Build thread for my 3 dof simulator platform

Hi,

I'm new to this business but I have read a big part of the FAQs and some build threads and finally decided to start my own build thread.

My plan is to make something similar to @Jymä motion platform for playseat, but with springs instead of u-joint (to be able to have heave in addition to pitch and roll) and wheels on the bottom, so it can be more easily pushed around.

I was wondering if it would be a feasible solution to put the whole platform on top of springs (idea from @willaupuis heave implementation) so that it would not be limited to 2dof due to the stiff u-joint.
I planned to put the springs as follows:
- One in each corner and two or three (or one-two with higher tension) under the center of gravity.

Also this would mean that I would need 3-4 motors to implement the motion. /if 4 then one in each corner of the platform, if 3 would be sufficient then one in middle front and two in back corners of the platform.
(I will put up a sketch later).

If that is not feasible, then I will just go with u-joint and forget about the heave and 3dof.

Stuff already ordered:
- 2 moto monsters
- Some VGA heat sinks
- 2 HP DPS-600PB
- 1 Arduino UNO R3
- 6 caster wheels (2 with locks and 4 without)

Stuff I already have have:
- Wheelstand pro v2
- G27 wheel+pedals+shifter
- X55 hotas

Stuff still needed to order /find:
- 2-4 Motors ( probably ZYT90, 3200rpm, 12V, 27A, 60:1)
- 2 Tabletops for platforms (mounting platform for electronics and motors, and moving platform for seat and wheel etc)
- 5-7 clutch springs
- Sport seat
(- 1-2 motomonsters If the spring system is doable)
(- 1-2 HP DPS-600PB If the spring system is doable)

Found from thrash:
- Drive shaft for old BMW (if I should go with U-joint and 2dof)
- Metal plate (if I should go with U-joint and 2dof)

3.3.2016 update:

For now I'm going for the 3 motor 3DOF build with spring assisted heave and adjustable wheel/pedal rack.
I bought 2000n springs which I believe are too stiff, so I ordered some 1000n springs to go along with those. I will report more about the springs when it comes current in the project.

Still should buy the base plywood and I'm waiting for MMs and motors. I don't have good idea how to build the lever for the output shaft (I read the FAQ and initially planned to go with rigid coupling, but I find them either expensive or hard to find).

29.3.2016 update:
Most of the electrical work has been done and every individual electrical part (3 PSUs, 3 motors, 3MMs, 3 pots and 1 arduino R3 uno) has been tested and proved working.
I got the levers from a workshop and plywood from a "lumbermill".

Most of the mechanical work and planning is still ahead.
Caster wheels have been installed to bottom base and seat + pedal/wheel combo have been installed to top plywood ( I need to take them off as I start building anti-twist system etc, but the holes for bolts are ready and assembly of the top takes only couples tens of minutes).

Due to an unusual situation at work the progress has been slow and continues to be.

Welcome to the forum.
Good luck with your project!

Thanks Blame73
For some reason I cant edit the OP. Anyway I draw a (really) raw sketch.
The red pylons represent springs and blue boxes motors.

I have hard time finding suitable motors. I did check the DC motor shopping list from FAQ
but most of the links are old and those suppliers don't sell those products anymore.

I asked from Motion Control UK, and they responded that they don't have the motors I asked (90ZYT series with worm gear boxes).
I could get the motors from China, but the unit price would go up to 200€/unit after shipping and taxes. Which I find a little high as the motor is "only" 100$.
I'm waiting reply from Motiondynamics Australia, but I don't believe that the bill will be any cheaper after shipping and taxes.

I believe that I do need quite powerful motors as I plan to move the whole platform.

P.S. MotionControlUK suggested following:
12V Geared Motor with 75:1 ratio Gearbox
Power: 150 W
Speed: 12 RPM
Current: 18A
Output Torque: 0.5 Nm

But I believe that that motor is far too slow and a tad weak for simulation purposes.

hi @E1m0 !
Welcome on the forum.

12rpm and 0.5Nm, you can't do anything with a such motor...

@willaupuis and I, we ordered some motors for motion simulators to get better prices if you want (120w and 350w). Please send me a mp if you want one. Where are you living (because we deliver only in Europe) ?

Some update:
I ordered three 90ZYT156 with NMRV40 gearbox(ratio 60:1) So that the output speed will be 50rpm and the output torque is 30.79Nm.

I should get those in a couple of weeks (as I ordered them from manufacturer in China). And the delivery time is 7-10 working days when the payment has cleared.

I found a used sport/racing seat for 50€ and got a quotation for two sheets of 30mm x 1500mm x 600mm plywood (should be sturdy enough) from a local lumber mill.
Still waiting for most of the stuff I ordered (springs, wheels, MMs, arduino, wires, etc). Potentiometers and power supplys I got already.

@Wanegain Thank you for the offer of the motors, but I will try these ones I ordered. With custom, taxes and shipping they should be around 140€/each delivered.

You're welcome ! I'm sure they will do the job

Motors I ordered (350w) are 60 rpm and torque is 45Nm and we sell them 159€ without shipping cost.

Got my springs and they are a bit too tight, I mean that they are really high tension. Using 4 of those under the seat (only seat and me) they compresses maybe an inch or two (total length 15cm). I ordered a couple of smaller springs to play with. Motors are a little delayed as the factory forgot to produce the shafts, but they are coming.

@noorbeast : About the motor strain, what are the symptoms for that? I was just wondering that I wont damage the motors with too high spring rates.

For the lever connections:

I read the FAQ's http://www.xsimulator.net/community/faq/how-to-attach-levers-to-wormdrive-gearboxes.182/ but I can't find reasonably priced rigid couplings for 18mm output shaft (040 in the factory datasheet (attached): key is 2,5mm high and 6mm wide).

I did find taperlocks ( http://www.ebay.com/itm/1108-18mm-T...949533?hash=item20f2b5ba9d:g:xhgAAOSw~gRVywZX ) that do seem quite the same except that you cant use the curb screws to tighten the shaft.

Should I try the taperlocks or just go with kind of a hollow shaft connection like the one in FAQ?
The thread inside the end my output shafts is supposed to be M6.
I didn't really get what @Nick Moxley meant with the codder pin, but that is probably with a truly hollow shaft.

I got information from the factory that they forgot to produce my output shafts so the shipping of the motors is 5 days delayed. They have the motors and gearboxes ready though....

Also I started building adjustable wheel and pedals mod for G27 and wheelstand pro ( basically just attaching them to seat rails).
It is ugly but (kind of) working. Still need to attach it to the base (I haven't bought the plywood yet), build pedal holder and invert the pedals.

I do know that the adjustable pedals/wheel will affect COG but I thought that they will affect it less than adjustable seat.

Edited the thread title for you. Let me know if I can help further.

Good luck with your build

Thanks

This will be (probably) quite a long project as I don't have all the parts yet, many of them are coming from abroad and I'm not in a hurry

Couple of early photos of the pedal/wheel-system.
As said, not a fancy system, but seems to work. Would be lighter if I would loose the wheelstand pro, but it gives quite sturdy base and nice adjustability for the wheel.
Under the plywood/wood-rack there are rails (you can see the rail handle between seat and wheel. Also G27 pedals are inverted. Seems solid, I can give it quite rough pedal pressing and it won't shake nor wobble almost at all.

Of course I will cover it with something (textile, rubber mat, etc.) and before that probably dismantle couple of times and cut / work on some parts

The base is not going to be that what is under the seat or pedal/wheel-system. That is just some MDF that I might need at some point.

Just got the motors a couple days back.
Still having some trouble to find lever for the motors, but an acquaintance of mine works in a machinery work shop and could probably make those for me.

Do you guys have any suggestions about motor placement?
If the platform would be symmetrical this would be easy, just put the motors symmetrically.
But as it is a rectangle I don't really have any good idea how far away from the COG (sideways and front/back) I should put the motors and whether should I put 2 motors in the front or in the back of the COG.
The platform will be heavier on the rear side but the longer front side will produce greater lever when the system is tilting.
Or is the motor placement some what fine in the early draft in the 3th post?
Thanks!

The project is lagging because some work related problems that leaves me with very little free time, but I'll try to complete the project before summer...
And also because I'm still missing all the MMs.

Getting the levers in a couple of days and already got the MMs.
I don't have much sparetime at the moment, so progress is really slow.

The wheels (6 pcs) attached make moving the sim really easy even though the total weight is going to be massive (80-90kg).
The spring attachment is still off in the photos (I have fixed that), but you get the idea. I also need to make some columns for the springs so that there is enough room for the motors etc. between the plywoods.

For some reason I can't find rose / heim joints in Finland (probably I just can't find the right word for those in finnish).
I would need them just to make the anti-twist system. If I cant find them I'll use fork joints and M10 threaded rods for stiffening the body.
Bellow you can find some photos:

Photo from side

Photo from behind

I started doing some first wiring and I can't get anything else out of my potentiometers than 1023 (which is max that arduino reads as analog output)?
Nothing happens when I turn the potentiometer. I double checked the wiring and tried with basic arduino code that only read the analog signal. I tried with two different potentiometers (bought 4) and both are acting similarly.

These are the ones I bought (10K ohm version) http://www.ebay.com/itm/321976303071

Can someone comment if those are not suitable to use with arduino?

10kohm and linear taper.
These pots are fine.
As for the wiring, +5v and ground on the outer terminals of the pot and analog/signal wire in the middle.
Check that you are using the right analog inputs on arduino.

A pic showing the cables would help find any possible errors.
Code too.

Sorry but I dismanteled it already.
The connections were arduino GND to first terminal of the pot, A0 to middle terminal and 5V to last terminal.
I tried with two different jumper cables and tried switching between the 5V and GND.
The code was SMC3 V0.7 and when I didnt get the reading out from that I tried the basic AnalogReadSignal code that is built in to Arduino SDK

Spoiler: Arduino analogreadsignal

// the setup routine runs once when you press reset:
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
// read the input on analog pin 0:
int sensorValue = analogRead(A0);
// print out the value you read:
Serial.println(sensorValue);
delay(1); // delay in between reads for stability

There is nothing wrong with the code.
If I disconnected the middle terminal the value started to get random readings. Same happened with both of the pots.
If everything was connected I got 1023 and nothing more.

I probably should test the pot with voltage meter.
EDIT: After testing with the meter, one of the terminals of other pot didnt give any readings. Other was working just fine. Maybe my jumper cables are bad.
If I have time tomorrow I will try again.
Checked the data sheet of those potentiometers. Apparently the middle one is a terminal .