12V DC Motor 6DOF Motion Sim Project

You got it mostly right. In axis assignments you will set up 6 axis (one for each motor) and then also set up 6 dofs on each axis. For each dof you will then set a percentage of that dof to use on that particular axis. Add up all the dof percentages on a particular axis and you will have the total amount of movement (as % of possible movement) on the axis. Some dof’s you will set to 0 when you don’t want any movement from that dof on that particular axis.

As far as that statement, Simtools will not do that in and of itself. However, Simtools 2.0, at some point, will get a 6dof math plugin that will do that for you if necessary. But when you set up all your motors and connection points at even and equally spaced intervals, it somewhat negates the necessity of using a 6 dof math plugin. At least it appears that way since a few members here are running their 6dof's now without it.

Edit: The percentages of a dof can be different on each axis so you can make it work to some extent as you asked, but it won't automatically vary the percentages based on the current angle of the platform. We need a math plugin for that.

Also, in your example with 3 ards, you would do something like putting <Axis1> and <Axis2> on interface1, <Axis3> and <Axis4> on interface2, and <Axis5> and <Axis6> on interface3.

So if the axis and DOF set improper, the force of each motor will exclude and if the force is strong enough may broke the platform structure, right?
What I see near every 6DOF project has different structure design(motor has different layout, different angle), how to adjust and without broking the platform?

Attached some design I found in forum, if change the motor location, I guess the setting should adjust also. looks so difficult. The test function of Sim tools is impossible to simulate all the racting data.

The two with the triangular platforms look geometrically the same to me. The hexagon platform design looks like it would offer steeper angles.

I haven't done a 6dof myself though so maybe when @SilentChill isn't tied up doing the latest update to the Elite Dangerous plugin or when @SeatTime can find a little time, they can tell you more in relation to their 6dof rigs and the setup and settings they used.

I'm curious myself about whether a 6dof using linear actuators would benefit more from a math plugin or if lever actuators would. Can you guys share a few of your thoughts?

Preparation progress:
12V DC motor: inquiry price on line, the seller has 200W to 600W motor, I'm worried more power more noise.
3 Ards and 12 MMs: book on line
6 POTs: book on line
6 Flexible Shaft Couplers: book on line
PSU: book on line

but there are something I can't find, any one can give me some suggestions?

12 Ball Joints: I found it on line now.
CTC shaft: can’t find it.
Long shaft (connect to CTC shaft): find some pole, maybe can be use. attached the picture.
Connector of CTC shaft and long shaft: can’t find it

Preparation progress:
12V DC motor: still not decide where to buy(too expensive to ship to Chile and too much tax). so bought 8 small motor to DIY a model first .
5 Ards and 15 MMs: received
7 POTs: received
8 Flexible Shaft Couplers: received
PSU: book on line

This weekend I will start my model. It's time to upgrade my rig with DOF.

Having used software with a 6DOF math plugin (BFF) and software without a math plugin (Simtools), I really can not feel much difference. What does make a difference are other settings currently not available in simtools - Eg. adjustable centre of rotation and the ability to adjust roll and pitch based on acceleration. I have had a chat to @yobuddy about this and he was kind enough to produce a custom plugin to give some of these abilities, it worked well, although still allot of work to do. If you really want to understand how a stewart platform works then building a model is a great way to learn. The angles formed by the actuators to the rig are very important. If you don't get this right, the rig will not properly support itself - For a recent example of this see @poman rig which he is currently sorting out. For information here is his video (I hope he does not mind )

the Motor works

one question, what is the reason for setp 5, 6, 8?

Initial Setup

I strongly recommend you follow the steps below if this is the first time you are using SMC3 with your simulator to reduce the risk of damaging anything.

1. Disconnect the motor power supply
2. Make sure Simtools is not running – we’re not ready for that yet!
3. Wire up the Arduino (with SMC3 installed) to your H-Bridges and connect to your computer via USB
4. Run the Windows SMC3 Utility software and make sure it communicates with the Arduino (There is no need to set baud rates, they are not configurable)
5. Set the Kp, Ki, Kd, PWMmin, PWMmax, PWMrev to 0 for ALL motors (This will make sure the motors don’t move)
6. Set Clip to 255 (you need to do this first) and Limit to 255 (This will give you plenty of margin if something goes wrong while setting up)
7. Turn on the power to your motors – nothing should move at this stage!
8. Set Kp to about 400
9. Now slowly, increase PWMmax… at some point the motor should start to move. When it does check the “Green” feedback line is moving toward the “Blue” target position.
   • If it is then that motor and feedback is wired correctly - proceed to test other motors.
   • If it is moving away turn off motor power immediately (or quickly reduce PWMmax again). In this case you need to either reverse the wires to the motor being tested –OR– reverse the +5V and GND wires to your feedback pot for the motor being tested (do not do both). Restart the test from the beginning.
10. Do the above for each motor

http://www.xsimulator.net/community...3dof-motor-driver-and-windows-utilities.4957/

the POT I bought as attached picture, which one should I connect to +5V and which one should I connect to GND? the else one I will connect to A0 and A1 in Ard.

You can connect 1 and 3 either way. If the motor runs out of control then they are reversed so change them around.

or swap motor wires

Just to minimise damage. Some new starters know more or less than others and if you're not careful it is possible to have motors zoom off and damage the sim, for example if the POT is connected in reverse.

If you take care and do things slowly and carefully this is not necessary.

I guess Step 9 is to find out the matched initial "location" of POT and motor due to each POT with different initial angle. Do I understand right?

More so to check that the POTs/Motors are running in the correct directions. If one is in reverse the motor will just speed up and keep spinning. That is why recommended to increase slowly and see what happens on the chart so you can stop and reverse the wires if necessary. If you are testing with model motors it is not a huge risk, but if you are testing with a complete sim and they are wired wrong it may damage something with the powerful motors.

Again it is just a recommended approach - if you take care and progress slowly you don't have to do it this way.

First draft version model, working on POTs, used to study and test.

Thanks all.

Looks the model works. but the 2nd left motor works not fine, only when the motion amplitude large(I choose motion mode in SMC3Utils v1.01 tool) the motor works. what could be the reason? the motor, Ard, or MMs?

when I increase PWMmax for moter it become more responsive.
why each motor has different responsive PWMmax? my motor 1 is about 30, but motor 2 is about 200.

Possible unserviceable MM driver chip.

the troubleshooting procedure would require that you swap one motor with another and check
then swap one MM with another and check...
etc

this will tell you where is the default

It is recommended to load test all monster motos before installing. There are some suppliers that are selling faulty units. Follow @RacingMat advise for finding fault.