One of my wheelchair motors overheats and stops working

[sophiecentaur]

Used to be a brand new car cost a couple months's of an average workingman's salary . Now it's about a year's. We're going backward.

Things are different around the World, I think. I remember, when I was a teenager, a new family saloon was about £600 and a teacher earned about £800 a year. A teacher starts at around £23k now and you can get a pretty nice new car for that. For your £23k, you get loads of other stuff bolted on that they didn't have in 1963. Plus, a vastly higher percentage of families have cars nowadays.
In the US, you have had very stagnant salaries for a long time; much longer than we. in UK have had to put up with. I am actually amazed that you haven't had French - style demonstrations about work pay and conditions. Politics and human nature are much harder to analyse than an Electric Scooter.
Car manufacturers make very little profit, if any, on their new cars. All the profit is in spare parts and 'Finance', so I'm told. It is hard to make comparisons but a TV was incredibly expensive in the UK in the 1950s but a big new LED screen can cost less than one month's pay for many people. The Mobility scooter is now within most people's range (wage earners). That's amazing for many people who would be house bound, otherwise.

I’m told that the ailerons and other such flaps on even the most modern aircraft are still moved by linkage, cable and pulley. Why might that be, do you think?

 

[Stephenk53]

Things are different around the World, I think. I remember, when I was a teenager, a new family saloon was about £600 and a teacher earned about £800 a year. A teacher starts at around £23k now and you can get a pretty nice new car for that. For your £23k, you get loads of other stuff bolted on that they didn't have in 1963. Plus, a vastly higher percentage of families have cars nowadays.
In the US, you have had very stagnant salaries for a long time; much longer than we. in UK have had to put up with. I am actually amazed that you haven't had French - style demonstrations about work pay and conditions. Politics and human nature are much harder to analyse than an Electric Scooter.
Car manufacturers make very little profit, if any, on their new cars. All the profit is in spare parts and 'Finance', so I'm told. It is hard to make comparisons but a TV was incredibly expensive in the UK in the 1950s but a big new LED screen can cost less than one month's pay for many people. The Mobility scooter is now within most people's range (wage earners). That's amazing for many people who would be house bound, otherwise.

At this rate we may as well move these posts into a new thread, but anyway my mom is a Special Education Teachers assistant and makes 15k US dollars a year, we live happily but I think it should be increased given she often runs the classroom herself with the teacher out of the room and she directs other TAs in the room since the class is highly disabled several TAs are required at all times

 

[sophiecentaur]

At this rate we may as well move these posts into a new thread, but anyway my mom is a Special Education Teachers assistant and makes 15k US dollars a year, we live happily but I think it should be increased given she often runs the classroom herself with the teacher out of the room and she directs other TAs in the room since the class is highly disabled several TAs are required at all times

It's much the same for teaching support staff in UK. "Happily" has more to say about your attitudes to the situation than how acceptable it should be considered by Society.
But, apart from comparing the car prices to income, yes, the thread is lurching a bit (to the left`?).

 

[sysprog]

Invacare service manual and parts catalog - find your exact model ?http://www.invacare.co.uk/sites/uk/files/product_documents/fd17eeac3b23549bb92035e6b4c8910fda3649bc_558bb3d29301cc5c6a8b9c74.pdfhttp://www.invacare.co.uk/sites/uk/files/product_documents/a60e2c71cd2d8f0a3e89fe1514da8daa163acd19_MIRAGE_invacare_EN_2016_11_29_19_11_58.pdf

...and the Invacare Mirage user manual:
[WARNING: User Manual contains so many warnings that user is apt to ignore warnings.]
http://www.invacare.ie/sites/ie/files/product_documents/a01c108da4b10953c17d07252a025616eb2244a7_Mirage_User_Manual_Aug_2017.pdf

 

[jim hardy]

the Invacare Mirage user manual:

page 43
you can disengage the whole drive unit and use it as an ordinary wheelchair but i see no provision to disengage just the brake.

 

[sophiecentaur]

The electromagnetic brake's function is to make the chair stop when the motors are off (obvs) and to allow the user to navigate with accuracy. It would be not too hard to fit an extra switch to dis the brake. But which way does the brake work? Is it applied when the solenoid is powered or is it disengaged by the solenoid? (Like some Air Brakes on trucks). A friend of mine had a very similar chair and I 'played' on it. As I remember, you couldn't move the thing when the key switch was off which implies a 'powered-on' function (The solenoid could even be in series with the motor circuits). The symptom could be the result of an open circuit fault in the motor circuit. The printed manual doesn't have such details.

 

[Guineafowl]

If the solenoid were in series with the motor, that would disable the motor in the event of an open circuit. That would just leave a mechanical fault possible, with the brake mechanism sticking despite the solenoid being energised.

Solenoid in parallel leaves both mechanical and electrical faults possible.

As power is cut to these wheelchairs, they come to a fairly abrupt halt. Imagine doing that sort of binary braking with your car. That must cause a significant amount of wear to the friction material of the brakes. The resulting dust could easily bind moving parts.So, when is the stripdown, diagnosis and repair being done? ;). Pictures please!

 

[sysprog]

The design is such that the electromagnets draw power to disengage the brakes to which they are attached. When the electromagnets are not empowered the brakes return to their default engaged position. That design is suboptimal for maximization of travel distance; however, it is reasonable as a safety feature that the device will not roll freely when out of power unless the motor/brake apparatus is manually disengaged.

 

[sophiecentaur]

So, when is the stripdown, diagnosis and repair being done? ;). Pictures please!

If it were easy to take it all apart (as with a motor car starter motor or alternator) I think it would have been done already. The complaint has been made that there's too much sealed unit and not enough nuts and bolts. Replacing the whole motor / brake unit could be an easy job though.
There could be another problem though. If the units on both sides are not replaced together, the braking could be asymmetrical and that could be a real embarrassment if the chair slews every time the motors are shut off.
I suspect that the brake is only designed to engage when the motor is at low speed and that 'engine braking' would be what slows the chair from walking speed. More of a 'parking brake' than a motion brake, perhaps. You can bet the design did not involve the spending Formula One development type money so it may not be optimal.