Puma in a 26 inch wheel at 72V

Hello

Well its raining now of course but went out and tested the Puma at 72V, first impressions are its very good indeed, it pulls very hard up to 30mph and then creeps up to a top speed of 38mph on the flat, this is with super nobbly tires though I may get a bit more with smoother road tires and a bit of fettling.

I think in ideal conditions (no wind and rain) on the flat in normal temps 40 mph would be easily held, hill climbing was great 26mph up a hill my trek normally takes at 15mph, so looking good.

The testing was going great until I noticed the power roll off, one of My Andersons has gone bad and I was only running on 2 phases, so have changed and will report back when the weather is better, will do a film as well with the gps on the bars, I can put the gps in my pocket now.

I am going to really put this motor and wheel through its paces soon to see how it fares as I need to make sure its rugged enough to stand the test of time.

Cheers

Knoxie

so pretty much the same top speed as the X504 then? 20 mph at 36 volts 40 mph at 72 volts. though i imagine it has loads more torque.


what happened to the anderson? was it corrosion? I've been wondering if corrosion on my anderson is contributing to higher voltage sag than I was getting before.

Hi Nick

Yes it will perform the same I will let you know as soon as its not wet and I can get out with camera.

The Anderson connector was one I had not crimped correctly and not noticed, it had been arching inside and was badly worn, it got so bad that it pulled away and at 72V was just not going to work.

Boy it was sweaty cycling back!

All good to go again now!! will let you know how it runs in the week.

Cheers

P

Do you have any pictures of the Anderson?

hi

hah i binned it, the xlyte controller power leads come with cheapo copy andersons, so do the batteries, the are like Chinese copies and are really poor quality, I change them for real ones as soon as I get a controller.

Cheers

Knoxie

wow i have never seen the chinese Andersons. those bastards will copy anything and it is usually junk. too bad, since they can do better.

for those who have not used it, there is this cool stuff called dielectric grease you can use to protect the connectors. it keeps water out and prevents corrosion. You just smear it in the connector housing and when the contacts mate they push it out of the way, but it stays there surrounding the connection and keeping oxygen and water out. you can get it from electrical supply or auto parts places.

Hi Bob

Yes the problem with the cheap copies is that the terminal pushes out of the housing really easily, its not the contact so much as they look ok (ish) its the housing, its really poor.

The dielectric grease tip is a good one however it is very expensive for me to buy, I use Vaseline works very well indeed.

Yep they will copy anything bob, expect to see a production version of your cruzebike next month :wink:

Cheers

Paul

Hi guys, yes, any grease is "dielectric" and may be employed.

We'd just want it to be acid neutral, without addtives that may tarnish copper or tin.

Silvered contacts work just fine if tarnished because silver oxide is conductive. But we wouldn't want to oxidize the base metal beneath the silver.

Hence, I think the best grease would be a stiff silicone synthetic grease--absolutely inert stuff.

Worst? Any sort of animal fatted grease.

knoxie said:

Hi Bob

Yes the problem with the cheap copies is that the terminal pushes out of the housing really easily, its not the contact so much as they look ok (ish) its the housing, its really poor.

The dielectric grease tip is a good one however it is very expensive for me to buy, I use Vaseline works very well indeed.

Yep they will copy anything bob, expect to see a production version of your cruzebike next month :wink:

Cheers

Paul

Click to expand...

And the knock off housings melt easily...

some of my andersons are seriously corroded. interstinlgy its the ones that get used all time. i cleaned them up with with some alcohol and they instantly gave me a couple of extra volts under load. however they've since gone back to how they were. I'm going to replace them and use grease this time, I think the silver plating soon goes if exposed to water and constant use. I'll get some pics when I do the rewire.

Do your andersons wiggle in their housings ? or are they cramped in there tight ?

If they don't wiggle.. the spoons won't sit paralell to each other and result in a very small contact patch.. and corrosion from arcing..

I think the silver plating soon goes if exposed to water and constant use.

Click to expand...

Silver and silver compounds oxidize (tarnish) with normal exposure to air.

http://educ.queensu.ca/~science/main/concept/chem/c03/C03DEEA1.htm
"Silver tarnishes because it undergoes a chemical reaction with sulfur-containing substances in the air.Silver combines with sulfur to form silver sulfide, which is black, and darkens the silver.The silver can be made shiny again by removing the silver sulfide coating from the surface. "


Entries about proper silver polishing:
http://educ.queensu.ca/~science/main/concept/chem/c03/C03DEEA1.htm
http://en.wikibooks.org/wiki/Polishing_silver

The Silver Battery Tarnish Remover:
http://www.faqs.org/faqs/sci/chem-faq/part7/preamble.html
"A very popular technique for removing tarnish ( silver sulfide ), involves an electrochemical cell that utilises the electrochemical series. In an electrochemical cell, oxidation occurs at one electrode, whilst reduction occurs at the other. Electrical contact between the two metals provides the pathway for electron migration to occur from the anode to the cathode, and when immersed in an electrolyte, charge will be balanced by transfer of the sulfide ions.

The standard electrode potential at 25C of Ag+ + e- -> Ag is +0.799V, and if the other metal is anodic relative to silver, the silver in the sulfide at the cathode will gain electrons and revert to metallic silver. The metal at the anode will be oxidized by the removal of electrons. The sulfide ions can travel to the anode via the electrolyte. The electrochemical series indicates metals that will work, and some readily-available and cheap metals are iron, zinc, aluminium and magnesium. The standard electrode potential at 25C of Al3+ + 3e- -> Al is -1.66V, and aluminium foil is cheap.

When aluminium is the anode, and water is the electrolyte, the aluminium surface will eventually be coated with an insulating film of aluminium sulfide - which will gradually decrease the cleaning speed. Adding sodium bicarbonate ( baking soda ) or sodium carbonate ( washing soda ) to the electrolyte will assist in the evolution of hydrogen as the silver is converted, and the hydrogen will combine with the sulfide ions to produce some hydrogen sulfide gas ( rotten eggs smell ). The aluminium at the anode will be converted to aluminium oxide. "

thanks for the info guys

yeah, one of them is a bad fit, so that might be the problem. I'm going to rewire the pack anyway so i'll take them off and photograph them. from the colour of them they look las if all the silver is gone! but too soon to say. will get pics soon. Another strange thing that might be related is that my braindrain reads 21 watts at 48 volts even with the contoller disconnected. reads 10 watts at 24 volts, be interesting to see if what happens when I rewire everything

Have you tried setting the Zero Amps option in the DrainBrain setup?

whats that?

Ach!

We don't want to remove silver tarnish, because

it is perfectly conductive!

If we polish thin silver plate, we're removing beautiful conductor,
thinning the plate, allowing the base metal beneath to, itself, tarnish (which is basically irremedial!)

Don't polish black silver contacts. Just don't do that, please!

Milspec stuff from before WWII is all silver contacted, and still working without a need for a "polish". It's nickle plate, tin plate, zinc or any other metal, that causes contact resistance. But not silver! Silver is better than gold.

NPSP!

that's my hector-lecture for today, lol!

never polish silver plate unless it's granny's pisspot