Electric Mobility Scooter - ETV

[JagLite]

Greetings from Alaska,

I just joined the forum because I am working on an electric vehicle and I have zero experience and knowledge of what is involved.

I am building a mobility chair/scooter/4-wheeler for my Father who is 89 and can barely walk with his cane.

I started with this kid size made in China ATV



And this electric motor kit from Amazon:


It is 48V 1800W Mophorn(?) kit

The first step was to take it apart and see what I needed to get for it.

The patient is on the operating table:



Front end is off:

All in pieces:

The pieces:

The axle carrier is rusted up, the bearings are rusted and the axle only turns with a lot of force:

I read up online to find out if there were any hidden c-clips or other parts holding the axle in place and once finding out there weren't any I just whacked the end of the axle several times with a dead blow hammer and it finally broke free of the bearings:

The bearings were really rusted in there so my bearing removal tool came in handy to drive them out:

I sprayed the inside of the carrier well with Liquid Wrench but you can see how much rust was inside:

Cleaning parts in my deluxe parts washer:

And after cleaning:

Everything will get painted eventually but I have learned not to paint parts early on since I am often making modifications to parts and then have to repaint them.

To be continued:

 

[JagLite]

Well, I found out I can only post 15 images so I had to redo everything... oops.

Continued, (I hope)


All the suspension bushings are worn out and need to be replaced.
There was zero grease in any part of the machine even though it has several zerk fittings installed.

One of the suspension arms was missing the inner bolt sleeve so of course that wheel had flopped around a lot.

Lovely, just lovely...

The toughest one was the swingarm pivot.
I had to drive the bolt out and it took the inner sleeve of the end bushings with it leaving the rubber and outer sleeve of the bushings stuck in the swingarm tube.

I spent far too long trying to get the steel outer shell of those bushings out before cutting them and then bending them in:

Even at this stage they were still stuck fast and pounding on it would not move them:

I clamped my vise grips on it and twisted it loose finally:

To be continued:

 

[JagLite]

Continued:



Next I took the frame outside to cut off the foot board extensions since I will be making my own:

I do all the dirty, messy work I can outside to try to keep the shop as relatively clean as I can.

I searched online to find new bushings for all the suspension arms and the swingarm with no success. One place carries them but was out of stock and would not get any more for at least 2 MONTHS.

So I made one out of some UHMW-PE I had on hand:

New on the left, old on the right.

Easy to do but very time consuming on the mini-lathe and there were a lot of them to make so I kept searching online.

Nada, zippo, zilch.

Then I looked at the common Japanese kids atv's to try to find the dimensions of the bushings they use. What a pain that was. I had to find the bolt size, then follow backwards guessing at the sleeve O.D. and the bushing O.D. to fit in the tube.

I finally narrowed it down to a Yamaha atv and ordered a kit of the bushings on Amazon. When they arrived I was very happy to find that they fit.

I was not able to match the king in bushings with anything so I ordered some PE and made the four of them that I needed:

Lunchtime is over, back to work for me.

Next up will be modifying the axle to be one wheel drive.

Sometimes the little things can take so much longer to do than the big things.

To be continued:

 

[JTSpeedDemon]

Try uploading your pictures as thumbnails from your file system instead. With the way you have it, most mobile device users will have a hard time viewing this page, since it will take forever to load.

Looks like you have a well equipped shop! Looks like the only real help you'll need is some of the nitty-gritty details about wiring and such.
I would recommend a live axle over 1WD. I have a 1WD kart, and it always wants to turn right, not good for stability, which is what you want on a mobility device.
Live axles can still turn well, if you design it right.

How powerful is that motor? You may have to limit it somehow, I can't see an uber-powerful ATV/mobility device being turned over to an old person with limited faculties turning out well.

 

[JagLite]

Ah, thanks.
I've never done pictures as thumbnails, I will figure that out.
I use SmugMug photo hosting for my thousands of pictures of projects.
(Although PhotoBucket still has a few thousand of my pictures held hostage, fortunately I have copies on two other computers)

I've already modified the axle by removing the splines on one end and bought another front hub with bearings for the other rear wheel.
The axles for these things are only about $50 so if we find it going in circles I can switch it back with no trouble.

The motor is the Mophorn 48V 1800W which I see now from reading more is a bit much for the intended use.

It is all an experiment so if the motor is not ideal I will replace the kit with one with the 24V system and keep the 48V system for a moped project I have waiting its turn on the operating table.

I plan for a 10 mph top speed and see that I will need a jackshaft to reduce the gearing enough. I found a place that sells them as well as a toothed belt conversion to make it quieter, but now I can't find where I saved that site...

It will take me a few days to get the thread up to date.
I will see if I can redo the first posts to put in thumbnails to save those with tiny devices.

James

 

[JagLite]

Axle

I have a little bench top hobby lathe so I turned one end of the axle down (removing the splines) to fit a bearing hub like the front wheels use:

That took three evenings to cut because the tool rest bolt on the lathe broke and I was unable to find a replacement locally so I had to make one. Argh...

That fixed, I made the missing bolt sleeve for the a-arm that never had one:

Then put the suspension back together with the new bushings:

All bolts are just finger tight because I will be taking it apart and putting it back together several times during the build.

The shock will be replaced, they are just place holders for now.
And they are absurdly stiff springs. I weigh 185 and I can stand on the frame and jump a bit and barely make the shocks move. Ridiculous! A kid would never move the suspension with these things.

I have been searching but so far I have only found these shocks by length and a few places list spring diameter but none give the spring rate, Anyone have a recommendation?

The stock springs are 7mm dia and the smallest I have found is listed at 6.8mm which are still probably too stiff.

Can you guess which is the new hub for the rear?

Installing the new swingarm pivot bushings:

Coming up next time...
What's that steel for?

 

[itsid]

What a terrible advice JT gave you...

What he intended to tell you is:
Use out attachments to upload pictures!

detailed description on how to post pics

That way we see thumbnails and can epand them to a decent size when needed.
just looking at those postage stamps is terrible..

My monitor is 3feet away and not being able to expand the images is actually
as annoying as having to wait for huuuge images to load

Most external hosters are a pain (photopukedit you know how terrible they are by now )
but still likely they have a "bbcode" option somewhere
that way they do show thumbnails at first and then link to the full size
(sometimes spamming others with ads and annoying popups and whatnot.. so still not exactly great but smugmug looks to be okay from here)
but it'll work well for the most part.

'sid

 

[JTSpeedDemon]

Yes, what I meant is upload the pictures from your file system. Not through a photo hosting service.
Those pics are better, but instead we can't see anything since we can't enlarge them.

 

[JagLite]

Too big? Too small? Just right?

Where is Goldilocks when we need her?

Try again with picture sizing...

I ended up with some steel on the floor:



Time to make a tire bead breaker like I have thought about for several years. The pieces of steel are from my scrap, errr... stock of steel to give some choices to decide what would work best.

My hobby is motorcycles, primarily dual sports and the tire beads have been mostly easy but once in a while I would get a really stuck bead. Well, these little atv tires were bonded to the rims it seemed and none of my usual methods worked.

So I drilled a couple holes, cut a piece of Uni-Strut I had and made a simple bead breaker lever:



The axle is too long to use the tail stock on the lathe so I had to make do as best I could:



And this is how it will work.
(or not...?)



To be continued

 

[JTSpeedDemon]

I took screenshots at just about every step of the process to upload pictures as thumbnails. And I used that very process to upload those screenshots. These pictures as you see them are what we're trying to say is ideal, as thumbnails.
The highlighted buttons in each picture show which ones you should click.

 

[itsid]

I took screenshots at just about every step of the process to upload pictures as thumbnails.

A bit late, after he already did that
but a good idea..
just for fun.. click on the link I posted earlier

...
detailed description on how to post pics
..

just sayin'

'sid

 

[JTSpeedDemon]

Oh, oops. I thought that link directed to the "How to post pics" thread that Robert posted.

 

[JagLite]

It is good to see there is a sense of humor here.

 

[JagLite]

Well, it is a bit of a pain remapping the pictures in the first couple posts.
I will go back and do more when I have more time than my lunch break here at work.

For now, picking up where I left off...

I ordered a couple tires to replace the ones with cracked sidewalls that leaked.
They were mailed up and arrived looking like this:



Those of us in Alaska love Amazon free shipping!

Time to remove the old tires and paint the rims before putting two of the old ones back on and the two new ones.





Much better looking.
I only use the best spray paint on my projects, or whatever I have on hand. Paint covers a multitude of sins.

Boy these atv tires (16x8x7) are a bear to take off and put on.



Once the tires were on I tried and tried to get the beads to seal without success. I watched a bunch of YouTube videos of different methods and I tried everything other than igniting something flammable inside them. Nothing worked.



So I took them to the Yamaha shop and had them inflate them for me. Only cost $59... Ah, well, if you can't do it yourself you shouldn't complain about what others charge to do it.

Okay, done with the tires it was time to turn to the fun stuff.
Cutting metal and welding!

First up is to modify the steering to give it a tighter turning radius by lengthening the steering stem plate:



I cut a piece of thin plywood to drill and bolt the tie rods to so I could make sure they would clear the frame tubes. Then I cut a piece of flat bar and welded it on:





And what it looks like bolted up:



Well, I did a preview and I see that I am getting the pictures mixed up as I insert them. Hmmmmm...

Since the attach number doesn't match the image number and I have no memory so I can't remember which is which I may need to do much shorter posts with just 5 images.

I don't suppose anyone who looks at this project will mind.

 

[JagLite]

Steel Surgery

The doctor is ready to operate...

Since my Dad needs this to be a step-through like a scooter I need to reinforce the frame for removing the top tubes.

Again I dug through the steel pile to see what I have that I can use.

Some 1.5"x0.75" tube will be good and just enough for the two sides:









Next time, welding!

 

[JagLite]

Welding

Before anyone posts saying that won't be enough to strengthen the frame without the top tubes...

Here is the bracing going in:





Generally I weld inside the shop but the diagonal braces and end caps would require trial fitting, grinding, trimming, and then welding I decided to haul the welder outside and do it all there.

I cut pieces to cap the top tubes at the rear so that the square tube I was using for braces could tie into that instead of into the round tube.



I see that I got busy and forgot to take any pictures of the rear braces...
Here are the front braces being fitted before welding:



After everything was welded up it went back onto the table inside:



Yes, I am NOT a welder, I am a grinder as I have been told by those who actually know how to weld. I am also told that my welding is good enough and plenty strong for my projects. Anything that requires precision I would take to a pro the same as I do with my lathe turning.

Next time, building the motor mount

 

[JTSpeedDemon]

You can upload up to 10 thumbnail pictures. All you have to do is upload 5, wait for them to finish, then choose & upload the other 5. And pages with thumbnails load quickly and can pack a lot of posts in.

 

[JagLite]

Motor mount

More cutting, grinding, and welding... and more grinding.

Back inside and out of the snow it is time to figure where to put the motor.



I need to keep the area clear for Dad's feet so how about mounting to the swingarm above the carrier?
Actually, the location was decided on before I started the project.

By mounting it above the axle I can put a jackshaft on the swingarm in front of the shock and I can run the motor sprocket on the right side and the final drive sprockets on the left.



After lots of measuring, contemplating, and then grinding...





Time to make smoke:











Uprights are welded in, now we need a motor mount plate.
Looking through my steel pieces I decided on a piece of angle that used to be a bed frame. (handy, eh?)



Holding the steel in place is often a bit of a challenge...

 

[landuse]

This project is coming along nicely Looking good

 

[JagLite]

Motor mount continued

After welding the angle on I cut a 45 on the vertical leg for looks and cleaned the edges with the grinder and set the motor in place:







Yep, right about here:



There will be an aluminum plate that will bolt to the angle.



That's a little big.