OT My second electric bike

Pictures have been added. So far, so so. Have taken it around the block a few times, and taken it about 2 miles to and from the store. The DCD995 gearcase makes more noise than the DCD780. It's more powerful and top speed is higher. The gearcase seems to get warm easily. I'm using Park Tool grease in the gearcase. Strangely, there seems to be no slapping/banging against the freewheel pawls when throttle is applied. This time I'm using a derailer for the chain tensioner instead of using a homemade semi-rigid chain tensioner. But I don't understand how that stops the banging when the sprocket catches up to the wheel speed. Maybe it has something to do with the brushless motor. Whatever, if it is as it seems to be, that's great. Still to be determined is top speed, miles per amp hour, and durability.

On Thu, 5 May 2016 03:05:13 -0000 (UTC), John Doe Gave us:

Dude, you are almost at the same level as Skybuck Flying.

You could have saved pennies in a piggy bank and gotten together enough for a hub motor AND a battery by now.

You'll be lucky to get a 200 foot range with that at 3 miles an hour.

An old 50s style automotive generator configured as a motor would do better. I made a go-cart with one back in '72.

On Thu, 5 May 2016 03:05:13 -0000 (UTC), John Doe Gave us:

You should try whale oil.

On Thu, 5 May 2016 07:40:28 -0000 (UTC), John Doe Gave us:

You are just pissed because I properly pegged you as being even more stupid than the group invading Skybuck idiot is.

What you did is not a metalworking craft, nor is it electronics, dipshit. Go the f*ck away, boy.

Nor is it a viable method of propulsion for even a single human.

You are so stupid, you likely do not even know what a sun gear is.

And you are a stupid Usenet top posting retard, AND you are a stupid Usenet group adding dumbfuck.

I'm writing a magazine article about cordless power tools. I'd like to use one of your photos (or maybe you'd like to shoot one just for the article) and a few lines about your experience. I need it by early next week.

Interested? If so, send me an email to my business email address, which is snipped-for-privacy@techgenmedia.com

*Version*=1&*entries*=0

I housed the shunt in a plastic conduit tee fitting. The separate ground power and sense leads are necessary. It does NOT read reversed current.

--jsw

Might be pricey as it's Fluke, but there are probably cheaper ones out there.

The 100A model has a separate shunt you put in the negative cable from the motor to the battery, and then run four thin sense wires to the remote display. The 20A one has an internal shunt and is better suited to mounting in the charger. They read current and calculate power in one direction only so you need two if you want to monitor both charge and discharge.

If the drill battery has a temperature sensor connection be sure to extend it as well as the power leads, unless you want to leave a trail of red flame behind you.

--jsw

I don't think that one has a remote display, though. JD would like to have the display on the handlebars, but does not want to extend the wire on the bike to get there.

It displays voltage as ##.##V, current to #.##A with decent accuracy, plus power (Volts * Amps) to 0.1W and the accumulated energy in Watt-hours since the last reset. The Watt-hours consumed in a mile, divided by the battery voltage, gives you the Amp-Hours used.

--jsw

The meter's microcomputer stores the accumulated energy value in nonvolatile memory so it doesn't need to be powered continuously. I plugged mine into the nearly dark solar panel a few minutes ago, without a load, and it still shows 1041Wh from when I discharged a battery through it last winter.

The only real electrical consideration is to be aware that the thin wires to the display are directly connected to the battery and could burn if shorted to each other or the frame. I made the connections at the conduit tee fitting that encloses the shunt with in-line fuseholders similar to these:

--jsw

On Fri, 10 Jun 2016 16:05:41 -0000 (UTC), John Doe Gave us:

You ain't real bright. Ever heard of a shunt and a voltmeter?

Sheesh.

On Fri, 10 Jun 2016 16:19:17 -0000 (UTC), John Doe Gave us:

With your lack of grasp of electronics, you should be over in the basics group.

On Fri, 10 Jun 2016 17:29:21 -0000 (UTC), John Doe Gave us:

The fact that you are oblivious as to this BASIC electronic principle proves you should not be in this group.

BASICS is the group you should be in, and you barely qualify for that one.

Yes, then you measure the *voltage* across the shunt. This can be done with small wire. The primary concern is mechanical.

That's exactly what it means. ;-)

Ignore AlwaysWrong. He doesn't how to do this anyway.

[ ... ]

"This group" happens to be two newsgroups. It is cross-posted. The newsgroups header is:

====================================================================== Newsgroups: rec.crafts.metalworking,sci.electronics.design ======================================================================

He started out discussing this in rec.crafts.metalworking and I don't know whether *he* added sci.electronics.design to the newsgroups list, or whether someone else added it, expecting it to be a better place to get the needed information. If the latter, he may not even have noticed the addition of your newsgroup, just as *you* did not notice rec.crafts.metalworking was part of the cross-posting.

You could add the basics newsgroup to the Newsgroups header, and result in even more vituperation -- especially from those who do not notice the other newsgroups.

And -- you could add a "Followup-To: " to the headers, which would make only the replies to your articles go to the named newsgroup(s), and other replies would still be cross-posted as before, so it is a loosing battle.

Yes, a good shunt down at the motor/battery interface to measure current, and two more leads for the voltage across the motor should allow display of everything he wants. (Actually, three leads would suffice, if done right) But if routed up to the handlebars, while light gauge wire would do nicely to carry the voltage signals up to the meter on the handlebars, I would advise fuses in all wires, in case they get pinched together. (I don't know whether anything is grounded to the frame, but a pinch which cuts through the insulation could get exciting if the wires run along the frame near his thighs.

Enjoy, DoN.

I tried three leads so I could exchange the shunt connections with a DPDT switch to read current in the Charging direction. The backlight draws enough current to significantly offset the sensed shunt voltage, which is only 75mV full scale, and 75uV at 0.1 Amp. It really needs separate power and sense wires.

--jsw

On Fri, 10 Jun 2016 20:21:06 -0400, krw Gave us:

You're an idiot, and you know nothing about my abilities.