Hydraulic cut-off brakes
- Thread starter Matthew
- Start date
Tom L
1 kW
This is how I created eBrake switches for my existing hydraulic brakes.
I purchased two surface mount reed switches from element14 http://au.element14.com/jsp/search/productdetail.jsp?sku=1081695&CMP=i-55c5-00001621 and some 3mm rare earth disc magnets from eBay.
Yep those are millimetres:
Tacked in place with superglue (note the stack of magnets on the lever pivot):
Secured with epoxy resin (magnets and reed switch):
Covered with black Sugru rubber putty:
Ignore the spit residue (used to smooth the putty).
It was quite easy to find an optimal position for the magnets, so the switch activates at the slightest pressure on the brake lever but not so sensitive that going over a bump would activate it.
The only problem I had was that I forgot that my twist throttle had magnets in it! The additional magnetic field caused the reed switch to activate far too easily. Snapping the epoxied magnets off and repositioning slightly further away from the reed switch solved the problem.
Cost:
$14 for the reed switches
$3 for the magnets (with plenty left over)
$7 for the Sugru (1 of 3 packets used, $21 for three packets)
Total of $24 for two ebrake switches.
I purchased two surface mount reed switches from element14 http://au.element14.com/jsp/search/productdetail.jsp?sku=1081695&CMP=i-55c5-00001621 and some 3mm rare earth disc magnets from eBay.
Yep those are millimetres:
Tacked in place with superglue (note the stack of magnets on the lever pivot):
Secured with epoxy resin (magnets and reed switch):
Covered with black Sugru rubber putty:
Ignore the spit residue (used to smooth the putty).
It was quite easy to find an optimal position for the magnets, so the switch activates at the slightest pressure on the brake lever but not so sensitive that going over a bump would activate it.
The only problem I had was that I forgot that my twist throttle had magnets in it! The additional magnetic field caused the reed switch to activate far too easily. Snapping the epoxied magnets off and repositioning slightly further away from the reed switch solved the problem.
Cost:
$14 for the reed switches
$3 for the magnets (with plenty left over)
$7 for the Sugru (1 of 3 packets used, $21 for three packets)
Total of $24 for two ebrake switches.
full-throttle
1 MW
Don't have the links but here's what you need. DIY stuff on the left, original on the right.Dlogic said:You might want to share the link of those parts so everyone here can enjoy this cheap source of parts.
- Couple of syringes (rubber plunger best for degassing, plastic works best with mineral oil)
- Some plastic tubing (Tygon)
- Couple of fluid fittings
- Clamps for degassing
CEGB
100 mW
I've been struggling with the ebrake portion of my build for a while now. I have a very nice set of Hope 6 pot calipers and 8 inch discs I want to use, but naturally, they're not compatible with any off the shelf solution for ebrake switching. I bought a magura switch, but then found it's only compatible with mineral oil systems. Hope use DOT fluid... 
so I guess that Magura switch will be redundant.
I have had an interesting conversation with Hope Technology tonight though. I went to the London Bike Show tonight where they are exhibiting, and during our chat I proposed that they should get involved in ebike parts. The product guy there says they already are... They are developing ebike parts with a partner firm, including brakes with internal switching. He couldn't give an indication of timeline for product release, but its good to know that a company as serious as Hope can see a marketplace for us.
For the moment I'll go without. I have a new Cycle Analyst which will take care of any throttle voltage excursions outside the normal range, which should account for most faults that are likely to see me propelled into a hedge without warning. The Hope Mono 6-Ti calipers and 200mm discs will stop a train, so I don't think they'll have much trouble overhauling a runaway GNG.
so I guess that Magura switch will be redundant. I have had an interesting conversation with Hope Technology tonight though. I went to the London Bike Show tonight where they are exhibiting, and during our chat I proposed that they should get involved in ebike parts. The product guy there says they already are... They are developing ebike parts with a partner firm, including brakes with internal switching. He couldn't give an indication of timeline for product release, but its good to know that a company as serious as Hope can see a marketplace for us.
For the moment I'll go without. I have a new Cycle Analyst which will take care of any throttle voltage excursions outside the normal range, which should account for most faults that are likely to see me propelled into a hedge without warning. The Hope Mono 6-Ti calipers and 200mm discs will stop a train, so I don't think they'll have much trouble overhauling a runaway GNG.
jateureka
10 kW
Tom L said:
Nice work Tom.
I see those reed switches are normally open (NO contact, form A), so are closed when near a magnet/brake lever is at rest.
Just curious, how are you using that setup to active the e-brake ?
Most controllers use a normally open brake circuit that is active low - you short a wire to ground to cut power, so most use switches that are the NC type, so are open when the brake lever is at rest and close when you pull the magnet/brake lever away to apply the brake.
The reed switches here are NC type and the ones down the bottom come in left and right cable exits, may be ok to mount on the under side of the brake lever housing
http://au.element14.com/jsp/search/...ions=false&ref=globalsearch&_requestid=112473
Tom L
1 kW
jateureka said:
The action of the brake lever moves the magnets near to the NO reed switch, shorting the ebrake line to ground.
beazee
10 mW
That's what I needed! A creative way to use Sugru sitting in my fridge! Thanks!Tom L said:
jateureka
10 kW
Tom L said:
Ah, thanks for pointing that out, I thought you were pulling the lever back in the photos so we could see the magnets, now I see how it works. Not so easy to do it that way on the levers I have, so need to use NC reed switch...
5 minute video of GCinDC demonstrating reed switches as a power cut-off on a hydraulic brake system. I'd fast forward to 2:50...
https://www.youtube.com/watch?feature=player_embedded&v=PlNwYSsmzMM
https://www.youtube.com/watch?feature=player_embedded&v=PlNwYSsmzMM
Hi guys,
I'm really interested on those magnet switches. It is exactly what I was looking for. Let me know if I got this right: If I connect this wiring to the controller (having on the brake the magnet) it works the same way as the normal wiring? How can be sure that the electrical signal the magnet sends to the controller (to cut off the power) is the same as the normal wiring?
So far I've only seen in the thread the description for the magnet and not how it is connected to the controller.
Thanks in advance
sb
I'm really interested on those magnet switches. It is exactly what I was looking for. Let me know if I got this right: If I connect this wiring to the controller (having on the brake the magnet) it works the same way as the normal wiring? How can be sure that the electrical signal the magnet sends to the controller (to cut off the power) is the same as the normal wiring?
So far I've only seen in the thread the description for the magnet and not how it is connected to the controller.
Thanks in advance
sb
The brake cut-offs are switches. When you join the two wires, the controller cuts the power. They all work like that, so you can use any switch you want as long as it switches on when you apply the brake.
Some controllers have three-wire connectors for the brkes in case you want to use a hall sensor switch. You can stilĺ use any other switch, but you connect to only two of the wires - ground and signal.
If you want to use a reed switch and magnet, there's two things to look out for. If the magnet is too strong, it can damage the reed switch. Secondly, you either need to make sure that you bring the magnet towards the reed switch when you operate the brake or you need a normally on (NC) reed switch, which is off with the magnet next to it and goes on when you move the magnet away from it . You can get either type, but most common are normally off (NO).
Some controllers have three-wire connectors for the brkes in case you want to use a hall sensor switch. You can stilĺ use any other switch, but you connect to only two of the wires - ground and signal.
If you want to use a reed switch and magnet, there's two things to look out for. If the magnet is too strong, it can damage the reed switch. Secondly, you either need to make sure that you bring the magnet towards the reed switch when you operate the brake or you need a normally on (NC) reed switch, which is off with the magnet next to it and goes on when you move the magnet away from it . You can get either type, but most common are normally off (NO).
ok this is how it goes.
1st picture: This is my fathers ebike controller which he doesn't use anymore and I'm going to use it to convert my MTB to ebike.
2nd picture: From all this crazy wiring I figured out the wires that come from the current mechanical e-brakes and this is how they are connected on the controller. I have disconnected one of the two to take a look. So on the left (or top) we see the part that goes to the controller and on the right (or below) is the part that goes to the lever.
So the questions are
1.do I replace the right wire that goes to the lever making a new one (with blue and red little wires in it) attaching the reed switch at the end of it?
2. If yes, how do I know if it has to be NC or NO as you said?
3. And finally how can I be sure that signal of the reed switch is the same as the signal of the original mechanical ebrake? Maybe it might be stronger or not strong enough right?
Many thanks in advance I hope I'm not to demanding but I'm quite new on the sport
Cheers
1st picture: This is my fathers ebike controller which he doesn't use anymore and I'm going to use it to convert my MTB to ebike.
2nd picture: From all this crazy wiring I figured out the wires that come from the current mechanical e-brakes and this is how they are connected on the controller. I have disconnected one of the two to take a look. So on the left (or top) we see the part that goes to the controller and on the right (or below) is the part that goes to the lever.
So the questions are
1.do I replace the right wire that goes to the lever making a new one (with blue and red little wires in it) attaching the reed switch at the end of it?
2. If yes, how do I know if it has to be NC or NO as you said?
3. And finally how can I be sure that signal of the reed switch is the same as the signal of the original mechanical ebrake? Maybe it might be stronger or not strong enough right?
Many thanks in advance I hope I'm not to demanding but I'm quite new on the sport
Cheers
Attachments
It's not a signal. It's just a switch - on or off. The colour of wires doesn't matter, nor does the orientation of the wires. All you have to do is connect the two wires from the reed switch to the two from the controller. How you do it, doesn't matter.
Most reed switches are NO. NC ones are not so common, so it'll say "NC" in the listing. You can get dual mode ones that have three wires: One pair will be NC and the other pair NO, so you can choose which two to connect. You can find out which pair is which with a multimeter, or it'll say in the listing.
Most reed switches are NO. NC ones are not so common, so it'll say "NC" in the listing. You can get dual mode ones that have three wires: One pair will be NC and the other pair NO, so you can choose which two to connect. You can find out which pair is which with a multimeter, or it'll say in the listing.
Dlogic said:My custom built bikes needs brake lights that turn brighter when the lever is pulled. The german TÜV doesen´t accept any type of switches on the levers outside. So i´ve started to mill an adaptor that will be built right into the hydraulic hose. An oil pressure switch will do the trick. Once finished, you´ll get all the details.
The brakes that will be modded are the Avid code r.
Did you manage to pull this off? Do you have any details?
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