Need advice on buying a scooter

[puddleglum]

Hi guys, hope you can help me out. I've got an oddball idea for making a lightweight, folding mobility scooter for my disabled son using a stand up e-scooter for the drive. I'm not sure the idea is even workable yet so I am still in the research phase. There are a couple of potential scooters for sale around here, but I don't know anything about them to know if they would be suitable. Razor E100's seem to be the most common, but I understand that they have to be push started. That won't work for me. Is it because of the small motor or because of the controller design? Is there an easy way to get them to take off on their own? There is also a Bladez 450 for sale. It looks like a much stronger scooter, but I read that they have an on/off throttle. Is that in the throttle control or in the controller? Whatever I use, I will be wanting to slow it down as a 6-8mph top speed would be plenty. Any help would be appreciated.

[Lock]

Hi puddleglum

The E100's may seem common only because they are rated as 100 watts so can be imported into Canada as childrens toys. AFAIK Canada Customs justs looks the other way, as on the books electric scooters are not legal in Canada. If more powerful scoots get across the border it's because the importer knows to have them labelled by the shipper as "Restricted Use Motorcycles", which the provinces then deem to be off-road vehicles and not legal on any road or sidewalk...

Having said this, the little 24V 100W brushed motors and controller on the E100 can be... made a bit more robust. How heavy is your young guy? How steep and how long would be the worst possible hill he might EVer have to climb, and what would be the longest distance he would EVer have to travel on one charge?

Lock

[sk8norcal]

I have that Bladez 450 with that crappy on/off throttle, lever style throttle.
some models might have a twist throttle, (not on/off)
but replacement throttle and controller are fairly cheap... from the right vendor...

http://www.bladezscooters.com/catalog/i ... cPath=3_53
http://www.myworld.ebay.com/e-crazyman/
http://www.tncscooters.com (parts)
http://www.electricscooterparts.com (parts)
http://www.monsterscooterparts.com (parts)
http://www.neoscooters.com
http://www.thesuperkids.com/scooterparts.html (parts)
http://www.bigandlittlescooterparts.com (parts)

also razor e100 have urethane rear drive wheel, not air rubber wheel...

what exactly are you making? a sit scooter with 3 or 4 wheels?
http://wackyboards.blogspot.com/2010/05 ... ooter.html

[puddleglum]

thanks for the replies. My son isn't that young, he's 20 and 150lb. He walks, but can't go far and doesn't really like using a wheelchair that much. I thought about a regular mobility scooter, but they are very heavy and awkward to transport. I want to build something that could fold up for transport and would be small and light enough to lift into the trunk, without filling the whole thing, for when we travel out of town. I want it to be able to maintain a normal walking pace for 6-8 miles minimum and be able to go on gravel or dirt walking paths as well as on pavement. I'd like it to have enough torque to pull him up a good hill if we went walking in the mountains, although it wouldn't need to be fast up the hill. I think most of it's use would be on fairly flat ground. It would have to be able to take off from a dead stop, even up hill, and have a smooth throttle control. My idea is to mount the seat on a tripod that would have a wheel on the back two legs and the front leg would mount to the scooter.
I want to do this as cheap as possible, but if I build it, I want it to work when I'm done. Am I right in thinking that an E100 is not the best choice for what I want to do? Another thing I saw was a Razor pocket mod scooter, but I would have to do major modifications to make it work. It would almost be easier to start from scratch, which might be an option as well. I'm not locked into any particular scooter at this point so I'm open to suggestions.

[melodious]

Not sure if you have a deadline with your purchase/D.I.Y.

http://www.scootair.com/

looks pretty nice. This guy, actually used to ride (or may still be riding) a similar type of device, but with a Goped electric scooter. You should contact him and maybe get the ball rolling for your son and Trev. Didn't see a price point, so that may be a hurdle. Hope this helps.

[sk8norcal]

I have seen the earlier goped version,
this new one looks much nicer,
using trikke hub motor kit according this video...




If using a wheelchair is not desired,
I really like this one for compact and lightweight design,

[puddleglum]

Thanks guys, those links are awesome. That travel scoot is almost exactly what I had in mind.

[sk8norcal]

also recommend Izip/ezip scooters, common find on craigslist...
http://www.currietech.com/currie-techno ... ooters.php

[puddleglum]

Well I found a scooter that I think I can make work, I'm not looking for high output. It's a Chinese import, so quality isn't high, but the basics are there. It will need quite a bit of modifying, but the steel frame should be easier to work with, even if it is heavier. It is supposed to do 18kph, but the most I can get is 12kph at 21.5-22v. The SLA's were sagging to 19v and it wouldn't pull itself, so I used the best one and temporarily added a 90Ah SLA I had to try it. With my weight too it was over its max weight limit. I'm guessing that the weight combined with the voltage sag would account for the low speed. Is that reasonable? I really don't know what to expect from this. Its got a 300w brushed motor and a 24v/35a controller. To reduce the speed, I've thought of three options. First is to add a resistor to the throttle. Simplest, but if i'm understanding this right, has the drawback of reducing the overall power as well as the speed. Second is to add a larger rear sprocket. Third is to add a gear reduction on a jackshaft and use two chains. Both would give a torque increase and ease the motor load. I'm leaning toward the jackshaft idea right now but I'm open to ideas and critiques. I definitely need to get batteries, but the pack has to fit into the 9.3x6x3" box. I'd like to go with LifePo4, but I'm not sure what will fit best, Ideas?

[sk8norcal]

[Lock]

Its got a 300w brushed motor...

puddleglum, just a caveat... brushed controllers have a rep for failure with power full on, so ya might consider a Big Red Button

ed125.jpg (8.57 KiB) Viewed 1045 times

...or lanyard attached to a dead man's switch as seen on personal watercraft

locK

[puddleglum]

Lock, not a bad idea. It does have a power cut brake lever though.

[Kin]

So, when brushed motors do that, I imagine it's because the controller is shorting through or something like that, and a brushed motor with applied voltage just spins.

In that case, if you're using lipo batteries, shorted through the battery, I'm wondering why the fuse wouldn't simply blow. Might be safer than it seems.
*THAT SAID* I put 44.4v on a 24v brushed controller and the motor went full power for ~1-2.5s before I flipped the switch and so I guess it didn't blow the fuse.

[puddleglum]

I'm back again with one more question. My project is nearing completion, I may do a build thread if anyone is interested. Anyway, I bought second scooter as well, for parts. I now have a 250watt motor/ controller as well as the 300w setup from the first one. I'm wondering which one to use for the mobility scooter. I'm thinking of adapting the spare to his recumbent trike, but that is not my priority at the moment. the scooter will be a lot slower (extra 43%gear reduction), so may need less power, but the other side of that is he can't pedal the scooter if it run's out of power on a hill. What do you think?

[Kin]

It's unclear to me what you're asking, but I recommend if you're deciding between two scooters, one for parts, one for main, choose the one with a more robust frame as the main one.

[TylerDurden]

So, when brushed motors do that, I imagine it's because the controller is shorting through or something like that, and a brushed motor with applied voltage just spins.

The common failure is throttle... if it fails it usually fails WOT.

A pullcord on the mains is a good idea.

[Kin]

So, when brushed motors do that, I imagine it's because the controller is shorting through or something like that, and a brushed motor with applied voltage just spins.

The common failure is throttle... if it fails it usually fails WOT.

A pullcord on the mains is a good idea.

Why would the throttle to a brushed motor fail any more often than the throttle to a brushless motor? We're talking about failure in brushed vehicles, not failure in brushless, which I guess one of the only and therefore by nature most common power-driving failures of a brushless would be a throttle failure. But thats because any other failure of the controller would not switch the phases well and the motor would lock up and we wouldn't count it as a power-driving failure.

But you also always have very informative answers, so I am not asking this to disagree while assuming I'm right, I'm asking it as a question while presenting my rationale for questioning.

Pullcord on the mains is always a good idea, I agree. Especially if as Tyler said the throttle fails, then the whole "oh the fuse will blow" business is not as all correct. Pullcord is also better than assuming a fuse will blow.

My idea for "Oh if it's just a short through the controller then the fuse will blow" was very amateur. Because if you're up to speed then directly putting power to the motor will not pull much current at all. So entirely disregard it, you still need a kill-switch/pullcord.

[TylerDurden]

I'm no expert, but I have read a couple of anecdotes:

Runaway Bike!
viewtopic.php?f=2&t=34491

[Kin]

Cool, TD, I read through that thread and it does seem to be about brushless controllers. Makes sense as it's one of the few ways those motors could fail and still be powered.

I think the risk for brushless motor is higher because not only could the throttle fail like that, but if battery supply shorts through the controller, you will also have full power. So whatever X% risk exists for that on a brushless, it is increased Z% for a brushed motor, by the other mode of full power failure, namely controller short.


So kill switch devices all the way, as you recommended.

[TylerDurden]

Moar good reading...

viewtopic.php?f=2&t=41232

[puddleglum]

Thanks for the response. What I was trying to decide is if I should use the 250w or 300w motor for the scooter. I'm already using the frame from the larger one, but it looks nothing like it originally did. I think I'm going to go ahead and use the 300w motor anyway. I can change it later if I want.

[Kin]

Thanks for the response. What I was trying to decide is if I should use the 250w or 300w motor for the scooter. I'm already using the frame from the larger one, but it looks nothing like it originally did. I think I'm going to go ahead and use the 300w motor anyway. I can change it later if I want.

It's a good idea to use the bigger motor, I suppose. At least in my mind. So you're fine with the 300W motor. Just as I don't have any pictures of it, I want to be sure that it's actually the bigger-looking motor, by your assessment. Since motor rating is somewhat arbitrary, the 250W motor could be a more powerful motor and simple underrated, but in reality they're probably very similar and won't make much of a different. So, sum, is 300W motor is the one to go, unless it looks wimpier for some reason.

[puddleglum]

Thanks again for the help. I used the bigger motor/controller, but I think I may try the smaller one instead. It did see some pretty high peak outputs when testing, but it also is really easy to spin the wheel and it feels like it has too much power to me. I posted some pics of the finished product on the photos board.