Handicare Puma 40 won't track straight

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Handicare Puma 40 won't track straight

Postby greybeard » 08 Dec 2021, 18:12

I have hardly used my backup Puma 40 in the past year but recently I've had no choice. I have discovered it is difficult to get it to track straight on the very uneven pavements round here even at way less than 6mph.

I suspect that it may have been like this for some time but I got used to it when it was my daily driver. It's likely that my finger/wrist dexterity has declined too. There have been no programming changes other than me fiddling with deadband (now 20) and tremor damping (10), without really knowing what I'm doing, via OPB but with little improvement.

It occurred to me that I might now benefit by fitting a R-net gyro if I can find an unwanted one for a reasonable price. I understand by reading P&G that they are basically plug and play (?). Is this correct? Would one help? Anyone want to offload one to a good cause? lol

If I can borrow a programmer, are there other adjustments that I can make that would help ie motor comp etc? Any other suggestions?
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Re: Handicare Puma 40 won't track straight

Postby rover220 » 08 Dec 2021, 18:49

yes they are plug and play but your chassis may not have the necessary mounting preparation for it.

i have one if required.
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Re: Handicare Puma 40 won't track straight

Postby LROBBINS » 08 Dec 2021, 19:19

Motor compensation too low is a good candidate as a cause for wandering on uneven surfaces, as is delayed turn acceleration/deceleration (which leads to "pilot induced oscillation" as the chair never ends up pointed where you think it should).
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Re: Handicare Puma 40 won't track straight

Postby greybeard » 08 Dec 2021, 19:41

LROBBINS wrote:Motor compensation too low is a good candidate as a cause for wandering on uneven surfaces, as is delayed turn acceleration/deceleration (which leads to "pilot induced oscillation" as the chair never ends up pointed where you think it should).

Both turn Acc & Dec are 100%. I'll have to get hold of a programmer to check motor compensation.
Thanks for the tips.
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Re: Handicare Puma 40 won't track straight

Postby greybeard » 08 Dec 2021, 19:44

[quote="rover220"]yes they are plug and play but your chassis may not have the necessary mounting preparation for it.

i have one if required.[/quote
Is the mounting something a drill could sort out?

I'm sending you a PM.
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Re: Handicare Puma 40 won't track straight

Postby ICEUK » 08 Dec 2021, 19:54

Geoff if you need to programmer let me know. I did have a gyro but one of the members on here scammed me off it.
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Re: Handicare Puma 40 won't track straight

Postby Burgerman » 08 Dec 2021, 20:13

Is this rear or front drive?

If its front drive then you definitely need the gyro and even then its never going to drive well.
If its rear drive and you have the stock setup (way too nose heavy) then again you will never go where you want. The rear motors even with gyro or fine tuned motor compensation just dont have enough power to control the chair in front of them, with you sat with your weight on the casters. It will head downwards on any uneven stuff and may also lose traction.

As for gyro on a rear drive? Mine is disabled. I keep it only so I can play about and understand it but it makes everything worse and less predictable. Its a bad substitute to a properly configured chair.

And:
Both turn Acc & Dec are 100%

Hopefully that includes MINIMUM TURN ACCELERATION and MINIMUM TURN DECELRATION as well or again it will feel uncontrollable. You may find that with less than perfect hand control or controller position that turn speed may need reducing.
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Re: Handicare Puma 40 won't track straight

Postby greybeard » 08 Dec 2021, 20:23

Burgerman wrote:Is this rear or front drive?

If its front drive then you definitely need the gyro and even then its never going to drive well.
Both turn Acc & Dec are 100%

Hopefully that includes MINIMUM TURN ACCELERATION and MINIMUM TURN DECELRATION as well or again it will feel uncontrollable. You may find that with less than perfect hand control or controller position that turn speed may need reducing.


Front drive. I'm well used to it as I've driven FWD for getting on for 10 years. I have only recently realised how badly it steers even at my usual slow speed while dog walking. Mind you the pavements/sidewalks are attrocious and are not getting any better!

Yes, Max and Min turn acc and dec are 100%. I will try reducing that a little.
I have been offered the loan of a programmer so can check the motor comp. What approximate setting would you consider best for my circumstances?
Thanks
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Re: Handicare Puma 40 won't track straight

Postby greybeard » 08 Dec 2021, 20:25

ICEUK wrote:Geoff if you need to programmer let me know. I did have a gyro but one of the members on here scammed me off it.

Hi John. A borrow would be great. Thanks. Do you still have my address?
Geoff
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Re: Handicare Puma 40 won't track straight

Postby Burgerman » 08 Dec 2021, 20:40

Yes, Max and Min turn acc and dec are 100%. I will try reducing that a little.

You could reduce turn accel but not turn decel as that will just make it worse.


I have been offered the loan of a programmer so can check the motor comp. What approximate setting would you consider best for my circumstances?
Thanks


Depends on battery condition, motors type etc, and temperature. Just add 5mOhm at a time and test. But front drive? Will never steer properly. And MUST have a gyro. You must already have one. If you have then it exadurates all the turn accel settings and must be set lower.
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Re: Handicare Puma 40 won't track straight

Postby ICEUK » 08 Dec 2021, 20:41

Send me address again. I dont think i have it .
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Re: Handicare Puma 40 won't track straight

Postby greybeard » 08 Dec 2021, 21:20

ICEUK wrote:Send me address again. I dont think i have it .

Sending PM.
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