Linix motors squeaks at low speed

[prorider]

Otto Bock Juvo Linix 10km/h, RNet 120A
I noticed squaks at speed <4km/h, only in forward direction, when > 3km/h decrease to total silence.

Is it normal, based on low voltage steering or something wrong with motors?

New powerchair has total distance about 40km.
I am not if it was from new.

On Meyra Optimus 2 at low speed under <1km/h similar.
On Invacare Storm 3 Euro probably never.

[Burgerman]

Depends... Can you record this squeek?

[prorider]

Ok, I can send you now on PM only slow repark sounds, in normal, driving use maybe tomorrow.

[expresso]

YES i have the same squeaks i bet - same motors - i have it on my older chair moving it around in the house slow - not sure if both directions or one - but it does have a squeak

when using it outside you dont hear it - or its not doing it - seems only when its slow


now i got my new chair and guess what - after using it once - it got the same squeak also - who knows what it is - just use the chair and dont worry about it - its one of those things that wont ever be found - could be the brushes - sounds like its coming from the motor wheel area - i wanted to spray something there but then what am i spraying - could be the hub area -

as long as they work

[Burgerman]

Its just the noise these linix motors make. I only worry about other noises... Like bearings or whatever. Brushes always make noise.

[expresso]

its more of a squeak - i think of a little bird


its not a wine as when its in motion - when i went out the other day - depends if out in the open or closed in

left side i heard nothing - rigth side i heard all kinds of sounds - i had to stop and lean over at one point - could be tire what ever

but not the squeak - that i only hear when moving the chair indoors slowly - and i think empty only also - not sure now -

you would think with all this fancy electronics that you would get a indication of a motor issue before it actually stops - which happened to me once - i just got home from a long ride - while lifting the seat to transfer - i just got off the chair and it died -

but it was my fault that i didnt realize the symptoms i was having before also - i was fighting the JS alot - and i though it was the roads sideways or my hand etc,

anyway - that time had nothing to do with the squeak i have now - and on my brand new chair same squeak - seems like the same side also right side

[hank]

Bring back German AMT

[Burgerman]

Those are less reliable!

[rover220]

I've replaced lots of brakes on the linix motors, usually the end cap is full. Of dust, maybe your brake is dragging slightly.

[expresso]

I've replaced lots of brakes on the linix motors, usually the end cap is full. Of dust, maybe your brake is dragging slightly.

did it have the squeak also ?

how would i know if its draggin seems fine - and this is also my brand new chair - same thing - after first use

[Burgerman]

Mine too. On 2 chairs. I think you are all expecting a mechanical thing to be silent. Also the low throttle slow speed is a small pulsewidth at an audible frequency.It cam make your motors "sing". My 61 year old eard dont hear it well. My old dog could. Used to make him stare at the motors and cock his head on one side.

[expresso]

Mine too. On 2 chairs. I think you are all expecting a mechanical thing to be silent. Also the low throttle slow speed is a small pulsewidth at an audible frequency.It cam make your motors "sing". My 61 year old ears dont hear it well. My old dog could. Used to make him stare at the motors and cock his head on one side.

ok i guess its nothing then - i have good hearing sometimes - seems i can hear when no one else can - at night quiet - i hear the silence very good -

[Burgerman]

I dont know what frequency this pulsewidth control the R-Net uses. Motor controllers vary from around 8K to higher like 25K precicely to keep it out of hearing range. Your hi-fi typically works from 20 to 20k hz. Your ears can hear in that range if normal and can hear up to 25k if under 10 years old.

The roboteq has an option to choose for yourself withing a range.

The R-Net like all modern controllers doesent control voltage. It chops the 24V into small pulses. So that a 6V equivelent would be a 25% ON and 75% OFF. It does this at some frequency that the designer chose. The lower the frequency the better the efficiency and the less heat generated.

This is what I think you are all hearing. It causes the motors to be powered in many small pulses at high frequency - your audible squeek.


This shows a 12 battery powered motor. The controller chops the power on off. This happens at say 10k or 15k cycles per second. Can be an audible frequency. Causes the motor to "sing" like a loudspeaker at a single frequency or high note/whistle. Jut not a very loud one..

[expresso]

what ever - i dont recall hearing this years ago - even on my older chair with same motors - at some point it started to squeak like a bird

now the brand new chair - used it once - got home moving it around empty and there you go - i hear it there also now - as long as its not a problem -