New 2DOF DC motor sim

I'm about to start the build of a 2DOF sim. This is what I've got so far:

RCI 8000S Poly Baja Highback Seat
2 DC gearmotors from wheelchair lifts
K8055
Sabertooth 2X25 motor controller
2 10K pots
4 Ball bearing rod ends
400 watt PC power supply

The motors run 270 rpm @ 12v so I'll have to gear it down. I'm planning to use the gears off an old bike to get the rpm to between 55 and 70. This will also increase the torque.
Tomorrow, weather permitting, it's off to swap meets and bike repair shops to gather more parts.

Dave

any sketch for you frame?

Not yet. I'm waiting to get the reduction gearing sorted out.

Dave

Any hint of a fix update soon? And what is the workaround for vm110 k8055?

Have you thought about Pololu JRK 12v12 boards? These are a good board for 12v motors. I run mine at 22.5 amps error, (they will go up to 30amps) with heat sinks and two 500w pc psu's on wiper motors. They do the job well on my 2 dof frex. Perhaps if yo uconsider a change of control board, advertise what you have here, you may be a buyer.
Cheers, David.

I may yet go with the Pololu boards, but early testing with the Sabertooth is going well.

Dave

I'm not sure if this problem should be posted here or not ( not sure it's a profile issue).
I've got a profile, dirt2 plugin and a sender config file loaded, the program tells me a game has been detected but when I hit Start and play the game, all the inputs stay at 0. The 'game is in action detection of sender' button is unchecked. My sim output screen has 'game paused' always checked. Before I connect any outputs I want to make sure all the different modules are communication with each other.


Thanks,
Dave

Have you selected the official developer plug in ? Also have you tried it with another game and profile?

Yes, the official plugin is loaded. Dirt2 is the only game I've got that has listed plugin. The test panel plugin works fine though.

Dave

From what I can tell from the pic, you have clicked try sending data instead of play game.Perhaps change the game exe file location and try starting the game with that, as well as click start of profiler.

I think I got it. I edited the hardware config file to change the ip from dbox to 127.0.0.1 I can see the values change as I drive.

Dave

I forgot about that bit.... :
That should help.

I was originally planning on using the 2 wheelchair lift motors I had. Their rpm was too fast so I devised a reduction from bicycle gears to get it down to about 60-70 rpm.

I wasn't happy with how it was going so I stopped of at the local salvage yard and picked up 2 wiper motors ($15 each). They have plenty of torque and should work well. I'll work on the frame next.

Dave

Hi Dave - using gear reduction with bicycle components does work, but from my prototyping I can tell you that this configuration is compromised. Yes you will get a speed reduction and power advantage through the use of gears, but you will also lose power and gain speed from the increased length of the lever (centre of the axle to edge of small cog : Centre of axle to arm connect on big cog).

I believe that you will also experience difficulty using bike components, as they do not connect in the way your diagram shows... the hole in the centre is much bigger.

For a step by step guide on how to set up cogs and chains on a wiper motor, check out Page 17 post 5 in my thread... later on in the same thread, there are pictures and videos of this setup in action... very poor performance by comparison to other configurations - this configuration could barely lift 10kgs... other configurations I have tested were capable of throwing a 2m sofa around with the same motor!

Good luck! :thbup:

Tim

The more I looked at my design, the less I liked it. It seemed like more trouble than it was worth. I'm now collecting components for your wiper relay circuit.
Although I have a Sabertooth controller, it's not doing exactly what I want. It may be due to dirty pots, so I've got more on order.

Dave

the problem with the pots is more likely to be a shielding problem, or not using the full range of motion rather than dirt on the contacts...

Another tip for you is to use 10K pots rather than 1k... in my own tests they have proved to be far less jittery... may make the difference for you!

Tim

ps. I have found some multiturn pots from the far east (10 turns, 10K) that are absolutely superb... I will be running some more tests this evening, and will post the spec and data sheet if they continue to prove satisfactory

My problem was I had my speed/trigger value @0 so it would just yo-yo. I imagine this is like a 'dead zone' adjustment. After raising it a bit, I tried it with an old 5K (really 4.16K) linear pot and it seems to work. With linear pots it should be easier to get a linkage that will use almost the full range. My new 10K's should be here in a few days.
I'm not ready to give up on my Sabertooth just yet, but I plan on building your relay circuit and do a comparison.

Dave

Should I move the steering wheel and pedals with the seat or not? It would certainly simplify things if I didn't. I noticed the Simxperience sim doesn't.

Dave