VFD's and 3phase Induction motors FAQ corner / pls. Read all first

Hi every one ... If you're using/want a VFD unit with a 3phase AC motor controlled ... and want some answers ... start asking them here ... we all glad to help ...






and here is my project and what kind of action can a VFD produce ...

Good thread.
I'll be using 3 - VFD's for AC Platform. In process of welding frame. Still a few weeks away, but will need help with VFD's.
Have a blessed one and Merry Christmas.
Tom

Thanks @cthiggi Sure I'll be happy to help . Merry Christmas to you/all Christians, Happy New Year to me.

Now first ...
Why using AC motors for simulators ?

-To get your body up in the air and give you the special Heave effect " The Action Effect "...​

The Heave effect is the most difficult and the most amazing joyful up and down feeling while playing [ changing your Altitude ].



As other effects can be produced easily with cheap motor and DIY motor driver without effecting it's timing or force accuracy on your body ...
And most Simulators in simple or complicated designs have the ability to roll, pitch ...

See the following sliding mechanism as premium example and many others plus more modification with the same principles we get [Roll, Pitch, Yaw, Sway, Surge, Heave ] ... But not the Heave


... If you still want it !!! continue to read .



That's not an easy cheap effect if you want it .!! you have to pay more attention and money for it ...
AC motors is what will give you the full 100% satisfaction instantly and over days of playing with .


Enjoy ...

abdo_tahan.
Thank you for the great info. I started out with a platform design and AC for Flight Sim, 3 dof - as I wanted heave. Since then, and through another friend in England, I have really become mesmerized with
Racing. Have bought the T-500 etc and several Racing Sim titles - ALL because my friend said I could get faster and "more radical" motion by increasing the frequency on the VFD's. I have purchased the 1hp motors and Boston Gear 30rpm output gearheads. Have everything ready to go "with exception" of the SimX boards, VFD's etc. Have started welding the frame - Have u-joints - well you get it. I've spent the better part of
a year making wife happy with remodeling and renovation our 18 year old home - go figure....and I "mentioned" to her when the remodeling began, that when finished, it was my turn - and the Sim Platform was next on my agenda.....
Mechanically, I'm pretty good at it...electronics, a dummy..........so as I progress I'll need the forums help.
Again, thanks for bring this thread into the mix. Good to know.
BTW - that sim video - darn thing looked like it was out of Starwars or the Alien??? Geeze.

Have a blessed New Years!

Tom

One thing fellas , you dont need 240v to produce heave, this has already been successfully used in 24v and 12v sims, secondly with most sim designs here on site the sway and surge motions are only simulated around the roll and pitch axis, as in surge is to move the body forwards and backwards on a horizontal plane not a rotation (like a lot of us do, me included) this can easily be done in 12v with linear rails same for sway as in a horizontal side ways motion, not a roll motion.
If you want to mess with a decent mass and not work about restricting it in any way then yes 240v is the way to go , but with clever engineering skills it is not needed at all. Just need to be clever in your design.

The speed of 240v gear is my work 20-30rpm is way to slow for high speed racing motion, even a lot of commercial units fail like this, for example the ckas is only 14rpm , pitiful fail, they up to 28rpm recently and still pretty bad, as I have driven them then gone back to my 180rpm seat mover, sorry cant compared seat mover kicks its arse for feel.

This is why Im personally finally looking at the 240v systems again been 3 1/2 years away from them , some one must have created a better vfd by now, what was restricting them before, 400hz too slow for real life racing direction changes.
Once my card arrives I can start investigating anf join in too Yipee.

Thanks Tom, from me and behalf of your wife that you put your home and family in the first priority of DIY .

Dear @eaorobbie ... 240v is the best of the best ways to go in all applications ... from the kitchen up to factories ... I see here that many are used to use wiper or winch motors ... it's OK as long that supports there needs ... and since we are not talking about small robots ...
VFD's is giving you the option to convert a single phase into 3phase voltage to drive a 3ph motor with it's max. torque constantly all the way up from zer0 start to double the max. rated RPM .

Now ...My friends the second big question .
what to do ?

Here is a good guide for wire things up including types of cable, routing, termination, noise management.. a must read for anyone starting their project.
http://literature.rockwellautomation.com/idc/groups/literature/documents/in/drives-in001_-en-p.pdf

-You have to do almost nothing in electronics " just some wiring " +"5-10 settings adjustments in the VFD S/W " it's like the settings in your new mobile phone ... and that's another beauty side of the concept ... of course not all wirings as the picture in the first post... you don't need all of that .
Just listing all wiring options for many driving cases all in one picture as example of a certain model .​

And to prepare your mind in advance for what will be needed ...​

after you have prepared the motion controller board ... connected and configured .

you have to connect four wires from it :
-the ground.
-the PWM signal .
-the two direction control signal .

some types of VFD's accept the PWM and direction control signals as it is provided "digital level " from the motion controller board ...

some types are not full compatible "good news these types are cheaper" with the signals that is provided and we have to convert these signals to fit the VFD's input . a very small circuit then is needed just to convert the PWM signal into a 0-10v analog signal ... Exactly like the one @yobuddy did before ...
that's all ...
I guess you're following me tell now for that ?

Speed is my only issue, control is easy as you have described is correct but I feel a vfd that capable of more than 400hz is needed, but maybe with quicker motors and better gearing we may be able to address this issue in time.
Im all in for working this out... not against sorry if previous post reads that way.

Hi eaorobbie,
Thanks ALL - glad more are getting involved - as I said, when it comes to electronics, "me dummy".
My platform will be for "66 year old me, and my grandsons"....and three years ago, about the only thing I could find that would accommodate flight sim was the CKAS "type" platform.....so away I went, spending two
years sourcing parts etc......NOW, I have to make my investment ALSO "simulate for racing" - MY my understanding was that I could increase frequency on VFD's to get a "racing simulation", maybe not the best, but one I could have great fun with and of course, the grandsons'.

Heres a couple of VFD's that my friend in England has suggested:

http://driveswarehouse.com/p-2525-wj200-007sf.aspx
http://www.automationdirect.com/adc...S3_Drive_Units_(230_-z-_460_VAC_SLV)/GS3-21P0

Both are sensorless.......maybe/// you guys can look at these as give me your blessings or other suggestions?

I'm so excited that more folks are showing interest or their experiences...........I kinda thought I was the only one which didn't make me feel very smart..AND as I have said several times, I have no choice but to
make this baby work as I have about 1600.00 US in all my hardware.

Thanks so much and have a blessed one!

Tom

Something needs to be clear here ...

@cthiggin for me both VFD's looks good ... but give me a look on your motors and gears name plate on there body to tell you which one is the best one that suits ... and I'll state why .
And If possible give us a quick peak on the general idea of what you're intending for the simulator chases or frame .

Dear @eaorobbie ... easy now ... why quicker or better ? show me what you got first ...
In my sim actuators I use a 3ph - 1/2hp -50Hz-1735RPM SEW motor with it's gear that gives out 43Nm torque on it's shaft ... I'm using a max driving freq. of 70Hz in the VFD that's almost one and half the original freq. ..." see the video of my sim again "... and the total actuator have a max linear speed of 25cm per second ... and I took a bunch that knoked me back almost on the ground one day when testing it's capability at the first beginning ... so I had to reduce it's speed also not to give me an overshooting problem with the total motion .


If a motor on the name plate is coded with 60Hz and 1735RPM ... Like the above example .
then when driven on that frequency it will give that rpm ...
when driven on double that frequency it will give double that rpm ...
But not all motors windings can handle such over speed for long time ...
so when programing a VFD ... A 80-100Hz max driving frequency is very very good setting to be saved and used ...

See this video as the motor runs on 6000RPM with a 200HZ driving frequency ... breaking the sound barrier

Thank you for the information, yes we use 4500rpm motor with a right angle worm box to give us a 160-180rpm speeds in DC driven gear but if we look for the right motor and gear box the magical min of 50 - 60 rpm can be achieved easily and your information make that a lot easier to work out , thanks.
Thinking out of the box on design this driving a ball screw could result in some impressive speeds and power.

Using a ball screw preserves you from using a gear box .... just connect it directly to the motor shaft ... lol

Hi fellows,
I'm build a CKAS type frame/platform - 3'x4' bottom frame / 3' x 5' top frame - AC 1hp / Boston Gearheads - 60:1 - output = 30rpm @ 1800rpm / 60hz

MOTORS I have purchased x 3 - http://www.automationdirect.com/adc...Motors_(by_Voltage,_208,_230,_460,_575V)/Y364

BOSTON GEARHEADS - x 3 - Ratio 60:1 - Rated for 1hp Motors - Torque - 979 in.lbs. / or / 81.5 ft. lbs.

Here's a vid I saw earlier this year using SewEurodrive AC -
Looks like his bottom frame is flexing badly - and if it was stable, he would have some quick motion.

I will start sending pics first of year after New Years' -

Thanks so much for the continued interest and information.
Have a blessed one.

Tom

Hi Tom ...
Great numbers ... that's really nice .

So basically without stressing the motors or the inverters using up normal freq. or any odd VFD adjustments :

-If you'll use a 10cm rotational arm attached to the each output gear shaft to move your chair like @vicpopo did above ... BTW " use a thick good fixed one " cause 10cm arm will give you over the 100Kg lifting force with each gear . check the torque here

So with an output shaft speed 30 RPM/60 = 0.5/RPsecond ... you will get a [half revolution ] = 180 degree in 1 second by that rotational arm ...​

-If you attach a push arm between the tip of the rotational arm and to be mounted beneath your motion base parameter ...

that would be a 20cm/second change range in altitude up/down for each side of your chair per second [ that is your max linear speed ] ...
And that would be the amount of maximum tilting for your motion base ... use longer rotational arm 15-20 cm with the front motor if you need more pitch .​

Excuse my bad drowning ... but I guess my idea is clear .

@vicpopo was sitting his frame on an old tires so he can get more dizzy

abdo_tahan,
THANKS so much - GLAD my hardware is GOOD!!!!!!!!!! Happy my choices for the VFD's are spot on.
I'm going to use 1/2" steel rods to attach the pivots to the top and and to gearhead shaft...want it heavy duty with no flex in rods.
You're stating that 20cm or 4" total travel - this would be +- 2"up/down - My thoughts were to use 3" or 4" arms from center of gearhead shaft to center of bottom pivot arm - giving me a total of 6" or 8" of total travel - 3" or 4" up/down from center - and I was confident that my motors & gearheads could easily handle it???? What are your thoughts on arm length??? I will be using 3/8" solid aluminum for the arms, and a keyway slot for the gearhead shaft / and a through bolt/nut to tighten the arm to shaft.

With the stated outputs you stated, I "SHOULD" be able to make the platform more radical with an increase in VFD, used for racing????

Also, with my hardware, "me don't think" I'll need a center spring under u-joint for assist - as the hardware should easily handle it??

So Sorry Tom, but actually I don't know that much about your frame dimensions ... I'm just explaining the potentials that you may have ... you got me here in the electronics side ... is there any photos or a building plan or a thread that might have some more information ?
you are a step ahead now ... you cann't take the second step without a plan ?

abdo_tahan,
I apologize for getting "ahead of the game". What you have contributed so far has really been up-lifting for me.
As I start sending in photos of the mechanical build - I can ask more questions about "pivot arm lengths", a potential assist spring under platform, etc.
Just got very excited with all the information and got too "off topic".
Thanks so much and I will post more in a new thread, come back to this one for help in electronics etc. - Sound like a plan you would like?
Have a blessed one,

Tom

OK, nice plan ... And I didn't take any pictures of the welding stage of my frame too ... looking forward for you .

abdo_tahan,
Thank you and ALL who have contributed to this thread.
You folks sure have made this old guy very happy and have eliminated a lot of the "unknowns and fears" away - What a New Years' Gift.
In a couple weeks after New Years' I will start my build thread and we can proceed.
Thanks again and have a very very Blessed New Years.

Tom

Guy's ... What do you think is moving this car ?

In the first part, I thought I heard an air driven piston releasing air????? Maybe not...
Would be nice to know.
Thanks for the vid.
Tom