2DOF simulator based on CKAS Thruxim

[Mertensbart20]

Hello Riton,

We indeed use helical-wormgear motors (for a picture see the attachment). The advantages are:
- less costly motors
- the motor keeps its position on standstill
- a smaller less costly brake is needed because the inertia is smaller since the motor comes very quickly to a standstill (because of the wormgear)

But as said there are disadvantages:
- for the same torque you need a bigger motor
- the lifespan of the motor is shorter which is a disadvantage with simulators for commercial use (in our case this is not a problem)
- the motors must be mounted in angle but as you can see in the pictures that doesn't pose a problem in our design.

For the encoders there is another solution. You can buy a motor with hall-sensors built in (a very cheap option). These hall sensors give the position of the motor up to 60° degrees accurate. But since the sensors are mounted on the electromotor and not after the gearbox the accuracy can be divided with the gear ratio. For instance, my motors have a gearratio of almost 100. This means that with those hall-sensors I can have an accuracy of 60°/100 = 0,6°. It would be cheaper than buying a separate encoder and you don't have the hassle of connecting the encoder.

Should I have to buy the motors again I would choose the same motors but with hall-encoders, a BMK-brakerectifier (for fast brakeswitching - new installed) and forced cooling. Now we also have to install extra cooling because of the extra heat generated buy the raped movement of the motors. And for other readers, watch out with the how the axis is placed (left or right). I bought two identical motors but because the shafts came out on the same side I couldn't mount them. I had to take off one terminal box to be able to place them. And refitting a motor costs the same as a new motor .

Greetings,
Bart

[vicpopo]

Hi ,

I'm a little bit surprised when you speak for a forced cooling.
Look at this configuration with sew motors.That was a question before building the sim .I never reached to get them hot.I always could put my hand on them without problem.The temperature didn't never exceed 40 ° C.
The post :http://www.x-sim.de/forum/viewtopic.php?f=37&t=293&start=30#p5506

But you're right that come from the gearunit probably.

For the encoder , I ask me also the question with the simple cheap encoder on the motor(sew has got this encoder).But the question was how to interface it with the driving board ( my case was an amc1.6).This coder need to be supplied and that is a sinus , cosinus encoder ( 6 wires I believe). With amc 1.6 ,there is 3 wires , vcc gnd and the postion mesured.

Best Regards

[Mertensbart20]

Helllo vicpopo,

It could be that the motors won't overheat with normal cooling. But SEW recommends forced-cooling for our application (see the attachtment "motorcharacteristics"). In the motorcharacteristic you can see that if you want the nominal torque at low speeds you should apply forced cooling (dotted line in the graph). This is because the motorfan doesn't make enough RPM's at the low speeds to cool the motor adeqautely. And to make sure that it will not be a problem we are going to place extra coolers. And if you use the fan of an old computer powersupply and one extra powersupply to drive the cooler it doesn't cost you anything.

About the encoders, you are right. The cheap solution of SEW with hall-sensors is probably not an option using the AMC1.6. It is a typical solution to use in combination with a PLC that has an encodermodule. Because of the curriculum my students have to use a PLC. But that PLC is also quite expensive (about 500 euro's) and not an economic solution for the average X-simmer.

Here you can find a rather cheap encoder:
http://www.robotshop.com/productinfo.as ... lang=en-US
But watch out, they don't supply the coupling. I prefer the encoders that we use from Sick (see previous post). They are more robust and have a higher resolution. And combined with the coupler they supply you have industrial quality. I think it would cost about 40 euro's more but they are definitely worth it. And as a school we get a discount of 30% which makes the SICK-encoders a bit cheaper than the one in the link.

Greetings,
Bart

[Riton]

+1, i have a forced-cooling .

[Mertensbart20]

Hello everybody,

The wooden structure of the cockpit is ready. Next up will be installing the transducer, seat and pedals. The seat and pedals will take a while since we will keep this as the last part. Don't mind the colour, that is the schoolcolour . I would be prefer black or red but the principal insisted on the green colour .
For anybody who would be interested, the plans for the platform can be found here:

http://www.ricmotech.com/store/diy_chas ... kpit_plans

Tomorrow pictures will follow from the steel structure. I Hope to start testing movement next week.

Greetings,
Bart

[motiondave]

nice looking sim.
green is good, think of it as a version of "British racing green" , maybe motion simulator green.'
otherwise, excellent progress.
You get an a+ from me !

[Mertensbart20]

Thanks Motiondave,

In the meanwhile the students have spraypainted the platform and assembled the motors and encoders. Below you can find some pictures, a drawing and two animations of how it will work. When the simulator is ready I will make a detailed document so that others can build the simulator should they want to.

First manual test seems to point a maximum roll- and pitchangle of 16°.

Greetings,
Bart

[Mertensbart20]

Hello everybody,

The platform is almost finished. Below you can find a video of the movement. Exact positioning is already possible. Speed can be much higher but since the limit switches are not in place yet I tested at lower speeds for the moment.

The goal is:
- pitch and roll-movement of 16° (already tested)
- speed of maximum 40° per second (of the platform)
- load 180 kg (already tested with 150kg).

I hope to have the platform operational next week. The cockpit will be installed soon after.

Greetings,
Bart

[RafBR]

Hello everybody,

The platform is almost finished. Below you can find a video of the movement. Exact positioning is already possible. Speed can be much higher but since the limit switches are not in place yet I tested at lower speeds for the moment.

The goal is:
- pitch and roll-movement of 16° (already tested)
- speed of maximum 40° per second (of the platform)
- load 180 kg (already tested with 150kg).

I hope to have the platform operational next week. The cockpit will be installed soon after.

Greetings,
Bart

I am really impressed It is so silent, right? No fidgety movement. Now I want my new simulator running even more

[Mertensbart20]

Hello everybody,

Below you can find a test with the platform using the game rFactor. The video may look gittery because I had to drive and film at the same time (and thus you see mostly crashes )

I hope to have the cockpit mounted next week and do some proper testing.

Greetings,
Bart