Greetings from Zurich

You dont have to, but its interesting!

MAIN WEBSITE: www.wheelchairdriver.com

Greetings from Zurich

Postby miro » 15 Feb 2016, 01:37

Hello folks,

My name is Miro and I'm a student from Zurich.
You might know the project I've worked on for the last one and a half years.
We built the stair climbing wheelchair Scalevo https://www.youtube.com/watch?v=3lb_8nmy90c.
We posted here before, but never introduced ourselfs properly to the community.
I have been lurking here for quite some time now and we got a lot of valuable information from the forum!
Thanks for that! :)
miro
 
Posts: 3
Joined: 15 Feb 2016, 01:30

Re: Greetings from Zurich

Postby Burgerman » 15 Feb 2016, 02:52

I don't know what to say. Or where to start. These keep cropping up year after year.

First of all - if any "add on" it makes the normal use of the chair any worse by even a small amount than its already blown out. Life is too short. We are busy active people. Worse means heavier, less range, slower to react, more complex, less manoeuvrable, longer, heavier, less ground clearance, less sharp in ANY shape or form, less responsive, or whatever then its already failed.

Question 1. What on earth makes you thing that stair climbing is of any importance to us? Did you ask? It interesting ONLY if it has no negative affects at all on the day to day use of a chair, A minor interest at best. But sadly it does detract from *everything*.

Question 2. Why does it steer like its got a ton of mass, and way too much turn acceleration delay and turn deceleration delay? As seen on your vids?

Question 3. Why is it so slow? Both moving "normally", and stair climbing. Nobody has that much time to spare. We need some ZAP! If it takes longer to go up a stair or step than an able bodied user, or requires you to transition like a "transformer" and become a spectacle, then its WAY, WAY TOO SLOW! and its embarrassing,.. So we wouldn't bother doing it. There's always a better way.

Question 4. Range? My own chairs are good for 45 to 50 REAL WORLD miles. Does this chair improve on this?

Question 5. Speed. My own chairs are good for 16 mph, does yours improve on this? Or is it worse?

Question 6. Battery service life. And Range. (50 miles at least) The biggest problem for many users. Mine is good for 10 years plus. Lithium ion phosphate, and huge 3.2kwh and no nasty BMS to ruin the pack. And a large enough pack to give the cells an easy service life. So how does yours compare?

How would you expect us to use a really long heavy device, with no ability to acc hard or to go on soft ground with its skinny tyres? t would be a liability indoors on a daily basis.

Question 7. Tyres. I use large cross section TUBELESS and many plies, including radials on my latest chair. Because tubeless offers masses better reliability, and far less deflations from punctures. And I use Kevlar reinforced puncture proofed tyres too. Because a harsh ride from "solids" isn't an option, and punctures are not acceptable.

Did you actually ask any of these questions?

Question 8. My charger is 1340 Watts. And balances cells at 1A (Lithium Pack). As such it can put back 3.2kwh of energy, accurate on a cell by cell basis (graphed on pc) to 0.003mV per cell. And it works from home or in a car at 40A charge. What does yours do?

There's a lot more. But for now this is enough.

I suspect you wont actually want to discuss any of this. And will just run away to your school like all the rest!
User avatar
Burgerman
Site Admin
 
Posts: 46793
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Greetings from Zurich

Postby Burgerman » 15 Feb 2016, 02:59

Basically what you have done is taken a Segway chair setup -- which works great other than it lacks control and range, and is a little wide. And added some stuff that ruins the entire simple light small concept!

Burgerman.
User avatar
Burgerman
Site Admin
 
Posts: 46793
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Greetings from Zurich

Postby miro » 17 Feb 2016, 17:58

Thank you for the inputs!
You have to understand, that this wheelchair was built in 9 months from scratch. We laid a big focus on usability throughout the project and I feel like we did a pretty good job at that. Regarding your point about Segway wheelchairs. If we compare our wheelchair with Genny http://www.gennymobility.com/genny/design we see, that we we are only 66 cm to their 63 cm wide, 100 cm (less in the next iteration) to their 69 cm long, 100 to their 89 kg heavy and actually 15 km/h to their 12 km/h fast. But we can climb stairs. And go under a table. And raise the seat by 30 cm. All things which a simple, "lightweight", "small" Segway wheelchair can not do.

The points you made are valid for a product, which should sell on the market. Since we plan on developing our wheelchair to that stage are most points already in our pipelines

1. The project started as an education program for students. We received a lot of positive feedback (10+ mails of people wanting to buy it per week) from wheelchair drivers around the world. We also got contacted by dozens of wheelchair distributors which want to sell our wheelchair or which got requests for it. We also set up a survey http://www.scalevo.ch/survey to asses the needs of potential customers around the world. Around 70% of all entries would like to use the Scalevo as their only wheelchair.

2. The prototype has a lot of flaws at the moment, and we know that. The controls are on top of our to do list and will be the focus of our next iteration.

3./5. During the time of filming we were still in early testing. For the safety of our disabled driver were the motors limited in power. The max speed of our wheelchair will be 15 km/h while balancing and one step/sec. This is about as fast as an able bodied user.

4./6./8. Since this was our first prototype we did not test the maximal range yet. For a functional prototype this was obviously not our focus. We have a similar charger as you do with 1500W/60A. We know, that range is a deciding factor for daily use and plan on implementing sufficient range in to our final prototype.

7. Your praise for wide tubeless tires was actually a deciding factor for our choice of the tubeless Segway tires!

I hope this answers your concerns and questions. We are very open for ALL constructive feedback and discussion.
miro
 
Posts: 3
Joined: 15 Feb 2016, 01:30

Re: Greetings from Zurich

Postby Burgerman » 17 Feb 2016, 18:23

I still dont understand the fixation that students have with stairs. You keep on trying to fix the one problem most of us couldnt care less anout. While ignoring the things that we do. Year on year.

Even when its finished, removing all those chains, tracks, added wheels etc will remove lots of weight and complication and allow the chair to have larger batteries, wider tyres, and be shorter overall. THAT wouyld make it way more useful as a daily chair for most users.
User avatar
Burgerman
Site Admin
 
Posts: 46793
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Greetings from Zurich

Postby miro » 17 Feb 2016, 19:42

I can only speak for our team, but in short:
Students like challenges. Simple as that.

Not to take away from the engineering you have done on your chair, but for most students it would be a quite boring task to build a wheelchair very similar to the 1000 already on the market but with a bit more range, a bit higher top-speed and a bit more comfort. This is the task of the industry. Which in my eyes seems to fail at this pretty hard.

A stair climbing wheelchair is a niche product. Not everyone needs one, not everyone wants one. But some feel it is a necessity. That does not mean, that all wheelchair drivers need more battery life and a higher top-speed. It might be cheaper and more convenient for a old hotel to have one stairclimber for their yearly wheelchair driver guest instead of building stairlifts on all staircases. The same argument can be made for old people unable to walk stairs in their family home. If wheelchair manufacturers and students only focus on tuning the current products without trying new and potentially innovative prototypes the industry gets stale, as shown best in the current wheelchair market.
miro
 
Posts: 3
Joined: 15 Feb 2016, 01:30

Re: Greetings from Zurich

Postby Wanttheimpossible » 17 Feb 2016, 20:27

Hi,

I know a normal wheelchsir might seem boring, but actually what the market needs is a realisable chair which goes indoors and outdoors/off road enough to walk a dog across a muddy/stones park or field equally as well as nip around a small kitchen or go to a friends house without worrying about knocking into things because of the chairs dimensions or that it's going to slide sideways off a pavement, and with instant reactions. When you want to look through a window your brain tells your legs to stop as soon as that thought occurs. Also it would be great to exit the cinema or theatre part way through a show silently without the noise of the chair alerting everyone that you are popping to the loo for example. Yes, it's the simple (maybe boring, who cares if it's not exciting) everyday things that you take for granted that we rely on our powerchair to be able to do. I've never walked up a flight of stairs and to be totally honest I wouldn't trust any wheelchair to take me up a flight of stairs - I still get everywhere I want or find a great alternative.

To be simple a chair needs to be. Realisable, safe indoors or outside, as compact as possible, comfortable, good traction, and get me there at least as fast as someone can walk/run but preferably quicker, and the software and seating needs to be adjustable allowing for different people's seating and steering needs.
Wanttheimpossible
 
Posts: 17
Joined: 15 Feb 2016, 11:33
Location: UK

Re: Greetings from Zurich

Postby LROBBINS » 17 Feb 2016, 20:35

John,

If you tried to find an accessible location for a meeting in Firenze (Florence) as I have you might begin to see the attraction of a stair-climbing chair. If stair climbing seriously compromises normal use, it's a no go, but if someone finds a solution that does both it would be a breakthrough for those of us living in countries where accessibility is enshrined in law and almost entirely absent in practice. (Italy has the most beautiful, best written, laws in many spheres, and almost never puts them into practice! For the politicians, having something on paper is the same as having it for real, so that's where it stops. I am ashamed of so many things in all three of the countries to which I have ties - the U.S., Italy and Israel - but I guess that's also a sign of love. If I didn't care about them, I wouldn't be ashamed.)

Ciao,
Lenny
LROBBINS
 
Posts: 4534
Joined: 27 Aug 2010, 09:36
Location: Siena, Italy

Re: Greetings from Zurich

Postby Mark » 17 Feb 2016, 20:57

miro wrote: It might be cheaper and more convenient for a old hotel to have one stairclimber for their yearly wheelchair driver guest instead of building stairlifts on all staircases. The same argument can be made for old people unable to walk stairs in their family home. If wheelchair manufacturers and students only focus on tuning the current products without trying new and potentially innovative prototypes the industry gets stale, as shown best in the current wheelchair market.


Could I point out something that won't have occured to you if you are not a full-time wheelchair user....

For someone who is dependent on their wheelchair all day, every day, their wheelchair is a very precious thing. I don't like to be parted from my wheelchair or for it to be out-of-site as it is my independence, is normally very valuable, and often has many personal items in it. Even if I was prepared to sit in a wheelchair climbing stairs and therefore providing the entertainment for any passing person, what would I do at the top? My wheelchair would be downstairs, and I wouldn't be happy at a function upstairs, or in a hotel room overnight with my personal wheelchair "somewhere" downstairs.

I've not even touched on the fact that the seat would be the wrong width / length / height for me so I would be uncomfortable after a short time.

I have a similar problem with people who think a stairlift is a substitute for a lift. I will not use stairlifts. First there is the effort of transferring, then what do I do at the top with my wheelchair still downstairs? I've actually had people say " Oh don't worry we'll get a couple of people to carry your wheelchair up the stairs for you" Sure, all 130kg of it! I'm not going to risk that being dropped and wrecked.

Your wheelchair, and stairlifts might work for people who can walk short distances and who transfer without effort, but they are a minority of wheelchair users, and probably use those overgrown pavement-clearing scooters anyway.

However, I agree it presents a challenge for students. It must do because I don't think a year goes by without a student, or group of them, writing here saying they are designing a new, better wheelchair. Unfortunately, the reality of wheelchair use isn't anything like they imagine, so their goals are often solutions to problems we don't have, or would cause problems they haven't had to think about.

Sorry this sounds so negative. I can't think of any other way of explaining it.
Mark
 
Posts: 245
Joined: 07 Aug 2014, 18:42
Location: Derby, East Midlands, United Kingdom

Re: Greetings from Zurich

Postby Burgerman » 17 Feb 2016, 23:07

I couldnt use your wheelchair. For a lot of reasons. One reason I now have a chair with 3X the range of a normal hi end powerchair with 75Ah batteries (3.2kwh lithium) is because a set of massive lead batteries do not allow me to get through a normal day. For eg. I fly model planes. At a grass airfeild. In winter I need wide tyres. Its soft to flooded at one end... And about half a mile long.

Those tyres you have will just sink and get stuck. You dont have enough floatation or ground clearance. Worse that chairs battery would be destroyed rapidly on soft ground as you dig grooves half a mile long. It would not get up and down that soft runway half a dozen times before it died. Yet I need to do that and then drive into town to the bank, and then go home and do some gardening/cleaning, then go back into town to eat and then to a pub or club. That long heavy over complex chair will still be stuck on the airfeild with a dead battery. And its way too slow to waste your life driving up and down the airfeild at slow speed. So in those situations 12 to 16 mph is extremely important to me. As is the 3.2kwh of energy... What does yours have? I cant spend all day watching battery meters.

This is why this has fat tyres for summer use: download/file.php?id=4326&mode=view
And this has fatter ones for winter: http://www.wheelchairdriver.com/BM3-con ... air-11.jpg

And the thing needs to be programmed to go/respond fast! I havent got all day. Yours appears to be like sailing a boat?

Anyway, stairs or even curbs are of far less interest to me, than using that track space, for extra rubber for cumfort or floatation, or more storage of power (you need about 3kwh or at least 2kwh since its brushless. And to decrease the weight. Did you ever hear of KISS? Keep It Simple Stupid. I would rather have my own chairs built to suit my preferences than anything else "added on". Every inch matters. Every lb matters. Just like a manual chair.

How LONG is your chair? Mine is 37 inches total. 939mm. I can turn in a 939mm corridoor. Can yours? It really matters. Mine has narror central footplate, and close together rear anti tip wheels, so it has no corners and it makes it easy to turn into doorways etc. How about yours? Mines got 5 inches of ground clearance which is important! How much has yours got? Mine is light! It matters! Esp on sand. How does yours work on sand or snow which just happens to be starting...

All of this matters to ME.
These things are pesonal. The stair climbing thing may interest others like lenny above. But all of us want something different. I personally tested the pre production iBOT 3000 and 4000 chairs. Both did stair climbing, and balanced, and rose up high and 4x4 for off road. But they were TERRIBLE daily chairs. For a number of reasons. But this guy likes it. https://www.youtube.com/watch?v=IKcxOpjpBqs I used to leave mine at home and use my faster better controlled chairs because they *worked*...
User avatar
Burgerman
Site Admin
 
Posts: 46793
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Greetings from Zurich

Postby Burgerman » 17 Feb 2016, 23:23

Lets say you can speed it up by 3 or 4 times, fix the turn acc and deceleration issues I can see in the images, and get some decent ground clearance, (4 inches minimum) figure a way to make it lock into my van, (tie down bolt), and shorten it by 100mm, and so on.

Answer these questions if you will.
1. What battery does it use, voltage, type, C rating, capacity? And charger capability. Please dont say it uses a damned BMS! http://www.wheelchairdriver.com/BMS.htm
2. Will there be EXTENSIVE user programability. And I dont mean just a few basic settings?
3. How much power does the controller have? (volts are battery volts), but max motor Amp capability and cont Amp capability?
4. How are you going to move the tracks at the front that are sticking out that will hit every doorway?

Thanks.
User avatar
Burgerman
Site Admin
 
Posts: 46793
Joined: 27 May 2008, 21:24
Location: United Kingdom


Return to Introduce Yourself!

Who is online

Users browsing this forum: No registered users and 5 guests

 

  eXTReMe Tracker