Off-Road Or "Beefed-up" Casters?

[baldfatdad]

A manual wheelchair that can accept a 4" caster as well as an 8" caster has to be large, heavy, and hard to maneuver. Big price to pay.

This is not true. I am still in my 1983 Quickie 2. It weighs 24 lbs with cushion and air in the tires. I can put casters wheels on from 3 inch to 8 inch. Its a 16x16 seat chair. I don't have a tape with me, but its not more than 24 inches wide. And back in the day, I played basketball in it and did obstacle courses.

[ProPulse]

IMO you cannot rebuild the chairs to fit oversize casters. In most cases not even 6X1.25 inch could be used even it they fit due to often fixed dump and caster steering axle angle. My TiLite ZR has 5 inch solid casters which I cannot improve. When I put it back in service with a power add-on I will use the add-on with a Free Wheel.

I see, so the best solution that you've found so far is pretty much the freewheel. It would work really well with PropPulse. I just wish there was a cheaper way that wouldn't make the wheelchairs footprint so much large.

One more question. Let's assume we sell the power assist as is and the user has "normal" sized casters. If you are holding a joystick (like the one below) with one hand, is it possible to still wheelie over an obstacle?

[ProPulse]

If I go more than 4" casters, they will hit my feet while turning. They will also be more apt to hit the wall and furniture. Hence, if I were to go large on the casters, it would have to be custom for outdoors. Maybe you don't have that problem. But it's a consideration.

That makes sense. Do you have any suggestions for us and trying to make our power add on safe when you have to go over a large crack in the pavement? Or is the answer simply to just avoid them at all costs?

[nonoise]

I see, so the best solution that you've found so far is pretty much the freewheel. It would work really well with PropPulse. I just wish there was a cheaper way that wouldn't make the wheelchairs footprint so much large.

One more question. Let's assume we sell the power assist as is and the user has "normal" sized casters. If you are holding a joystick (like the one below) with one hand, is it possible to still wheelie over an obstacle?

You are asking about a one handed wheelie. Seems to me that would cause one to turn in circles. So the joystick would have to compensate for the other push. I think the learning curve is too steep for me to do it without turning if at all. August probably can.

[Gordy1]

One more question. Let's assume we sell the power assist as is and the user has "normal" sized casters. If you are holding a joystick (like the one below) with one hand, is it possible to still wheelie over an obstacle?

It may be possible for a small percentage of wheelchair users, but if you are relying on this ability to be able to use your device safely, then you won’t be selling many!

[baldfatdad]

I see, so the best solution that you've found so far is pretty much the freewheel. It would work really well with PropPulse. I just wish there was a cheaper way that wouldn't make the wheelchairs footprint so much large.

One more question. Let's assume we sell the power assist as is and the user has "normal" sized casters. If you are holding a joystick (like the one below) with one hand, is it possible to still wheelie over an obstacle?

Have you changed your idea from your original of an add-on to a whole system or a complete chair? What you had that I saw was a good idea. Now it seems you are trying to be all things to all people.

[nonoise]

It may be possible for a small percentage of wheelchair users, but if you are relying on this ability to be able to use your device safely, then you won?t be selling many!

That joystick, any joystick for that matter reminds me of the thumb throttle I used to use with my cloned and later hacked SD MX1. Unlike a 300 lb power chair they can provide too quick of an acceleration on a light weight manual wheelchair. To avoid being flipped on my back again I have converted to both a motorcycle style twist throttle and wheelie bars.

[ProPulse]

It may be possible for a small percentage of wheelchair users, but if you are relying on this ability to be able to use your device safely, then you won?t be selling many!

This is just for the users that have hand dexterity! We are creating a mount for the wheelchair for anyone that doesn't have the dexterity to hold the joystick.

[ProPulse]

Have you changed your idea from your original of an add-on to a whole system or a complete chair? What you had that I saw was a good idea. Now it seems you are trying to be all things to all people.

It is still an add on. I take everyone's input into consideration but they don't all get applied to the prototype. The nature of the ProPulse has not changed. It is still a light weight power add on with 360 turning that can easily be attached/removed.

[ProPulse]

That joystick, any joystick for that matter reminds me of the thumb throttle I used to use with my cloned and later hacked SD MX1. Unlike a 300 lb power chair they can provide too quick of an acceleration on a light weight manual wheelchair. To avoid being flipped on my back again I have converted to both a motorcycle style twist throttle and wheelie bars.

We've also added a nice and smooth ramp up acceleration function to make it extremely unlikely to accelerate too quickly. I remember you telling me about your motorcycle style wrist throttle in the past!

[August West]

This is not true. I am still in my 1983 Quickie 2. It weighs 24 lbs with cushion and air in the tires. I can put casters wheels on from 3 inch to 8 inch. Its a 16x16 seat chair. I don't have a tape with me, but its not more than 24 inches wide. And back in the day, I played basketball in it and did obstacle courses.

That was the year of my injury, so I probably had the same chair. It was a folder. If I recall it wasn't too heavy or wide. But it was long. Instead of having your knees at 90 degrees and your feet positioned under your knees, your knees were bent forward and your feet stuck way out. That's how you are able to get such large casters. Because your feet are sticking out so they clear the casters. I guess some people are ok with their feet sticking out. But that presents it's own problems. But you're right, it wasn't very heavy or wide.

[August West]

I see, so the best solution that you've found so far is pretty much the freewheel. It would work really well with PropPulse. I just wish there was a cheaper way that wouldn't make the wheelchairs footprint so much large.

One more question. Let's assume we sell the power assist as is and the user has "normal" sized casters. If you are holding a joystick (like the one below) with one hand, is it possible to still wheelie over an obstacle?

I can wheelie with one hand. But the caveat is that if you push off one handrail only to start the wheelie, you're going to turn as you wheelie. Not very practical. It's more showboating that anything else.

[August West]

That makes sense. Do you have any suggestions for us and trying to make our power add on safe when you have to go over a large crack in the pavement? Or is the answer simply to just avoid them at all costs?

This is a problem I have with the SmartDrive. I am glad you are addressing it. Sometimes you just can't avoid such obstacles. It doesn't even have to be a large crack in the pavement. Even a sidewalk cutout that don't transition well to the street (bump up/down) can knock off the SmartDrive, especially if it's at a steep angle.

The answer to your question comes down to mechanical design. I really can't comment on specifics without seeing it. But in general, there will be a tradeoff between ease of access (getting the device on/off) vs secure attachment. The SmartDrive gives priority to ease of access. You simply drop the SmartDrive onto a clamp that attaches to your axle. I like it. Because it goes on/off with one hand, even while I am in the chair. That's huge. Because the harder it is to use something, the less you will use it. If I had to transfer out of my chair every time I attached the SmartDive, I wouldn't use it as much.

But there is room for improvement to make it attach more securely while still keeping it easy. For example, after you drop the device into place, step two could be to engage a push pin that secures the device to the clamp. That way, it's won't fall off and is still easy to attach.

[ProPulse]

But there is room for improvement to make it attach more securely while still keeping it easy. For example, after you drop the device into place, step two could be to engage a push pin that secures the device to the clamp. That way, it's won't fall off and is still easy to attach.

Agreed!

Also, I've never heard of anyone's smartdrive popping off during operation. That's interesting.

I still haven't thought out a solution to the whole obstacle problem. Below is a link to some pics of the ProPulse. That can hopefully give you a better idea as to the mechanical design.

https://www.instagram.com/p/B4C9j7JpPkS/

[spinner]

I've gone over some big stuff with one and falling off was never a concern. The fact that it pushes you has been a problem sometimes. Just as if someone was pushing you and your casters stuck on something, and they keep pushing, the chair jumps up like a wheelbarrow being emptied. I spent the last three months getting over having done that very thing. Damaged my hip. It was the first and last time I'll skip the free wheel. My town has really bad sidewalks.