Deeply disappointed in TDX SP...

[SweetBearCub]

Warning, long post ahead

Ok, so here I sit, a bit more than 10 months after the day my chair was delivered. In that time, it has been in the shop no less than 4 times.

Twice for failures that stranded me (Motor cables came off the controller, one per stranding and shop visit - Crappy design!) and twice for motor & gearbox related issues. The first motor issue - The left motor was driving jerkily and binding - Was solved by replacing the motor and gearbox as a unit, barely even a month ago. This time, the chair is making a nasty grinding sound from the left side primarily, but also the right side to a lesser degree. I took it in for diagnosis yesterday, and the the tech was stumped. he agreed that the sound was screamingly obvious. I'd post a link to the video I made of it on YouTube, but the forum software is being difficult; apparently I haven't made enough posts yet to have that privilege. He said that he would have to get in touch with an Invacare technician, and that in his opinion I would likely be getting new motors and gearboxes for both sides if his suspicions panned out.

I questioned him on the seeming lack of quality in the chair (4 visits in less than 11 months?), and his reply was that the TDX SP was the best chair that CA Medi-Cal would fund, so it was what I was stuck with. He told me that the motors and other parts are now made in China, so I should be prepared for the chair to have problems as a matter of course. He also said that my drive parameters might be contributing to the problem (100% forward speed, 100% forward acceleration, 50% turning acceleration), but I responded that as an example of why I am not responsible if that is the case, that Invacare made chairs that went faster than 7.0 MPH in the past, but then decided that was too fast, and updated their programmers to reign in all fast chairs when programmed next. If Invacare felt that my settings were unworkable, they would have disabled the programmer from setting them that high.

He also commented that I am an extreme user - I am in my chair for 12 to 16 hours per day, and I routinely drive the chair several miles per day in the city on the sidewalks, usually at top speed, though I do slow down for foot traffic blockages and when going up or down crappy curb cuts and pieces of crappy sidewalk. he tried to suggest that I start riding the city bus to/from the places I go, but I responded that one, my chair had no tie-downs, and was hence unsafe on the buses. He then suggested I lie to a nearby transit company and claim  to be their customer (I'm not) and get free fabric web tiedowns for my chair. As for reason number 2, in the time that it takes for a bus to arrive at the stop and at my destination, I can usually pace (if not outright beat) the city bus by a block or more most of the time.

Basically, this is a group 3 chair. It is supposed to be specced for daily outdoor usage on city sidewalks. To quote a part of my Certificate of Medical Necessity for the chair prescription:

"..requires a group 3 level power chair as the chair will be used for several hours per day outdoors on the city streets. The group 3 chairs are designed to withstand such continued use outdoors over the expected useful life of the chair; while group 2 chairs are intended primarily for use indoors with only occasional use outdoors."

Is Invacare selling a chair that they know is fundamentally incapable of meeting the design parameters of a group 3 chair?

If so, what can I do to get this remedied in a permanent fashion?

[KiwiJenn]

Hi SweetBearCub:)

Sorry to hear you have had a few issues with your TDX SP, that can be annoying when your busy and moving around the place.  I have to say your TDX SP has done well for the 11 months with only 4 visits to get it fixed.  Some people have had more problems in 11 months or a year and then again some have had none.  I think pole mototr problems can arrise from many things, not just the motor/gearbox itself.  

Programming settings on all powerchairs come as a set default and then the user get's the settings changed to suit there driving needs and to help the chair perform well for them.  Having 100% acceleration is way high:eek: and maybe causing motors problems.  I do remember years ago when I used a chair with pole motors that I alway's liked my settings high and fast, but the downside to that was I went through motors/gearboxes too often. Well I was doing crazy things too:D  I was basically killing the motors hehe

Yea he's right about the motors and other parts being made in China now.  

Invacare, from what I've heard (I'm in New Zealand) reduced the speed due to having speed limit in certian places for powerchairs..jakeyboy correct me here as I'm not 100% sure

Your TDX SP should handle the driving your doing.  I guess if you had battery drainage problems then yea using a van or whatever would be better, but you don't have that problem.  Sounds like the Buses system is the same as ours, we don't get strapped down, we just park ourselves in the disabled area on the bus (1-2 wheelchairs could fit) and then the bus is off.  It's the same for trains, just get on off we go.  But then no one on the train or buses wear seat belts.

Is it possible for you to post your settings, I be interested to see what they are and maybe some of us can see if any are too high.  Sometimes if you have two settings set high it could add strain to the pole motors.

I hope someone can answer your question:) I can't since I don't know the Groups info fully.

Apart from the problems, how has the chair been for you?

Due to spammers, everyone who joins needs to have so many posts before they can post links.

[SweetBearCub]

KiwiJenn,

Thanks for your prompt reply.

Are you implying that having a chair in the shop four times in less than 11 months for serious issues is a GOOD ratio? Even as the consumer is "trained" to expect less quality in the drive for even lower prices and higher profit margins, I don't "buy it". The chair lists for $5,600 USD on Invacare.com, and most insurance providers define a useful lifetime as 5 years on average. Given that my chair has ready access to servicing, is custom fit to me, and the fact that is a purpose-built and heavily tested vehicle, I would expect it to last that long, if not longer, even with the demanding way in which I drive it. At this rate, it won't even last to the 2 year mark I fear. Over here, we call that "shoddy workmanship".

As far as my programming setting possibly contributing to my problems, let me lay out the scenario. SPJ+ control, no PSS, so only 1 drive profile. All parameters are at the factory defaults except for three that are very important to me.

1) Forward Acceleration - Changed from 30% to 100%
2) Forward Speed - Changed from 95% to 100%
3) Turning Acceleration - Unknown default, raised to 50%

As far as the possibility that the extreme forward acceleration setting is contributing to my issues, even if that's true, it shouldn't be possible. Allow me to more fully explain. Several years ago, Invacare marketed chairs that could exceed 7.0 MPH as their top speed. For whatever reason, they decided at some time later that this was unsafe. In response, they limited all their power wheelchairs from that point on to a maximum of 7.0 MPH. They also released updates to powerchair programmers that prevent the programmer from selecting a speed above 7.0 MPH, even if the chair is capable of a higher speed. If they think that for safety or reliability reasons that a setting of 100% for the forward acceleration is unworkable, they have had plenty of time to figure it out and restrict it at the programmer level, yet they have not done so.

As for the fact that I would choose such a high setting, I admit that I am a speed demon. I tried the chair at the factory settings, I tried the forward acceleration at 65% (I split the difference between 30% and 100%, 70%, in half), and I finally settled on the 100% setting as the right setting for me. I have sufficient motor control in my hands to safely control the joystick, and my reaction times and vision are good enough as well. I also opted to increase the turning acceleration so that the chair would be more responsive when turning, and may yet have that increased a bit more in the future.

When I am in a situation that makes touchy acceleration dangerous, such as in a crowded room, I simply lower the maximum speed from 100% on the joystick, down as low as 20%, its minimum. This has the effect of suitably dampening the chair's responsiveness.

As a point of note, even with my high settings, the chair has never overheated, but I do live in a cool climate.

If having high settings can "kill" the motors and gearboxes, then Invacare needs to rethink their design. Many years ago, I was taught in the field of computers, that software (AKA programming) should never be able to damage hardware. If there is a possibility of that occurring, for example when programming is driving a step motor out of bounds of the motor's ability, the hardware should have internal limits that prevent bad programming from damaging it.

As for battery drainage, I have a suspicion that my range is dramatically lower than the 20 miles that the manual specifies, and am looking into a way to get reliable sets of measurements to verify that one way or the other. Of course, as I test the range, I will have the programming parameters scaled back to less aggressive settings to compare the effect on range.

As for taking public transportation, I usually only do that when it's raining and I have more than a few blocks to go. Otherwise, I drive my chair. I consider the bus unsafe, as the tiedowns have difficulty latching onto my chair. It has broken free of them twice while in motion, since I do not have the transit securement kit on my chair. Insurance would not pay for it, nor would my provider allow me to pay for it. I had my feet mangled pretty well (bruises only, thankfully) when a bus stopped suddenly and sent my chair sliding. Not only these, but public transportation also costs money. If someone is willing to pay for me to take alternate transportation, great, but otherwise, I don't see why I shouldn't drive my chair, unless the real reason is that the chair isn't capable of serving as it was advertised and it is a known issue, which goes back to my 1st expression of crappy quality.

Apart from the problems, how has my chair been? In a few words, overly slow and too basic. 5.8 MPH top speed? Come on now, I'm not an invalid. As far as I know, the general design is safe up into the 8 MPH range. No lighting options? No outdoor horn? No odometer or speedometer? No compartment for house keys, phone, diabetic glucose tablets, etc., small things that you need to keep ready? These are all glaring omissions in a supposedly high end mobility product in my personal opinion.

Hi SweetBearCub:)

Sorry to hear you have had a few issues with your TDX SP, that can be annoying when your busy and moving around the place.  I have to say your TDX SP has done well for the 11 months with only 4 visits to get it fixed.  Some people have had more problems in 11 months or a year and then again some have had none.  I think pole mototr problems can arrise from many things, not just the motor/gearbox itself.  

Programming settings on all powerchairs come as a set default and then the user get's the settings changed to suit there driving needs and to help the chair perform well for them.  Having 100% acceleration is way high:eek: and maybe causing motors problems.  I do remember years ago when I used a chair with pole motors that I alway's liked my settings high and fast, but the downside to that was I went through motors/gearboxes too often. Well I was doing crazy things too:D  I was basically killing the motors hehe

Yea he's right about the motors and other parts being made in China now.  

Invacare, from what I've heard (I'm in New Zealand) reduced the speed due to having speed limit in certian places for powerchairs..jakeyboy correct me here as I'm not 100% sure

Your TDX SP should handle the driving your doing.  I guess if you had battery drainage problems then yea using a van or whatever would be better, but you don't have that problem.  Sounds like the Buses system is the same as ours, we don't get strapped down, we just park ourselves in the disabled area on the bus (1-2 wheelchairs could fit) and then the bus is off.  It's the same for trains, just get on off we go.  But then no one on the train or buses wear seat belts.

Is it possible for you to post your settings, I be interested to see what they are and maybe some of us can see if any are too high.  Sometimes if you have two settings set high it could add strain to the pole motors.

I hope someone can answer your question:) I can't since I don't know the Groups info fully.

Apart from the problems, how has the chair been for you?

Due to spammers, everyone who joins needs to have so many posts before they can post links.

[KiwiJenn]

Well it's not good but as I said before some people have had more problems in 11 months.  When I got my TDX 5 I had 2 new sets of HDTTGB motors replaced in the first week I got it due to faulty motors.  

Are you implying that having a chair in the shop four times in less than 11 months for serious issues is a GOOD ratio?

Powerchairs are not vehicles, powerchairs and wheelchairs give us users the mobility our legs are not able to do.  Those of us including me use the chair like a car to get from A to B and if we live close to places we tend to wheel there rather than use public transport.

Given that my chair has ready access to servicing, is custom fit to me, and the fact that is a purpose-built and heavily tested vehicle, I would expect it to last that long, if not longer, even with the demanding way in which I drive it.

On any powerchair, if you have high settings on most settings you can cause overheating and motor problems. The chair does have a saftey cut out if the chair gets too hot and will either stop or start stalling.  When I had an Arrow with GB motors which is way more powerfull than the TDX SP, I play wheelchair hockey, soccer and rugby in it and I had high settings and in the end I ended up with overheating issues.  I had to turn some settings down to prevent this.  I also knew that some of the driving I was doing was not helping during the play of sports.  I love speed too and most of us will have 100 forward speed:)  But I think having high acceleration, high turning speed and even high turning acceleration 'all together' is too much.  Not all users need the high settings so there's the option for us all to have the settings that suit our driving needs.  If you want them high then I think you need to prepare for a few motor problems like the gearbox.

If having high settings can "kill" the motors and gearboxes, then Invacare needs to rethink their design. Many years ago, I was taught in the field of computers, that software (AKA programming) should never be able to damage hardware. If there is a possibility of that occurring, for example when programming is driving a step motor out of bounds of the motor's ability, the hardware should have internal limits that prevent bad programming from damaging it.

I'm trying to push Invacare in adding back the Drive Select options to the MK6 electronics, as they were on the MK5.
Drive Select options are..
The Display Select option enables the user to view one of these options on your LCD.....
Miles or kmh
AH
Volt
AMP
BATT (good/bad)
KM

I'm very independent and live alone and as for keys, I got two long chains (small in width) and hooked them up to make one long chain then I hooked my keyring onto the end of it and at the other end of the chain I've attached it to my armrest:)  I then put the chain and keys attached into my armrest sidepocket.  As you have the van seating, you don't have the armrest side pockets that Invacare provide, but I guess you could attach a small bumbag or something to the side of the armrest.  I did that on my older chairs to put things in.

Due to wheelchairs being funded for 'Mobility for Indoor Use' only then Invacare and other companys don't add lights to there wheelchairs as it be another extra cost.

All the other little things you need, again use a bumbag or a small bag.  With my cell phone I had a small piece of strap bolted to an area on my two post armrest which held the cell phone in place.  But now I just have my cell phone hooked up to a strap/landyard and put it around my neck or I sometimes hook it up to my seatbelt.

Good Luck and I hope your chair requires 'less' repairs:)  

Apart from the problems, how has my chair been? In a few words, overly slow and too basic. 5.8 MPH top speed? Come on now, I'm not an invalid. As far as I know, the general design is safe up into the 8 MPH range. No lighting options? No outdoor horn? No odometer or speedometer? No compartment for house keys, phone, diabetic glucose tablets, etc., small things that you need to keep ready? These are all glaring omissions in a supposedly high end mobility product in my personal opinion.

[John McKee]

Sweet Bear Cub you want to set the torque (ohms) to 60.

My SP has stopped on a hill. I waited a few minutes for the motors to cool and made it to the top.

My SP has a top speed of 6.5 mph at 100% forward seed.  

I've had the seat controller replaced twice in one year. I'm lucky in that I have a 3G Arrow with GB motors as a backup.

None of the DME's have parts in stock for the Invacare Powerchairs... we have to wait for parts to be shipped from Ohio.

I do have a competent, good natured tech that makes a 2 hour drive to service the TDX SP.

[SweetBearCub]

John,

I do not recall seeing a torque setting (in ohms or otherwise) when I got a brief look at the programmer at my DME's shop. What is the effect of that setting, if it is available on my chair?

Despite the fact that I have taken my chair up (and down) some exceedingly steep hills that Invacare would not condone in any way, it has never overheated. Perhaps this is due to the famously mild San Francisco climate. Perhaps luck. Who knows?

I'm not sure how your got your TDX SP up to a speed of 6.5 MPH, but Invacare own official documentation states a top speed of 5.8 MPH, or 5.0 MPH if the chair is equipped with the heavy duty (400 LBS weight limit) motors. I would be very interested in this. If your figures are correct, your chair is 10.76% faster than mine. While it's not 8.0 MPH, it would be useful.

Even though power tilt (and possibly power recline as well) would help my condition, I was not able to get them prescribed. Perhaps later, but at this time, my chair has a basic van seat with no power seating options.

Thankfully, both times when my chair stranded me, I was able to get help pushing it home and to the shop. I can push it for maybe 2 blocks, but that's it. Then I'm spent and useless.

Sweet Bear Cub you want to set the torque (ohms) to 60.

My SP has stopped on a hill. I waited a few minutes for the motors to cool and made it to the top.

My SP has a top speed of 6.5 mph at 100% forward seed.  

I've had the seat controller replaced twice in one year. I'm lucky in that I have a 3G Arrow with GB motors as a backup.

None of the DME's have parts in stock for the Invacare Powerchairs... we have to wait for parts to be shipped from Ohio.

I do have a competent, good natured tech that makes a 2 hour drive to service the TDX SP.

[John McKee]

The Torque settings on the 3G Arrow with GB motors had a range of 0 to 100%. The TDX SP came with the Torque set at 36 ohms. It is posable to set it to a max of 60 ohms. Torque and Power Level allow you to put the max amount of current quickly into your motors. High settings drain your batteries. If you want to set up your chair for max efficiency (max range) it is best to set the Torque and Power Level to 50% or 30 ohms. Slow acceleration and moderate speed will give you max range. I use the max Torque and Power to climb ramps and thresholds.

I take the TDX SP on concrete trails. Some of the hills are much steeper than the 12% recommended for wheelchairs. A ramp should be 1 inch of rise over a foot of travel. Some of the hills I encounter are almost a 60º incline. I also was keeping pace with a person walking. I have sense hit the hills at a faster speed and have had less problems. I was use to my old 3G Arrow with the GB motors. It had 4 inch wide tires and was a great off road chair. I was able to travel dirt and gravel roads in the desert.

The narrow tires on the TDX SP are best suited for hard flat surfaces.

I calculated the speed of the TDX SP with a GPSr. I made several runs in different directions on flat asphalt. I adjusted the speed with the programer until I got the readings on the chart.

Here is a blank chart to record your chairs drive settings:

The SP would swerve at the higher speeds. I adjusted the TREMOR and TRACTION to allow max speed without the swerving. The SP’s front castors have a tendency to chatter at high speed. It may be the weight distribution. I have a vent and extra external vent battery on the back of the chair.

The tilt and recline were prescribed to allow changes in position to reduce bed sores. I spend 14+ hours a day in the chair. With the tilt / recline and a Roho cushion I am comfortable and have had no skin breakdown. The ELR’s allow better circulation.

If my chair breaks down I have the motors disengaged and the chair is pushed or pulled. Luckily it has only happened once at the San Diego Zoo. We put the chair on a charger for a few minutes and I was able to climb the ramp into the van. Sense then I have carried a 24 VDC charger, when we stop for lunch or dinner I charge the chair. I put extra vent batteries and a 12 VDC charger in the first aid station at amusement parks.

When you contact Invacare or your DME have the delivery date of your chair, the chair # and serial #.

I have had my DME tech contact Invacare to have their tech contact me and talk me through trouble shooting the powerchair with the MK6i Programer and Pro Memory Card. By reading the error codes and performing tests it is possible to determine the defective part.

Phone Numbers:
Your DME:
Your  DME tech:
Invacare Customer Service: 800.333.6900
Invacare Technical Support: 800.832.4707

Online pdf manuals @ http://www.invacare.com
Info Booklet - Form #06-055
Mk6i electronics - Form #06-110
TDX SP/SR Parts - Form #06-105
Formula CT Powered Seating/Front Riggings - Form #07-077
Owner’s Operator & Maintenance Manual - Part #1143155
Owner’s Operator & Maintenance Manual - Part #1143190
MK6i Electronics Field Service Guide - Part #1141471
MK6i Electronics Service Manual - Part #1143203
Formula CG Powered Seating Service Manual - Part #114173

[Kevin G]

There are many great "posters" on Invacare Boards but John I have to say you go the extra mile sometimes to benefit us all.  The additional time you put into some of your posts saves us all a lot of time and anxiety by being informative and educational in usable and practical ways....

On behalf of all of us thanks again.

[SumBuddy Else]

I agree, thanks John for the helpful post. A couple of those downloads will greatly help.
Also, hearing the complaints "Deeply Disappointed" from a few people, I think they need to put things into perspective. I have the same chair, it's my third Invacare power chair, and yes it was a major adjustment. But, I read everything I could, and knew in advance, the limitations in speed, & a real change in mobility from the dragster style Storm, to the CG 6 wheel set up. I even spoke with several Invacare people, and weighed the pros and cons. So I made the informed jump, and it took quite an adjustment. It's a little slower, it does swerve easier, and it's not as rugged.
But I didn't get the narrowest wheels, there were options, I got the more powerful batteries, got the programmer, and mostly I'm satisfied. A power footrest motor failure, a tech advanced adjustment of my reclining system (something I can now do on my own with my programmer-that's my list of repairs in 9 months.
I know the Storm chair is still there, still available, and great for rugged heavy-duty and faster travel. If someone wanted those features, they were available. I wanted more mobility with curbs, and tight turning radius, which is a real bonus. I'm 6' 4", and turning on a dime was worth some trade-off. I can navigate bars (and friends homes) much much easier. I think everyone had a chance to learn the pros and cons. Setting a chair at 100% in some settings is asking it to do something the user should have known it wasn't capable of. Even though a Toyota has a speedometer that goes to 120, I don't think people would get much life out of it if they drove at that speed very long. That is for extreme need-I think the same with 100% acceleration settings. That's my $.02, and I'll agree, it takes me a while longer to navigate uphill from the San Clemente pier, but I think all the margaritas have something to do with that.