cusom electronics needed please help!

[cruiserkb]

As some of you may know I am scalling back on my RC. I am 100% wheelchair bound and I am getting into addaptive sports. I currently am racing track in a specialized racing wheelchair and am also riding distance in a handcycling club. My ultimate goal is to compete in ablebodied triatholons.

I am haveing a custom hancycle built by Blackswift bicycles Handcycle to help MS | an I am in need of someones electronic skills to make me something. I am going to be using a Rohloff hub SPEEDHUB: www.rohloff.de in conjunction with an electronic shifter AboutUsPage . What I am looking for is to eliminate the wire that is going from the unit to the buttons. Per the UCI (cycling rule makers) my shifter has to be on the hand grips (pedals on normal bikes). I want to eliminate the wire from flapping around, so I thought maybe it could be done without wire, and who is the best at non wired controlers, the RC cominity. If anyone would like to posibly tackle this you can leave me a pm and we can go from there. I want to thank you in advance for any information on this and I apreciate your time.

Moderators if this is the wrong section please feel free to move it.

Thanks
Kevan

[JohnRobHolmes]

That will be really tough to do in a small form factor. Maybe a little bluetooth module would be small enough. The shifter controller uses digital signals for up and down shifting, so it won't be a complicated signal to send. Sending it and relaying the signal is your hurdle. If you are up for a project search sparkfun for wireless and browse through the little boards they have for such a task.

[JohnRobHolmes]

You should contact the maker of the shifter to see if they have any ideas or would be willing to do it. No telling what they are using for voltage on the buttons either, it may be full pack voltage or it could be logic voltage.

[cruiserkb]

Originally Posted by JohnRobHolmes

You should contact the maker of the shifter to see if they have any ideas or would be willing to do it. No telling what they are using for voltage on the buttons either, it may be full pack voltage or it could be logic voltage.

I will definately check that all out. Thanks for the responce. I have already emailed the maker for information on the unit, so I can check and see what they san do.

[Charlie-III]

JRH made some good recommendations. Frankly, I may also look at using the existing buttons and use a slip-ring to transfer the control inputs from the buttons to the chair.

[JohnRobHolmes]

A slip ring would be easy enough to fab. The base plate for the rings could be held on by the bottom bracket, with two or three contactors on the crank arm that ride them. The second plate could mount under the pedal spindle with the contacts on the hand pedal.


Housings would be needed for weather resistance.

[cruiserkb]

I heard back from the company and the buttons are only used for a ground conection. The buttons conect up with the battery pack and that interns conects up to the shifting unit. the system works on 5V.

I apoligise if this is a dumb question but what is a slip ring? I am not well versed in this.

Thanks

[JohnRobHolmes]

Slip Ring Assemblies - Sibley


So basically the buttons just turn the motor on and off? Sounds easy enough to engineer around. Did they say anything about helping you with a wireless solution?

[Charlie-III]

Originally Posted by cruiserkb

I heard back from the company and the buttons are only used for a ground conection. The buttons conect up with the battery pack and that interns conects up to the shifting unit. the system works on 5V.

I apoligise if this is a dumb question but what is a slip ring? I am not well versed in this.

Thanks

Slip rings can be 2 different shapes:
Disc
Barrel

They can also have 1 or more "rings" to increase the number of circuits.

Basically it is a way to have the "brush" on one side and a "ring" on the other side of a rotating joint/connection and allow voltage to pass either for controls or motive power.

Wiki... Slip ring - Wikipedia, the free encyclopedia

A pisture... What is a Slip Ring and How does sliprings work?- SenRing

A common slip ring is inside an automotive alternator.

[cruiserkb]

Thanks for clearing up about the slip ring.

John, I emailed them back explaining my situation and have not heard back yet. I will wait a day or so and email again. I apreciate all of your help on this.

cruiser

[YJ_Driver]

Originally Posted by cruiserkb

I heard back from the company and the buttons are only used for a ground conection. The buttons conect up with the battery pack and that interns conects up to the shifting unit. the system works on 5V.

I apoligise if this is a dumb question but what is a slip ring? I am not well versed in this.

Thanks

Then something like these may work:
Universal Remote Control Receiver and Transmitters
Amazon.com: LOGISYS RM02 12v 15A relay w/ remote control kit: Computers & Accessories

I searched for "remote control relay", I've seen some in general automotive stores too.

If you want to use a different button just open up the transmitter and connect the wires to the built in button contacts.

[Charlie-III]

Originally Posted by cruiserkb

Thanks for clearing up about the slip ring.

John, I emailed them back explaining my situation and have not heard back yet. I will wait a day or so and email again. I appreciate all of your help on this.

cruiser

No problem, I'm sure all here will agree, "It's the least we can do to help......it's the right thing to do!"

Please feel free to ask further questions, we will help where we can.

[cruiserkb]

Well the makers got back with me. They never looked into doing it this way. They stated it would not be worth it since the market is so small. I did respond with the ideas that you all provided, we will see what they have to say.

[cruiserkb]

Here is a picture of the cranks I am going to use:



I would be placing the buttons on the left hand side.