Tuesday, 26 May 2020

passing time

My newest purchase: a Seiko SNK805 K2

For most of my life I've had a watch,  however I've only had three (before). Back in 2007 my third watch finally ran out of battery, and I saw no point in paying for another service (well and none was properly available to me). It was a Seiko Sports 100 Analogue electronic watch. My first had been a simple mechanical and my second a (Seiko) digital and my third (before today) an analogue faced but electronic digital hybrid divers watch.

Anyway, having been more or less content with a phone (and a Garmin training pedometer) for some time, a friend sent me a picture of a Finnish Military (replica) watch and it got me thinking that maybe something like that would be interesting (thanks Anthony). I began discussions with another friend (hello Miles) about some of his adventures in watch collecting and he suggested a Seiko 5 (fully mechanical automatic) might fit my desires. So a quick fish on eBay and I found an SNK805 for a good price. The Green one


I was attracted by the compact nature of it (I'm not built like Arnold Schwarzenegger so I do want something slim) appealed to me. While its a gamble as to if it will last the usual 5 years I got between battery changes on the old Seiko the cost of this watch (less than  AU$140) is less than the cost of the last (back in 2003) service of my (even then rather worn) Sports 100 divers watch (last time we went diving together was 1999 and I could no longer rely on the ratchet of the bezel timer).

This watch

I love the nice touch of the display back to allow people to see the complex, yet somehow simple, nature of the watches inner workings (*when I'm not wearing it).


It fits nicely and despite my ageing eyesight I can comfortably and quickly read the time. I like the outer part of the dial being minutes too.

Lastly I understand that the Seiko 5 has quite the "self repair and modder" community, so that suites me down to the ground too.

I have since read some people don't like the strap ... big fukkin deal ... buy another one. Myself I liked it and it was actually thicker and heavier duty than I expected at this price point.

Money Well Spent

Tuesday, 5 May 2020

scoots and reality

I've got two things I call "my scoot" (well 4 if you count my Widewheel 500W, 1000W and the two pictured)


Interestingly they both cost the same amount to buy, but there are differences.
LHS = left hand side
RHS = right hand side

  • LHS is a month old and has under 700km on it, RHS is 13 years old and has 128,706km on it (almost comical isn't it), I anticipate at least another 40,000km while I seriously doubt that the LHS will ever mange 10,000km
  • RHS one lives outside rain hail or shine, LHS would be dead soon if expected to do that
  • LHS doesn't work well in the rain, RHS been ridden plenty of times in pouring rain
  • LHS has a top legal speed of 24kmh and a top speed of 55kmh, RHS has a top legal speed of 100kmh and a top speed of 160kmh
  • LHS really only good for short around town trips while RHS does everything from long highway hauls to nip up to the shops
  • LHS has questionable insurance cover for personal injuries RHS has full and proper insurance for that
  • operating costs of LHS unknown expect depreciation to by the killer, doubt that it'd do 10,000. Meanwhile RHS has oil changes every 5000km (costs me about $40), oil filter changes every 10,000km (adds $15 to oil change cost), belt change every 40,000km 
  • RHS I could ride 2,000km tomorrow if I chose to, LHS its not even a laughing matter to consider that without a steady stream of stops to recharge every 50km (assuming I only do 27kmh (taking 10 hours, so overnight) so LHS is not even remotely a long distance touring machine
  • recharge LHS costs 1c per km RHS = 7c per km
  • recharge time for LHS is over 12 hours (with standard charger), which might be able to come down to 6 with a high amp charger, RHS is about 5 minutes at the servo
Some years ago I wrote this post:  Do electric scooters dream of being petrol powered?

things are perhaps a bit better now ... but not by much.

If I have to go to the next town I know which one I'll take ...


Mercane Widewheel battery and durability testing

So, about 5 months back I did this test on my Widewheel capacity and found that it performed pretty well and indeed pretty much within expectable specs as delivered. This is despite my regularly (audience gasp) charging it to 100% (because kiddies on reddit are so much more competent battery experts than the engineers who design BMS's and that's clearly going to destroy my battery).

Then again (because it was a fun way to spend half a day) last month took my Widewheel out on another long trip but as that has less hills (than this one) I wanted to do my torture test. Also I wanted to add another few km to the journey to see if it "still made it" and see what the outcome was with respect to voltages.

I thought I'd start not with the full trip, but with just the fastest parts of the down hill, which shows the sorts of speeds happening in more details


So pretty much what I experience in this older video:


As I mentioned this time I added a little extra distance to the trip (compared to the one last year) and so this is the new journey:


which is about 3 and a bit km longer back down off the mountain.

Data

I returned up my street (mild uphill) with about 44.5V showing on the handle bar and it recovered as soon as I stopped (because taking the load off) to 46.5V and a little later recovered to 46.9V. I discussed this discharge curve of batteries in this post about what I believe represents a good model of my own batteries (even though this is a cell) and I've adjusted the Y axis to reflect the series numbers of batteries in my pack.

On this occasion 431Wh was absorbed by the battery during charging, as opposed to the 410 of the last trip.

Considering this in gross terms (ignoring hills, winds and whatnot) this is 17.91Wh/km and on the previous run 19.7Wh/km. Given this run had less hills for the last additional 3.3km and that the previous above mentioned distance run (also not up a mountain) returned results of  16.4Wh/km that's about right.

So (depending on hills) about 15 minutes more riding would be expected before walking at this point, or about another 5 km remaining in the battery. This is essentially very close to what I recorded 5 months ago, and while I wasn't getting as detailed what I found nearly a year back too; which bodes well for "no measurable loss in battery" in the last year of operations.

Looking in details to the trip there and back (I zoomed in on the app for higher precision than seen in the summary) while I had a head wind all the way there which seemed to weaken somewhat as a lesser tail wind on the way back its interesting to see that despite the lower voltage the cruise control clearly does not "suck the battery hard" because similar speeds were seen both sides of the mountain



Worth noting that the climb on the way back is a down hill seen in reverse, so the beginning of the up hill and the end of the down hill were still making around 24kmh.

Consistency is good in this respect and the scoot does not feel significantly like its running out of grunt; which were one running on "unrestricted mode" not only would it not get this distance it most surely would feel more "limp" on the way back (from whatever trip it could make).

Discussion

Generally speaking the scooter gives pretty consistent consumption of energy over distances that are at the limits of its range. It has continued to do this for its life with me so far. Lacking a speedo on the Widewheel I can only estimate the distances done, however if I draw from the experience of my MX60 (which does have a speedo) it's done over 600km in the first month I owned it, and as I've had the Widewheel dual for 10 months now I think that well over 2000km is about the least it would be.

Meaning that its fair to conclude from these tests the following:

  • the Widewheel is durable if maintained in at least a simple manner (adjust the brakes, keep an eye on things)
  • the battery in the Widewheel (who gives a fuck what it is) is up to spec and also durable
  • fully charging the battery would seem to have no observable influence on the batterys ability to perform over that year of hard work (and I don't fully charge it on every trip, I follow the charge it when needed approach)
  • one can estimate that "flat" routes will use 17Wh per km and steep routes (where you'll come back down) may use about 19Wh/km. Using this and knowing the Wh of the battery and adding in a little common sense about the difficult nature of the last few Wh contained in the battery you can plan trips reliably.
Hope this helps

Monday, 4 May 2020

MX60 sidestand fix

When I first got my MX60 I felt that the stand leg did not come down far enough and that unless the scooter was on a slope with the back down to hold the stand down it would roll off the stand.

So I checked out my angle grinder wheel for size and found it would fit in nicely:


allowing me to grind a little off that pin.

So I took the stand off, mounted it in a clamp and carefully ground and inspected in stages.


when I was satisfied enough was offm I could then rotate where I ground off to allow the leg to move further forward. I used a pair of small vice grips to grasp and rotate the pin (I ground it from the left side so have rotated it around 180 degrees).

So now it is more reliable.


a cheap fix and now it works better.