Throttle Limiter and Emergency Stop Added

knoxie

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Joined
Jan 3, 2007
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Hello Folks

Well after a bit of an incident with my bike flipping up and over on me at the weekend I decided to add in some safety features! now more than happy with the top speed of my bike I actually am being more careful now about safety.

I picked up one of those cheap Mini Motorbike Emergency stop buttons off ebay, I have positioned it right by my left thumb so I can hit that quickly should my throttle stick or short out (this has happened before). This is wired in to the brake circuit of my xlyte controller and works superb.

Also I find when I go out on long rides that my wrist aches as I have to hold the throttle just so to achieve the best compromise between speed and range, this can be painful on 40 mile rides so I decided it was time to slow things down :lol:

I picked up a good quality waterproof potentiometer and made an interface plug and socket to fit the pot between the positive feed and the throttle, so now I have a nice potential divider, I can ride along and tweak the throttle to the speed that suits me, then I can just leave the throttle wide open with no worries.

This is a modification that I have been meaning to do for a long time, so glad that I have done it as when I am running 60V on my bike just a slight blip in the throttle can make the power jump by up to 800W or so! not good on transmission, batteries or controllers so this will help there as well, its not really designed as a throttle smoother its a pure throttle limiter.

It was cheap to make, I used some conduit clips to make the bracket and some heatshrink and hot glue to waterproof it all, it should be good for ever.

Here are some snaps, I now officially have no room left on the bars! ha ha.

Have a good week

Knoxie
 

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Hi

Yes at 60V or so its a mean beast, I was messing about with a throttle that had failed and it flipped right over and lay on its side screaming away at me! was very scary and damn nearly broke my fingers off! very scary, just like a rodeo horse Im not kidding!! yahooo!!

I think I can tame the beast now!! calm her down a bit on those long rides and cut her throat when she gets naughty! ha ha she? ha ha

Cheers

Knoxie
 
once u try pot.
u can't live without it LOL
 
lol, watch that flipping trick knoxie ;)
you'll have to show me how to put one of them kill switches in - better to be safe i reckon :)

D
 
Ha ha yes thats the kind of pot they cant arrest you for my man! ha ha, my drug is ebike! I suppose its technically illegal ha ha 8)

Oh yes the Lipo, I have split one! ha ha must post the pictures, I am going to fit it in to a Bionx style case with a switch, fuse charging socket, it will look sweet, The BMS will be kept well away from the lipo cells, these are wax wrapped and will be in another section of the box, should look nice and we will be able to get the factory to ship them like this, frame mounted with a key release 37V 15AH Lipo, plug and play!

Oh Deecannio yes the Kill switch is easy to fix in, some of the xltye controllers do not have the brake inhibit, if not you can take the wiper off the throttle through it.

Cheers

Knoxie
 
http://tinyurl.com/2v3bsp

Its this one DC, cheap nice long lead and easy to fit not too big, a lot easier than messing about trying to fit reed switches to my brakes, have tested it and can slow the bike and hit the switch, so its not a problem, if that doesn't work I jump off the back! ha ha

Cheers

Paul
 
Hi Richard

I used a 4k7 3W high quality cermet resistor, its spot on as it allows me to drop it to a crawl and the pot spans the full range, I have been meaning to do it for a while, it helps a lot as I also find at full speed you can back the throttle off quite a bit and save power but keep the same speed, this lets me knock back the throttle to suit the conditions, its just so much more comfortable when you go out on long rides, I was thinking about a cruise control but this will work fine for me the same really and is safer.

Cheers

Knoxie
 
Hi

No back pack all the batteries are on the bike, I only use the back pack when testing the batteries like I said before, this happened when stood to the side of the bike I wasn't on it at the time, I then grabbed it when it went but I couldn't stop it, then it flipped and spun out.

Never had a problem with the back pack? its only got 10lbs in it anyway, my concern with doing this mod is to trim back the top speed as in town and generally I am dumping far more power in to the motor than I need to, its very hard to govern using a throttle as the power flies up so quick.

The addition of the stop switch and the throttle limiter really help, the throttle limiter works like a charm and I can still seem to make good top speed with minimal peddle input, its great as I can dial in the exact amount of power I need, my NIMH packs don't sag at all running like this and I get a little more exercise which is a good thing.

Cheers

Knoxie
 
What does the yellow button do Knoxie? Can I press it?? Go on, go on, just once!

I bet the kids just love your bike :D

Is that a 5k Magura throttle? If so, I guess the same mod would work on my motorbike for running around town.
 
Hi Malcolm

Ha ha well the kids love the BMX and the KMX more! and yes it is a 5K Magura throttle, this pot just goes in the red +5V line from the controller making a potential divider, it works very well and yes you could run the same rig on your bike as well.

The yellow button is the light switch for the halogen, the white button is the warp speed button, If I push this it activates the time degenration crystals that I keep hidden inside the frame, it pushes the bike faster than the speed of light, handy for quick trips to tescos and the library!

Have a good One

:lol:
 
knoxie said:
Hi

Yes at 60V or so its a mean beast, I was messing about with a throttle that had failed and it flipped right over and lay on its side screaming away at me! was very scary and damn nearly broke my fingers off! very scary, just like a rodeo horse Im not kidding!! yahooo!!

Cheers

Knoxie

We want a video of that :D


The throttle limiter looks like a nice setup. For a hall effect throttle the pot might have to go in series with the signal (wiper) wire instead of the +5v. As I recall, I measured the throttle input resistance of the Xlyte controller to be around 150k, so something like a 250k pot in series with the wiper should have the desired effect.
 
If I push this it activates the time degenration crystals that I keep hidden inside the frame, it pushes the bike faster than the speed of light, handy for quick trips to tescos

That's a neat way of beating the speed cameras, and now I know why you don't have rear view mirrors :wink:
 
might want to add a momentary push button, L thumb, to bypass the perfectly set pot, for temporary boost.
 
Matt Gruber said:
might want to add a momentary push button, L thumb, to bypass the perfectly set pot, for temporary boost.
:idea: :idea:
(humor follows)

You two, Paul and Matt, are one, no, two, hundred Watt light blubs.
Kudos!
Great ideas!
I will copy, call them my own and waive fees for you guys
for one royalty-free flush-button potty throttle bike apiece.
Deal?

-Bill Gates-
:wink:

_____________
Seriously, Paul: nice idea!
You may go on now and use it---yes, you have my permission.
Technically, in this app, you've wired it as an adjustable resistor,
not as a pot to piss on.

-Bill Grates-
:twisted:
 
Hi Folks

Ha ha no videos of me flipping the bike! ha ha thats too scary to do again, the adjuster is neat I can really tweak it down so its all I need as I just dont need 2KW of power all the time but I can if I want turn the dial up.

I had thought of putting in a button but dont think I will for now, as the sudden jump in amps is kind of the reason I put the potentiometer in.
I can dial in easily whilst riding as well.

And yes Richard it may be a little different with a hall throttle, its funny as I never thought I would want to slow it down! ha ha so glad I have now and I would recommend this to anyone with a higher power bike, its a great mod.

Cheers

Paul
 
Hi Reid

Yes it is a good Idea and I have thought of it and may add it at some point, I want to try not to as I want to try and keep within the speed I set for myself.

I like to exercise and stay fit as well as get the benefit from the assist, the gearing on my mtb means any useful peddle input tails off at 25mph, the bike will do 32mph all day, so the mod was put in place for safety and also my general well being, fitness! its too easy to push a button but harder to reach over and turn the dial 1 handed! ha ha

I did the mod in the week, now the weekend is upon us I intend to do my first ride with the mod in place, I will hook in the watts up meter and see just how much it helps, I will do at least 30 miles my usual route and dial in an assist of no more than 15mph and will report back how i find it.

I am back down to 48V now, my NIMH packs are wearing a little as I think I must have hit 250+ cycles on them, still they are working but do sag under heavy amps now, maybe time to go lipo for good soon.

Cheers

Knoxie
 
How much do NiMH packs sag under load?

Indications of their series resistance, both when new, and then increasing with age, dissuaded me from going that much cheaper way.

I think it was estimated that a 36V pack of F cells might sag more than 6V at my bike's max draw of say 20 or 30 A.

That's too much wastage of emf gumption to be attractive here.
 
Reid Welch said:
How much do NiMH packs sag under load?

Indications of their series resistance, both when new, and then increasing with age, dissuaded me from going that much cheaper way.

I think it was estimated that a 36V pack of F cells might sag more than 6V at my bike's max draw of say 20 or 30 A.

That's too much wastage of emf gumption to be attractive here.



Assuming the BSpace figure of 5 milliohms per cell when new, 30 cells in series would sag 3 volts at 20 amps & 4.5V at 30 amps.

Vsag=I*Ri*n
 
Hi

Yes I think if I was going to go the NIMH route again with my greedy bike I would run 2 x parallel packs at about 40V, that would ensure longer cycle life and still a nice high split amp draw off each pack.

Its the deep discharges that deplete the batteries, If you halve it they will last twice as long. My batteries are still ok and can dish out 13A hours, its just they sag under heavy load. 48V down to 42V

I am going out for a nice run today so we will see how they cope, I have got so many choices thanks to Mark at Team Hybrid and his Aladdin's cave of batteries! ha ha I am quite literally spoilt for choice.

I still like NIMH but Lipo packs are amazing, there are so many new lithium based packs coming up through the system its really a sea change time.

Have fun

Knoxie
 
Hi Reid

You can pretty much use what ever pot suits, is your throttle hall or resistive? if it is hall you will need a relativley high value, Fechter has covered this and it will need to go in the wiper not the feed.

The pot i used is this one, you should be able to get an equivalent one in the states, this one I chose as it is waterproof works even under water!

Here it is

http://tinyurl.com/37w3nx
 
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