Extractor wobble

[Jules59]

Tension and movement are the two complementary mechanisms that allow a body to cope with a force.
In the case of an extractor, the force is induced by the axis of rotation (motor). The honey is extracted as a consequence of the centrifugal force generated, while the support and the extractor suffer tension in their material. If the elements are unbalanced in the plane of rotation, a torsion force is produced that tends to make the extractor rotate. If it has braked wheels, this tension accumulates and causes vibration in the legs. If the wheels are not braked, the extractor will rotate on the vertical axis. For this reason, an elastic is installed at the bottom of the legs, which, by allowing a small displacement, reduces the tension of the legs, damping vibration due to torsion.

Centrifugal or lack of centripetal force ?
Can of worms - Centrifugal force - Wikipedia

 

[fian]

Centrifugal or lack of centripetal force ?
Can of worms - Centrifugal force - Wikipedia

It is perfectly understandable what I mean in an informal language but if you prefer a technical language then I accept the correction.

 

[robmort]

To reduce wobble when unloaded it helps if you can balance the cage with a small (stainless steel) weight attached somehere. Support the cage horizontally on a knife edge at each end and fix the weight so the cage doesn't want to settle in one position.

In any case rollers on the feet will help see A platform for the extractor

 

[Ian123]

As has been said previously pay attention when loading it really becomes second nature. Start slowly before building up speed.

I bolt mine to half a sheet of ply that you can stand on whilst extracting, there is no wobble

 

[blackcloud]

But that means the machine is absorbing the stresses itself.
If you can get it loaded well enough to stay still on castors then the stresses are released without long term damage to leg joints and bearings
My machine has to see out my beekeeping days....

 

[Sutty]

Castors in a larger dish-shaped castor cup could be a good solution - let it move but settle back to the same spot.

 

[Stiffy]

Occasionally get a ‘wobble ‘ from our extractor, which mostly down to not adding frames equally. A piece of horse stable mat stops the extractor moving dancing around the tiled floor
https://www.slip-not.co.uk/products...NZFysU90JyxHukMH6gO1vaMwHaqh_B34aAjO4EALw_wcB

 

[Wilco]

Occasionally get a ‘wobble ‘ from our extractor, which mostly down to not adding frames equally. A piece of horse stable mat stops the extractor moving dancing around the tiled floor
https://www.slip-not.co.uk/products...NZFysU90JyxHukMH6gO1vaMwHaqh_B34aAjO4EALw_wcB

Was wondering about this material.

@robmort I like the idea of a counterweight if I can locate the right place to fix it.

Thanks all for replies thus far.

 

[Antipodes]

To reduce wobble when unloaded it helps if you can balance the cage with a small (stainless steel) weight attached somehere. Support the cage horizontally on a knife edge at each end and fix the weight so the cage doesn't want to settle in one position.

In any case rollers on the feet will help see A platform for the extractor

Yep, my thoughts exactly and as per Blackcloud in post #19. Perhaps use a stainless steel pipe clamp as a weight?
The balancing of a propellor is not dissimilar, so this video might help demonstrate.

 

[Antipodes]

which runs absolutely still at top speed when unloaded.

Yep. Nicely balanced.

 

[WoodenBeam]

Hi all,

I was given one of the Maisemore budget electric extractors last Autumn. It sat in the box until the weekend. I've fully assembled it today and am trialling extraction. Whilst I appreciate not having to turn a handle, it seems to wobble a lot to the point I don't feel happy to ramp up the speed so my extraction is rather slow.

I suspect it is slightly off centre straight from the factory as it wobbled even when unloaded. Loaded, despite being fairly well balanced, I can't turn it beyond about 45% power without it going walkies. However, I've little experience with operating electric extractors.

Those of you with electric extractors, do you find this is normal and would a triangular base with casters likely solve the issue?

Do you find your extractors also wobble when unloaded?

Ensure the surface you’ve sat your extractor on is level. We’ve a very minimal slope to a central drain & that makes a difference - a 2mm plate under a leg levels things up and rebalances.

 

[drex]

Like Ian above, it is the loading of frames that is important. I put full frames opposite each other and similarly for half full. If they wobble at half speed, I keep that speed and the wobble usually settles ( unless I have overlooked uncapping one side of a frame - yes, it does happen) and I then speed up. I don't have castors etc and my machine dances rarely

 

[Jules59]

It is perfectly understandable what I mean in an informal language but if you prefer a technical language then I accept the correction.

Indeed, nearly everyone has a simple idea what centrifugal force is; which works fine in day to day practical terms. But the scientific reality is rather different and more complicated. A bit like "how does a bicycle turn" ? Its not what most people think.
Back to extractors - what about fixing the feet to heavy lengths of wood to act as mass dampers?

 

[Gilberdyke John]

Indeed, nearly everyone has a simple idea what centrifugal force is; which works fine in day to day practical terms. But the scientific reality is rather different and more complicated. A bit like "how does a bicycle turn" ? Its not what most people think.
Back to extractors - what about fixing the feet to heavy lengths of wood to act as mass dampers?

That will result in stress in the legs and their attachment points to the barrel of the extractor. For thin stainless steel barrels could ultimately result in cracking if such stress hasn't been factored in at the design stage (which I very much doubt).
Has anyone explored using rubber feet on the legs?

 

[Hedgerow Honey]

Our fritz arrived with rubber feet, but now it is firmly bolted to the floor, haven't got the time to mess about getting it perfectly balanced when loading and like always its a compromise.
Not had any issues with the legs or drum yet.

 

[fian]

That will result in stress in the legs and their attachment points to the barrel of the extractor. For thin stainless steel barrels could ultimately result in cracking if such stress hasn't been factored in at the design stage (which I very much doubt).
Has anyone explored using rubber feet on the legs?

rubber feet, isn't that similar to the approach I made?

 

[Ian123]

That will result in stress in the legs and their attachment points to the barrel of the extractor. For thin stainless steel barrels could ultimately result in cracking if such stress hasn't been factored in at the design stage (which I very much doubt).
Has anyone explored using rubber feet on the legs?

Most commercial guys I’ve seen simply bolt to the floor and obviously balance as much as possible. I’ve seen some of those rubber door stops drilled out and placed between.

 

[JamezF]

A bit like "how does a bicycle turn" ? Its not what most people think.

That's an amazing bit of physics to get one's head around. I found a YT video some time back where someone riding a bicycle was told to turn in a specific direction at the same time as the handlebars were remotely "locked" so they wouldn't turn the opposite way. The bike was all but unrideable.

The same is true of motorcycles of course, and "countersteering" is a fundamental part of riding fast, tight bends such as are found at race circuits. I could never get my head around doing it intentionally though.

James

 

[Sutty]

That's an amazing bit of physics to get one's head around. I found a YT video some time back where someone riding a bicycle was told to turn in a specific direction at the same time as the handlebars were remotely "locked" so they wouldn't turn the opposite way. The bike was all but unrideable.

The same is true of motorcycles of course, and "countersteering" is a fundamental part of riding fast, tight bends such as are found at race circuits. I could never get my head around doing it intentionally though.

James

Countersteering becomes much more obvious on a motorbike. On a push bike most people aren't aware they do it. If you make them think how they are steering & they don't believe they do it, they are likely to fall off!