cx5my's rig

Hello everyone, am new member reportin-in.

I'm Malaysian, but working and living in Hong Kong, Electro-acoustics graduate from England 2001, audiophile fanatic since 1989, KE70 swap 4AGE and many mods since 2001, don't know Arduino at all. After many readings (thank you all, amazing you guys) finally figured-out a possible small-floor-area-footprint approach (because Hong Kong no space), hopefully low-cost too (most parts will be sourced from China taobao estimate total US$200 for a 3 motors setup pitch+roll+rear_sway). Also hope to be least metal-works i.e. no welding, no cutting metal sheets/pipe/tubes I hope.... just drilling holes to add nuts and bolts I hope, to screw on motors, to add tie-rod etc etc, simple DIY I hope........ how???? simply bought another rear-seat-frame-rig (in hope to mount all the motors in the center low down as anchor and placed under a regular racing-chair-rig+G29 (entire rig bought used US$260 in Hong Kong 2019).

parts from China taobao, prices converted to US$, make life easy for you guys.

1. US$25 motors each 24volts 200rpm 500watts, received one unit for testing, it weights 3kg...... very beefy versus wiper motors, but the spindle is not linear silky smooth, it stops at specific angle..... hmmmmm may be not what we want???
2. US$2.34 BTS7960 each, but after reading so many blow, smoke and fire...... hmmmmmm
3. US$6 tie-rod 11cm with arm 5cm, realized too small when received one unit
4. US$4 tie-rod both ends 24cm, may be usable??? considering.
5. US$13 24v power supply 10amperes, hmmmm sounds like fire disaster waiting to happen.
6. US$27 rear-seat-frame-rig (without seat)
7. Arduino Mega2560 US$5 (used parts in Hong Kong carousell)
8. US$ 0.5 potentiometer (forgot to buy one to test, probably rip one out of an unused amplifer )
9. did I forget anything???

sorry if too long, should I move it to a new thread sharing my attempt?

yesterday just forced copy and paste the SMC3 code into Arduino IDE and upload to Mega2560 finally SMCUtils no longer says unable to find arduino, now the motor lines potentiometer lines green blue etc etc appear and moving left to right like those hospital heart beat monitor. This weekend will connect up one motor to see if it moves.

Tiny progress solder signal wires. Still many to do, next take out potentiometer from redundant amplifier, replace positive power cable for motor, shipping damage.

Just realized forgot to buy 8 pins socket.

I was planning to prepare to upgrade to 6DOF, hence bought a Mega2560, then later realize there's no SMC6.

@noorbeast, thanks for reminder of universal joint, the reason I haven't bought is because I might start 3DOF, heave + pitch + roll instead of what I wrote in 1st post. A lot of decision not made and a lot of dilemmas ......... we'll see how it ends up .......

got 99% wiring up for real, correctly placed pins/wire/signal, not just mock up, am making final checks then power on, god bless no smoke i.e the China BTS7960 !!!!!

but I'm using external 5V power supply for BTS7960, not sharing with 5V from Mega2560 to potentiometers, hence there's a GND wire not yet connected, seen nearby POT, am wondering if I could just link it with GND of POT with Mega2560 ..... pondering......

Hello, got many small quick questions, if anyone can spare me some time to answer, much appreciate, much thanks in advance. Regarding Mega2560, Arduino IDE says upload SMC3 successful, running SMC3Utils shows SMC3 v1.0

When I turn the POT, connected to motor2, there's good response, seen by the green line, but the motor doesn't move, I think because I haven't setup in SimTools which axis pushes which motor, something like that, I know I have to re-read some instructions seen previously,
...........but what I want to ask is when I click on motor_1 and motor_3 and then I turn the POT, the green line also moves...... this is weird to me........ or is it OK?
...........hence now the worry SMC3 is coded to UNO_R3, not Mega2560, could this be the problem???
...................obviously the screenshot also shows all 3 motors are OFF.......
...................there's no PWM signal changes in SMC3Utils.

and more...... obviously got to do more reading ...........

oh, and I didn't know Arduino don't need external power supply 12v in order to output the 5v, it just gets it from USB, convenient, one less, but curious, if I still plug in the 12v simultaneous with USB, would it be OK?

OK, links to motors and others are: -

motor = https://item.taobao.com/item.htm?spm=a1z09.2.0.0.30bc2e8de4nu6i&id=549113495954&_u=9b8lko6b75c

power supply = https://item.taobao.com/item.htm?spm=a1z09.2.0.0.30bc2e8de4nu6i&id=554468900539&_u=9b8lko68244

BTS7960 = https://item.taobao.com/item.htm?spm=a1z09.2.0.0.30bc2e8de4nu6i&id=574874517481&_u=9b8lko61b6c

hello.. I really curious about the part you use, but I can't open the link, it must log in, but I don't understand the language lol.

Thanks @noorbeast , no luck for me jumping to Mega2560....... will buy a UNO R3 instead....

oppppssss, I try to provide another link and PDF just in case, for the motor only.

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.30bc2e8de4nu6i&id=549113495954&_u=9b8lko6b75c

or if you search the keyword = 12v24v500w, in https://world.taobao.com/ the first result should be it.

Chinese language text.

the BTS7960 and power supply ....... am not very confident of their safety to be honest.......

Thanks.. I just blow up my PSU, so need a alternative which psu that I need to take.

I'm using a 5ampere 24v from this shop just to test motor moving, It costs US$6 only, gives no confidence to be honest ...... can drive the G29 well I'm sure......

https://item.taobao.com/item.htm?spm=a1z09.2.0.0.2af82e8dHmLl1P&id=554468900539&_u=ab8lko61229
if this link doesn't open, then reference to PDF attached.

Personally I'm not confident to sit on the sim-motion to test, because with nearly 100kg rig+human weight loadindg 3 motors for a HEAVE motion push up against gravity, assuming 10ampere PSU achieve 240 watts without lost, each US$13 (1st post PSU), total 720watts....... might work, might blow when stressed long time.....

3 motors total 720watts I would test it on dry rig weight (estimate 20kg) without human, but not use for real.

That's why I'm also thinking of running 6DOF, 6 motors, each 200watts (40watts power lost), 1200watts, at least this would reduce load on each motor......... but I'm thinking too far ahead when I can't even make a single motor move now.

So, above only all talk and day dreaming, lets see how I progress and how these cheap parts perform or hold up......

After reading more cases here of things blowing up...... I realize I might be another case and prepared my mind to buy proper parts at proper costs later.

After hearing your one blow, I'd recommend you buy from a local shop where you get to return for warranty replacement. Good luck.

that PSU not a different from mine before lol
right now I been waiting for my mean well PSU to arrive. I see on the several YT channel that disassembly a branded/commercial motion rig or wheel, they use Mean Well PSU. so I think it's a safe choose, and it come with 2 years warranty.

Hello everyone, I bought a Arduino UNO, motor doesn't move at all under SMC3Utils.exe and behaves exactly same my Mega2560. oppppsssss

the yellow PWM line does move once in a while when I rotate the POT, both on Mega2560 and UNO, makes me wonder if the BTS7960 might be the problem ???

Good morniong from Hong Kong, thank you so much @noorbeast , much appreciated. Amazing history and database here .......

Good day gentlemen, thanks @noorbeast your link made my recheck wiring, 【it all works】 is the quick report title.

Details:-
1) I wrongly wire ENBABLE and PWM pins, my own fault.
2) I didn't clear all ZERO in SMC3Utils.exe, sorry. When only set Kp to 500 and PWMmax increase slowly to around 100 or 150, suddenly the motor spins..... hooray....... I think 50 was still no spin, then 100 spin really slowly like 1_rpm but the happinest moment, can't believe my eyes,,,,,, you know...... stumble for a few seconds, was I dreaming??? just work up and not seeing things right??? Then push to 100 and indeed faster and 150 and finally settled on 200rpm.

After the motor spin, I approch to inspect the messy mockup parts and wiring, suddenly the motor stopped spinning......... then I thought must be a loose connection and started slowly touching / moving bits of parts and motor spin again...... so
3) my own mistake/hiccup, the power cable to motor was intermittent bad connection, my own fault.

Next stop using SMC3Util.exe and start using SimTools.exe assign axis, connection settings, at first no movement, finally found output bit-range must be 10 bits and motor will spin as in Tutotial - SMC3, when 8 bits are used motor stop as in page46 of SimToolsUserManual. May be because I used 500,000 kbaud from Tutorials instead of 115200 from UserManual, ie I must follow everything in either or, cannot mixed the parameters .......... so it all works, pushing slider right in SimTools.exe TEST MODE will spin the motor forward, pulling slider left will reverse the motor.

...Motor movement is smooth, no jerking, no stepping, no jumping, no section by section, luckily, unlike when hand rotate the spindle.
......Motor angle can be controlled in fine angle.... or at least I think ......

also my Arduino was reported by device manager as Serial_USB_CH340...... which didn't give me, I confident, I thought I bought the wrong UNO_R3.

didn't test Mega_2560......

next step, buy more motors, BTS9760, PSU, wiring, 8pins connectors, etc etc etc ....... thanks again @noorbeast and so many predecessros !!!!!

hello again gentlemen, I've got a big important question needing advice : which arm LENGTH would be recommended for 6DOF motor rotation type, not pushrod actuator.

I found below 2 choices, US$9 each for 110mm arm LENGTH versus US$11 each for 175mm, so cost is not the question here, but sensible dimensions to allow 6DOF, considering tie-rod angles needed I suppose ???? my head going to explode visualizing what LENGTH I need......

vertical imagination is easy enough, am considering when motor rotate angle from bottom -180degrees up to maximum heigth +180degrees, assume I buy the 110mm arm, then the race-chair-rig from bottom -110mm will rise to 0mm height (motor 90 degrees) then up to maximum height +110mm (motor +180degrees). I get total 220mm travel from bottom to top, a lot lor, more more than enough, overload I think. All the motors rotate simultaneously, ok, I think easy imagination, but then horizontal???

For Horizontal when move side to side (SWAY), how ah ???? I don't understand yet. Only 2 motors responsibile to move SWAY I think or I thought, but the other 4 motors although no need to move, but also need to move in order to make way for the 2 responsible motor....... ohmy head gonna explode thinking about it.....

so the quick question still remains, which arm length is sensible suitable not overboard overkill. I'm worried the 175mm will be too much...... or because I don't understand and didn't consider enough some neccesary room / freeplay (wrong word, I don't know the right vacabulary).



thanks guys.