scooter build

Lightweight / Folding / Portable EVs - seats optional
aethyr
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scooter build

Post by aethyr » Tue Mar 28, 2017 12:33 pm

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This is my scooter. Got it off craigslist for $100. I removed the motor and wheel. The wheel bearings were completely missing :lol:

I've read through ElectricGod's threads and comments and decided on going Big Block for my motor. It's probably more than I'll need, but it seems like nobody has regretted it :D

And as recommended, going 219 chain size.

A few questions:

Where do you find motor sprockets that fit the 12mm shaft? There are a million sprockets all with different bore sizes and I can't seem to find one with the right bore size and tooth count.

How are you mounting the sprocket to the shaft? I've previously used set screws on a smaller scooter and they seem to hold up ok.

I need new wheels - this seems like an obvious one, but where are you guys finding quality wheels? All my searches turn up with scooter shops that seem only sell replacement wheels for well known brands, like Razor.

And once wheels are sorted, how are you finding and mounting the wheel sprocket? I have no idea whether the wheel sprockets sold on the various kart sites will mount on the scooter wheel due to hole pattern discrepancies.

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ElectricGod
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Re: scooter build

Post by ElectricGod » Tue Mar 28, 2017 9:52 pm

I seriously looked at this smaller scooter before I built out mine. I would still buy one if I found one used.


1. If your wheels are fine, don't replace them...what's the point? You said you need new ones. What's wrong with your existing ones?
2. The front and back wheels very likely have the same bearing. Get Japanese bearings that have ceramic balls and are sealed. They will cost something like $5 each.
3. The big block is a great motor. There are better motors, but for the price, it is pretty tough to beat. It will make your scooter into a seriously powerful beast.
4. The big block has a 12mm shaft. LR sells a stainless steel adapter from 12mm to 3/4" that has internal and external keyways. You will want one of them. He also sells motor or driver sprockets. This is the adapter. You will need a key for the shaft keyway too.
http://lightning-rods10.mybigcommerce.c ... w-adapter/
5. You need to measure the circumference of your tire. That length will tell you how far the tire travels in a single rotation. Divide 5280 feet by that length to find out how many rotations are in a mile. Then a little math will tell you how many RPM's of your tire equals X MPH. Once you have that, you are ready to figure out the gearing ratio. What voltage are you going to run at? Mutliply that with the motor Kv (62) to determine the motors maximum RPM. Now you have a ratio...motor RPM:wheel RPM. Drivers come in 11 to 18 teeth. Let's say you're running at 16S or 65 volts, that's 4030 RPM. Lets say your target top speed is 40mph and that equates to 600 wheel RPM. Obviously I am making numbers up for your tire size, but you get the idea. So that is 4030:600 or 6.72:1. Let's say you chose a 14 tooth driver, that means you need a 94 tooth wheel sprocket to maintain that 6.72:1 ratio. Very small drivers tend to wear quicker than larger drivers because of the fewer teeth. Go with the largest driver you can, BUT you can't go too large because you need to maintain that gearing ratio and too large will mean the wheel sprocket is too large for your back wheel. With your smaller wheels, that could be a problem. You can get drivers through LR's site in 11 to 18 tooth. Some sizes he may not have in stock because they get used rarely such as 11 and 18 tooth, but he can get them for you.
6. Wheel sprockets for KART or 219 can be purchased all over the place for $10-20 each. I've bought several on ebay. KART sprockets commonly have a 6 bolt pattern that is a standard bolt pattern. You need to measure the bolt spacing for your back wheel. You will need an adapter that matches that bolt pattern and the standard KART bolt pattern. An important consideration to make is that the 6 bolt KART pattern diameter wont allow for a wheel sprocket smaller than 60 tooth. If you need a wheel sprocket smaller than that, then LR can make you a custom sprocket that matches your bolt pattern in the tooth count you need. He has made me several, but it will probably take some time to get his laser cutter to make you one.
7. 219 chain can be purchased just about anywhere. I usually buy it on ebay, but you can buy it from LR as well. Get a 219 chain breaker. They cost about $20 or more, but you can't make up the chain length you need without one and bike chain breakers are not going to do the job.
8. The big block is quite powerful. Set screws won't hold that much torque. Fortunately the keyway on the shaft will do just fine.

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ElectricGod
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Re: scooter build

Post by ElectricGod » Tue Mar 28, 2017 10:00 pm

Can you post some pics of the back area where the old motor was mounted? Also, put the back wheel in place and measure the distance between the front of the back tire and the back of the frame. The motor needs to fit inside that distance. There was probably a motor like this in that space, but without the bracket. The big block is a little larger in diameter than this motor so it will sit closer to the back wheel. Also, you will need to make a bracket that can attach to the motor and to the existing frame.

Image

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Re: scooter build

Post by ElectricGod » Tue Mar 28, 2017 10:10 pm

I've had LR adapt a couple of these for me in the past. The outer hole pattern is standard KART bolt spacing. Then I've given him the bolt pattern I needed to mate to my wheel. custom parts take a while to get done, but be patient and he will get them done...as soon as his laser cutter has free time to make the parts.

http://lightning-rods10.mybigcommerce.c ... l-adapter/

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Re: scooter build

Post by aethyr » Wed Mar 29, 2017 1:11 am

EGod,

Thanks for your input!

1) I need at least a new rear wheel because the outer shell/ring of the bears are stuck inside the wheel bore. The actual bearings/inner ring was blown out ages ago and that outer ring is oxidized in there and I simply can't remove it. If you have any suggestions on how I might remove that, then I could keep the wheel.
Below is a pic of the side of the wheel with the outer bearing ring/shell stuck.
Image
The other side had an intact bearing I was able to remove, as you can see, it doesn't have that outer ring. It does have a stop to keep the bearing in place. That also makes it impossible for me to push out the stuck outer ring from the other side because the bearing stop blocks access to it.
Image

Below are pics of my rear housing. I measure about 124mm from frame to wheel, depending on where I lockdown the axel to the frame. Pay no attention to the caliper measurements in the pic - it's wrong. How large is the big block?

Image
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The 12mm to 3/4 is perfect! So I'm assuming that 3/4" bore is standard for #219 motor sprockets? What size is the keyway?

I plan to run at 20s LiPOs because they're cheap. Although I probably should just bite the bullet and try my hand building my own pack. I remember you mentioned you had a good source for 18650s? And what BMS would you recommend?

I'm using this http://toddy616.blogspot.com/2013/07/el ... lator.html to determine my drive ratios. My tires are 10" diameter. I figure with the Big Block I can run 2.5:1 or so to get me to 50mph at 20s with 10" tires.

That link for the adapter shows it as a freewheel adapter. I forgot to mention I would like a freewheel as well. I think I remember you recommending the White Industries freewheel. How does the freewheel, sprocket and wheel all mate together?

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Re: scooter build

Post by Speirs » Wed Mar 29, 2017 3:25 am

Hi aethyr,

Is yours the 60v 2000w model? I have something like yours in red.

Here's a pic of it:
https://www.instagram.com/p/BRkcRlpg9Uy/

The scooter is not moving now something screwed it up which I have no idea how to fix it. I was riding it and it just stopped moving. I changed the throttle and it started moving again but not for long it started moving intermittently after 30mins of riding. I turned it off and on again the scooter throttle off by itself...good god i was able to catch it in time and switch it off.

I'm also getting the big block by LR strongly recommended by EG. And following EG' s advice I have also gotten the watt meter and Kelly controller.

Seems like my wheel size is the same as yours 90/65-6.5.

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Re: scooter build

Post by aethyr » Wed Mar 29, 2017 3:37 am

Its a 36v 800w. But I assumed that all these scooters with the same generic frame are the same size, so I didn't care about the stock voltage/wattage.

I hope the big block actually fits.

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ElectricGod
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Re: scooter build

Post by ElectricGod » Wed Mar 29, 2017 2:45 pm

Use a long flat blade screwdriver. I bet you can just catch the inner edge of the bearing or the race from down the axle tube. Hit the screw driver handle with a hammer and drive the outer race out. you will want to drive it straight out so don't just drive it out in one spot. Don't worry if you bung up the ID or that ledge a little that stops the bearing. As long as it's 80% there, it will work just fine. From the end of the axle opening, if you file down the edge of the screwdriver to a fairly sharp and curved edge, I bet you can wedge it under the bearing race with the hammer in several places to get it moving. I can guarantee you that if I had that wheel in my possession that I could get that outer bearing race removed and still be able to use the wheel afterwards.

Since you have a micrometer, measure those 3 bolt holes and the OD of that lip. You will need the hole spacing and that lip OD to get an adapter made that will fit your wheel. Contact Michael (LIghtingRods) and ask him to make you an adapter.

There are two things to think about regarding free wheels. Do I want regen or do I want to coast freely. You can't have both. I want the extra run time I get from regen so I don't use a freewheel anymore. Once I switched over to the new wheels, that eliminated the ability to have a freewheel anyway. The WI freewheel is stellar. I have several cheap Chinese freewheels...they are crap. I would only recommend using the WI freewheel. If you look through my Currie thread, you can see that the back wheel has freewheel threads. I took a fixed bike sprocket and drilled it as an adapter for LR's KART adapter. I just don't need or want a freewheel anymore. Regen is better IMHO. On your wheel, you have no threaded section where a freewheel can be screwed on so you are going to use a fixed wheel sprocket no matter what. You probably don't have sufficient width between your drop outs for a freewheel to fit anyway.

This is the original back wheel from my blue scooter. That threaded section is where the freewheel threads on.

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The big block is 142mm wide from bolt to bolt. That means across two opposite ears that hold the whole motor together. In the below picture and looking at the black cover, there are two ears for larger bolts. They are 8mm. Place them down and use them and those three other 6mm bolt holes to mount the motor. You can also use the long bolts that hold the whole motor together to attach a bracket for support of the back end of the motor. That's what LR does. You measured 124mm. Put the wheel axles as far back in the drop outs as you can and see how much space you have. If you don't already have axle tensioners, you will want to get a set to hold the wheel from sliding forward.

Image

3/4" ID is pretty standard for KART sprockets. Asusa Engineering is where LR gets them from, but they don't like dealing with small purchases so they may not sell you a single driver sprocket.

If I remember correctly, there are two different sized keyways on my blue scooter. I'm not sure if that is still true for motors that LR sells now or not. Anyway, they are 3/16" and 4mm. I think the 4mm is on the motor shaft and the 3/16" one is on the driver. I haven't tried putting an adapter or driver on my opened up big block yet so I don't know what the two keyways are now. Regardless, if you get the big block, just talk to Michael about that stuff and he will get you the correct parts. LightningRods only makes excellent parts and the big block is no different. His mid drive kits are 100% legit and well made. He doesn't skimp on quality EVER...unlike the bafang BBSHD kits which are pure crap and way over rated. The big block is sold as a 3000 watt motor, but I know for a fact that it will do lots more and not run hot. LR undersells everything he does or makes. Other guys...well they want to sell crap and over rate it excessively.

20S...on the big block on this tiny scooter...well it's going to be fast and quite powerful...probably 50mph or more and you will out accelerate all the cars. I don't know the dimensions of your battery box, but that will directly determine the amount of batteries you can put in the scooter. At 20S I draw 40-60 amps while accelerating hard. 20 cells takes up a lot of space and whatever cell count you go with, it will need to be able to deliver 60 amps continuously...if not more. Higher voltage means more cells to make that happen.

Regarding LIPOs vs LIONs...
LIPOs are cheaper for the same amount of mah than are LION. LIPO packs tend to deliver loads of current for a 1P pack while LION needs many cells in parallel to get the same current delivery. LIPOs have fairly short life spans...about 1/3rd as long as LION. It's not unusual for a LIPO pack to reach 50% of it's life in 50 charge cycles. Once LIPO cells start dropping off they lose capacity quickly. LIPO as a result actually costs a good bit more than LION in the long run. You will get close to 3X more charge cycles out of LION than you will LIPO. Also, if you build two packs...one LIPO and one LION and both have the same voltage and mAh, the LION pack will probably be smaller and lighter. I use LIPO for things, but LION is far better. I have a spot welder and welding supplies. If you are in the USA, perhaps you can buy the LION cells and have them sent to me and I will weld up the pack for you. Just about any battery pack maker can do that for you too. You just need to give them the dimensions it will fit in, cell type, voltage and capacity and they can get it made for you.

You will want a BMS for your battery pack. We can talk about that later.


aethyr wrote:EGod,

Thanks for your input!

1) I need at least a new rear wheel because the outer shell/ring of the bears are stuck inside the wheel bore. The actual bearings/inner ring was blown out ages ago and that outer ring is oxidized in there and I simply can't remove it. If you have any suggestions on how I might remove that, then I could keep the wheel.
Below is a pic of the side of the wheel with the outer bearing ring/shell stuck.
Image
The other side had an intact bearing I was able to remove, as you can see, it doesn't have that outer ring. It does have a stop to keep the bearing in place. That also makes it impossible for me to push out the stuck outer ring from the other side because the bearing stop blocks access to it.
Image

Below are pics of my rear housing. I measure about 124mm from frame to wheel, depending on where I lockdown the axel to the frame. Pay no attention to the caliper measurements in the pic - it's wrong. How large is the big block?

Image
Image
Image

The 12mm to 3/4 is perfect! So I'm assuming that 3/4" bore is standard for #219 motor sprockets? What size is the keyway?

I plan to run at 20s LiPOs because they're cheap. Although I probably should just bite the bullet and try my hand building my own pack. I remember you mentioned you had a good source for 18650s? And what BMS would you recommend?

I'm using this http://toddy616.blogspot.com/2013/07/el ... lator.html to determine my drive ratios. My tires are 10" diameter. I figure with the Big Block I can run 2.5:1 or so to get me to 50mph at 20s with 10" tires.

That link for the adapter shows it as a freewheel adapter. I forgot to mention I would like a freewheel as well. I think I remember you recommending the White Industries freewheel. How does the freewheel, sprocket and wheel all mate together?

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Re: scooter build

Post by aethyr » Wed Mar 29, 2017 6:39 pm

I'll give that wheel bearing another go...

Wow 142mm width for the big block. I'm not certain I'll have enough clearance with my existing rear frame. However, I found this: https://www.aliexpress.com/item/High-Qu ... 129.gnZPXm Image, that seems to be a clone of the rear frame you guys have on your scooter. Maybe I can replace my rear frame to comfortably fit the big block. I just need to confirm the width and mount points are compatible.

You convinced me to go regular lithium cells. What would be a good vendor to purchase from? I appreciate the offer to build the pack for me. I'm in the US, so that would be great! However, I do want to try to diy first and see if its something I can do. If its out of my league, I'll defer to the expert and maybe take you up on your generous offer.

You also convinced me to go regen. Initially I didn't because I was going to use LiPOs, which aren't regenable with existing controllers. But now that I'm going reg lithium, I can go regen.

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Re: scooter build

Post by aethyr » Wed Mar 29, 2017 11:50 pm

Could anybody with a scooter with the rear frame (hyperpowersports scooters and similar) above measure the following:

Image

Green: The inside distance between the forks
Yellow: The distance between the mount hole and the spring mount
Blue: The height of the spring mount

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Re: scooter build

Post by ElectricGod » Thu Mar 30, 2017 12:31 am

aethyr wrote:I'll give that wheel bearing another go...

Wow 142mm width for the big block. I'm not certain I'll have enough clearance with my existing rear frame. However, I found this: https://www.aliexpress.com/item/High-Qu ... 129.gnZPXm Image, that seems to be a clone of the rear frame you guys have on your scooter. Maybe I can replace my rear frame to comfortably fit the big block. I just need to confirm the width and mount points are compatible.

You convinced me to go regular lithium cells. What would be a good vendor to purchase from? I appreciate the offer to build the pack for me. I'm in the US, so that would be great! However, I do want to try to diy first and see if its something I can do. If its out of my league, I'll defer to the expert and maybe take you up on your generous offer.

You also convinced me to go regen. Initially I didn't because I was going to use LiPOs, which aren't regenable with existing controllers. But now that I'm going reg lithium, I can go regen.
Those are the rear forks on my scooter. It will definitely fit your wheel and the big block.There is a long bolt that secures the pivot point for your swing arms. What is the distance across the swing arms pivot point? I can measure mine and tell you if these will fit your scooter or not.

LION is more expensive up front, but worth it in the long haul. You will want to get a spot welder. Do NOT solder onto the individual cells. This will sound weird, but they are a legit seller out of China that can get any 18650 cell you could want for a good price. I've bought from them several times. You will want to contact Littlebear...like said it would sound weird. She will get you a price that includes shipping to you. I would not hesitate to buy lots more from her....oh wait already have. :)
littlebear@cl-rd.cn

Building a pack is not rocket science...just don't screw up and weld in cells backwards...that's sort of bad...really bad. LOL!

Whether you wanted a freewheel or not you can't have one so yeah...might as well take advantage of regen. Glad I could help.

Where did you read that you can't use regen on LIPOs? THe only thing the controller has to do with anything is whether it can do regen or not. My blue scooter has had LIPO and LION cells in it nearly the entire time I've had it and I've been using regen for close to a year now in it. It's not a problem regardless of the cell chemistry. What does matter however is that you use a BMS. I strongly suggest using a BMS regardless of the battery pack type. It also makes charging super simple. You never need to balance the packs or worry about running them down too far. The BMS takes care of all of that for you.

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Re: scooter build

Post by aethyr » Thu Mar 30, 2017 12:53 am

My rear fork pivot point distance is about 147mm, which I think is basically the width of the entire rear frame.

Looks like ms little bear has an alibaba site. Which brand (pany, samsung, lg) is best? What about getting them with tabs? What is the typical max discharge for each cell I should be looking for? What about nominal capcity?

I think if yours is wider, it should be ok because I could just get a longer bolt and spacers to fit the wider rear frame. But it does help to have some concrete numbers to see.

Regarding LiPo regen - I've always thought you should balance charge LiPos and that overcharging them would be catastrophic. I wasn't certain that a typical controller could balance and also ensure no overcharging for LiPos.

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Re: scooter build

Post by ElectricGod » Thu Mar 30, 2017 1:41 am

aethyr wrote:My rear fork pivot point distance is about 147mm, which I think is basically the width of the entire rear frame.

I think if yours is wider, it should be ok because I could just get a longer bolt and spacers to fit the wider rear frame. But it does help to have some concrete numbers to see.

Regarding LiPo regen - I've always thought you should balance charge LiPos and that overcharging them would be catastrophic. I wasn't certain that a typical controller could balance and also ensure no overcharging for LiPos.
LION BMS work on LIPO. Since LION cells charge to 4.1 volts, not 4.2 volts, that works for LIPO and keeps them from fully charging by about 5%. This is good for LIPO since that means they live a bit longer at a small loss of total capacity. The BMS keeps the individual cells for over charging. There are limits to over voltage that a BMS can deal with, but regen is not likely to exceed that. I think people who are afraid of regen are probably not using a BMS and then yes it is possible to apply a regen voltage that's too high for the batteries. My charger is set to 82 volts or 4.1 volts x 20. However, when the pack is partly discharged and I plug in the charger, the batteries pull down the charger to whatever is the pack voltage. Regen is just an on board charger. I doubt it is able to feed the batteries 100 volts when they are running at 72 volts. The battery pack will pull down the regen voltage to something close to current battery voltage. At close to full charge is the only time that you would likely apply more than maximum battery voltage to the pack when regen was happening. Even then...only if there was no BMS.

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Re: scooter build

Post by Speirs » Thu Mar 30, 2017 8:57 am

This is how it looks like on mine.
The motor is a boma 60v 2000w.

https://www.instagram.com/p/BSQ7aXEAnP1/

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Re: scooter build

Post by ElectricGod » Thu Mar 30, 2017 4:12 pm

Speirs wrote:This is how it looks like on mine.
The motor is a boma 60v 2000w.

https://www.instagram.com/p/BSQ7aXEAnP1/
Thanks for posting that pic. It explains a lot about how these scooters mount the motor. I have one of those 2000 watt BOMAs. I burned it out while running it at 3500 watts. The motor would have been fine, but the screens on the vent holes clogged up and it couldn't keep cool. This is a 1500 watt BOMA. They are the exact same external dimensions as the 2000 watt version. I added these heat sink fins to help it shed heat better. I ran it at 2500 watts. Anyway, the motor inside is smaller by 1/2" in diameter, but the length is exactly the same. The BOMA has a smaller diameter, but it is a fair bit longer than the big block. The BOMA extends out the side of the swing arm in your pic. I think the big block will neatly fit inside the swing arm. You would be able to use the through bolts that hold the motor together to mount the back of the motor to the swing arm. The big block is about 4 5/8" long including the bolt heads as compared to the BOMA which is just short of 5".

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BTW...I got this motor custom made. It cost me a good bit more than what you will get. They don't normally come opened up or with a fan shaft or radial fan from LR. This is the back of the motor with the opened up end plate and fan shaft. I intend to run this one at 130 volts and 5000 watts continuous. I need to keep it cool. The driven side end plate is opened up as well. I'll probably replace the magnets as well with much stronger ones after a while. There's nothing wrong with the ones from the factory, but stronger magnets will allow for more torque. Pushing more current through the windings will only get you so much and then the magnets can't do more work since they have a limited amount of magnetic force in them. To get more torque requires stronger magnets and I already know what this motor can do and I will want more out of it.

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This is what you will get from LR, but without the sprocket or bracket. I run mine at 3500 watt continuous, but I could go more without overheating it. BTW...that 3500 watts is plenty powerful to run my 120 pound scooter while carrying my 240 pounds on it and still out accelerate most cars and top out at 50mph. You should get similar results or better on a lighter EV.

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Re: scooter build

Post by aethyr » Thu Mar 30, 2017 5:38 pm

EG,

Thanks for all your help so far. Can you measure your rear frame dimensions as shown here, when you get a chance?

Image
I intend to run this one at 130 volts and 5000 watts continuous.
This is pure insanity :lol:

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Re: scooter build

Post by ElectricGod » Thu Mar 30, 2017 8:50 pm

aethyr wrote:EG,

Thanks for all your help so far. Can you measure your rear frame dimensions as shown here, when you get a chance?

Image
I intend to run this one at 130 volts and 5000 watts continuous.
This is pure insanity :lol:
Ha...yeah...meant to do that already.

It's 7 5/8" from the inside of each arm at the pivot point. The distance from the center of the pivot point to the shock mount bolt center is 5 1/2 inches. BTW...these shocks come in quite a few lengths so this isn't a super critical number as long as a sufficiently long shock exists that will work. The length of the standoff that the shock bolts to isn't important either. It's 5/8" long, but if that's too short, just add a spacer between the shock and the stand-off. I have drilled out a 3/8" nut and used a longer 10mm bolt to push my shocks out a little from the swing arm assembly. THat's all you need to do if the stand-off is too short. There is a lot of sideways forces on the 10mm bolt so use a grade 8 or 10 bolt if you need a longer one.

Look at my "E-Bike XB-502 (Moped) conversion project listed in my signature. This is my moped project where the opened up big block will go. I currently have an 82 volt , 32000mah LIPO pack built for it, the controller, motor and all the support electronics to get it going. I need a better back wheel, but the existing one will work for now. I could use the old back wheel from the blue scooter as well. Anyway the moped has been back burnered until I finished up the Currie which is super close to completion. Then that "Pure insanity" will be a 60mph moped designed to top out at 25mph that's as fast as some motor cycles. Should be fun!

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Re: scooter build

Post by aethyr » Fri Mar 31, 2017 6:07 pm

OK, I ordered the new rear frame.

I've decided to go Samsung 30Q batts. These have a real world 20A continuous discharge (some e-sig guys tested and found it was underrated). What average and max amps were you seeing, EG, with your Big Block?

In the meantime, time to research spot welders and learn how to build a pack :D

Also what BMS would you recommend?
Look at my "E-Bike XB-502 (Moped) conversion project listed in my signature. This is my moped project where the opened up big block will go. I currently have an 82 volt , 32000mah LIPO pack built for it, the controller, motor and all the support electronics to get it going. I need a better back wheel, but the existing one will work for now. I could use the old back wheel from the blue scooter as well. Anyway the moped has been back burnered until I finished up the Currie which is super close to completion. Then that "Pure insanity" will be a 60mph moped designed to top out at 25mph that's as fast as some motor cycles. Should be fun!
Read through it. Still crazy - although didn't you say you've gone 60 on your kick scooter? How come you decided to go lipo on the moped?

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Re: scooter build

Post by ElectricGod » Sat Apr 01, 2017 12:27 am

aethyr wrote:OK, I ordered the new rear frame.

I've decided to go Samsung 30Q batts. These have a real world 20A continuous discharge (some e-sig guys tested and found it was underrated). What average and max amps were you seeing, EG, with your Big Block?

In the meantime, time to research spot welders and learn how to build a pack :D

Also what BMS would you recommend?
Look at my "E-Bike XB-502 (Moped) conversion project listed in my signature. This is my moped project where the opened up big block will go. I currently have an 82 volt , 32000mah LIPO pack built for it, the controller, motor and all the support electronics to get it going. I need a better back wheel, but the existing one will work for now. I could use the old back wheel from the blue scooter as well. Anyway the moped has been back burnered until I finished up the Currie which is super close to completion. Then that "Pure insanity" will be a 60mph moped designed to top out at 25mph that's as fast as some motor cycles. Should be fun!
Read through it. Still crazy - although didn't you say you've gone 60 on your kick scooter? How come you decided to go lipo on the moped?
The 30Q is a great cell. Good choice! At 20S look for 40-60 amps. My pack is capable of 100 amps and that's limited by the BMS, not the battery pack. Have you thought about the controller you are going to use? I have some suggestions.

This is a pretty decent BMS, but they only work at 20S. There are two versions of it. One charges at 50 amps and discharges at 50 amps. The other charges at 10 amps and discharges at 80 amps. My blue scooter has two of the 50/50 BMS in it. The 10/80 BMS wasn't available at the time. I have several of the 10/80 version and they work well. Truthfully longer charge times is preferable to more limited discharge rates. They have a set of LEDs on them that light up when a cell is over charged, but all the rest of the time the LEDs don't do anything. The BMS uses a Microchips 4 channel charge controller component. For an inexpensive BMS, they are my favorite.

http://www.ebay.com/itm/112290923316?_t ... EBIDX%3AIT

I have this spot welder. Get a separate hand held spot welding pen. The two pins on the welder are fine if you are welding a single row of cells, but if you are welding in the middle of a pack, well you need the pen.

http://www.ebay.com/itm/252770210205?_t ... EBIDX%3AIT

http://www.ebay.com/itm/New-Battery-Spo ... Swux5YL~3H

LIPO on the moped is a temporary thing. I had the packs so I made them into something that would fit the moped. Later, it will get LION, but I lack the $$ right now to do it right so I'm short term using something I already have. Also, the LIPO pack is only 82 volts, not 130 volts or 32S. I want 130 volts and my controller is capable of 150 volts. The LIPO pack will get it going for now.

60mph...to be 100% honest it was really 59.5 mph, but close enough to 60. Anyway, I was using the factory wheels at the time and they are crap, wobbly and unbalanced. The new wheels are so much better made. I was cruising along pretty good (59.5mph) and the scooter was getting unstable. There was a lot of shimmying and side to side wobble and it was getting worse. I was concerned that I was going to wreck so I backed off until things stabilized again. 60mph doesn't sound like a fun wreck on a stand up scooter. But yeah on a 120 pound scooter with a 240 pound rider and a big block, I was doing almost 60mph. I hadn't run out of acceleration...just will to go faster.

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Re: scooter build

Post by aethyr » Mon Apr 03, 2017 11:42 am

I just ordered the spot welder. That spot welding pen seems really overpriced - its some electrodes and thick wire? Is there any more to it? Maybe I could make one.

EG, what was your sprocket ratios and wheel size when you hit 59.99999 mph?

Also, I can't seem to find a #219 sprocket smaller than 66t and/or motor sprocket greater or equal to 22t. With 10" wheels, I need at least a 3:1 ratio to just hit 50mph (loaded) at 22s. At 22t/66t, I can just touch 50mph. But largest motor #219 I can find is 18t. Any ideas?

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Re: scooter build

Post by ElectricGod » Tue Apr 04, 2017 6:34 pm

aethyr wrote:I just ordered the spot welder. That spot welding pen seems really overpriced - its some electrodes and thick wire? Is there any more to it? Maybe I could make one.

EG, what was your sprocket ratios and wheel size when you hit 59.99999 mph?

Also, I can't seem to find a #219 sprocket smaller than 66t and/or motor sprocket greater or equal to 22t. With 10" wheels, I need at least a 3:1 ratio to just hit 50mph (loaded) at 22s. At 22t/66t, I can just touch 50mph. But largest motor #219 I can find is 18t. Any ideas?
I know...those pens are over priced...but you will want one. THe voltage at the tips is pretty high so you need some decent dielectric to keep from getting shocked. If you used some 10 awg silicon wire...that probably will work. Then some kind of clamping mechanism that you bury in multiple layers of heat shrink would probably contain the voltage. That's essentially what the welding pen does.

Smaller wheel sprockets can be had. LR makes a 50T wheel sprocket. I have one on my blue scooter. He adapted it to my 3 bolt pattern on my back wheel. Standard KART sprockets are limited to the diameter of the 6 bolt pattern. I have a 60T wheel sprocket. That's all the smaller they can go and still bolt to a standard KART adapter. The 50T wheel sprocket at 3:1 will be a 16 or 17T driver.

22S...LOL...good luck finding a BMS that can do 22S. They typically are 12, 16, 20, 24S...multiples of 4. It's common that a BMS wont work at less than all of it's cells or only in groups of 4. I'm just saying 22S is not a logical choice. Go with 20S or 24S. 50mph is no problem at 20S.

Since my wheels are much larger than yours my gearing ratio is not relevant to your setup, but I normally run at 3.8:1 or 50:13. I think I installed a 15T driver. The scooter was slow off the break, but eventually it got up to speed and it drank current. 40-60 amps is pretty typical for me and this gearing got me 80 amps and really poor acceleration. You want to set up your ride for the best acceleration and best top speed with the least amount of current draw. Get a controller that has phase current control in it. initially set it up for 100%, mess with gearing to get the best combination. Now lower phase current to 50%. You will notice that acceleration is less. Turn up the phase current a little...60% and try it out again. Try 70% and so on. There will be a point where acceleration does not improve, but current draw keeps going up. Limit your phase current to just less of that point. This is the best efficiency you will get...the motor runs the coolest and uses just enough current to reach it's maximum potential.

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Re: scooter build

Post by aethyr » Fri Apr 07, 2017 10:10 pm

I've looked at some DIY spot welders and from what I can tell, I should be able to make a pen - I can just use the electrodes that came with the welder itself. (which just arrived - thanks for the suggestion). Now just waiting a bunch of other parts...

I've decided to ditch a BMS. I already have a good RC charging setup - 2x250w balancing chargers which I don't want to go to waste and will have better balancing capability than a BMS. I'll put a bunch of battery monitors on my pack to monitor it during riding. I figure a BMS is another point of potential failure and the monitors will let me know if a cell goes too low. So I get to keep my weird 22s :D

Yes, I knew your ratios wouldn't directly translate to mine, but taking into your wheel diameter into account, then I could calculate the equivalent ratios for my 12" wheels. I'm currently ordering custom 40t rear 219 sprocket from Mike at LR and plan to shoot for a 2.50:1 ratio which should get to me 60mph loaded at 22s. I'm sure reality will make me want to go lower, closer to 50mph which will allow me to have better acceleration.

And thanks for the tips on calibrating the controller. I plan to get a "mini" 130a kelly controller.

Stupid random question: What are the shunts for that you guys are installing in your builds?

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Re: scooter build

Post by ElectricGod » Sat Apr 08, 2017 1:20 pm

aethyr wrote:I've looked at some DIY spot welders and from what I can tell, I should be able to make a pen - I can just use the electrodes that came with the welder itself. (which just arrived - thanks for the suggestion). Now just waiting a bunch of other parts...

I've decided to ditch a BMS. I already have a good RC charging setup - 2x250w balancing chargers which I don't want to go to waste and will have better balancing capability than a BMS. I'll put a bunch of battery monitors on my pack to monitor it during riding. I figure a BMS is another point of potential failure and the monitors will let me know if a cell goes too low. So I get to keep my weird 22s :D

Yes, I knew your ratios wouldn't directly translate to mine, but taking into your wheel diameter into account, then I could calculate the equivalent ratios for my 12" wheels. I'm currently ordering custom 40t rear 219 sprocket from Mike at LR and plan to shoot for a 2.50:1 ratio which should get to me 60mph loaded at 22s. I'm sure reality will make me want to go lower, closer to 50mph which will allow me to have better acceleration.

And thanks for the tips on calibrating the controller. I plan to get a "mini" 130a kelly controller.

Stupid random question: What are the shunts for that you guys are installing in your builds?
This...found it on ebay. I use 200 amp shunts everywhere. These brass ended shunts are really small. Most shunts are much larger/longer...like the top shunt. I solder the ends of the main shunt wires to make them solid, Then I drill 2 holes on either side of the larger hole and tap it for 10-32. The battery wire goes in the big hole and 2 set screws crush the wire from either side. I use 8 awg for all my battery wires. It is a little smaller than those larger holes. The 2 set screws smash the battery wire a bit and it fills the hole more. I put some blue locktite on the set screw threads to make sure they never work loose. The blue scooter has had the same shunt in it for 1.5 years and it has worked reliably using this binding method with this shunt. I bring out the battery wires and monitoring wires out one end and then wrap the whole thing in a couple of layers of heat shrink or electrical tape. The small wires, I zip tie to one of the large wires so they can't be stressed and break inside the heat shrink. I use silicon wire for everything.

Image

Here's a pic of the 200 amp brass shunt compared to the the original shunt like shown above. They are very small and cost about $5. I haven't terminated the main wire ends, but I use either 8mm or 5.5mm bullets for all power and phase wires. You can't read the labels on the wires or connectors. The smaller wires are your monitoring wires. A typical DMM can't measure these low of resistances so it will be useless after you close up the shunt. It doesn't matter which end of the shunt is BATT- or LOAD- so just pick one. What does matter though is that the monitoring wires match up with the main battery wires. Before I close up the shunt, I label all 4 wires. IE: There is a large wire and a small wire on the same side of the shunt labeled BATT- and on the other side of the shunt labeled LOAD-. Then when I close it all up in heat shrink (Yes I know these shunts are wrapped in electrical tape. I later redid it on the smaller shunt.), I don't have to guess. I always use a BMS and I strongly recommend that everyone does. I've gone 6 months without using a BMS so it is possible, but I don't recommend it. Charging is so simple with a BMS and you never have to worry about running your packs down too much. Anyway, the BMS has a connection on it that goes to the negative end of the battery pack so you can't connect the BATT- end of the shunt to the battery pack or else you are bypassing the BMS. A BMS also has a LOAD- connection on it. This is where the BATT- end of the shunt connects. THe LOAD- end of the shunt becomes your new negative end that all the EV electrical stuff connects to. The two small wires go to your watt meter for measuring current draw from the pack.

Image

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Re: scooter build

Post by aethyr » Tue Apr 11, 2017 3:00 pm

Sorry, I meant what are the shunts used for :) I'm guessing to be used for current measurement?

Also, does the kelly controller handle greater than 90V? What happens if you exceed the voltage spec? I'd like to go 24S (yes, you've convinced me, EG, to go 24 instead of 22), but then at near full charge, input voltage exceeds the 90V limit of the controller...

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Re: scooter build

Post by ElectricGod » Wed Apr 12, 2017 11:53 am

aethyr wrote:Sorry, I meant what are the shunts used for :) I'm guessing to be used for current measurement?

Also, does the kelly controller handle greater than 90V? What happens if you exceed the voltage spec? I'd like to go 24S (yes, you've convinced me, EG, to go 24 instead of 22), but then at near full charge, input voltage exceeds the 90V limit of the controller...
You will want to get a watt meter so you can see battery and load status. The shunt connects to the watt meter. Look in my scooter threads, you will see the watt meter I use.

Depending on the Kelly you are using, yes 90V max, others 150 volts and others 60 volts.

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