Orthopedic Knee Scooters. What to buy?

I am in my 2nd week after having my big toe bones fused with a titanium plate and 9 #8 screws and am going to be laid up for 6 weeks before I can use a walking boot without crutches. I am in the market for a knee scooter and have spent hours searching for one on Amazon.

I started looking at the ~$100 range ones but those seem to all be total junk. 

This one looks promising ~$150 without too many complaints but has drum brakes and wagon style steering:

Amazon.com: KneeRover Steerable Knee Scooter Knee Walker Crutches Alternative in Green

How about an all terrain model for ~$300 has a bicycle style hand brake and kingpin style steering but has a mile wide turning radius. I don't plan on doing much cruising in the winter though.

Amazon.com: KneeRover All Terrain Steerable Knee Scooter Knee Walker Heavy Duty Crutches Alternative in Blue

They even have a 4 wheel steering one with a disk brake for ~ $250:

Amazon.com: KneeRover Fusion Knee Scooter Patent Pending Crutch Alternative with 4 Wheel Steering

I will eventually need another surgery on my other foot but unless it's battery powered, I'm not looking to spend all that much money for this thing. What have other foot surgery patients used and what were your experiences?

Is it possible to rent a good unit from a Durable Medical Supply company in your area?  These are generally the people that sell wheelchairs, lift chairs, hospital beds, oxygen machines and similar.  

Will your insurance cover the rental costs?  

I had foot surgery a while back and was going to be on a knee scooter for a couple months. I looked at several types and didn't like the ones you usually see with the little wheels. They seemed too unstable.

I ended up getting that exact all-terrain one you listed. It wasn't great at turning, but that wasn't a problem in practice. If there wasn't room to do a 9 pt turn, I could just pick it up and spin it around. The brake wasn't great, but you shouldn't be going fast enough for it to matter.

The bigs wheels really helped. I was able to navigate grass parking lots and soccer fields without too much trouble. If I ever have to use one again, I'd go for the same style of scooter.

And after I was done with it, I sold it for almost as much as I paid for it.

Good luck with your surgery and hope you have a speedy recovery.

In reply to John Welsh :

Good question, rental is $100 per month. I will have to check on that insurance tomorrow.

Edit: That's $80/month. Wife says nope on the Insurance. I was thinking of building something like a shop stool with multiple swivel castor wheels merged with a skate long board with handle bars and just Velcro it onto my leg.  I just need a shoulder strap to carry the Long Knee or the crutches. 

also check with churches & other non-profits.    There is one by us (a non-profit) that has a large library of medical devices that they loan out for free.

Funny side note, I have never broken any bone in my body and haven't ever needed to use crutches. I have however been collecting senior medical aids over the years including walkers, crutches, and a rolling walker/seat. Mrs Heretic told me before the surgery to practice on the crutches but I thought that they would be a breeze and just how hard could they be to figure out. She was right and I was way wrong. Just made my first trip down into the basement and back up the stairs because of a blown fuse.

That is similiar to the one I used.  If you are going to use it outdoors, look at one with larger tires.  I used to scot back and forth to work, (about  block) and took a few spills encountering a rock in the road.

Thanks for all of the help and advice. I am ordering the Rover off road 3 wheeled knee scooter. Should be here on Friday except for the blizzard coming my way. I wonder if I should modify the steering linkages to increase the turning radius of the front suspension? I will also have to check and see how much Ackermann geometry it has. 

Now to figure out how to slide this wheel onto the back end.  

Walcrap.com: KneeRover All Terrain Steerable Knee Walker Knee Scooter Heavy Duty Crutch Alternative with Basket in Blue

All I know is they can't lean so they highside you if you try to turn with any aggression.

MrJoshua said:

All I know is they can't lean so they highside you if you try to turn with any aggression.

That got me to wondering how they made those leaning trikes and this is what I found: How to build Reverse Tilting Trike Motorcycle (in 42 minutes)

The Rover Scooter showed up today.  It was very well packed and assembled easily except that I have a few washers and nut left over. It also appears to be very well built.

It appears that there is no Ackermann in the steering and I will try to measure and draw it in AutoCAD and figure out how to add some. I also want to increase the turning radius. To add Ackermann, the steering arms need to aim from the spindle pivots towards the center of the rear axle. This can be accomplished by bolting a bracket onto the existing arms that will move the wheel side tie rods inwards after shortening and re-threading them.

It is also possible to move the steering pitman arm so that the tie rods angle forward to the spindle steering arms by lengthening the pitman arm with a bolt on extension which will also increase the turning radius plus speed up the ratio. I suspect that it will be a little of both. There is a welded-on steering lock that prevents an easy way of increasing the steering angle.

Next is to widen the rear fork for the electric wheel and figure out 24 volt batteries and then add leaning front wheels. It's going to weigh too much to lift into a car. I might have to start a scooter racing series.  And paint it titanium white and then 10 coats of candy red or sapphire blue lacquer.

Well, I finally hobbled out into the garage and found my angle finder and propped the scooter up on a wall and measured the steering angle and spent several hours figuring out how to model the steering angles in AutoCAD Architecture. This isn't something I do every day so it took some time and trial and error to figure out how to change the steering angels.

Here are all of the attempts I tried and the last two on the right appear to work. The first is using the original center steering pitman arm connected to the spindle arms with tie rods. The second is using a single tie rod connected to the right spindle steering arm with a crosslink connected to the left spindle.

Here is a link to an animation of Ackermann in action. Wikipedia.org: Ackermann steering geometry

Is the turning radius the average of the two spindles angle?

Looks like you're trying to overcomplicate a simple machine.

I'm late to the party with my suggestion. We got this one for the wife back in 2015 (https://www.amazon.com/gp/product/B003VMAKVS/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1) and it's been great. I thought I could get away with selling it after she was back on her feet after that first surgery but she would up having a total of six surgeries on her left foot, and I'm not sure there won't be more down the road. So it lives in the shed just in case.

In reply to Claff :

I love this scooter in every way EXCEPT for the mile wide turning radius which makes using around a small house ridiculously hard to navigate with. There is no reason to have to have to get off of it to pick it up and re-aim it all of the time.

I am going to make spindle steering arm brackets out of 3/16" aluminum bar stock that will bolt onto the existing arms to move the tie rod mount locations to a better location for tight turning. And with the same bar, bolt on a pitman arm extension to increase the turning radius. Then make a cross link bar to connect the two steering arms together. The only tools I will need are a jig saw, vise, and a drill. It will also be completely reversible. I mean, this is Grass Roots Motorsports, right? The electric motor and leaning suspension stuff is just a pipe dream though. 

Ok, after 11 different modifications I have finally got it figured out. AutoCAD kind of sucks doing something like this. Every little change had to be done with intersecting circles. I tried it with just one tie rod going from the pitman arm to the spindle arm with a cross link to the other spindle which worked out great turning to the right, but wouldn't turn sharp enough to the left.

These last three versions show the conversion point with just 1/16" difference between the length of the pitman arm pivot with the far right one the one I am going to build. Turning radius should be 30". 6mm threaded rod and two more female rod ends should be here this weekend so in about another 2 weeks when I don't even need this scooter, I should be good to go. 

holy poop, after 40 hours of drawing, 10 hours of building and 5 hours of driving to Max's Hardware to buy metric and SAE bolts, nuts, and washers, I have reduced the $3000 3 wheeler scooter's turning circle from an 8' diameter to 4'. 

I tried to grind the center turning radius stop using a flapper disk and a couple of small diameter stones in my drill with little progress, finally I just gave up and cut it off with the grinder. For some reason, without a stop, something is binding up in the steering and the maximum turning angle is just before the tie rod arms go past 180 degrees. I need to take it down Hiawatha Street (the steepest hill in our town that I have only once rode up on a 10 speed) to test it out.

Surprisingly, fixing the Ackermann while still keeping the outside tire turning angle of 35 degrees didn't change the original turning circle of 8'. I had to eyeball align the toe angle which wasn't easy looking through trifocals and being half blind.  Edit: I will have to modify my Cad drawing to reflect the new steering angles. Now to find people that want to buy the greatest, most expensive $5000 Knee Scooter in the world.

Know I just need help with converting it all over to 48 volt rear hub drive battery powered.

I think this needs to be moved to the builds section. 

Finished the steering upgrade: I tried out the new improved steering at Walcrap and it works wonderfully. Even though I cut out the steering lock, under normal driving, for some unknown reason the inside wheel never went over 180 degrees relative to the steering tie rod link which would result in an immediate wipe out. However, I can imagine if I hit a rock or groove, it could go way past 180 and lock into that position preventing returning to a straight ahead position, so I added a couple of steering locks.