Permobil C350

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Permobil C350

Postby JoeC » 08 Aug 2010, 17:04

This review is written from the perspective of me, an able bodied mechanical engineer who has been fixing and building chairs for my wife for the last five years. I have had my wrenches on the Invacare Ranger X 3G, Quicke P222SE, Quickie S626, Quickie S646SE, Quickie P200, and have had the chance to see a wide variety of chairs in a less "up to my elbows" capacity. My wife is presently using the Permobil C350 as a demo to see if she is interested in making this her next chair.

Overall Impression:

The Permobil C350 does seem to be well built, and many of the parts are made from machined castings. The moving parts of the chair are well hidden, so it is probably attractive for people who don't want a lot of visible mechanisms or wires on display. The standard adjustments to arm rests, leg rests, etc,are all made with metric hex keys. When I tried to adjust the foot rest height, the screw was so tight that I was afraid of breaking it off before it would loosen. It doesn't make the chair easier to work on, but it will make it more attractive for people who care about not having a lot of screw heads visible. Overall, the chair looks like a polished product and it looks like it will be fairly durable. It does have front and rear tie-down points.

Driving:

I drive a heavily re-programmed Quickie P200 about two miles once a week (meeting my wife at the gym for her soccer practice- her P200 is built for sports, not for comfort), so I have more experience driving powerchairs than the majority of able bodied folks. The Permobil C350 we received was programmed very poorly. The joystick is very delayed, steering is very soft, and indoors it is had to pull up to a desk or turn around in small places because the chair will hesitate before moving and then jump. This could probably be fixed with a real programmer, but we weren't given one.

The motors are geared for 6.5 mph, slower than we are used to. They are very quiet, and with the R-net controller they did not seem to have trouble going up any ramps or curb cuts, or going through a loose gravel patch on the way home. This was with my 220 pounds in the chair, and I also found that he four-wheel suspension was very effective in absorbing bumps in the road. They were especially effective in dealing with curb cuts- the sharp upward slope would typically slam the Quickie P200 hard enough to cause me some discomfort, but the Permobil handled it so well that I didn't even feel it. Going over broken joints in the sidewalk still gave a small jolt, but in my opinion the suspension was better than the one in the Quickie S646SE.

Seating:

The swing-away joystick rotates to the side. This is stupid. Almost every chair I have seen uses a parallelogram mechanism to move the joystick back to allow you to pull up to a desk while keeping the joystick pointed forward. With the Permobil, you need to mentally rotate your joystick input, pushing to the right if you want to go forward, pushing forward if you want to turn left, etc. The swing-away is also very stiff, and my wife can't do it on her own.

The arm rests flip up, which could be useful if you only do slide transfers or use a lift. They flex down if you support yourself on the ends of them, so I wouldn't expect them to be very trustworthy for someone who does stand-and-pivot transfers. The foot rests also flip up instead of swinging out, so if you do stand-and-pivot transfers, this chair is not for you!

The power seating all needs to be configured in a particular sitting posture before the chair will unlock the full forward drive speed. This is surely able to be changed with the right programmer, but we don't have access to one. I find a little bit of hysteresis in the position when the chair thinks its OK to start driving- you approach the proper position from one direction and the point when the light switches to indicate full speed, and then approach the proper seat position from the other direction and the light comes on at a different point. This suggests to me that they are using potentiometers to determine seat position, and in my professional (and wheelchair) experience, position potentiometers are not very reliable. They drift, they go out, and when they do they need to be replaced and/or recalibrated. This was one of the things that went seriously wrong with her Invacare's seating system. The problem with this is that the sitting posture that she uses for driving outside and maintaining her balance is not the one that Permobil dictated must be used in order to go full speed. Maybe for somebody who likes to sit the way they say you need to sit, this would be fine! Not for her.

On the topic of maintaining balance, the whole seat rocks in all directions like you are sitting on a huge spring. This is because of the seat elevator- most chairs I have seen with seat elevators are like this. If you prefer to feel like you are sitting on top of a solid stack of steel, this might bother you.

Chair Size:

I measured 25 inches wide, 44 inches long from the anti-tips to the heel of the foot rest when in the "ok to drive" position. This puts the chair length at about 50 inches with the foot rests flipped down (12 inches longer than her present chair), although you can flip the foot rests up (if you can physically reach to do that) and retract the legs, and get to a length of somewhat less than 44 inches. This is still a full 6 inches longer than her Invacare Ranger X 3G with 90 degree fixed angle swing-away foot rests. The arm rests are at least an inch wider than the wheels, making the chair even bigger than it needs to be. The spacing of the front casters is wider than on her present chair, about as wide as the drive wheels. This makes it harder (or impossible) to pull into certain narrow spaces that she could reach before, like under her desk. She can still make it under the desk, but only at one particular angle, and it's like threading a needle- not easy when the chair is lunging and jumping with delayed response.

About the arm rests- I know that I'm not being picky by complaining about their width because although this is a demo chair that still has the tags on it and has barely been used, the outside of the armrests are already covered in streaks of white paint from whatever hallways somebody has tried to navigate.

Conclusion:

You'd have to try this one for yourself, but if you have a technician who is really on the ball (and can actually program it), then it is worth considering. Not for people who do stand-and-pivot and can't flip up a footrest. Not for people who like to keep themselves balanced in their chairs but don't have a lot of muscle to make corrections if the seat is springy. Not for people who particularly care about their sitting posture while driving at full speed (to be fair- this could be fixed by the right programming, and you may try it and like the sitting position they picked for you). Not for people with very small houses vans. Not for people who need to work on their own chair, or need to take it apart and fit it into a non-ramped vehicle. Probably also not good for flying, since it is quite heavy and I have a hard time seeing any immovable frame pieces.
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Re: Permobil C350

Postby JoeC » 16 Aug 2010, 23:27

Just a couple of updates-

We have noticed since using this chair that it is possible to get precise control for fine maneuvering by selecting the "indoor" drive mode. The problem is that the maximum speed in this mode is something like 3mph, and if any of the drive inhibits from tilt/recline/elevate etc are activated, then it gets cut in half to a completely unacceptable snail-like crawl. Unless you are terrified of moving quickly and have no confidence in giving your powerchair safe commands for movement, I see no point to limiting speed to well below 2mph. If this chair was actually programmed properly, maybe it wouldn't be so terrible to use.

We also encountered somebody who uses this chair on a daily basis, and they had swing-away leg rests installed instead of the really impractical (for my wife) elevating central-support leg rest. If these were installed, it would also be more practical for her use.

What these changes would not fix is that the chair is much larger than it needs to be. The arm rests are really wide, the front casters are very widely spaced, and the anti-tips stick out quite a long distance behind the chair. Although it is comfortable to sit in, my wife has a rude nickname for this chair and won't use it outside of the house.
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Re: Permobil C350

Postby Burgerman » 17 Aug 2010, 10:37

The nickname? Or the chair? Do you have a photo of this chair? If so post it here and I will link the site menu to this thread!
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Re: Permobil C350

Postby JoeC » 17 Aug 2010, 18:28

She won't use the chair outside of the house (except once to get some sun in the back yard, the recline and leg elevate functions were useful for that), and won't use the nickname in polite company.

I'm attaching a photo- not the best quality, but it was taken with my phone.
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Permobil C350
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Re: Permobil C350

Postby Katilea » 29 Sep 2010, 16:45

I think the price of these chairs are ridiculous considering the amount of problems people have with them, I have seen bad reviews for the chair on other sites.
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Re: Permobil C350

Postby JoeC » 29 Sep 2010, 17:53

That goes for most chairs! It's completely commonplace for each of the component parts to be marked up 100% above the price you can get for single quantity pieces. Motors for example- I can get brand new motors equivalent to certain powerchair motors for HALF the price that wheelchair companies will charge you.

I think that most of the cost goes toward endless documentation and testing that is required for anything with FDA approval, which is odd considering the level of quality found in most of the crap that makes it through the scrutiny and into production.
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Re: Permobil C350

Postby underwurlde » 02 Dec 2010, 23:47

I think that most of the cost goes toward endless documentation and testing that is required for anything with FDA approval

You'd think so, wouldn't you? 90% of my job helping to design the controllers for powered wheelchairs is just this: Testing & documentation... TUV, CE, 510K, FDA, ISO etc.

BUT, this cost is NOT passed on to the manufacturers (i.e. cost of development & testing added to sale price). I will also say, that although our controllers are extremely cost effective (and I take pride in stating that) it would be unfair to call them 'cheap'. They are not. Yes, they are designed to meet a very low target price, but we would never allow that to compromise the extremely high quality of our products. Again, I take pride in stating that and if they were not we could not be in business. Over the years we have never allowed cost to compromise quality.

Now back to those tests. A generic set of tests allows us to build up 'packs' for each standard (TUV, CE, etc) - in other words they are not done in isolation (no point doing the same test twice, after all). We can only do those tests within each standard that are pertenant to the controller itself. Hence these packs are then passed on to the manufacture to complete for any given individual wheelchair the manufacturer produces that the controller may be used on.

Thanks again,

Andy
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Re: Permobil C350

Postby JoeC » 03 Dec 2010, 00:36

You say it's not passed on to the wheelchair manufacturers, but you're not doing the compliance for free, are you? And the tests they have to do on their chairs aren't done by volunteers.

I hope it's clear that I agree that the electronics in most chairs is the most reliable, most tightly controlled, best manufactured parts. The design practices and manufacturing quality is top notch, and in my experience they do an excellent job of meeting the operating requirements set forth by your customers and legal regulations. In actual practice, the wheelchair manufacturers do a terrible job of configuring the controllers they put into chairs, and they cut lots of corners on the (usually correct) assumption that people don't drive outside much, and the (usually incorrect) assumption that what people want is a joystick that acts like a delayed, directional "on off" switch, and that nobody can handle a direct proportional control.

It's true, a chair with direct control of full power and no delay CAN be made to jump and slam around if you drive it by pushing the stick all the way in the direction you want to go and waiting for the reaction. It can also be driven with exquisite control. When I drive a demo/loan chair with typical programming, I absolutely do slam into things. When I drive my wife's soccer chair, which has very little delay and a well positioned center of gravity, I can move around with precision and confidence. If I had to drive this C350 through a china shop, I'd get out and push it. If my wife was driving her soccer chair, she could very easily aim between gaps only a few millimeters wider than the drive wheels.

I don't know if we can "blame" any given business, but the combined effect of business realities, the legal and regulatory environment, and the way wheelchairs are paid for ends up creating a lot of effort spent that doesn't advance the quality (as perceived by the end user) any perceptible amount. My wife decided to get another Invacare Storm series chair that has advanced hardly at all from the first one she got over ten years ago. It's just as heavy, uses the same batteries, and the only option installed that wasn't available in 2004 when she received her last chair is a new configuration of powered seating- which was designed by an outside company and purchased for re-badging by Invacare!
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Re: Permobil C350

Postby Burgerman » 03 Dec 2010, 00:58

I am sorry to say that to get any real advance from 12 years or so ago (other than marketing and a fancy screen and more colours) you have no choice but to Do It Yourself.

Its amazing to me, that my home designed/heavily modded chair is by far the best powerchair NOT available for almost every powerchair user I ever meet... Built with a budget of err hundreds, and in a bedroom... By a huge team of one.
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Re: Permobil C350

Postby JoeC » 03 Dec 2010, 01:55

You weren't hampered by the need to maintain a design history file showing why you made each choice, when you made it, what it impacts, and how it relates to regulations. You also weren't requires to document what tests needed to be done, why they needed to be done (or why you were exempt from them) and show that you had a design team review of all of the above, signed and dated, reviewed and approved. You weren't required to explicitly perform and document engineering calculations for EVERY design choice (why did you use an M6 screw? Why was only one screw enough? What happens if it breaks? How much torque is required to install it? What grade must it be, and why do you say that?), with similar reviews and signatures all around.

Honestly, I have a lot of respect for what folks in the medical industry have to go through to get ANYTHING done, anything at all, because of all this soul sucking procedure and paperwork. You'd better believe you'll get shut down and have your products pulled from the market if you don't respect all these requirements- it happened to the plant I used to work at before I got there, and people were talking about it for years afterward. The vast majority of people at that plant had to go home without pay for many months while the paperwork and procedure was brought into accordance with legal regulations. Nothing was allowed to be built or sold until it was square, so perfectly functional (but uncertifiable) products had to be scrapped.

I am not joking even a little bit- we had to have our RULERS calibrated and certified, or we couldn't measure a piece of wire with them!! And no wire could be used if it wasn't measured and documented! Each of those papers had to have the calibration numbers "certified good until" dates included for any measurement. Numbers and equations were required, and none of them were allowed unless they came from traceable calibrated certified sources. Everything had to be signed with an encrypted smart card and password.

I did a design project that would have saved the company several times my salary every year, but it was never implemented because they were too terrified of jeopardizing their 510k. I am thankful every day that I was laid off and found work at the exciting startup where I am now. I have done more design, and more exciting design, in the last six months than I did for the entire year and a half at the medical place.

I don't know what it's going to take to make a better powerchair that people can actually buy instead of DIY. It will probably take a single individual with a vision and very deep pockets. Maybe an incoming executive at a major company who wants to make a name and likes gambling. Maybe billionaire technology maverick will find him or herself (or a loved one) in a powerchair, and realize what a piece of junk the existing chairs on the market are and decide to do something about it. Maybe a country somewhere will decide that quality of life, real mobility, and meaningful access to the outside world for people with disabilities is a national goal, and makes laws or grants to do something about it.
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Re: Permobil C350

Postby Burgerman » 03 Dec 2010, 03:09

But the above just leaves us with unusable and frankly dangerous and unreliable powerchairs. So its all completely pointless. Its about time things changed. A lot.
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Re: Permobil C350

Postby JoeC » 03 Dec 2010, 03:34

It's damned near impossible to do it as a business, so what's left? Change the laws?

Burgerman wrote:But the above just leaves us with unusable and frankly dangerous and unreliable powerchairs. So its all completely pointless. Its about time things changed. A lot.


Not if you stay inside your house or a hospital, then they're perfectly safe.

Without turning this into too much of a political rant, I would suggest that this is the next step in disability rights. People in wheelchairs didn't used to be allowed to go to university, have many jobs, or do a lot of things that walking people take for granted. Discrimination was allowed to be as blatant as any apartheid. Now the passage of certain laws, there's a hole in the wall. There's a hole, but it's going to take a lot of work, a lot of will, and a lot of attitude adjustment (and some radicalism) for enough people to see that wall and tear it down. I think your website has a great place in this. It's opening people's eyes to what is possible. You're spreading the word that it's possible to move around and have control of your mobility- something better than what's offered by the system in place today. It's up to the people reading to stand up and fight for the rights they're already supposed to have- to go out in the world and live.
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Re: Permobil C350

Postby Burgerman » 03 Dec 2010, 09:18

Unfortunately disabled people generally have so many other issues to deal with that they dont have the energy or even time to fight all the time. So as a group are already at a big disadvantage.

Although I am an exception according to almost everyone I have to deal with. And they really dont like it.
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Re: Permobil C350

Postby underwurlde » 03 Dec 2010, 12:00

You say it's not passed on to the wheelchair manufacturers, but you're not doing the compliance for free, are you? Nope.
And the tests they have to do on their chairs aren't done by volunteers. Nope.


Cost may be recouperated through other means.
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Re: Permobil C350

Postby terryfielder » 23 Jan 2012, 14:41

iv had this chair for 5 years (ish) but mines called a permobil street in those 5 years iv only had 2 issues with the chair the 1st issues i have is theres a clicking noise that comes from the front right wheel at low speeds. I have changed the bearing multiple times but this only stops the noise for a day or two iv given up on trying to fix this i think it could be the bearing turning in the wheel. Next time the wheels off im going to swap it for a wheel off my permobil chairman 2k the other problem i had was my own fault i re-programed the control like BM but wheelie-ing every where must of dislodged the freewheel leaver because the chair could drive but i had no brakes and i drove it for weeks like that. iv swapped the rear tyres for some 3.50 x 8 Bridgestone Knobbly Tyres there not the best at gripping on footpaths/roads but when i go to festivals i dont get stuck unlike my friends in wheelchairs. My next upgrades will be to swap the rear shock for some fox float rp23 shocks, i got them to put on the front but they wont fit with out cutting and welding the frame.

i remember seeing a workshop Manuel for this chair but forgot to bookmark it if anyone has it can they repost it
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Re: Permobil C350

Postby PWCMechanic » 04 Apr 2012, 23:19

Katilea wrote:I think the price of these chairs are ridiculous considering the amount of problems people have with them, I have seen bad reviews for the chair on other sites.

I will say that Permamobils are definitly high-dollar but I am kind of curious about the reviews you read. From my experience working on them, compared to Invacare and Pride power wheelchairs they are a step above in quality. The older ones most common issue I've come across is seat actuator issues and dead batteries but thats about it. I think I've replaced one drive motor and that's only because it was ran through deep water and started making noise. Not to up-talk them more but I'll also give them a little credit on the fact that it seems that the engineers actually listen when we bring problems to their attention.
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Re: Permobil C350

Postby Sully » 22 Apr 2012, 17:43

This may sound a bit stupid, but if we could get the base unit removed from the "MEDICAL" domain and only the seating, that is specialized for individuals be kept in that domain, wouldn't that cure the big problem?

It seems the techinical issues with certification and documentation would just sort of go away if this were done. While I have known there to be problems with mixing medical with commercial products, I have never seen it in writing just how stupidly complicated the design of the base unit is made to be, simply because it is considered a DME. These bases are truly controlled robots. Now would this issue be worth pursuing in some fashion? What are the negative points? Would it make the base unit inexpensive by removing the idiotic part of theese regulations?

It seems to me that John has already made some inroads into this hell. A govt. entity has approved you creating a base unit and supporting it with public funding. This seems like it is a quantum leap ahead. While I don't want to put the Kibosh on your way of doing things, you have, in my simple mind, at least proven how to build a better base unit, and yes it is being copied by individuals as well as companies in the field.

You also have seemingly defeated the Patent issue because you have made it open and public domain, no secrets, no private intellectual property. Am I missing something here?
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Re: Permobil C350

Postby Burgerman » 22 Apr 2012, 19:02

Are we talking about me?

Yes they gave up trying to sort out a chair for me because I took the piss publically and had a lot of fun at their expense in a bunch of big wig meetings with many heads of dept and NHS bosses. I embarrassed them and built better myself. And showed them how frankly clueless the "experts" were. So having proved I could do better for less they decided to let me!

Its not about a "base" though its about a chair. They throw the money at me, I sort out my own mobility however I see fit. Its a "personal budget for powerchair". A new pilot scheme. I could for eg use it to buy an X5 or V6 and retro fit it with lithiums, roboteq and 45 volts... My choice!

It will not work for you though as you live in the land of unfathomable rules, chair groups, insurance, liability, and a system nobody understands.

As of today theres just me on this pilot. And it will soon be expanded to all of the UK. Theres no distinction between "base" or chair, or seating. My chair was designed light and short, and would need a redesign to work with heavier seating or higher seating. But it was never designed to be copied. I just built what works for myself. And improve it incrementally year on year. So there is no fixed BM2 / 3 design as such. Its just easier to refer to them this way. My BM1 chairs now have some BM2 features like fast charging, soon lithium, etc All get updated to a greater or lesser degree. BM3 chair was meant as a fun chair rather than everyday.
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Re: Permobil C350

Postby Sully » 23 Apr 2012, 15:20

I think you have missed the point I was trying to make. Yes you are one of a kind, we can probably all agree on that.

The point is the base of a power wheel chair is NOT a piece of Durable Medical Equipment which puts the manufacture of it in some sort of mysterious domain. All the things you and everyone else might find fault with blamed on manufacturers can be laid at the feet of the Medical Manufacturers rules and regulations. To wit; Joe C's posts, he makes a good case for getting a bunch of idiotic regulators out of the chair base business.

Like many things that go on in this world I think we are blaming the wrong people. I agree that the US system is f----d up, the folks who use these Power Chairs are not all US citizens, but we all get pretty much the same products, made by the same manufacturers who all work under some really idiotic rules. If you are afraid of the ripples you have made in this pond of confusion, so be it. The rules manufacturers work under are regulation for regulations sake, and record keeping for record keepings sake, not the practical or safe use and manufacture of a tool, that we use. Removing the base unit from the medically necessary seating, that some people require might be beneficial to more than one single persons wants and desires.

You have shown that you can build a proto type of seat base for a fraction of what a mass produced base costs. You have departed from the norms that the regulators have required. Doing so shows me that it is the regulators who are the likely problem, to a whole industry.

Now I am hardly any sort of expert or even fully knowledgable with all the concerns with making a practical and fully functionable chair base. I am just interested in learning if anyone see's any reeason to discuss this issue. Government's are all stupid when it comes to particular issues of any kind. The members of any legislature need to be prodded and forced to become educated to the issues of anythimg they are required to judge. As you have had some real fun making fools of many of the "so called" experts. They are the ones feeding the information, to the advisors, to the legislators, that is three layers of "EXPERTS" or more before the person who makes the rules gets to hear the first word about any subject.

We are the whale shit at the bottom of the ocean, but the ones affected by their impressions, and rule making. This is a forum where the whale shit might get to make a stink, but we should do it in an appropriate way. Not antagonistic, but with reason, and tact, that is if we can figure out if any of it is even worth it. If one government listens others and yes even the "MIGHTY" USA might listen. I am gambling that at least one govt. official does read forums like this one, even if it is because they are one of our number, a Power Chair user themselves.

Is this worth discussing? JoeC you seem to know the industry, as does PWC mechanic, put in your 2 cents worth, am I whacked? Or is there a way to get some attention from the Legislators of at least one country, or is everyone too scared to lose what little we have? Burgerman Quote; "Unfortunately disabled people generally have so many other issues to deal with that they dont have the energy or even time to fight all the time. So as a group are already at a big disadvantage". Is this why we drop the subject?
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Re: Permobil C350

Postby Burgerman » 23 Apr 2012, 16:24

I have one relevant comment here...

A properly designed powerchair works as one. The base and the seating should be designed by one guy with the vision and not built by a committee.

The base/seating thing is one of the problems to get rid of.

I would love to design a one bit carbon monocoque with no seperate seat/footrest etc. It would be super light, strong, with only brushless motors, and lithium battery and controller mounting threads built in. Including carbon fibre wheels, and caster forks. Done properly, aerospace style autoclaved carbon the whole thing could be lifted with one hand and be super strong, and motors and batteries could be super efficient and tiny.

The whole seperate base to fit an unknown seat idea is a bad one... It means you cant design the base properly, as you dont know what rediculous crap someone else will add. That changes the battery, stability, length, width, tyre options, c of g choice, etc. Higher C of G for eg means a wider base track for stability reasons and caster shake reasone. That alone could rule out the fas low pressure tyres I use for decent off road/comfort/and tubeless kevlar lined freedom!

Seating absolutely affect the design of a base. I have been warning people about fitting car style seating on the BM2 chair for years. It will make it have pitch and roll instability as well as caster shake issues! It was not designed for this.
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Re: Permobil C350

Postby Sully » 23 Apr 2012, 22:15

Then further discussion of this is a waste of time.
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Re: Permobil C350

Postby Burgerman » 24 Apr 2012, 01:51

Well it would work for less optimised or less developed chairs. It in fact already does. EG look at prides / invacares offerings. They are far from optimised for any user. Hence all the endless complaints. One size fits all, badly!

And the retards developing the base plus "other" seating dont even know why thats a bad idea! Thats why we get the chairs we do,

Its either "modular" and works in a multitude of ways for many people badly and is designed by committee, or its designed by one guy with some understanding and viision to do one thing for one type of user properly.

I hate modular! EG a chair like the Groove. It is rear, mid, front drive. And useless at all of those because of it. It can have masses of motors/controller sizes/battery sizes. So its not great with any, and wastes space and dimensions. Etc... The ultimate one chair does every eventuality. Badly. If McLaren designed an F1 car that seated four and went off road too, it would be a crap race car and a crap shopping/family/4x4 all at the same time.
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Re: Permobil C350

Postby ex-Gooserider » 24 Apr 2012, 08:23

I agree to some extent, but I also think that a BM 2 / 3 style power-base could be designed that would at least allow some range of rehab style seating options to be fitted without requiring major sacrifices in what your chairs can do...

What I'd be interested in is if that would be an option for someone wanting to make a production chair without running into issues w/ the regulators - just make a base and tell people to put their own seating on it, possibly with some design suggestions as to how best to do so...

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Re: Permobil C350

Postby Burgerman » 24 Apr 2012, 09:25

If you made it a little longer and more nose heavy, with longer lower wider spaced anti tips that might work. And dumbed down the controls a bit. Lateral stability would remain an issue with the narrow rear track and fat squashy tyres.,
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Re: Permobil C350

Postby Sully » 24 Apr 2012, 17:40

You're missing the whole forest because you are looking at individual trees.

By moving the seating an inch or so changes the whole front/rear balance, raise it and you change the center of balance. a 160# guy does not balance it as a 250# guy does.

The way the BM is set up allows for some change, a bit longer attachment point will allow those changes to suit an individual.

The point again is you have actually shown how to design a base unit that is user friendly. Not complex and can be ajusted by the average mechanically adept person. If a tech cannot figure out why that rig won't work they should be sweeping floors, not fixing someones proxy legs. Parts available in less than a half a year.

I feel like a salmon going up stream to breed, and when I am done I'll probably just die, because I will be so exhausted by procreating. The process of buying a chair or getting it fixed because if government gobbeldy gook Insurance and the inter-relationship with the medical equipment laws just excacerbates the whole process. Now I try to circumvent this by buying my own chair, I do everything I can to avoid the bureaucracy. But just try to buy a stock part from a vendor and you or I are just thrown into that mixer again.

What you have also done is shown how to build a base that can be supplied with standard parts found on the shelf of most industrial suppliers. It is not all a mystery, and can only be serviced by the most holy priests of a particular medical supply house. (A little sarcasm here)

How can this be done publicly to insure some attention of law makers and embarass all those involved that make the design, building, repair and financing of mobility chairs? A chair that whole sales for $1600 to $2000 on the computer NEW the Insurance companies govt or private pay $6000 to $8000 for I don't know how that interperts in Euro's or British Pounds, but it is too much.

Consequently lots of folks who absolutely require these for mobility are left without, partially due to greed but also complex medical rules. I myself would never leave my house without the use of my chair. even with medication it just hurts too f----ng much.

I dare say your chair base is the Rolls Royce of personal mobility vehicles. I am going to try to build ONE somewhat similar, hoping it will last me the rest of my life. I'll be too old to ever do a second one.

Having a good everyday chair, that I can repair or instruct someone to do it, that can easily be loaded into my van, go onto the beach or to the woods, and then just shopping or visiting will be a dream come true. And I will be free of the bureaucracy to boot.

At this point you have made a little crack in the dam, it is up to the folks of like mind to open that crack up. While you may hate modular, you have actually shown how it may be practical to use it to make rear wheeled wheelchairs or what might be called all purpose personal mobility/transit vehicles.
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Re: Permobil C350

Postby Burgerman » 24 Apr 2012, 19:27

You are better doing two at once. It doesent cost much more and you have a backup to fix when using the other... Mine cost me about 1700 uk pounds each (BM2s). About 2700 for the lithium one. But thats because I know people that can help with machining parts, and welding/fabrication that are cheap and work from my beermat drawings. The labour is mine so free. Theres another member of this board that paid 4 times that to build his very similar chair. It depends what you know and how you go about it.

But be careful. Its not easy to build to the high standards of accuracy and finish that I do. As others have found out. And these things need to work right, from the off. There no development curve, or rescue system. I am lucky having spent many years designing and building all sorts of stuff, from race engines with one off turbo/nitrous systems (fabricated from scratch) to gas turbines, and automotive dynamometers. Lots of experience of whats available, how stuff works, and metals/physics etc. To me its easy. I always had the best engineered bike, the tightest nitrous V8 installation in cars that were never intended for V8s etc... Running my own nitroys systems, and set up and tested on my own rolling roads to my own design.

I was a high tech motorhead. Most people dont have this experience to help. But when I landed in a powerchair and saw how crap / expensive they were I wasnt very pleased!
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