Jackson’s Vespa-Piaggio project he doesn’t have time for thread

[jps8460]

So the magneto output is or isn't already rectified?

That thing you got from Bezosmart is probably not helpful and might work against you. With such a wide range of inputs I'm thinking that the LED lamp may have it's own PWM inside. It should not need the DC-DC in that case and might work against you feeding a switcher with another switcher.

If the magneto is unrectified AC all you need is a couple of diodes and a cap, even a bridge like they put to allow AC into that DC-DC is kind of overkill and doubling your drop unnecessarily (you'll drop 2 x diodes per cycle, so ~1.4V less than Vpeak).

If you can tell the part number on the bridge you might find a datasheet but cheap rectifiers often have appallingly slow recovery so you might get reasonably DC as idle but at speed it'll be barely DC. They are intended for 60 Hz and might extend performance out to perhaps 400 Hz. By 1 KHz they often aren't doing much anymore.

It’s not rectified. I think the front LED will be ok, but the tail light is what is causing me to try the circuit. It’s tough to find a bulb that will accept a wide range of AC inputs. So I found a circuit that could handle the power of both lamps. However I may try to just run the rear lamp with it.

You’re probably right, but it was cheap enough to try. The dumb 6v lamp is 35 bucks and not very bright at all.

My backup is to run the factory 6v bulbs and be happy. I suppose I could get some armature wire and turn the mag coils into a 12v…. There’s a bunch of conversion stuff on treatland etc. But all too expensive for me haha, I’d rather buy the Vespa ciao specifically tuned pipe

 

[DaveInDenver]

It’s not rectified. I think the front LED will be ok, but the tail light is what is causing me to try the circuit. It’s tough to find a bulb that will accept a wide range of AC inputs. So I found a circuit that could handle the power of both lamps.

You’re probably right, but it was cheap enough to try. The dumb 6v lamp is 35 bucks and not very bright at all.

I mean, like, you know they make magneto rectifiers just for this problem already, right? These are not going to be well filtered so that's why I suggest throwing a nice, big cap across it.

https://www.amazon.com/Voltage-Regulator-Rectifier-Connector-Scooter/dp/B0B2P44KL5

https://www.amazon.com/WOOSTAR-Rectifier-Regulator-Voltage-Scooter/dp/B07L3QWQ15

If this is too rich I have bins full of diodes and caps that would cost nuthin. I'd wire in a small battery into the circuit to smooth things out and prevent the lamps dimming at all, too. But that's just 'cause I'm stupid like that.

 

[jps8460]

I mean, like, you know they make magneto rectifiers just for this problem already, right?

https://www.amazon.com/Voltage-Regulator-Rectifier-Connector-Scooter/dp/B0B2P44KL5

https://www.amazon.com/WOOSTAR-Rectifier-Regulator-Voltage-Scooter/dp/B07L3QWQ15

If this is too rich I have bins full of diodes and caps that would cost nuthin. I'd wire in a small battery into the circuit to smooth things out and prevent the lamps dimming at all, too. But that's just 'cause I'm stupid like that.

I did see that first one (or a variant), but it seemed like it didn’t accommodate a very large buck in dc voltage, again could be totally wrong. The main “issue” is not getting above 12v until mid throttle.

 

[DaveInDenver]

It's just high(ish) frequency AC->DC. It won't buck anything. Did Vespa mix bulb voltages? That's so Italian. But how's it working now then? I'm not seeing why didn't you pick the right LED if you're converting?

 

[jps8460]

It's just high(ish) frequency AC->DC. It won't buck anything. Did Vespa mix bulb voltages? That's so Italian. But how's it working now then?

Nah it’s all 6vac incandescent. I was struggling to find a tail light and headlight led replacement that could utilize a 6v ac or dc input. Again, i’m guessing that the Vespa probably doesn’t get above 12v until about 2200rpm

Do you have a WF generator? I’d love to test this thing before strapping it to my mag haha

 

[Inukshuk]

Mount a 19W Baja Deigns S1 and call it good. Accepts 9 -28 VDC. 2320 lumens

 

[DaveInDenver]

Nah it’s all 6vac incandescent. I was struggling to find a tail light and headlight led replacement that could utilize a 6v ac or dc input. Again, i’m guessing that the Vespa probably doesn’t get above 12v until about 2200rpm

Do you have a WF generator? I’d love to test this thing before strapping it to my mag haha

I don't have a waveform generator that can produce much real power, 10Vpp into 50Ω, maybe. So like a watt at most. Well, you know, that might actually be pretty close to what this thing can do... But, no, the generators I'd have won't like driving low impedance.

It's more work than it's worth to try to simulate this. It's a cheap magneto, you know it's going to be horrible looking variable AC. The only reason this ever worked was filaments, condensors, points and ballast resistors don't care.

It's likely that any electronics like LED drivers are just going to go sideways with the stream of thousand volt spikes and end up being more trouble that it's worth. At which point you'll decide to do a proper rectifier, voltage regulator and electronic ignition that you should've done in the first place.

 

[jps8460]

I don't have a waveform generator that can produce much real power, 10Vpp into 50Ω, maybe. So like a watt at most. Well, you know, that might actually be pretty close to what this thing can do... But, no, the generators I'd have won't like driving low impedance.

It's more work than it's worth to try to simulate this. It's a cheap magneto, you know it's going to be horrible looking variable AC. The only reason this ever worked was filaments, condensors, points and ballast resistors don't care.

It's likely that any electronics like LED drivers are just going to go sideways with the stream of thousand volt spikes and end up being more trouble that it's worth. At which point you'll decide to do a proper rectifier, voltage regulator and electronic ignition that you should've done in the first place.

Haha or just be happy with 6v incandescents and a headlamp haha

 

[DaveInDenver]

Can you really call yourself an engineer if you don't have solutions looking for problems?

For the record, nothing wrong with changing to LEDs (other than the voltage spikes maybe throw on a couple of filtering caps). That's just an LED and current limiting resistor. The DC-DC converter (e.g. the wide voltage range "feature" of the PAR36 and the buck) is what I think is going to have fits unless the supply DC is rock solid.

Oh, yeah, that will also have it's own losses. It could be significant enough to matter here. The LM2596HV used in that DC-DC is around 80% efficient (figure around 0.5W at least is consumed by the converter). On the upside is it's got excellent regulation, 0.3% load. So the lamp will see 6V +/- 0.018V up to it's max 3A load.

It's an interesting test ... when someone else does it to their whip.

 

[jps8460]

My big Treatland order came in, so this weekend is game on.

On a side note, the handlebars are rusted into place, so I think I’m going to cut them and reweld them once they are apart. It looks like an old 1” wedgie thing like old bikes used to have. So, maybe I’ll just get some ape hangers for it…

 

[Curly]

My big Treatland order came in, so this weekend is game on.

On a side note, the handlebars are rusted into place, so I think I’m going to cut them and reweld them once they are apart. It looks like an old 1” wedgie thing like old bikes used to have. So, maybe I’ll just get some ape hangers for it…

I support the ape hangar decision. I am willing to contribute financially to prove my support for said decision.

 

[jps8460]

I support the ape hangar decision. I am willing to contribute financially to prove my support for said decision.

Haha

 

[60wag]

It needs a get-back whip.

 

[jps8460]

Well I ordered this cable kit that replaces all of the cables and they are pre-cut to factory lengths, I forgot about that…. So no ape hangers for now. Get back’s I could probably look into

 

[BritKLR]

My big Treatland order came in, so this weekend is game on.

On a side note, the handlebars are rusted into place, so I think I’m going to cut them and reweld them once they are apart. It looks like an old 1” wedgie thing like old bikes used to have. So, maybe I’ll just get some ape hangers for it…

Knowing you and the fact this thing will be seeing some "air-time" I'm thinking more like dirt bike straight bars with a set of bark busters and a nerf pad for those times you land hard.....just a suggestion.

 

[jps8460]

Knowing you and the fact this thing will be seeing some "air-time" I'm thinking more like dirt bike straight bars with a set of bark busters and a nerf pad for those times you land hard.....just a suggestion.

Gotta shake the rust out of that tank somehow!

 

[jps8460]

Made some progress today. Got the engine parts cleaned up and put together.

I put new crank bearings on, probably should have replaced the wrist pin bushing but decided to roll with what was there…. She was rocking .0034 of ‘erl clearance . But in a 2stroke, the force is always down right??

I made a real “Whiskey Tango” oil bath to heat the bearings up to 250 F to make them glide on. A few light taps and they went on. The old bearing was the perfect width to support the crank counter weights.

Took a break to help Chris Nelson erect his new TP, it’s pretty rad!

 

[jps8460]

Some before shots

 

[jps8460]

These things don’t run head gaskets (typically). My head was quite warped. I CNC’d a little fixture that used the spot faces for the head stud nuts to locate everything. I sent a flat head screw down through the spark plug hole to secure it and took about .010 with a fly cutter.

 

[BritKLR]

All I'm saying is just think about a MOAB Scooter Adventure Run.....

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Thanks AI. #ai #aiart #aiartcommunity #4x4 #overland #scooter #thanksai.

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