Not my video but got me wonder what causes the tub to hit the sides of the machine. I noticed this keeps happening on newer machines.
Tub banging sides- what causes it?
- Thread starter Chetlaham
- Start date
phillymatt53
Well-known member
POS!
henene4
Well-known member
Floating tub suspensions are usually paired with higher speed spins.
They are (probably) somewhat cheaper than other suspension designs, but from a purely engineering standpoint, low vibration at high spin speeds is the goal.
With an unbalanced load spinning, the tub is constantly changing direction.
A change in direction always means a kind of acceleration (not in the "go faster" sense, but in the physics sense).
As the tub spins slow, there is more time of the tub traveling in the same approximate direction.
As it speeds up, there is less time for the tub to travel in that direction.
The mass of the tub stays the same.
Force is mass times acceleration.
That means that at lower speed, the force is less (the tub has more time to change direction, so acceleration is less) but the tub has a lot of time to travel in a general direction.
That means the amplitude if travel is larger.
If an OOB system isn't fast enough to respond, that can lead to the tub hitting the cabinet.
However, at higher speeds, the tub has to change direction quicker - acceleration goes up.
That means force goes up.
BUT at some point the tub is changing direction so fast it simply has no time to travel enough into a specific direction to make contact with the cabinet.
Now, on the cabinet side, any force transmitted into it makes the cabinet move a bit. Any force always requires equal opposite force, and that opposite force results in movement in the cabinet.
And movement in the cabinet is vibration which is generally a big source of noise during high speed spins.
(You'll see the cabinet, despite being very "thin" does not move much.)
So, if the suspension is "soft" (aka low resistance) any force on the cabinet side can only get so big. Thus, vibration stays low.
And when forces get high (high spin speeds) you need to limit any force as much as possible.
The most extreme example is commercial hard mount washers.
You can just not have any movement at all. But the forces have to go somewhere. And that's a massive concrete slab in that case.
You can create very high spin speed machines that way aswell (see Milnor) - but why should you?
These TLs are the opposite - they use basically maximum movement. That allows to get very high spin speed with minimal opposite force.
But the danger is that maximum movement leads to "physical interference" - aka collision between tub and cabinet.
That should in theory be offset by OOB sensing - but that has it's limits as well...
They are (probably) somewhat cheaper than other suspension designs, but from a purely engineering standpoint, low vibration at high spin speeds is the goal.
With an unbalanced load spinning, the tub is constantly changing direction.
A change in direction always means a kind of acceleration (not in the "go faster" sense, but in the physics sense).
As the tub spins slow, there is more time of the tub traveling in the same approximate direction.
As it speeds up, there is less time for the tub to travel in that direction.
The mass of the tub stays the same.
Force is mass times acceleration.
That means that at lower speed, the force is less (the tub has more time to change direction, so acceleration is less) but the tub has a lot of time to travel in a general direction.
That means the amplitude if travel is larger.
If an OOB system isn't fast enough to respond, that can lead to the tub hitting the cabinet.
However, at higher speeds, the tub has to change direction quicker - acceleration goes up.
That means force goes up.
BUT at some point the tub is changing direction so fast it simply has no time to travel enough into a specific direction to make contact with the cabinet.
Now, on the cabinet side, any force transmitted into it makes the cabinet move a bit. Any force always requires equal opposite force, and that opposite force results in movement in the cabinet.
And movement in the cabinet is vibration which is generally a big source of noise during high speed spins.
(You'll see the cabinet, despite being very "thin" does not move much.)
So, if the suspension is "soft" (aka low resistance) any force on the cabinet side can only get so big. Thus, vibration stays low.
And when forces get high (high spin speeds) you need to limit any force as much as possible.
The most extreme example is commercial hard mount washers.
You can just not have any movement at all. But the forces have to go somewhere. And that's a massive concrete slab in that case.
You can create very high spin speed machines that way aswell (see Milnor) - but why should you?
These TLs are the opposite - they use basically maximum movement. That allows to get very high spin speed with minimal opposite force.
But the danger is that maximum movement leads to "physical interference" - aka collision between tub and cabinet.
That should in theory be offset by OOB sensing - but that has it's limits as well...
henene4
Well-known member
I did not watch the video past 2min that is correct.
But the motor does cut out at that point.
That almost looks like some weird resonance happening there - but it also does collide in the early ramp up phase.
And the TC5 spins at 710.
The TRs do spin at 820 - but they have a variable speed motor, with an inverter - and thus most likely OOB sensing & control.
BTW don't EVER do what they are doing towards the end there.
Don't ever try to stop the tub from moving with your hand.
You do NOT have the strength in your hand to stop 40lbs or so moving at that speed.
All that's gonna happen is your hand being crushed or your skin being ripped by any sharp point.
But the motor does cut out at that point.
That almost looks like some weird resonance happening there - but it also does collide in the early ramp up phase.
And the TC5 spins at 710.
The TRs do spin at 820 - but they have a variable speed motor, with an inverter - and thus most likely OOB sensing & control.
BTW don't EVER do what they are doing towards the end there.
Don't ever try to stop the tub from moving with your hand.
You do NOT have the strength in your hand to stop 40lbs or so moving at that speed.
All that's gonna happen is your hand being crushed or your skin being ripped by any sharp point.
Right- but my point still stands- Speed Queen with their milk stool suspension provides superior balance with superior vibration mitigation.
Hanging suspensions are more to cut cost than anything else.
There is some weird resonance going on I think. Very odd.
henene4
Well-known member
Again - never said you can't design a high speed system different ways. Actually explicitly said it is done.
Just said that this way is not inherently wrong in any way.
And everybody acts like cost cutting is in itself bad.
If something gives you an equivalent outcome for less money nobody would complain.
It's an issue when longevity and performance (in this case noise) suffer.
The issue is not a floating suspension by itself.
The issue is a floating tub design with bad/slow OOB detection and sub-par component quality.
Just said that this way is not inherently wrong in any way.
And everybody acts like cost cutting is in itself bad.
If something gives you an equivalent outcome for less money nobody would complain.
It's an issue when longevity and performance (in this case noise) suffer.
The issue is not a floating suspension by itself.
The issue is a floating tub design with bad/slow OOB detection and sub-par component quality.
The difference is that people are not getting an equivalent outcome for less money. People are complaining. They are getting less than they used to get. Hanging a suspension on a top load washer has inherent limitations that other methods like sliding tripods and milk stools do not. In fact good suspensions were able to do away with electrical balance sensing and detection.
henene4
Well-known member
And the old school designs have inherent limitations as well.
They are bulky, heavy, use a lot of materials...
Again:
Never said this is acceptable.
Never said one is necessarily better than the other.
But makeing nuanced points has long since been a useless attempt on here...
I'll check out of this thread, have fun!
They are bulky, heavy, use a lot of materials...
Again:
Never said this is acceptable.
Never said one is necessarily better than the other.
But makeing nuanced points has long since been a useless attempt on here...
I'll check out of this thread, have fun!
Direct drive top loads used minimal material in comparison and were one of the best suspensions ever built.
I get the points you are trying to make, however at the same time you can only take a poor design (that is fundamentally flawed to begin with) so far.
There gets a point when cheap is too cheap.
I get the points you are trying to make, however at the same time you can only take a poor design (that is fundamentally flawed to begin with) so far.
There gets a point when cheap is too cheap.
GE top load washer, tub assembly, banging around
Chet, it’s useless to post a silly video like that we have no idea what’s in the tub. He may have a bowling ball in it for all we know.
You have predetermined ideas of what you like and don’t like and that’s good but as a servicer, we never get calls like that. The machine is banging around on heavily used VMW style whirlpool built top loaders. We occasionally get a call with the machines, not spinning well, and we put a new strut kit in it but the hanging type suspension is here to stay. It’s a genius suspension system that allows machines to spin up to 1000 RPMs and some cases or a little more, which was not possible with the old style suspension systems without excessive vibration.
If you wanted to see excessive vibration, you should’ve been around back in the day when Frigidaire Unimatics we’re jumping all over the place GE filter flow machines had terrible problems with banging about one supposedly went through a wall in a Levett built home up in Bowie Maryland years ago, and look at all the complaints that have been on this site about Maytag washers that people couldn’t keep still, so yes you can always find an example of something that’s not working well, but it’s not because it’s a new design that you don’t like.
John L
Chet, it’s useless to post a silly video like that we have no idea what’s in the tub. He may have a bowling ball in it for all we know.
You have predetermined ideas of what you like and don’t like and that’s good but as a servicer, we never get calls like that. The machine is banging around on heavily used VMW style whirlpool built top loaders. We occasionally get a call with the machines, not spinning well, and we put a new strut kit in it but the hanging type suspension is here to stay. It’s a genius suspension system that allows machines to spin up to 1000 RPMs and some cases or a little more, which was not possible with the old style suspension systems without excessive vibration.
If you wanted to see excessive vibration, you should’ve been around back in the day when Frigidaire Unimatics we’re jumping all over the place GE filter flow machines had terrible problems with banging about one supposedly went through a wall in a Levett built home up in Bowie Maryland years ago, and look at all the complaints that have been on this site about Maytag washers that people couldn’t keep still, so yes you can always find an example of something that’s not working well, but it’s not because it’s a new design that you don’t like.
John L
I doubt people are putting bowling balls in these machines to prove a point. Based on the dialogue in the video, it appears to be a service call where the machine is routinely exhibiting this behavior on various loads.
You might not be getting such calls, however others are.
I do not dispute that GE filter flos were walking, they had one the worst suspensions at handling slightly off balance loads. Other designs were terrible as well. Maytag was great but had to be perfectly level and adjusted properly.
However, Speed Queen, is superior to most every other suspension including hanging suspensions. I know because the Speed Queen I own despite being on a wooded first floor does not walk, shake, vibrate, transmit noise, or anything else like previous washers I've owned. You can be in the room across from the washer with the perpendicular wood beams running beneath you and you don't feel a thing. No washer is better at going unnoticed.
You might not be getting such calls, however others are.
I do not dispute that GE filter flos were walking, they had one the worst suspensions at handling slightly off balance loads. Other designs were terrible as well. Maytag was great but had to be perfectly level and adjusted properly.
However, Speed Queen, is superior to most every other suspension including hanging suspensions. I know because the Speed Queen I own despite being on a wooded first floor does not walk, shake, vibrate, transmit noise, or anything else like previous washers I've owned. You can be in the room across from the washer with the perpendicular wood beams running beneath you and you don't feel a thing. No washer is better at going unnoticed.
Speed Queens are made of actual metal, not tinfoil. Also, no matter what the design particulars, there will always be a period of time during spin-up or down when the speed has to pass through a resonant phase that may be outside the suspension's ability to control. A bang or so is probably normal for some washers, constant ruckus is a bigger issue...
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