WheelchairDriver

Posted: **07 Jul 2025, 16:59**

Hello everyone. My name is Anthony, living in N Georgia, US and I'm interested in Burgerman's BM3.

I am ambulatory but I have MS and I suffer from the typical fatigue. I can move about for short periods of time (grocery store, taking trash to the dump, etc) but I use a manual wheelchair when attending concerts with my daughter (who typically pushes me). I also have a power chair gifted to me that I have used at a regional amusement park (I don't even know what brand it is) but it requires a carrier to move. Some of the venues I have gone to are in hilly areas, and it's difficult for my daughter to push me, hence my interest in the BM3.

Hope to learn a lot!

Anthony

Posted: **07 Jul 2025, 18:00**

Well the first thing is that the frame I used, and modded, and the original chair isnt manufactured for many years or decades. So that is problematic.
The 2nd thing is that the complexity of doing this with higher voltages, and roboteq controller as well a the programming and understanding required is way beyond most people. The chance of success if you dont have a lot of experience and 1000s of hours building and understanding such things is very low.

I built it for fun, and as an excersize in engineering and to see how fast was practical.

And so I suggest you aim a little lower, and modify something that is available, and current to suit your own needs. So that parts and tings are at least available.

I also suggest you read the Roboteq thread at the top pinned as a starting point. Yes it ended up long! It wasnt easy. And is still an open book.

So whaat are you NEEDS and wants in a chair and why?
I might add that you likely wont know until you use one for a fw years and test many.

Posted: **16 Jul 2025, 18:37**

Welcome!

Posted: **16 Jul 2025, 22:32**

Greetings, one and all,

I'm Ian, a young hearted 70yr old from SW London. I'm currently a retired Electrical & Electronics Engineer and a full time carer for my disabled wife - who is a powered wheelchair user. We have had a number of chairs and encountered most of the common issues that wheelchair users find, especially (given my wife is a larger lady) power issues and battery longevity. I have over come the latter issue by changing to LifePo4 batteries. Suitable suspension to dampen the luna style surfaces of London roads and pavements is also a struggle. I have been making some basic changes within the scope of her current chairs but feel the best way forward would be to custom build a chair myself. Main issues I face are an inability to weld and limited resources. That's Me and where we are at.

Posted: **17 Jul 2025, 00:02**

Welcome ian! cheers

Posted: **17 Jul 2025, 16:17**

Hi Everyone.

I just spent an hour crafting my introduction and setting out what I'm interested in doing on this site and what I hope to get out of it - but when I pressed Preview to check it looked OK it told me I needed to be logged in and disappeared all my words

So second time around I'll keep it short and see how it goes.

My name is Ian (obviously we are bit like buses, you wait for ages then two come along together).

I also am not a wheelchair user, I am the carer for my wife who has recently become a chair user due to peripheral neuropathy that means her legs are no longer reliable and her hands are ropey at best. I have the role of chair technician for outdoor chairs (she has a WCS supplied Quantum Kozmo chair for indoors that is unexceptionable but would be lucky to survive more than a few metres outside the gate.

My aim over the next couple of months is to upgrade a recently purchased second hand 6mph Dietz Sango Advanced to something better than 'just about adequate' for everyday outdoor use and give her back some independence.
To that end I have several questions that tie in with current threads, so you will likely be seeing more from me in the near future.

Fingers crossed!

Kande_ian

Posted: **17 Jul 2025, 22:30**

Welcome to the Forum Kande_ian!

Where are you from?

Posted: **18 Jul 2025, 10:14**

Hi Martin, I'm in the UK, in south Cheshire - between Crewe and Stoke, so reasonably flat, reasonably green and a few small towns round about.
I am a physicist by training and have worked most of my life in engineering - mainly in R&D, inspection and testing.
I have seen there is a lot of good and very useful information on this site but the more current content is embedded in the boards and I'm very much still finding my way around and learning how to find (and get back to) the bits that are relevant to what I'm doing.
So far I have a shortlist of things I want to tackle.
1) Better wheels on the Dietz chair - I was about to start measuring up the hubs for an adapter for some wider 8" rims but then spotted that burgerman and shirley appear to have done that already, so maybe that one is easily sorted.
2) Programming - I'm not sure I need to do it immediately but I'm pretty sure I will need to engage with R-net at some time (see below) and not being able to do so will surely irritate me. It is a frequently asked question but I'm still struggling to work out exactly what permutations of dongle/programmers/access codes are needed and who they can be acquired from in the UK.
3) Remote contol - the chair is going to have to live in the garage because the house is already full, so I would like to be able to have it come to the door when my wife wants to use it (she has a WCS provided indoor chair and a desire to be as independent as possible). I have seen (on a different site) a wifi connected Raspberry Pi wired into R-net but I am wondering if anyone has used R-net bluetooth to control a chair rather than using it to control a PC with the joystick. Has anyone here done or seen anything on this?
4) What is the best option currently available for charging/monitoring lead acid batteries? I intend to swap to lithium in the future but as the chair came with a new set of lead acids they might as well see a bit of service.

Feedback and info related to any of these would be welcome.

Posted: **18 Jul 2025, 19:03**

1) Better wheels on the Dietz chair - I was about to start measuring up the hubs for an adapter for some wider 8" rims but then spotted that burgerman and shirley appear to have done that already, so maybe that one is easily sorted.

And tubeless. Which is massively better.

2) Programming - I'm not sure I need to do it immediately but I'm pretty sure I will need to engage with R-net at some time (see below) and not being able to do so will surely irritate me. It is a frequently asked question but I'm still struggling to work out exactly what permutations of dongle/programmers/access codes are needed and who they can be acquired from in the UK.

What control system does it have?
It will be R-Net or VR2.

3) Remote contol - the chair is going to have to live in the garage because the house is already full, so I would like to be able to have it come to the door when my wife wants to use it (she has a WCS provided indoor chair and a desire to be as independent as possible). I have seen (on a different site) a wifi connected Raspberry Pi wired into R-net

That was made by Woody GB who sadly died a few months ago. All my chairs are RC one way or another.

but I am wondering if anyone has used R-net bluetooth to control a chair rather than using it to control a PC with the joystick. Has anyone here done or seen anything on this?

No, works the opposite way. I also dont trust BT and its not got much range either.

4) What is the best option currently available for charging/monitoring lead acid batteries? I intend to swap to lithium in the future but as the chair came with a new set of lead acids they might as well see a bit of service.

Contact shirley.

Get one of these:
https://www.wheelchairdriver.com/board/ ... 20#p206668

BUT lead is garbage. They are useless compared to the 230Ah (244 in practice) lithium packs we are now building that fit the same space with 20 year plus lifespan, and 700% range... And less weight at half the cost of a decent set of lead bricks.

Even so that supply is 3kw OUT. 3.3kw in. It can do 0 to 70V and 0 to 50A. So can be used to charge lead (its also a user configurable 3 stage charger) or to power a hobby style lithium balance charger, or to charge via a BMS if you must...

Which for the price and build qulity is crazy good value.

Posted: **19 Jul 2025, 09:59**

Burgerman wrote:
1) Better wheels on the Dietz chair - I was about to start measuring up the hubs for an adapter for some wider 8" rims but then spotted that burgerman and shirley appear to have done that already, so maybe that one is easily sorted.

And tubeless. Which is massively better.
Yes, I already read your earlier posts about tyres - so was looking for large section tyres and suitable rims - was thinking about steel for starters but then I saw what Shirley was preparing for you - if repeats are available for mere money I'm interested.

2) Programming - I'm not sure I need to do it immediately but I'm pretty sure I will need to engage with R-net at some time (see below) and not being able to do so will surely irritate me. It is a frequently asked question but I'm still struggling to work out exactly what permutations of dongle/programmers/access codes are needed and who they can be acquired from in the UK.

What control system does it have?
It will be R-Net or VR2.
R-net - it's got a CJSM2 controller. As someone new to this whole subject I'm finding the main difficulty is working out what is available now and where from - if I need to be a business to buy R-net parts from some sources I can do that as well, as long as I don't have to prove I have a long established wheelchair business (which in general business terms would be somewhat strange requirement).

3) Remote contol - the chair is going to have to live in the garage because the house is already full, so I would like to be able to have it come to the door when my wife wants to use it (she has a WCS provided indoor chair and a desire to be as independent as possible). I have seen (on a different site) a wifi connected Raspberry Pi wired into R-net

That was made by Woody GB who sadly died a few months ago. All my chairs are RC one way or another.

This is what I was referring to https://github.com/redragonx/can2RNET?tab=readme-ov-file - it is mostly from about 8 years ago but has some updates from early this year - I've not gone into it closely yet because it isn't my first priority and the coding is well outside my comfort zone zone (but doesn't look stupidly difficult).

but I am wondering if anyone has used R-net bluetooth to control a chair rather than using it to control a PC with the joystick. Has anyone here done or seen anything on this?

No, works the opposite way. I also dont trust BT and its not got much range either.

In this case it wouldn't need much range - probably within 10m line of sight

4) What is the best option currently available for charging/monitoring lead acid batteries? I intend to swap to lithium in the future but as the chair came with a new set of lead acids they might as well see a bit of service.

Contact shirley.
Will do

Get one of these:
https://www.wheelchairdriver.com/board/ ... 20#p206668

BUT lead is garbage. They are useless compared to the 230Ah (244 in practice) lithium packs we are now building that fit the same space with 20 year plus lifespan, and 700% range... And less weight at half the cost of a decent set of lead bricks.

Even so that supply is 3kw OUT. 3.3kw in. It can do 0 to 70V and 0 to 50A. So can be used to charge lead (its also a user configurable 3 stage charger) or to power a hobby style lithium balance charger, or to charge via a BMS if you must...

Which for the price and build qulity is crazy good value.

Thanks for your insights and I hope I haven't mangled any site conventions with my responses here - I've not previously made a habit of participating in on-line forums

Posted: **23 Jul 2025, 12:17**

Discuss everything about wheelchair below to receive more advice.

https://www.wheelchairdriver.com/board/ ... 41#p211241

Posted: **16 Mar 2026, 23:20**

Switching from AGM to lithium batteries, was the first and best thing I did, many moons ago. In the early chairs I did find that battery level monitors were hopeless, because of the discharge profile, but newer ones seem better. But lithium are lighter, have better temperature range, last reliably for so much longer and far more of the stored energy can be used. (AGMs recommend not running below 30 percent). Caution is you want to travel. Airlines have strict rules about lithium. I always prefer Lifepo4 over lithium ion. They are far more stable and tolerant than lithium ion... and less likely to burst into flames.

Ian

WheelchairDriver

Hello!

Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!

Re: Hello!