I just bought a used Quickie QM 710 chair. I got it because it has a seat lift in it. It is a VR2 system. It seemed very twitchy and was hard to keep in a straight line at any speed.
It would go 6 MPH no problem.
When I opened the programing I found it was the speed was set to only 50%.
I thought that was odd since it would go 6 MPH. I changed the speed to 100%.
It was completely uncontrollable.
Motor compensation was set to 130. I dropped it to 50 and the chair seems great now. I haven't had a chance to experiment with the compensation yet . Did someone who didn't know what they were doing screw up on the original programing?
There were no OEM walls set at all and accelerations were already set at 100% and decelerations set at o %.. It did have an inhibit on chair speed when the seat was lifted. That was set to 10% and made it useless to try to move with the seat up since it was so slow. I disabled that which is great to be able to do. The chair seems a little hard to drive a constant speed as it seems to surge a little. It rather fascinating to be able to completely change the way the chair works.
I recently got a OEM R-NET programer to use on my MM X8. I had never been able to look at the programing on my Quickie Pulse 6 with R-NET that I got used and have been using for a while pretty much indoors only. What a surprise to find out top speed had been limited to 60% ! I took it outside for a ride to measure top speed and sure enough it would only go 3.5 MPH. I didn't notice just driving inside. I fixed that but my wife did mention something about not going 6 MPH in the kitchen. I think it is a personal problem and she just needs to get out of the way. I love the R-NET system and am glad I got a OEM programer. They are expensive but my insurance will not pay for a chair for me. Buying a little used chair for $250 and a programer for $430 is still very cheap. Thanks for all the help everyone. I would never even know why a used chair seemed so crappy if not for Burgerman and this forum.
The vr2 works a little differently iirc. The lower the number the quicker the accelerations.
I have not played with the programing again but I want to set the speed at 50% and raise the compensation slowly to see if I can get it to start moving past 3 MPH. I just think someone who had no idea what they were doing set this chair up. Amazing no one got hurt.
These are rather complicated machines we ride around on. I doubt that there are many technicians that have a full grasp of the chairs they are working on.
Burgerman wrote:.
Full grasp? Yes. So the real problem is that the sort of people you end up with as wheelchair techs tend to be those that were failed bicycle or lawnmower mechanics. Or the delivery driver that has been on a day course. Its just not an industry that attracts the best engineers. Its not a sexy subject. Most couldnt care less, have no real interest, dont even own the basic tools to program chairs properly and wouldnt know how if they tried. Although many like to pretend they do. Like car parking attendents with the tools to fine you, think they are something important! There are keen, enthusiastic on the ball techs out there. Like rover on here. But they are like rocking horse poo.
LROBBINS wrote:Going 6 mph with speed set at 50% was probably because of the excessively high motor compensation - essentially you had a runaway situation. Motor compensation works by measuring motor current and then estimates back EMF as (current x motor resistance) which is proportionate to load. It then adds that to what the stick is calling for - it "fakes" a higher stick position. So even though your stick was saying "go 50%", with the added excess compensation it told the chair "go full out". As you discovered when you took away the 50% speed limit, too much compensation is a very dangerous situation.
When adjusting compensation always start with a too-low, sluggish moving chair, value and raise it in small increments. As soon as the chair gets even a little bit jumpy then back off a bit. If you adjust it so that it's "perfect", the next day when the temp has changed, or after you've driven some and the motors are hot, or when you rest a while and the motors are cold, it will no longer be "perfect". Less than perfect and the chair will be less responsive, but safe. Being more than perfect is bad news. Motor compensation is a positive feedback loop and if even slightly too high is asking for trouble. It must be adjusted for slightly less than perfect.
Clif wrote:... motor compensation of 130 amps....
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