My Outrunner-Upgraded Small Light Viza Volt Scooter

[swbluto]

More user experiences at higher current levels:

The brakes started getting weak and really squealy after a stop-go commute home. Also, the back tire was at 130 degrees fahrenheit even though the ambient temperature was 72 fahrenheit. Something in the drive system is becoming more noisy as I'm hearing a "clack clack" while slowly walking it. With that, I have a feeling I'm going to be needing to take apart the motor sooner than I wished. The 14 gauge wire also apparently gets hot(I would describe it as 150 degrees fahrenheit) while pushing 40 amps and so do the 45 amp connectors(Although, that may of just been the wire's heating bleeding onto the andersons).

Anyways, all and all, it doesn't seem like my scooter is meant for constant 25-30 mph speeds in a stop and go environment. Bummer. So, I guess I'll just go 20-25 on a consistent path-way (10 to 15 on campus) and go WOT on the occasional smooth roadway.

Edit: I measured a typical 30 mph with intermittent 10-20 mph periods ride which meant the average motor current was probably something like 60 to 70 amps right before coming home, and I put my hand on the motor's can. Oh jeez, it was hott! By my estimation, it was probably around 140-150 degrees. That's the part of the outrunner that holds the magnets, so it seems I'm starting to pushing the motor's heat tolerances. It seems that heat tests for continuous hills would be necessary, and I probably won't ride another large hill until June 20th. In the other news, I haven't measured my controller to be above 140 degrees so far. I'm guessing the fact that the controller is no longer doing current limiting with relatively high currents means that the average switching losses has significantly decreased. Ironically enough, though, if I slow down, my current limit goes down which practically ensures current-limiting which means greater controller heat. So, in essence, for my situation...

more speed = less controller heat, greater motor heat
less speed = more controller heat, less motor heat.

It's a fine balance, I suppose.

On a hill, more throttle would generally mean greater controller heat AND motor heat since the "top speed" nearly always corresponds to a motor current level in excess of my programmed current limit, so there's no trade off there.

[swbluto]

Well, anyways, I was wanting to do some hill climbing testing and I attest there aren't any huge hills in the area immediately around here (I.e., walking distance), so I made due with a short drive-way. I measured the angle of the road to be 18 degrees which corresponds to something like 30%, and my scooter was able to climb up it at around 5ish mph. My ebike calculator seems to suggest that, suggesting my simulator is probably accurate for grade-related speed information. So, I could probably trust its assessment of 15-20 mph on an 8% incline.

As a comparison, my hub motor on the bike that consumed nearly as much power would come to a complete stop at 8% and its top speed was only 30ish mph. So, in essence, geared drives rock! (Or something's rocking that I'm not quite spotting. My batteries are putting out something like 1200 watts(30v*40 amps) and my ping battery put out like 900-1000 watts, so there's not too much of a difference in terms of input power. Aha! It must have to do with the much lower internal resistance of a higher-RPM motor that results in generally higher efficiency at lower speeds.)

[recumpence]

I have found high RPM geared down gives HUGE power with reletively good efficiency.

Your experience is the same as mine in that way.

Matt

[swbluto]

Indeed. Anyways, I went away from the "different battery" comparisons since I thought that might be unfair, and compared a 48v battery limited to 20 amps on my original c'lyte 407 bike and my scooter(Basically, same battery, different drive systems). The original c'lyte would've gone 10 mph whereas the scooter would've gone 16 mph up a moderate hill. I think that's significant.

In the news, I got a flat back tire. I looked at the tire and there are no visible puncture marks, so I'm guessing that the Mr.tuffy liner isn't appropriate for an 8" tire or I was simply bad at installing it. But, I can't confirm that as I don't have the tools to take apart the hub and replace the tire. So, I'm stuck until I find the right tools and, in the worst case scenario, that appears to be 1 month from now. I'm going to visit the local e-scooter shops in the area just in case I might luck out with whatever resources they have. Two companies that I'm thinking of is http://soundspeedscooters.com/ and http://www.levseattle.com/, but I don't get the impression they have anything related to my scooter. (Although, I think I saw that LEV seattle's store had a few scooters with 8" kind of wheels, so maybe.)

[swbluto]

I went to Soundspeed scooters and the guy there had this nifty tool that was used to pull off the brake hub. He went onto say something like "All you have to do is cut up these metal bars, drill a few holes, put a few screws here and there..." and I replied "But I don't have a metal fabrication shop.". And, $20 later, I was in business. I can remove the brake hub that's necessary to taking apart the wheel to replacing the tire so now I'm replacing it.

I just took it apart and found out that it doesn't seem like Mr.Tuffy does so well in 8-inch tires. Upon taking it apart, there was a ton of this black dust that I assumed to be rubber that came out immediately. Taking out the tire, I found Mr.tuffy bent backwards and wrangled up and the inner tube had a lot of rubber shaved off near the edges where the Mr.tuffy touched it. I blew the tire up and discovered the hole was, surprisingly enough, near the center of one of these "Mr.Tuffy" craters/ditches. So, I've ditched the Mr.tuffy and opted for the Green Goo in getting me threw the next set of inner tubes. In the mean time, I need to order more inner tubes and I think I should think about doing something to the front inner-tube that I don't believe I've done anything to.

[swbluto]

Ok, I replaced the back tire and it seems to work well, so far. I noticed that my back tire started skidding a bit when braking from 25-30 mph on some nice sidewalk-like pathway.

I noticed that my connector's pins on the serial back connector would be pushed back when connecting it. This was noticeable because my scooter wouldn't work when twisting the throttle. So I'm trying to use CA glue to secure the pins to the connector and I'll try to remind myself to not push too hard.

Other than that, I tested out my scooter on this 5% type of hill on campus to see how it would do and, man, it's awesome how this thing just eats hills - I was easily doing something above 20 mph! This is so much better than my electric hub bike, by like an infinity. I was also doing some simulations, and it turns out that the scooter's thrust in the lower area of the speed range is about twice as much as my bike which means... twice the acceleration(I've fallen backwards off it a few times!)! Twice the fun! And more hill climbing speed! I can only imagine was 60 amps would do.

But I'd have to upgrade my cables as they get pretty toasty right now (About 130 to 140 degrees).

[swbluto]

Ok, I was just doing some aerodynamic measurements. I found out that my "frontal surface area" was about .7 sq. meters standing up. I used google to do the conversion for me - average width is in inches and the height is in feet. Basic formula -

(average width*height*12) sq. in. in sq. meters

So I googled...

http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=Zvp&q=%286*15*12%29+sq.+in.+in+sq.+meters&btnG=Search&aq=f&oq=&aqi=

for example. I then bent down to see what my frontal surface area was in the "aerodynamic scooting position" and it came out to .4 sq. meters! Doing the simulation on that and I was achieving 35 mph! So I've been probably getting 32 mph on my scooter, in the bent down position, haha (I don't know if I'm accurately taking into account the bad bearings on my motor, though, so maybe it's more like 30). I don't usually hold it in that position for long periods, though, since it's not too good for the back, but I will for the occasional .3-.5 mile straight stretch of road. The thing I realized is that I'm taking up less cross-sectional area than I am on a bike. The bike requires the legs to go the side of the bike whereas the legs can go directly behind the handle-bar stem on the scooter in the right position. Also, I'm kind of forced into a slightly upright position on the bike and I'm not aerodynamic at all.

But, compared to standing up, the scooter does worse as I found my surface area .7 m^2 as opposed to the usual .55 m^2 during biking. But considering I'm standing up when my typical speed is more like 10-20, aerodynamics doesn't matter as much.

[swbluto]

Just a quick list of updates.

I've upgraded the bearings and added some extra epoxy to the magnets to help secure them. When I damaged the motor in the process of upgrading it, I noticed that it had difficulty installing everything on the scooter's mount and frame, but I tried to work around it and it's been successful so far. It seems that the clicking I tried to get rid of didn't disappear, but it does seem quieter and the motor seems to turn more smoothly. At a distance (say 100 ft.), the only thing I could hear was the whine of the electric motor, so it seems there should be no worries about reducing whatever reducible sounds that I think may bother others in the vicinity (I can't really get rid of the whine).

Also, the home-made Oak wooden motor mount split along the grain so I decided to revert to the aluminum and acquired some 1/2" 6"x48" aluminum stock from Earthworks Recycling and acquired the necessary machinery to work with metal (hack saw, special hole saw, metal-working radial arm saw blade) and then fabricated the necessary bits. One thing I can easily say is that working aluminum is much louder and slower than working with wood. I'm kind of glad that I now have aluminum stock hanging around because I have a feeling I'll be creating another motor mount for the other HXT motor I have.

Also, it really seems I have bad luck with the data-wire connector. The DB9 connector (standard serial port type, I think) seems great, but it doesn't seem like I'm hooking up the wires correctly or crimping it right or something because the wires have ripped out of the connector due to stresses and such. So, I'm looking into getting "the right crimper" (I thought my servo crimper would've worked) and trying again with official 9-wire ribbon cable instead of individual strands. Any suggestions for a 6-15 wire connector that has a pretty high connect-disconnect cycle life and is pretty easy and quick to connect while remaining relatively secure under moderate forces?

[swbluto]

Ok, so I got to experience my new and improved temperature sensor now that I've got it installed "correctly". I've programmed it so that it temporarily reduces the maximum current depending on how much over the limiting temperature is (and cuts out completely at the cut-off temperature) and I started to notice a significant decrease in power (i.e., my "top speed" wasn't nearly as fast). I at first worried I might've over-discharged my a123s but their resting voltages was at 3.24 volts per cell average, so I checked the ESC and it felt like it was about 190 degrees Fahrenheit. I let it cool for 10 minutes, and revved off again and it was as powerful as I had known it, with its 30+ mph top speed and all. So, yay, it works! It doesn't cut-out, it just becomes a noticeably poorer performer.

I also felt the motor's "can"/"bell"/case and it was pretty hot, like probably 170 degrees fahrenheit. It seems these HXT motors get pretty hot at what I'm calculating a ratio of 40 continuous amps for 700 grams or .7kg, so about 60 continuous amps per kilogram. Improving thermal transfer on these motors like livingforphysics has done would probably substantially alleviate this. It looks like the 1.5kg motor I have can put out 90 continuous amps, which corresponds to about 42-45 mph on a standard bike. With increased cooling effectiveness, maybe I can eke out 50-55. Although I'm only really looking for 40ish mph with power to spare on hills (And that seems to correspond to a gear ratio of 15 to 1, eeks.).

Also, the ground wire ripped out of the crimp-style DB9 connectors I've been using suggesting I'm not making these connectors correctly or something, so I decided to splurge on official connectors that already had wire attached and I just hacked that apart (The lack of ground wire effectively disabled my throttle and produced strange seemingly random behavior in the motor). I secured the dable at two points on the scooter's frame so that virtually no stress is placed on the individual wires that I twisted together and soldered to the brake and throttle lines. And I have 5 wires to spare, yes! I just wonder what kind of current carrying capacity 26 gauge is, however, cause I need to power the back-light to the LCD module.

Hmmm... it seems this place thinks it's about .4 amps. Shucks. Oh well, I guess I could power the backlight at 40% (It seems 100% corresponds to 1 amp).

[swbluto]

So I took the scooter through about .3 miles of grass fields since the alternative was dirt roads. It was bumpy, but it made it through! About 2 miles down the sidewalk, I felt noticeable clunkiness in the back wheel and upon further inspection, it seems the bearing had popped out and it was spilling its balls! So, uhhhh, I have to correct whatever to prevent that in the future. For now, though, it seems my electric vehicles are on hold. I could possibly get the bike up and running, but it doesn't really go that fast at lower voltages and I don't know of an easy combination with my existing batteries to produce a desirable top speed and capacity. (I have the following batteries - 10s2p a123 30v 4.4 Ah; "48v 10ah" more like 30 volt 8 ah ping 1.0; 24v 20Ah ping 2.0)

My 48V 10ah battery is problematic and is now more like 30 volts 8ah and it doesn't have any sort of protection on it, although I was building an LVC prototype for it originally. I guess I could combine that with the 24v ping to get 54V 8Ah. That would produce a desirable voltage and a range comparable to what I originally had (Like 10-14 miles). There's a significant weight and space penalty, though, for the unusable capacity.

The area around the bearing is pretty complicated to describe, but the wheel is tilted at a slight angle relative to the line of motion since the timing pulley on the wheel is about 1/2" to the right of the timing pulley on the motor. I wonder if this might've have encouraged it to pop out when the belt was spinning the wheel? Also, I noticed this small metal tube had penetrated the inner race into the bearing - I wonder if that arrangement was bad for it? I don't know how it was originally set up, but it seemed this arrangement has worked up until right now and it kind of seemed logical, but I'll admit I'm clueless about wheel-bearing mechanics.

For now, I'm guessing I'll want a longer shaft to put into the motor and I suspect that's going to take me time to source as it'll probably have to be custom made (But I don't have a lathe, I believe.), and that'll allow me to reverse the timing pulley to bring the timing pulley more in line with the wheel's pulley - that's the way it was originally set up on the original motor. And I'm thinking that I might have to do something about how the metal tube part was pressing on the inner race - I'm not sure if that was a bad thing to do. It seems like the inner race and shield doesn't move while the outer race does move as the wheel rotates, and I think I KNOW you're not supposed to press on the shield, so I guess it might have been O.K.

[swbluto]

I replaced the destroyed bearing with a sealed bearing I purchased locally. It looks like the washer had penetrated the inner race on one side suggesting that there was some pointed force that probably was the result of the wheel's slant and the immoderate forces involved with riding through grass on small wheels. The wheel's slant is due to the belt misalignment.

I'm trying to align the belt by reversing the timing pulley on the motor as my options are limited as its pretty space constrained. I also had ambitions of quieting the clicking by securing the timing pulley to the motor's shaft. In that pursuit, it seemed like 2 perpendicularly oriented spring pins sounded like a good idea but somehow the drill hole wasn't aligned enough for the spring pin for the first spring pin, so I became frustrated and reverted back to the set screw method. Also, my belt broke when launching from a start and it seems likely that's due to meager belt tension and whatever that causes skipping (Possibly the oscillating timing pulley that's causing that clicking sound?) and also possibly the belt misalignment. So, I got some belts and found out that it's the wrong size, so I ordered "official belts" from Viza motors directly. I don't know if the 500m "old version" or 535m "new version" would work best for mine, so I ordered both. Hopefully they'll both work so I'll have a backup.

Anyway, I think I'm going to stop riding this scooter for fun and personal transportation for at least some time (until I get a backup RC vehicle going). I have no problem fixing things but I can't temporally afford having a broken down RC vehicle, and something breaking on it typically means I have to order a part online and wait a week.

And, oh yeah, by the ways... "the motor" nor the controller has shown any problems yet. It's the other mechanical stuff on the scooter that's been causing me grief! That might have to do with the fact I'm exceeding its designed power limit by 6 times...

[swbluto]

The motor's sound making has changed from the annoying clicking to rubbing. I noticed that the timing pulley was topsy-turvy as the motor's shaft rotated and I think this led to rubbing on the motor mount. I was riding and suddenly the rubbing sound just disappeared and the scooter was just soooo quiet with its belt and my speed started increasing as well! I was hoping that whatever happened was going to be permanent, but stopping at the top of the hill proved otherwise. This is when I became motivated to achieve mechanical "perfection" after having a brief glimpse of what it was like and confirmation that it was possible.

So, I resolved to acquire the necessary supplies. It appears I "whollered" the original timing pulley when I was filing down the D-bore into a round one the shaft would fit in. So, I'm going to try to get a small-toothed pulley and enlarge the bore to 8mm (or whatever the diameter of the shaft is - I'll be getting a caliper soon to know); Further-more, I'm going to replace the shaft to make it longer so I can put the timing pulley on the shaft in the "right direction"; And, now that I'm going to make it longer, I'm thinking about adding an external bearing support to help take the load of the main motor bearings.

So in the process of taking apart the motor to find out what was causing this problem, I noticed that it was difficult to take the motor apart so I eventually evolved to a hammering it out using some rubber to distribute the pressure on the windings and a bench vise to hold it. It worked! The back bearings popped out to.

So, I thought maybe the magnets were rubbing against the bell - I looked at the magnets and they all seemed to be pretty scratch free. They were all still encased in the extra epoxy I used and none seemed to have "slipped", a common problem with the original epoxy (Apparently the newer versions of the Turnigy motors are more generous with the epoxy and they have better support). So I looked at the next culprit - The bearings. The back ones, the ones away from all the lovely pulley on shaft action seemed to roll as smooth as bearings. The one right next to the pulley, right where the scooter wheel flings mud and debris on the shaft, was slightly less smooth. Despite this, it wasn't clicking.

I then started checking the inner race using a small pick hook, and I noticed the pulley bearing's inner race was slightly wobbling around. I checked if the back bearings had this behavior and they didn't - they were as secure as could be. Uh oh. Place pressure on the front bearing started to cause a noticeable "click", so I thought I found the cuplrit.

Was it a small piece of dirt that inserted itself and wreaked havoc? It was an "ultra seal", which isn't exactly meant for off-roading, so maybe it was vulnerable to that damage. Or was is the fact it was closest to the point of belt tension and thus suffered the most stress? I don't know and I just want to find a solution (or set of solutions) that solves "everything", once and for all.

So, what's it going to be?

-Change out the front to rubber seals. Get pack just in case the back ones might need it.
-Lengthen the motor shaft to mount the pulley properly.
-Add an external bearing support on the outside of the scooter's frame to take the stress off the motor's miniature bearings.
-Get a new timing pulley. Make it a 15mm-5mm one and enlarge the bore to 8mm.

Where to buy
-Get the timing pulley and shaft from SDP-SI.
-Check with the local bearings guys to see what they have. If they don't have 8mm bearings (Surprise, surprise), get them from Boca bearings.

I also noticed that there's these "roller bearings" that seem to be easier to mount. Would those be more appropriate not considering their ease of installation?

[liveforphysics]

Take a few detailed photos of the current drivetrain layout, and of the parts that failed. I will help you arrive at a durable solution.

[swbluto]

Motor bearing

DSCN5910.JPG (94.14 KiB) Viewed 983 times

The bearing you see in the picture is the one with the inner race that wobbles. It's where the shaft goes through and attaches to the timing pulley.

DSCN5912.JPG

General drive-train layout

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Here's the general drive train set up. It looks like it could be lengthed 3 mm so I could use a 15mm belt and pulley. I was also thinking about lengthening it to mount an external support bearing on the "outside", using some kind of aluminum mount that takes advantage of the existing screw holes. To use an easy to use "roller bearing"(What's the name) with two holes for mounting, I think I'd have to include spacers to allow some room between the external bearing mount and the original frame.

[liveforphysics]

Can I get an under side pic?

Also, can you show pictures of the failed bearings, and the spot on the shaft that the failed bearing was? You can tell a lot about what caused bearing failure from looking at a failed bearing. You can tell if it was angular loading, over speed, foreign matter, side loading, etc etc just from a little peak at the bearing and shaft.

With out first understanding the failure, you can't intelligently begin to improve a design.

[swbluto]

Can I get an under side pic?

Also, can you show pictures of the failed bearings, and the spot on the shaft that the failed bearing was? You can tell a lot about what caused bearing failure from looking at a failed bearing. You can tell if it was angular loading, over speed, foreign matter, side loading, etc etc just from a little peak at the bearing and shaft.

With out first understanding the failure, you can't intelligently begin to improve a design.

EDIT: Understood. The below is my original post but I'll see what more pictures I can get. Do you want the underside of the bearing? I think I'll have to remove the bearing, which is what I'll need to eventually do anyways.

motorbearingHighlights.JPG

Some highlights

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The first picture, with motor right next to the shaft that's attached to the bell, has the bearing right in the center. It's silver colored. That's the only bearing that failed and the inner silver part wobbles (What I call the inner race). The shaft goes into the motor as shown - just imagine it being horizontally transposed in its current position and there you go.

I'm really hesitant about putting the motor back together since it was a huge pain to take it off. I'd really like to avoid that at all costs and just have everything fixed before reassembly.

How about a video showing the bearing's symptoms? "Wobbling" is a dynamic thing.

[liveforphysics]

Ohh, for some reason I thought you had a catistrophic bearing failure, and I was looking for pics of all the way around the inner and outer races. Looking at the outside of the shells is very tough to tell much, as the way the bearing is mount (press fit in aluminum and slip fit steel shaft) makes a lot of difference in how the surface will appear.

You should just stop by with it sometime, and we can machine up a whole new ultra beefy dual bearing support and motor mount plate, and TIG weld it onto your scooter chasis and call it a day. Probably only take a couple hours to make if you aren't worried about looks.

[swbluto]

Since experiencing "PERFECTION" once upon a rare moment, I sought to permanently attain it. I realized that it was possible to make this scooter relatively silent with the belt drive and all, and after engaging in the quest detailed in this thread http://endless-sphere.com/forums/viewtopic.php?f=28&t=11471&start=75 , I finally made the pulley wobble a relatively minimal amount and the pulley no longer scraped against the motor mount and it's quiet! Ahhhhh, what a dream. The 10mm hole I made wasn't exactly center, so it does have noticeably varying tension when the wheel turns, but I'll probably retry and center it when I service the motor or tire again. Thanks to Luke's excellent experience and suggestions, I may actually exactly center it and I've already benefited from the "Put the epoxy in a bag, knead it, and cut a hole in the corner for dispensing" trick which was quite awesome, by the ways! No mess!

Basically, I filled the malformed hole of the pulley with epoxy and then drilled it using the appropriate drill size corresponding to the shaft diameter. I had to learn the tricks behind "squaring" and general machining methods to get this result, though.

Since doing this, I've noticed the motor is now much cooler after a run. At 40-50 motor amps, it only seems to get maybe 115-120 degrees fahrenheit after a long run with few stops (The bell would usually be at 120 degrees and the timing pulley would be around 110 degrees, whereas before, the bell would be at 130-140 degrees and the timing pulley would be around 150-160 degrees). This suggests I could probably quite easily run this at 70+ continuous motor amps, which means greater speed, but I honestly feel its current speed is fast enough considering the brakes I have onboard and the feeling that a few other users of the road don't quite see me. What really matters is that I could up the current limit which means greater hill climbing power! I would want to center the pulley first before doing that, because I can see how the varying tension would aid in belt breaking and motor bearing damage at higher torque levels.

[swbluto]

Okay, so I verified that my scooter can "handle" 350 lbs. I had two people on this scooter yesterday night and it was fun in a hazardous sort of way. The person in the back had hold of the outer part of the handle bars (including throttle) and that was me, and then my cousin was in the front just standing along for the ride.

It was predictably slower(Like I felt our top speed was 15 around mph on flat land or maybe 6-8 mph up barely noticeable 1%-2% hills, which might actually have been good for our safety's sake) and my left-side visibility was limited, but it seemed fairly OK for short jaunts along pretty OK stretches of sidewalk with no other pedestrians. We were passing this one older lady and we were going maybe three times as fast (So I infer our speed at that time was probably 9 mph) and I can just imagine what she was thinking... "WTF?" or some other generation-adjusted phrase of bewilderment.

I don't think the brake would've handled that much weight for long, though. It tends to overheat and stop working when "over-used".

[swbluto]

Just an update.

I love my electric scooter. I traveled along an epic trail with an epic lack of people (It was 27 degrees fahrenheit today, ha.), crossed the border, went to a store, found out it got dark much earlier than I thought it would, spontaneously duct-taped my halogen light on (Thank god I brought it), and then pierced through the darkness at what felt like the speed of light on the way back. It was just...

epic.

There's no way you can get that experience with a car, and I've owned and have recently driven cars.

I traveled about 12 miles today in all. The bus transported me about 30 miles more.

[liveforphysics]

Just an update.

I love my electric scooter. I traveled along an epic trail with an epic lack of people (It was 27 degrees fahrenheit today, ha.), crossed the border, went to a store, found out it got dark much earlier than I thought it would, spontaneously duct-taped my halogen light on (Thank god I brought it), and then pierced through the darkness at what felt like the speed of light on the way back. It was just...

epic.

There's no way you can get that experience with a car, and I've owned and have recently driven cars.

I traveled about 12 miles today in all.

Good for you man! There is a special feeling with 2 wheel travel that 4 wheel travel just can't match.

[Storm]

I'm with you man I love my scooter too!! theres just something about their versitility.

[swbluto]

Yeah, that's what I kind of like about it is the versatility - it has the advantages of motorized speeds, but also it can go just about anywhere where a person can go: on the bus, up stairs, through narrow openings, in the trunk of a car, etc. That, plus it's super-fun and pretty comfortable compared to my e-bike.

Anyways, I'm kicking myself. My drive belt broke, AGAIN, for what I think is like the fourth time. But, I think I recognize the likely problem. After reassembling the scooter and tuning the belt, the belt was hanging over the edge a little but I thought it was acceptable. Well, after the first scoot, I'm supposed to "retune it" after the drive system settles into place after the bumps and jars of the first ride, but I neglected to do that. I take it out again today and it's a little wet, and I'm cruising at 15 mph with 25 amps going to the controller(which is much nicer to the belt as far as torque goes, as I was previously running at 40 amps.), and then I hear rumbling as if the belt was skipping, but I didn't recognize it until after I heard the familiar whining pitch of a free motor. There's two probable culprits - I didn't retune it (seems likely), or because it was wet outside (it was wet out about 4 different times previously, but it didn't break then).

Ok, lesson learned: Retune after the first ride!

Actually, I'm starting to think I want a chain drive scooter to be the main scooter (And then this belt drive one I have would be backup.). I'm hopeful chains aren't as pissy as belts seem to be to me.

[liveforphysics]

With a chain, you only need to get correct alignment, and keep the center to center distance fixed as rigidly as possible, and they run trouble free for a very long time.

Chains are very very reliable when done correctly.

[johnrobholmes]

The one thing I have learned from my spree is that I don't like V belt drive at all.