Fracomo Electromagnetic Wheel Lock

[lewisriverred]

Hi there! So my other electromagnetic motor lock burnt out yesterday and I don't want to pay $375 for it like I did for the last one. Does the coil have to be custom drilled to fit the motor it attaches too? Maybe that is why its so expensive? If thats the case can I buy one that doesnt have bolt holes and do that myself with my drill press?

I just left a message with Eurton about it but last time they were no help. I also emailed the Fracmo folks some pictures but also the last time I tried to get a part from them (or identify a part) they wouldn't help either.

I've decided to never tell anyone this is for a wheelchair. Now its a "robot"

Here's the picture of the coil and the motor. Any suggestions?

IMG_20140814_104649.jpg (52.43 KiB) Viewed 2424 times

[Burgerman]

At that price I would rewind them or throw them away. You dont really need them, I have an old chair with brakes thrown away...

[woodygb]

http://www.nithsdale-wheelchairs.com/el ... rakes.html

[Williamclark77]

If there are any "alternator repair" shops in your area they might could rewind them.

As BM said, you can do without them. Mine kept sticking and I couldn't find replacements (at a reasonable cost that is). I didn't really look hard though. I just removed them and connected the safety inhibit wires. It gets annoying parking on a hill or ramp at times. Chair will slowly roll, but better than hearing the clicking and paying the ransom costs.

[lewisriverred]

At that price I would rewind them or throw them away. You don't really need them, I have an old chair with brakes thrown away...

When I take the brake assembly off, the chair still gives the fault code for the left brake. How much of the brake assembly do I need to remove? I just took off the coil and twisted the two red wires together.

https://goo.gl/photos/GeeNTK9s9x3DacSw9

Could the programming know there's no brake?

[woodygb]

The controller needs to see a resistance ... replace your brake with a 24v relay coil.
e.g.

http://autoelectricalpartsuk.co.uk/prod ... wwodasAEEw

[Burgerman]

Or just a 40 to 100 Ohm resistor.

[LROBBINS]

You need a fairly high wattage resistor. With 100 ohm and 24 V, that would be (rounded to 25V) 1/4 Amp current or 5 Watts power to dissipate. At 12 V, half that. 100 ohm is a higher resistance than the actual brake coil, but should do OK to fool the controller. If you use 50 ohm - actually about the resistance of a 24V brake coil, you need a 10 Watt rated resistor (if brakes are 24V).
Ciao,
Lenny

[ex-Gooserider]

And note that if you push them towards their rated capacity, a power resistor will get HOT... Keep the need for heat sinking in mind, and be careful not to put them where they can burn someone, or cause other problems with getting their surroundings to hot...

ex-Gooserider

[lewisriverred]

Thanks for all the advice. I went ahead and ordered a replacement break assembly. $300 here in the states

Just for experimental purposes I'd like to see if putting a resistor will work like you folks are saying. I found a 560Ohm resistor in my Arduino stuff.

IMG_20150713_124521.jpg (191.56 KiB) Viewed 2314 times

If I put this between the red wires coming out of the motor... it should trick the controller into thinking there's a brake?

[Burgerman]

At 50 Ohm definitely. Even 100. At 560 Ohm I doubt it will, but it might.

[lewisriverred]

So your saying that the resistor might give too much resistance? I'm going to try a 220 Ohm resistor... I think its the lowest one I have.

[woodygb]

You could use the coils of 2 of 12v relays in series or 2 of 12v bulbs in series.

[rustyjames]

>>>Thanks for all the advice. I went ahead and ordered a replacement break assembly. $300 here in the states <<<

Wow, that's insane pricing. Can I asked where you bought it from? I've searched around for them in the past and they seem difficult find. At that price might as well go allthe way and buy a new motor/gearbox assembly.
,

[LROBBINS]

Not knowing the circuitry, I don't know how large a resistor will still be seen as "brake OK" by the commercial controllers. On my homemade one I detect coil presence by measuring voltage at the high side of the brake coil. Since the Roboteq closes the low side, that voltage gets pulled down if the brake is activated. That voltage stays high if the brake is not activated or if the coil is open or if there's no brake. If the digital output is calling for brake active, but the voltage stays high, there's an open coil (or missing brake). Doing it this way, even much larger resistors suffice to fool the controller - I was using 2.2k in testing, but suspect that 10k would work as well.

If P&G or Dynamic do something similar, a higher value resistor will work, and will dissipate proportionately less power as heat, so it's probably worth trying.

Ciao,
Lenny

[cheeky2]

Not sure if this is going to help you but i have just replaced the electromagnetic lock on my mobility scooter i have been repairing it with a 1k 1000 Ohm resistor rated at 0.4Watt. Originally the coil was around 60ohms from the manufacturer of the brake warner electric wr213 however the resistor required would have to been around 18watt resistor!
Not feasible as the heat generated would have been a complete waste as well as the power used by it!
So using a 1k resistor 0.4W it limits the current to less than 0.5W the controller doesn't bring the alarm up and its fully functional again less a electromagneteic brake! The heat generated is minimal on the resistor.
Though i will be trying to get hold of a reasonable priced unit ( seen similar ones around £50 on ebay).

Good Luck

[ex-Gooserider]

It might be worth contacting Eurton Electric, as they seem to be the only folks around that will work on this sort of stuff... I checked multiple local shops about getting parts for the motors on the Pride Jazzy that I've been dealing with (see other thread) and none (including an auto-electric shop) said they could / would do much, as they couldn't get parts easily....

OTOH, Eurton seems to do a lot of chair stuff, and be able to rebuild / service just about any kind of chair motor, and do parts like brushes and the like.

ex-Gooserider

[FelipeOliveira]

The controller needs to see a resistance ... replace your brake with a 24v relay coil.
e.g.

http://autoelectricalpartsuk.co.uk/prod ... wwodasAEEw

Good afternoon Woody
Could you send me an image of how to connect a Relay to replace the brake? This link is no longer available

[woodygb]

Disconnect the brake coil and replace it with a 24v automotive relay ...pins 85 and 86 in the pic.

https://www.google.com/search?client=fi ... 5iXY9qU6SM

You can use any 24v relay coil or SUITABLE resistance.

https://www.google.com/search?q=24v+rel ... irefox-b-d

[woodygb]

NOTE ...When replacing the brake with a resistance the whole brake assembly must be REMOVED from the motor.

[FelipeOliveira]

NOTE ...When replacing the brake with a resistance the whole brake assembly must be REMOVED from the motor.

Thanks
I have frequently come across a situation with a scooter ( CTL HS-559) with a 24v 16.8w brake, with a dynamic controller, in one month I received 3 with the same problem!
Is there anything that can be done to prevent it?

[woodygb]

Questions.
Had the brake coils actually failed ( burnt out ) ?
Had the controller been setup /wired up to give the brake coil the correct voltage ?

[woodygb]

I believe it is possible ... depending on the Dynamic controller ...to select NONE as a parking brake programming option.

Thus you could negate the need for the presence of a resistor .

Park Brake Testing Value: Park Brake Testing


Driving - The R-series checks the parkbrake for open circuit faults before and during driving.
Pre-Drive - The R-series checks the parkbrake for open circuit before driving, but not during driving. Use this option when the test during driving is very noisy and/or incorrect faults are generated.
None - The R-series does not check the parkbrake for open circuit faults at all.
This option allows the R-series to be used without an electric parkbrake.

Note: For safety reasons, the R-series always tests for short circuit faults. This can't be disabled.
Warning:
For safety reasons, do not use 'None' if the scooter has an electric parkbrake.

[woodygb]

NOTE ...When replacing the brake with a resistance the whole brake assembly must be REMOVED from the motor.

Thanks
I have frequently come across a situation with a scooter ( CTL HS-559) with a 24v 16.8w brake, with a dynamic controller, in one month I received 3 with the same problem!
Is there anything that can be done to prevent it?

Unless you can diagnose the reason for the failure , then it is not really possible to offer a solution other than replace the faulty brake.

[FelipeOliveira]

Questions.
Had the brake coils actually failed ( burnt out ) ?
Had the controller been setup /wired up to give the brake coil the correct voltage ?

https://www.alliedmedical.co.nz/product ... y-scooter/

[FelipeOliveira]

Here is some information regarding it

[woodygb]

The brakes seem to have overheated and then shorted out .... is there a possibility that they where 12v rated instead of 24v?

[FelipeOliveira]

The brakes seem to have overheated and then shorted out .... is there a possibilityu that they where 12v rated instead of 24v?

No ! All are 24v 16.8w 6N-m

[shirley_hkg]

£4 a piece. Same brand.

https://www.wheelchairdriver.com/board/ ... 3&start=90

[FelipeOliveira]

£4 a piece. Same brand.

https://www.wheelchairdriver.com/board/ ... 3&start=90

I found it interesting. But I didn't find how and where to buy it. Except for several photos!!
As for the brakes, I didn't see any with the same specification, in this case “24v 16.8w”.