Marks K8055 & Pololu wheelchair motor sim

Hi All,

I've been visiting the site since just before christmas. Most of my free time between then and now had been spent trawing through the forums gathering all the required, previously learned knowlege and experience of all those who have trundeled down this path to find the Holy Grail of simming I'm almost finished my sim so thought now would be a good time to post the details:

Components:
2 off Fracmo 24v 11A 40Nm wheel chair motors - £68 - ebay
2 off Pololu 24v23 cs - £100 - Technobots
1 off 24v 50A PSU - £40 - ebay
1 off K8055 kit - £35 - Maplin
2 off 360' 15% pots without stop - RS Components - £35
2 off hubs/actuator arms - £55 - local machine shop
Rod ends and plastic gears - £50 - bearingboys - (thanks TIM)
Motor mounts made from left over industrial roofing flashing - local farm - £0
Frame - chopped up an old glass topped metal table - £0
Plywood - scraps from other projects - £0
Land Rover steering colum and universal joint - given by a friend - £0
Other bits and bobs - everywhere - £50
Total - £437 - so far



http://www.youtube.com/watch?v=MnB_n2YsIaQ


http://www.youtube.com/watch?v=o0swhHqdll8

I ran it with Nimas ( : Rfactor Megane Nordschcliffe profile. At this point in time my knowlege is too limited to be able to edit this to give acceptable results in my sim and I found the movements to much and the lateral movements were the wrong way around. Maybee later

http://www.youtube.com/watch?v=0co_8XyyShI

For now I am experimenting with Bernards Rfactor template profile : modified for the K8055. I am finding this easier to understand and I will add to it as my experience grows.

http://www.youtube.com/watch?v=yLZ5S8JJkFk

At the moment I am running my sim on 12v and the Pololu cards and motors are cool to the touch. I have not used the 24v supply I have as when I tried it the Pololu cards almost melted even when the sim was stationary. I will need to look into this a bit more.

Overall I am very pleased with the results so far. The K8055 and Pololu combination have offered a quick and resonable priced solution. Now down to the next task of profiling.

I would like to thank all those who contibute to this forum for all the enthusiasm and effort that make it what it is.
Special thanks to Sirnoname and everyone who contributes to the software development of x-sim.


Kind regards

Mark

Re: Marks wheelchair motor sim

Thats a great simply design, looks good, and great movement! Well done!

Re: Marks wheelchair motor sim

Awesome work dexteria, I too have 2 Fracmo 24v 11.5A motors for my project also 4 pride mobility motors which I think are higher rated than Fracmo but there is no indication on them. I have a K8055 but I find the pwm output to be unsteady ranging between 4.65 and 4.68 unpredictably at max which isnt the full 5v so my motor will spin faster in one direction than the other. So I am trying a new approach now to connect my motor driver a Sabertooth 2x25 v2 direct to the pc by USO rather than synaptrixs, although I am now struggling with the drivers and the serial to ttl adapter. I just not having any luck.

I am hoping to build a 3dof using 4 pride mobility motors to move full rig and 3 nice and light led monitors.

Hey Mark,
In your assembly list you mention (1 off 24v 50A PSU - £40 - ebay) can you help me to find it

@BartS could the problem with your output voltage have anything to do with your input voltage to the K8055?

yeah it could be, the k8055 can handle upto 5.20v but even that wount be sufficient for a 5v on both pwm/dac output channel. I think my laptop supplies 4.96v through usb and my pc about 5.08v.
I hav'nt exhausted all possibilities yet and I dont like the unpredictable results I'm getting from different computers so I am going to try universal serial out direct to the sabertooth before i return to the k8055.

I am using Leo Bodnars BU0836A http://www.leobodnar.com/products/BU0836A/ for reading in inputs it is very good.

Hi guys,

Sorry been busy with other work, not touched the sim for weeks. I'll do some measurements at the weekend on the 8055 voltages. The 24vPSU I have wasn't new and I've not seen another one since. Not sure if I'll be using it, or if indeed it is the correct type. You are welcome to buy it off me I have tried using two 12 SLA batteries in series and in parallel to an intelligent charger that varies the amps according to the charge in the batteries. It runs well with this and is certainly faster and everything stays cool.

Mark

Hey Dexteria,

I want to do the same as you with the 2x12v SLA in series and in parallel with an intelligent charger, however I am scared I may wire up something wrong.
Did you use any diodes for this?
Did your intelligent charger have a 3pin XLR connector such as that on mobility vehicles, did you modify it in any way?
Could it be possible for you to draw me up a wiring diagram or point me to some instructions on the web?
I have basically bought a wheelchair with 2x12v 42ah batteries and an 8 amp 3pin XLR intelligent charger that varies amps such as yours I think.

Also is it safe to use the batteries while they are being charged ?

I found this for wiring in series and parallel : http://www.nyc-arecs.org/Connecting_Batteries_and_Chargers_in_Series_and_Parallel.pdf