MaxDamage's simulator ( 2DOF with DC gearmotor )

I have lurked for some months on this forum and i have seen a lot of fantastic projects from the forum members.
I'm a mechanical engineer, 35 years old and i live in San Marino.
I have a great passion for videogames and for mechanics so i think i'm in the right forum.
This week i was on holiday and i decided to start my project.
The project is for a 2 DOF simulator with 24V DC gearmotor ( 100W, 1:1000 reduction) with magnetic encoder by
http://www.fromautomazioni.com and electronic from http://www.solutions-cubed.com.
I have tested gearmotor and electronic control board out of the simulator frame and it works smooth after some hours of fine tuning.
I have spent today for balancing the system and now it's quite good.
Now i need some days to wire the motors to the control units and to build the 24V power supply because the one i have it's too small to supply 2 gearmotors at the same time.
I have taken some photos :

Great job so far :clap:

Regarding your MaxDamage Simulator... is that blood on the tiles? I hope you havent lost any extremities during the testing

If you dont mind, please tell us some more about the electronics which you are going to use. Which motor controller (not driver) exactly?

Looking forward to a video!

Regards

Welcome to the forums!

First, the mechanical design is excellent! :thbup: :
Very clean and stong, although I would like to see it flex with 150kg in it.

The controller??: http://www.solutions-cubed.com/Solution ... /MOTM3.htm
Not too bad!

Can you give more information on the gear motors? Just use 2 power supplies, 1 for each.

Keep us posted please

Hello , today i made a video of the simulator as requested.

http://www.youtube.com/watch?v=J0KR_7YxpGs

the sim is not yet finished , i'm supplying the gearmotors with 16 volts instead of 24v because
i have not yet found the correct power supply.
I have to change also the scissors linkages that connect the gearmotor to the frame with
a more stiff one, the ones are installed now are blending a little.

Hi

I have a question, which string USO you used with the module MOTM3?

Thanks

It's very easy, the string is for axis 1 :

p01 ~a01~ ~13~~10~

and for axis 2:

p01 ~a02~ ~13~~10~

You have to set 19200 baud for the speed of the RS232 and all works.
Be carefull, you have to use gearmotors with quadrature encoder with MOTM3.
You need a little tuning of parameters of PID but in less than an hour i had
the system working with the gearmotors i buyed that have quadrature encoder.
I use 2 serial port to control the 2 MOTM3, but it's possible to use only 1 serial
and connect more MOTM3 eachother with a special bus so you send the
command to the first MOTM3 with the serial port and it route the command to
the other MOTM3, you have only to send the commands :

p01 ~a01~ ~13~~10~ for axis 1
p02 ~a02~ ~13~~10~ for axis 2
.
.
p06 ~a06~ ~13~~10~ for axis 6

It's useful if you have a 6DOF system and you miss 6 serial port on the PC.

The gearmotors have 1:1000 reduction, a 24V DC 100W motor, and a quadrature encoder on it.
I buy it from fromautomazioni, they use it for automation of overhead balanced garage doors:

http://www.fromautomazioni.com/en/catal ... BX100.html

I bought only the gearmotor, without plastic covers, arms, ecc...
The plus is that the encoder is a quadrature magnetic encoder and it works with MOTM3 control board.
The backlash of the gears is very small so it's suitable for a simulator like the one i built.

Thank you for the information and the video!

What do you mean by quadrature magnetic encoder? There are quadrature encoders(optical), and there are magnetic encoders (halleffect sensors), but I never heard of both in the same unit. I assume the signal is the standard 2ch quadrature grey code like all encoders. If it was an analog signal like hall sensors, you could use standard potentiometers too.

I really like the MOTM3, although it would be nice to use pots instead of $50 encoders.

The encoder i have is composed by a magnetic ring with 4 magnetic pole bolted on the shaft of the motor and a quadrature hall effect sensor
that count the number of magnetic poles and the direction of the movement installed on the motor.
It's like optical quadrature encoders , but it's magnetic.
It is very cheap, something like 7 euro.
The MOTM3 can use also pots, but with this kind of encoder i think it's all more accurate.

Thanks! Could you post a link to those magnetic encoders? Or did they come with the gear motors?
If I understand correctly it is the equivalent to a 4 pulse/rev optical encoder. With 4x encoding it has the resolution of 22.5°/pulse.

In your case the encoder itself is not more accurate than a potentiometer (16steps/360°) compared to a 10bit ADC (1024steps/270° for a standard pot). BUT, if you place it directly on the motor shaft, with 1:1000 gear ratio, we are at 16000steps/rev. maximum, which is much better.

I wouldn't mind trying them out!

Hello

thanks for the reply
I have another question, reading the datasheet I see that you can use a potentiometer as position feedback, to use a potentiometer as feedback I have set the MOTM3 in mode 5 and set the FUNCTION.ADSERIAL function and other parameters, I set them to enter in binary mode?
or should I set them?

if I wanted to create a configuration like this my string use could stay like
p01 ~a01~ ~13~~10~
p02 ~a02~ ~13~~10~

could you post the specifications of the engines and their cost?
maybe some pictures.
:clap: Congratulations for your project :hi:
many thanks for your patience

The encoders come with the gearmotor but i think you can order also the single part with the magnet.
The encoder is placed on the motor shaft, so you have 22,5° / 1000 = 0,0225° of resolution on the final shaft.
The encoder is power supplied with 5 or 12v, i think it works in that range of tension.

Yes you can use mode 4 with encoder but you can use mode5 with FUNCTION.ADSERIAL bit ON so you can
use p01 a01 13 10 on the serial and use potentiometer as feedback with a 10bit analog-to-digital conversion.
I think that in the last firmware you can use more than 10bit for the conversion.
You have to choose the values for PIDSCALAR, ITERM, DTERM, there is a tutorial in the manual to calc
this values at first approximation, then you can tune the system, a thing of 1 hour in my case.

Thank you.
The gearmotors are 100x110x400 mm , 8 kg weight, 1:1000 reduction, 120 watt at 24V, with magnetic quadrature encoder.
This gearmotors are designed for automation of garage doors.
For the costs i have to find the invoice, i don't have it now, please wait tomorrow.

Hello, you did a perfect job. :clap:
What are the dimensions?
You used the AVR Thanos?
Think the wiper motors 12V could move the platform?

Regards,

The dimensions are 1000x2000x1400 (heigth) mm, it weights about 140 Kg.
I didn't use AVR Thanos but 2 MOTM3 control unit by solutions-cubed.
I think the platform could be moved by 2 100 watt wiper motors if you reach
a good balancement.

Why don't you just read the posts? Every answer has been already posted...

@MaxDamage: If you got the encoders on the motor, how do you know they are cheap $7 ones? I would really like to buy a couple for this price, which to me seems unrealistically low compared to what I have seen before. Could you give me the sources of your information on the price and where they are available with and without the motors?

I don't find the invoice, but there was the price for single parts, i remember encoder costs more or less 7 euro.
It's composed by a ring magnet and the sensor closed in 2 pieces of plastic with 4 wire , 2 for power supply and 2 for signals.
I don't know it they sell only 1 encoder or you have to order more, they give me all placed in the gearmotor.
There is also an option to have electromechanical limit switches on the final shaft, it costs 12 euro i remember.
I buy one but i don't use it because i use software limit switches, you can see the cable wired to nothing that fly on the left of
the simulator in the video...

Can you post the link to the place you got the motors from please? I would buy more than 1.

www.fromautomazioni.com

i think they are closed for holidays now

Thanks a lot! They don't have these items listed separately, but hopefully they will be nice and hook us up.

Are there any markers on the encoders or a brand name? Or is it completely burried inside the motor case? I'm pretty sure they are from an other manufacturer and could be purchased from other places too.