-corners to keep the force applied to the top and bottom of slide as equal as possible during movement.

In my case, my 23’ slide with probably over 1000 lbs of items installed on it (residential fridge, recliners, full kitchen, bedroom wardrobe, TV, cabinets) and even heavier when loaded puts an excessive amount of strain on the motor mounting mechanism.

With my slide moving evenly and without binding, I could peel the inside bulb seals back and watch the motors moving from the extreme torque during retraction. It is inevitable that the force placed on the 1/8” retaining screw will cause it to eventually shear off or begin to bend the aluminum plate it screws through over time until the screw pulls away from the motor.

So while I agree that issues with the retaining screw are a symptom of a problem, the problem is the Schwintek system is fine for smaller lighter slides but big/ heavy slides are a problem for the mechanism over time.

When I compare the design of the Schwintek mechanism to the Vroom mechanism and also watch how much smoother and quieter the motors are when the slide is operated, I’m convinced it is superior in design and materials and far more robust for a large and heavy slide.

Will some people be lucky and never experience an issue? Of course they will….. my slide held up for almost two seasons of regular use.

But when the time comes that it does fail as it does in many cases, spending $2K on the same Schwintek mechanism and hoping for better longevity and reliability is the definition of insanity.

As I said I am not an apologist for Schwintek, it is quite possible the system is under designed even for some of the Schwintek approved applications it is installed in. It could also be due to Thor putting it into an application where it is very near maximum capability when new. These type of installations would obviously tend to shorten the life of the components. Notice in my original post I said "SO FAR my slide operates smoothly" but in spite of my best efforts it could still fail tomorrow. Your experience would seem to bear this out also, as you are careful as well and your slide failed anyway.

I was trying to make the point that careful operation, adequate lubrication where needed, and addressing small issues before they become big will go a long way to prolonging the life of any machine, and ignoring those simple tasks can bring on problems quickly. I don't know if the slide in my Hurricane is heavier than the one in your Magnitude, but I do know it is heavy. I think the weight of the slide is not really the problem, though. It is how much friction is created when it is moving and how much motor torque is required to overcome that friction. Even if that slide weighed 2000# you could push it in and out with one hand providing the rollers and bearings it was sitting on were adequately designed, sized, installed, and aligned. Of course those bearings and their supports would probably add a LOT of weight to the coach! Cost vs performance is always a balancing act.

I don't think we really disagree on very much. Bigger, heavier, stronger, components for any machine will tend to last longer than smaller, lighter, and weaker components doing the same work. Manufacturers want to keep costs down, therefore come down on the side of lighter and cheaper whenever possible. Sometimes they go too far. I'm just saying that even if you have a marginal system to begin with pro-active maintenance can go a long way to keeping it functioning correctly for it's expected life.

One small note. I don't believe that small retaining screw is supposed to take ANY load during normal operation. There are 4 pins on the bottom of the motor that keep it from turning, not the screw. The screw just keeps the pins from working up out of their holes. Now wear or misalignment (or other things) could cause upward pressure on the screw in which case the screw would not hold for very long.

[Judge]

Originally Posted by Vibeman

One small note. I don't believe that small retaining screw is supposed to take ANY load during normal operation. There are 4 pins on the bottom of the motor that keep it from turning, not the screw. The screw just keeps the pins from working up out of their holes. Now wear or misalignment (or other things) could cause upward pressure on the screw in which case the screw would not hold for very long.

That is correct..... the motor is supposed to be centered by the four allen screws that protrude from the motor gearbox at the shaft end. They are also supposed to prevent the motor from twisting under load and theoretically not putting any load on the retaining screw.

However, because the motor is not securely held down vertically (that is the job of the retaining screw), the motor appears to have some lifting forces as it reaches its high-torque limits when moving the slide.

As the motor attempts to lift under load, it is putting force on the retaining small retaining screw. Given enough force it starts to damage and weaken the retaining screw. Again, with smaller / lighter slides, there is much less torque and upward force so it is not much of an issue but it is a different story with a large / heavy slide.

I have even had an independent LCI repair shop tell me they have seen the aluminum bend where the retaining screw is threaded into the motor. Now sometimes this is caused from obstructions, misaligned rollers, etc. but they also said it can happen with enough use of big slides.

As I've said, if you pull back the Bulb Seal inside the coach and observe the motor on a larger / heavier slide, you can see some movement when it is under its highest load.

If the four allen screws used for alignment were actually four vertical mounting screws, I think the Schwintek Mechanism could be more reliable. However, they tried to make the motor easy to replace in the field by not bolting it down and that just causes longer term wear and tear.

The two weaknesses with the Schwintel Mechanism is the motor mounting approach and a V-roller deisgn that is inadeqaute for a large / heavy slide.

The VRoom Mechanism addresses both of these deisgn limitations by incorporating a 4-point vertical motor mount and using high load bearings instead of a V-roller. Then they add a much better gear and track engagement.

Now I do agree that poor installation of the components like track alignment, mounting, loose screws, etc. will accelerate the problems people experience.

Another weakness of the Schwintek system from a Thor perspective is they use screws for the track mounting. I've read many posts about missing and loosening screws that wreaked havoc on slides. Some of this is because they over-tighten the screws at the factory. Vroom is using heavy duty rivets to secure the tracks so loosening screws is not an issue.

I also know from talking with LCI that the tolerances for the Scwintek Mechanism are 1/8" for all aspects of the slide and mechanism. Any of the components not within that spec will result in abnormal operation, wear and potential failure. From my perspective, needing an 1/8" tolerance for these coaches is wishful thinking.

One final word..... I also think that LCI's recommendation of holding the Extend / Retract button for 3 seconds to keep the motors synced contribute to this problem. When the motors stop because the slide is fully opened or fully closed and voltage is still being applied, the 500:1 motor is creating a very strong force on the entire motor mounting mechanism.

Vroom is redesigning the encoder on the top of the motor and the Controller to have more intelligence for keeping the slide motors synced so you don't have to hold the button for 3 seconds after the motors stop moving.

My goal here is just to provide information and give people options. After having the Thor Factory Service Center inspect my slide a year ago when I had it there for service at the end of my warranty and then talking to an independent LCI authorized shop when my slide failed during our recent trip, I decided spending $1000 - $2000 to fix the same system that might fail again made no sense.

[EA37TS]

Originally Posted by Judge

That is correct..... the motor is supposed to be centered by the four allen screws that protrude from the motor gearbox at the shaft end. They are also supposed to prevent the motor from twisting under load and theoretically not putting any load on the retaining screw.

However, because the motor is not securely held down vertically (that is the job of the retaining screw), the motor appears to have some lifting forces as it reaches its high-torque limits when moving the slide.

As the motor attempts to lift under load, it is putting force on the retaining small retaining screw. Given enough force it starts to damage and weaken the retaining screw. Again, with smaller / lighter slides, there is much less torque and upward force so it is not much of an issue but it is a different story with a large / heavy slide.

I have even had an independent LCI repair shop tell me they have seen the aluminum bend where the retaining screw is threaded into the motor. Now sometimes this is caused from obstructions, misaligned rollers, etc. but they also said it can happen with enough use of big slides.

As I've said, if you pull back the Bulb Seal inside the coach and observe the motor on a larger / heavier slide, you can see some movement when it is under its highest load.

If the four allen screws used for alignment were actually four vertical mounting screws, I think the Schwintek Mechanism could be more reliable. However, they tried to make the motor easy to replace in the field by not bolting it down and that just causes longer term wear and tear.

The two weaknesses with the Schwintel Mechanism is the motor mounting approach and a V-roller deisgn that is inadeqaute for a large / heavy slide.

The VRoom Mechanism addresses both of these deisgn limitations by incorporating a 4-point vertical motor mount and using high load bearings instead of a V-roller. Then they add a much better gear and track engagement.

Now I do agree that poor installation of the components like track alignment, mounting, loose screws, etc. will accelerate the problems people experience.

Another weakness of the Schwintek system from a Thor perspective is they use screws for the track mounting. I've read many posts about missing and loosening screws that wreaked havoc on slides. Some of this is because they over-tighten the screws at the factory. Vroom is using heavy duty rivets to secure the tracks so loosening screws is not an issue.

I also know from talking with LCI that the tolerances for the Scwintek Mechanism are 1/8" for all aspects of the slide and mechanism. Any of the components not within that spec will result in abnormal operation, wear and potential failure. From my perspective, needing an 1/8" tolerance for these coaches is wishful thinking.

One final word..... I also think that LCI's recommendation of holding the Extend / Retract button for 3 seconds to keep the motors synced contribute to this problem. When the motors stop because the slide is fully opened or fully closed and voltage is still being applied, the 500:1 motor is creating a very strong force on the entire motor mounting mechanism.

Vroom is redesigning the encoder on the top of the motor and the Controller to have more intelligence for keeping the slide motors synced so you don't have to hold the button for 3 seconds after the motors stop moving.

My goal here is just to provide information and give people options. After having the Thor Factory Service Center inspect my slide a year ago when I had it there for service at the end of my warranty and then talking to an independent LCI authorized shop when my slide failed during our recent trip, I decided spending $1000 - $2000 to fix the same system that might fail again made no sense.

The way I understand this is the Vroom system is a better rack and pinion suitable for heavy loads. Is that correct?

[Judge]

Originally Posted by EA37TS

The way I understand this is the Vroom system is a better rack and pinion suitable for heavy loads. Is that correct?

That is correct Dave...... I can tell a distinct difference watching and listening to my slide extending and retracting with the Vroom Mechanism as compared to the original Schwintek Mechanism.

The overall design plus use of needle and ball bearings offer far less resistance to movement so it is much smoother.

I think this is what allows for moving the slide easier should a motor fail and why they were able to add the ability to loosen a nut to disengage the shaft from the motor so you could push the slide in manually or use a wrench on the bottom of the shaft to move the slide in.

I personally think pure motor failures should be far less because they are under less load when moving the slide.