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by fechter
Dec 05 2021 7:14pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 628
Views: 37394

Re: C Cab Hot Rod Power Advice

It's very handy for troubleshooting later if you get a short in something. Pull fuses until the short clears to narrow down the problem. Or the fuses actually blow.
by fechter
Dec 05 2021 11:39am
Forum: Electric Aircraft
Topic: 3D printed 400mm EDF project
Replies: 35
Views: 1918

Re: 3D printed 400mm EDF project

I could see the video too. At least it held together this time. Which one gave the most thrust?
by fechter
Dec 05 2021 11:36am
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 628
Views: 37394

Re: C Cab Hot Rod Power Advice

That looks a little easier to follow. One nice thing is your dc-dc will also protect against shorts. It will be hard to burn up a wire on the 12v side.
by fechter
Dec 04 2021 11:27am
Forum: EBike Non-hub Motor Drives
Topic: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue
Replies: 174
Views: 50068

Re: DIY Fix for BBS02/BBSHD Pedal/Throttle Issue

I am currently looking for a source of Darlingtons. The joys of supply chain. Cheers and thanks for this thread. Pretty much any NPN Darlington will work. Some may have different pinouts or package sizes. There is a way to update the firmware on the controller to solve this problem See this topic: ...
by fechter
Dec 04 2021 1:24am
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 2226
Views: 153327

Re: la Nina rears her ugly head

And now a blizzard warning for Hawaii? https://www.msn.com/en-us/weather/topstories/blizzard-warning-issued-for-hawaii-with-at-least-12-inches-of-snow-forecast/ar-AARrtQV?ocid=uxbndlbing Event: Blizzard Warning Alert: ...BLIZZARD WARNING FOR THE BIG ISLAND SUMMITS... ...BLIZZARD WARNING NOW IN EFFEC...
by fechter
Dec 03 2021 7:03pm
Forum: EScooters/EMotorcycles
Topic: Supercapacitor
Replies: 6
Views: 139

Re: Supercapacitor

Yes you can put one on your bike. It will make it heavier and more expensive. Many people have tried this out but currently available supercapacitors have only a tiny fraction of the energy density of lithium batteries. It’s much better to add more batteries.
by fechter
Dec 03 2021 6:39pm
Forum: General Discussion
Topic: la Nina rears her ugly head
Replies: 2226
Views: 153327

Re: la Nina rears her ugly head

We sure need more rain here. Nothing since the big storm a few weeks ago. I went riding and the soil conditions were great. Not muddy and not dusty. The air quality wasn’t so great though. Seems everyone was burning wood for the holidays. Still made for an interesting picture. 5A8AA31B-4802-4B08-A39...
by fechter
Dec 01 2021 1:10pm
Forum: EBike Technical
Topic: Contactor question
Replies: 22
Views: 377

Re: Contactor question

You might want dissect one of the failed ones to see what exactly failed. If the contacts are fried, possibly your precharge circuit isn't working. If the coil is going open, then it is probably running at too high a voltage.
by fechter
Nov 29 2021 11:46am
Forum: Battery Technology
Topic: Battery Failure
Replies: 7
Views: 213

Re: Battery Failure

The pack was not getting charged AND had some kind of drain. I suggest charging it with a regular charger to bring it back up. If any cell gets below about 2v, it can be permanently damaged. You want to check the voltages with a meter and see what the solar panel is putting out.
by fechter
Nov 29 2021 1:20am
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 628
Views: 37394

Re: C Cab Hot Rod Power Advice

I don't see the point of the relay there. You can turn off everything with the dc-dc.

I suggest only using the parts of it you really need and not use the rest. You can trim off wires you don't need or stuff them behind it.
by fechter
Nov 28 2021 12:21pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 628
Views: 37394

Re: C Cab Hot Rod Power Advice

I guess it doesn't come with an ignition key switch. With a car, the key has ACC, OFF, ON, START. The start position is spring loaded and returns to ON. You don't need the start line. As ZeroEm states, the radio MEM line is always on regardless of key position. No clue what BPUBE is. I assume the re...
by fechter
Nov 26 2021 11:46pm
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 628
Views: 37394

Re: C Cab Hot Rod Power Advice

I'd just leave the main breaker off for storage. Don't forget to turn it on next time you want to run the car! (There's a story behind the advice).
by fechter
Nov 26 2021 11:44pm
Forum: Bike Mechanical & Structural
Topic: Parking Brake for my new ETrike
Replies: 2
Views: 102

Re: Parking Brake for my new ETrike

I've seen several types. There are locking levers for any kind of cable pull brakes. If you have hydraulic brakes, you can add a cable pull for just parking. I've also seen a simple hinged metal piece that attaches to the fork and swings down to contact the tire. It depends on your setup what will b...
by fechter
Nov 26 2021 12:43pm
Forum: EBike Technical
Topic: Power needed
Replies: 3
Views: 117

Re: Power needed

Essentially yes, assuming no inverter or charger losses. If you find an inverter that can handle a 60V DC input, please post a link. I have one similar to this: https://www.ebay.com/itm/223617288135?hash=item3410a107c7:g:5zMAAOSwEhNdTOJ9 A 48v nominal inverter will handle 60v input. I run mine off ...
by fechter
Nov 26 2021 12:36pm
Forum: EBike General Discussion
Topic: Does this make sense? (no chain or belt, pedal operated generator and wires to the rear hub motor)
Replies: 60
Views: 1602

Re: Does this make sense? (no chain or belt, pedal operated generator and wires to the rear hub motor)

But efficiency wasn’t the team’s main goal, and they consider the slight efficiency drop to be worth the tradeoff, which is the increased design freedom that should open the door to countless opportunities for interesting electric bicycle construction. If you want to go faster than standard gearing...
by fechter
Nov 25 2021 11:24am
Forum: E-Vehicles General Discussion
Topic: C Cab Hot Rod Power Advice
Replies: 628
Views: 37394

Re: C Cab Hot Rod Power Advice

The relay would be useful for any loads that are too big for a switch. You may not need it.
by fechter
Nov 22 2021 11:16pm
Forum: Battery Technology
Topic: APL's Pressure Contact Battery box
Replies: 144
Views: 3976

Re: APL's Pressure Contact Battery box

Trampa boards used a PCB with a small disk with a resettable fuse inside for current carrying. They didn't give any details about that proprietary part. Does anyone know of an available part that could be surface mounted on a PCB to provide electrical contact to a perpendicular cell? That sounds li...
by fechter
Nov 18 2021 5:14pm
Forum: EBike Technical
Topic: The bike is not working anymore
Replies: 7
Views: 235

Re: The bike is not working anymore

Carefully check any connectors between the controller and the display or wherever the on/off switch is. Look for damaged or pushed in contacts. If those all look ok I would open up the controller and look for a bad connection.
by fechter
Nov 17 2021 11:20pm
Forum: Motor Technology
Topic: Workshop Dynamometer using BLDC motor
Replies: 5
Views: 173

Re: Workshop Dynamometer using BLDC motor

I'm sure it will provide enough torque. The limiting factor will be heat buildup. As I mentioned earlier, the generator is going to need a fan to keep from overheating if the runs are very long. If your tests are short enough, you can get away without cooling. A temp monitor might be a good thing. T...
by fechter
Nov 17 2021 2:17pm
Forum: Motor Technology
Topic: Workshop Dynamometer using BLDC motor
Replies: 5
Views: 173

Re: Workshop Dynamometer using BLDC motor

The frequency is low enough that impedance won't be a significant factor if your resistor is purely resistive. V=IR will still apply. Things may change a bit if your resistor is a coil of wire and you get enough inductance to change things. A wirewound resistor will have less resistance at higher fr...
by fechter
Nov 17 2021 10:10am
Forum: Motor Technology
Topic: Workshop Dynamometer using BLDC motor
Replies: 5
Views: 173

Re: Workshop Dynamometer using BLDC motor

1. Yes, the voltage generated will be a function of RPM you can calculate using the kV. You'll get slightly less due to losses. 2. Yes, the torque will be a function of the current, so as long as you can control the current, you can keep the torque where you want it. Measuring the current will tell ...
by fechter
Nov 15 2021 11:19pm
Forum: Alternative Energy
Topic: Hubmotor hydro generator
Replies: 3
Views: 135

Re: Hubmotor hydro generator

The undershot wheel is what I was thinking too. You might be able to use a geared hub motor to get a decent rpm but the gears add loss. I tried something like a MPPT circuit but the losses were more than it made up for. It worked better without it. Mine was several hundred feet away and I ran two pa...
by fechter
Nov 15 2021 3:37pm
Forum: Battery Technology
Topic: APL's Pressure Contact Battery box
Replies: 144
Views: 3976

Re: APL's Pressure Contact Battery box

You have to balance between contact pressure, contact area and total contact force. If there isn't enough contact pressure, long term the contact tends to go bad from oxidation. If you get enough pressure, it will tend to keep out oxygen and prevent oxidation. Too much pressure and you either dent o...
by fechter
Nov 15 2021 3:24pm
Forum: Alternative Energy
Topic: Hubmotor hydro generator
Replies: 3
Views: 135

Re: Hubmotor hydro generator

The wheel will probably turn too slow for a direct drive motor to generate efficiently. Do you know the approximate velocity of the water? Of course this will depend on the width of the stream. Something like a trolling generator might work. Years ago I had a DIY hydroelectric setup. I had 46 feet o...
by fechter
Nov 15 2021 3:15pm
Forum: Motor Technology
Topic: Bafang G06 750watt rear hub Winding advice.
Replies: 1
Views: 109

Re: Bafang G06 750 (7) Winding advice.

Do you know how many turns the original motor had? Can you post a picture of it? I don't know what that one looks like. When you take it apart, you can measure the diameter of the stock wire and count the turns. From this, you can use some charts to estimate how many turns of a given wire size will ...