3dof with wipermotors and 360 degrees rotation/drifting

[vittobrambi]

Hi,

I discovered this awesome site about 8 months ago.
Since then I started building my own project.First I started with a 2DOF wipermotors
Then I moved to 3 DOF with added continuous rotation to simulate cornering and drifting

Here is the video
http://www.youtube.com/watch?v=MGFHFq1Swpw&feature=plcp

In this case the construction is more complicated because I had to put everything on board (PC, DC supply, Sabertooth 2x12, bass shaker, monitor)

Ciao

Valerio

[motiondave]

thats a great job there!

[ferslash]

ok man, that is insane!!!

some silly questions:

1. what kind of electronics did you use?
2. how you move (turn) the whole unit, is it using a wiper motor? connected to a wheel or how?
3. are you planning to upload some extra aspects of your monster?

best regards fer

[vittobrambi]

Ok i give some more details, but i am out of station so i cannot post pictures.
I use a velleman vm140. I had originally a vm110 but i needed the third axis, then i switched to the vm140.
The rotating wheel is driven by 1 wipermotor hanged to the shaft.
Its control is in open loop, therefore no potentiometer for feedback is required.
Left and right motors instead have linear wire potentimeters. Their control is in closed loop in dynamic mode kp=3

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Left and right motors are driven by sabertooth 2x12 and an adjustable dc power set at about 18 v. Nevertheless motors do not get very hot.
On the other side rotational motor is driven by a md22 + a 500 w pc supply modded. This motor gets very hit during usage since it is heavily loaded

---

Current problems i am facing (please help me with ideas if any)
1) connection between hanged motor and wheel shaft is really bad and it is breaking sometimes. I think i need a good joint between the wipermotor (threaded conical about 6 mm dia) and shaft (threaded m12). Any idea?
2) lever of left motor get loose and potentiometer looses 0 position. Also in this case a good joint connection is needed

---

New ideas:
1) use 3 rotational motors equispaced from rotation axis in order to increase speed and reduce thermal load
2) use a big spring instead of universal joint under the seat. (total new project for adding 4th z axis)

[floriske]

Nice looking project you have there!

One request though: if you post 4 posts within half an hour could you please use the edit button, this keeps stuff a bit more tidy

[motiondave]

I reckon look at some motors from this site,
Maybe these for the 2dof http://www.motiondynamics.com.au/worm-d ... orque.html
and maybe something like this with another gear for the drift http://www.motiondynamics.com.au/straig ... motor.html
For overall reaction times and ease of setup boards, try these http://www.pololu.com/catalog/product/1393 one per motor.

[vittobrambi]

Thank you for suggestions and sorry for multiple posting.
I like the gearmotor with hollow shaft maybe it is a solution. On the other hand i need a simple and reliable joint.
Something similar to this
http://www.directindustry.com/prod/mayr ... 15233.html
Do you know how other people joined the potentiometer to the gearmotor?

[motiondave]

how did you do the current ones?

[vittobrambi]

I cannot post pictures right *(i'll do asap). I try to explain:
1) pot to gear: i use a longer bolt than original to fix the lever to the gear shaft. I use the remaining hollow threaded part to insert a threaded rod. Then i make a flat face on the rod and the same on the pot. Finally i join them together by 2 plates Bolted together
2) gear to rotating wheel 3rd axis
I weld a small bolt for gear to the big bolt for shaft.then i drill the gear shaft and insert a pin 3 mm inside

[vittobrambi]

Hi,

it has been quite a long time without posting, in the meanwhile I have found some time to work on the simulator.

Following main updates:

1) I moved my simulator from my house to basement (my wife is very happy for that... )
2) I changed position of pc. Now it is under the pedals
3) I changed the position of electronics. Now is under the seat
4) I put 2 wiper motor for rotation for better response
5) I put one incremental encoder on the third rotating wheel (the one below the seat)
6) I added one Arduino UNO controller to calculate the actual rotating speed and compare with the simulator rotating speed
7) Added more robust structure for wipermotors and new pot connection
8) Added 2x100W auto amplifier for bass shakers

Here some pictures (I apologize for the mess in the basement...)

IMG_1871rid50.jpg (532.94 KiB) Viewed 6726 times

Assembly of simulator

IMG_1874rid.jpg (173.57 KiB) Viewed 6726 times

Amplifier and electronics (K8061 - sabertooth 2x12A etc..)

IMG_1873rid.jpg (140.77 KiB) Viewed 6726 times

Arduino UNO

IMG_1867rid.jpg (133.33 KiB) Viewed 6726 times

Encoder on rotational axis

IMG_1865rid.jpg (127.96 KiB) Viewed 6726 times

Wiper motor and pot connection

IMG_1864rid.jpg (129.03 KiB) Viewed 6726 times

Omocinetic joint for pivot point

IMG_1863rid.jpg (123.81 KiB) Viewed 6726 times

Bass shakers

IMG_1862rid.jpg (148.59 KiB) Viewed 6726 times

Amplifier and electronics view

Soon I will post a video showing the behaviour of the system

Ciao