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A vibrator helped me debug a motorcycle brake light system

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Re: A vibrator helped me debug a motorcycle brake light system

#41

Post by lstodd »

onethought wrote: post #37
lstodd wrote: post #31

On a bike you have the front brake lever at the throttle on the right hand. You always, always have to have at least two fingers on the brake lever and control the throttle with the thumb and palm. It is completely irresponsible to ride not doing that because sudden obstacle will not give you enough time to put them back on it. Then you lose 60-80% of braking power for a second or two. If you are doing it right then…

This technique is explicitly frowned upon in a number of licensing tests. Hand is required to be completely on throttle, or all four fingers completely on brake. So I'm not sure "completely irresponsible" is the right term, as it's actually taught that way. If you drop the throttle, you will already begin to decelerate from the engine your fingers are A LOT faster than "a second or two" in clasping the brake... easil…

Might be frowned upon, but it saved my life a few times.

If you drop throttle on a belt or variator transmission.. well the belt slips.

On a typical say japanese 600-ish cc with chain final drive, dropping throttle would not do 1/5 of what pulling the front brake will do.

If you have an emergency braking situation the rear brake is not only useless, it's a hazard, the rear wheel just lifts and loses traction and if you lock the rear wheel, not only you lose gyro stab effect, when you release front brakes what happens is that you highside. (crash that is).

Rear brake is for parking or slow coasting.

They all are really out there to kill you, so you must be ready at all times.

Re: A vibrator helped me debug a motorcycle brake light system

#42

Post by [deleted] »

randlet wrote: post #40
onethought wrote: post #37

Earlier quoted context omitted.

This technique is explicitly frowned upon in a number of licensing tests. Hand is required to be completely on throttle, or all four fingers completely on brake. So I'm not sure "completely irresponsible" is the right term, as it's actually taught that way. If you drop the throttle, you will already begin to decelerate from the engine your fingers are A LOT faster than "a second or two" in clasping the brake... easil…

Not to mention that the rear brake comes into play as applying the rear brake will transfer weight to the front allowing you to apply your front brakes harder.

[deleted]

Re: A vibrator helped me debug a motorcycle brake light system

#43

Post by lstodd »

maikhoepfel wrote: post #33
lstodd wrote: post #31

On a bike you have the front brake lever at the throttle on the right hand. You always, always have to have at least two fingers on the brake lever and control the throttle with the thumb and palm. It is completely irresponsible to ride not doing that because sudden obstacle will not give you enough time to put them back on it. Then you lose 60-80% of braking power for a second or two. If you are doing it right then…

I know a few bikers do something similar as you describe. I want to point out it is not generally accepted truth, e.g. the German ADAC explixitly teaches to keep fingers off the brake until needed. The idea being that if you're surprised by something, you're much more likely to slam the brake, introducing instability or locking up the front. You don't hover over the brake in a car either.

It is quite hard to lock the front going straight. A [edit] stoppie while spectacular is a quite simple trick. I basically did a couple the second time I rode a bike. Unintentional at that.

One can do a lowside, that is losing traction (not even locking, but just overspeeding and then braking, even engine-braking) in a turn. But this point is basically the first that must be taught: how to enter and exit turns properly.

I think ADAC is just being lazy / or too much ass-covering. But I don't know. I'm self-taught and not in Germany.

Re: A vibrator helped me debug a motorcycle brake light system

#44

Post by QQQQQQQQQQQQQM »

doodlebugging wrote: post #6

I too have repurposed a similar machine to try to help me solve a nagging problem. One of my vehicles uses a hydraulic clutch. By design, air bubbles can be trapped in the master cylinder due to factory bends in the lines and the orientation of the master cylinder when it is properly installed. If this happens it will be impossible to shift the gears (manual transmission) until the air is bled from the lines. I tried…

Your issue with the o-ring reminds me of the time my buddy and I tried replacing the flex-line to one of his rear brake calipers. We rented one of the vacuum bleeder pumps from Auto-Zone, replaced the flex line, slightly loosened the bleeder cap and went to town. Sucked a ton of air out as the new line filled, but then there was a constant stream of tiny bubbles. He wanted to make absolutely sure that the line was clear, so he kept pumping and kept filling the reservoir. At first we thought maybe something about the way his original flex line failed catastrophically had introduced air all the way through the system, but the bubbles just kept coming. A full bottle of DOT3 later, we were questioning and trying to figure out where the bubbles were coming from, which turned into a fine-comb search of the entire brake line all the way back to the front of the car looking for pinholes, weeping, etc. After maybe 2 hours of searching, we found nothing. Continued pumping through a second bottle of DOT3, and then we realized that the air was seeping in through the threads of the bleeder cap and could be safely ignored. We felt real stupid.

It's about time I do a brake flush on my car, so it's good I remembered this story so it's fresh in my mind.

Re: A vibrator helped me debug a motorcycle brake light system

#45

Post by RandomBacon »

gnfargbl wrote: post #35

From the original article, linked from this article: > Moreover, during intense braking scenarios, it flashes proportionately to the braking intensity. Is it just me who finds this behaviour to be a regression? If I see a brake light on a motorbike, I know that the bike is slowing, and I respond accordingly. An urgent flashing brake light doesn't make me react faster, but it does serve to confuse and distract my brai…

Flashing brake lights are super annoying. Flashing lights are attention-grabing and thus distracting when you are trying to observe the whole scene and not just fixate on the vehicle in front of you.

Or if you are the type of driver that fixates on the vehicle in front of you, and a vehicle to the side has flashing brake lights, then it distracts you from the vehicle in front of you.

They should be illegal, and they already probably are illegal - in my state, if the brake pedal is pushed, the brake light must be on, and if it is flashing, then it is alternating between on and OFF. (And a judge does not care if "technically it is 1% on and not completely off" - it looks off.)

Next time you are in traffic, imagine if every vehicle in front of you had flashing lights.

Re: A vibrator helped me debug a motorcycle brake light system

#46

Post by potato3732842 »

onethought wrote: post #38
potato3732842 wrote: post #36

Earlier quoted context omitted.

[flagged]

> I don't know much about motorcycle riding, but it seems my heuristic works well. If you don't know much about motorcycle riding, then maybe STFU. Also how could you judge if your heuristic works well, if you don't understand the topic? GP is actually correct.

>Also how could you judge if your heuristic works well,

Seems to work damn well on every topic I do know about.

Re: A vibrator helped me debug a motorcycle brake light system

#47

Post by lstodd »

randlet wrote: post #40
onethought wrote: post #37

Earlier quoted context omitted.

This technique is explicitly frowned upon in a number of licensing tests. Hand is required to be completely on throttle, or all four fingers completely on brake. So I'm not sure "completely irresponsible" is the right term, as it's actually taught that way. If you drop the throttle, you will already begin to decelerate from the engine your fingers are A LOT faster than "a second or two" in clasping the brake... easil…

Not to mention that the rear brake comes into play as applying the rear brake will transfer weight to the front allowing you to apply your front brakes harder.

Not in my experience (20yrs). If it's all-in-or-we're dead, you either do a stoppie and hope, or do a deliberate lowside and also hope someone will patch you up once they dislodge your parts from wherever you end up in.

In either case it's front brake. A bit of tilt for the second case. The rear brake is not needed at all.

If it's just a overspeed corner, you try to slow down gently, while maintaining both wheels on the trajectory. So just a little play with throttle and just a little front brake so that the bike stays balanced so to say. No rear brake at all because dropping the throttle a bit is all that's needed for the rear wheel.

If that is not enough, you're not going to make that corner, you have had too much speed coming in, and you will pay for that right now by crashing into something.

I learned this in 1990s when I first started riding.

Those are the basics.

Re: A vibrator helped me debug a motorcycle brake light system

#48

Post by bArray »

> So I needed a cheat code. Enter: a repurposed vibrator, No joke. I hooked it up to mimic the kind of high-frequency engine vibes you'd get ripping down a motorway. It wasn’t pretty, but it worked. I could test tweaks right from my test bench.

Those massage guns could be quite useful too. When finding a problem in the field, replicating it on the lab bench is always ideal.

> The current solution: The jitter helped, but it wasn’t bulletproof. Then I realized something deeper, the sensor has its own built-in sample rate, 400 times per second. If I read it too quickly, I might just be grabbing the same number twice. No new data. And if that repeat looks like a sustained deceleration, the light fires.

It should be a de-bounce based on time, not based on an arbitrary sampling rate. So you are looking for an average value threshold over a sliding window based in time.

Better yet:

1. On start-up it should be able to indicate an error via blink codes. You should for example be able to detect if an LED has burned out, there is moisture detected, that a brake signal was not detected over a X minute runtime, the temperature is outside safe limits, or the circuit draws current outside of the expected limits.

2. Use an IMU to detect de-acceleration events encase there is a break in the signal. It's obviously not ideal, but far better than nothing. Gravity is ~9.81m/s, and a braking force would be detected perpendicular to this. Again, you would use the error code on start-up to indicate that there is an issue.

3. Consider the use of an internal battery encase there is an issue with the supply voltage to the brake light. A bad power or ground could cause continuous resets, and failure to detect a signal.

Re: A vibrator helped me debug a motorcycle brake light system

#49

Post by epcoa »

dotancohen wrote: post #27
MengerSponge wrote: post #17

Earlier quoted context omitted.

As I understand it you can even source them with specific bend and taper profiles, which lets you optimize for the geometry of the system you're trying to flush.

I've seen one recently that seemed to be long and skinny enough where if OP could see the part, he could vibrate the part. I have no idea what part of the human anatomy such a device is necessary for. Maybe top-of-the-foot while standing?

Near field Teledildonics

Re: A vibrator helped me debug a motorcycle brake light system

#50

Post by randlet »

lstodd wrote: post #47
randlet wrote: post #40

Earlier quoted context omitted.

Not to mention that the rear brake comes into play as applying the rear brake will transfer weight to the front allowing you to apply your front brakes harder.

Not in my experience (20yrs). If it's all-in-or-we're dead, you either do a stoppie and hope, or do a deliberate lowside and also hope someone will patch you up once they dislodge your parts from wherever you end up in. In either case it's front brake. A bit of tilt for the second case. The rear brake is not needed at all. If it's just a overspeed corner, you try to slow down gently, while maintaining both wheels on…

With all due respect it sounds like you could use a refresher on motorcycle physics.
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