New Motion Sim Project Using AMC

Hi All, the past year I have been preparing to build a motion sim for FSX and RFactor and am ready to now go beyond the point of no return. It is a very unique design chassis that will hopefully inspire future builders but I am in need of some guidance in the motor driver department. Hopefully this will be a nice thread detailing the stages of design build from scratch and post all the latest files relevant to the recent design of AMC board :clap:

Later I will post pictures of my current chassis design but first i need to get my head around the AMC board before it goes off to print. Via the other posts I have ended up with the .pcb design file submitted by Thanos on behalf of another guy that modified it (R-Eng i think off the top of my head).



http://www.fsuipc.co.uk/files/PCBandPARTS.zip

Within the next 2 days this file will be submitted to http://www.expresspcb.com but i would appreciate confirmation that this is a good move before doing so if possible. My only experience with motor control is the system promoted by Ian @ BuiltforFun that is based on the PICAXE 28x1 and MD03. This leads me to a query about the way AMC board works because i was expecting to see some sort of DIP switch system on the motor power part? How exactly does the AMC deliver motion data to each motor because i cant see any way to differentiate between pitch/roll motor etc? There are 4 motor outputs on the above design, are they pre configured for pitch/roll...??

Thanks
Chris

maybe someone would like to split the cost of this pcb order because there is not much difference between the cost of 2,4 or 6

2 = $329.06
4 = $376.12
6 = $426.00

So if 4 persons split this then we all get a board for $94

Hi Chris

The AMC board is just a PWM signal generator for the DSMhb motor board. It sends to each motor drive circuit three signals, one that is the PWM signal that says to the motor how fast should rotate, and two more digital signals that indicate the direction of rotation of the motor. The DSMhb contains two motor driver circuits that are identical, so you can assign any axis to any motor if you like. The PWM signals for both motor channels are carried from AMC though a single connector that also exist on the DSMhb side. Note that while the AMC hardware is capable of driving four motors, our existing applications doesn't require more than two, so the software firmware of the microcontroller supports only two motors currently. Also there is a issue with the LCD that shares some digital connections with the second set of motor output, so if four motors are used, the LCD becomes unusable. Another thing about my AMC is that its programmed to read position feedback data from the motors using a potentiometer attached to their travel path (or their rotation output axle). The motion delivered from the AMC is proportional, that means it will move the motor to the new destination position with acceleration and deceleration that depends on the distance between the two positions.

I explained above roughly how the AMC works. So on your question about how DSMhb is work... No it doesn't have any relays or DIP switches cause it doesn't need them. The mosfets use the PWM signal to switch the motors ON and OFF so fast that you don't even hear it. The switching is done in 22Khz (or 18Khz depending on the crystal speed on the AMC) that is above the human hearing capability. The motor doesn't see this switching at all! In his coils it just pick up different voltage depending on the percent of PWM.

Here some videos of the AMC and DSMhb that you should see (if not already seen them).

http://www.youtube.com/watch?v=S7UlG830_sc

http://www.youtube.com/watch?v=xe2v6zZ7P28

http://www.youtube.com/watch?v=v3hJ30ixN0s


As I recall, the MD03 that Ian used, are I2C driven that is just a communication protocol. Not compatible with AMC! The MD03 produces its own internal voltage signals to drive the motors and its motion quality depends on the update rate from the main Picaxe chip.


I checked the cost of the expessPCB file you linked, and you are probably chosen something wrong. Using the Standard Service option (with no extra silkscreen and solder mask screen) costs about $190 (if you live in US) or $225 if you live in Greece :rofl:


Regards, Thanos

well i wish i did live in Greece! my only holiday ever was to Corfu which was very nice :clap:

i am understanding this about 50% but sure all will become apparent when i start fiddling with the real thing rather than what is in my imagination. Can you just give me an example of how this will work with Ian's BFF software,,, is it going to be plug'n play when attached to this hardware? (apart from obvious tweeking required). Also with Ian's software will the 2 motors automatically be associated to roll/pitch independently?

thanks Thanos

Chris

In the BFF configuration util you just select BIN mode and 115200bps speed and uncoupled motion profile. There is no other changes from the AMC part. Its compatible because Ian added BIN mode just for my AMC board!! Each of the 2 motors will be automatically be associated to roll/pitch independently!

BTW. Ian is using HEX values with his Picaxe microcontrollers with lower speed (4800bps) that mean he sends double length characters to his electronics with 24times less serial speed!! What does that mean? Less update rate between positions of the simulator. My AMC is capable of updates for new positions every 2ms using new x-sim2 profiler2!!


Regards, Thanos

excelent! after all i might just go with the x-sim software then. The BFF software annoys me because Ian only allows me to run it on one computer specifiacally. Recently I upgraded my cpu and was required to get another reg code from him :thbd:

Just one more thing please before the printers get my email tommorow..... is there a good reason why I cant have the controller and motor power on one board by simply not cutting it in half? maybe there is a noise issue or similar? If there is no problem then can a series of trace lines run from controller to motor power so there is no need for connector wires initially?

thanks
Chris

Its better to build each to separate board as there is a chance that you will experience EMI noise that cames from the switching of the mosfets.

Here is some photos from Erich's project that had to use shield between the two boards to get the AMC started properly.







:brows:


Regards, Thanos

here is the motors I have, 24v dc high torque reversible. Not sure but I think they are just big wiper motors?



and here is the power supply I plan to use for them (24v dc 6.5a). Ebay gave up 4 of these for £20 :


oh and for the sake of it here is a hollow shaft pot with spec of 350 deg electric travel / Infinite mech travel


Those pots had me choked for £80 each but they are the only way to get infinite electrical travel with 350 degrees electrical. believe me i am not rich, just very determined :yes: oh and assume the resolution on them is NASA style :yes:

Sorry if this is a silly question, i know the AMC will allow upto 50v but would the controller work with any other commercial motor driver way above that? Maybe even a 240vAC motor? Just curious for possible larger projects in the future

thanks
Chris

Yes, you can use large AC type motors and VFD drives as long they have Analog voltage input (0-10v). read these posts:

post14488.html#p14488




Thanos

thats good news! it opens the way for affordable motion base systems using the VLC2800 or similar unlike this $20,000 contraption


So i see this new schematic you posted is good for 2-dof but that leaves me wondering what the connectors for motors 3-4 can be used for?

Thanks
Chris

well thats more good news! thanks RaceRay : I will send them what I assume to be the latest files plus the pdf just in case and get a quote.

AMC1_5_gerber_excellon.zip

now what would be super cool is to mod the AMC board to include the 'heavy duty' circuit as an optional connection. Make the AMC power input 24v, split this input between AMC and the 15-20v required for optional actuator. This would be such a good circuit with multiple use that i am actually willing to pay someone to do it. Any takers?



Chris

now here is a mighty motor to move any man mountain in a sim for a mere £135. Obviously a China effort but available to buy 10 miles from me!



HELICAL WORM GEARED BRAKE MOTOR
TYPE SKIS40-71L/4 WITH BRAKE
OUTPUT SPEED 28 RPM
POWER 0.37 KW
1 PHASE BRAKE MOTOR
VOLTAGE 240-1-50HZ

I have not looked up the 'Brake' motor thing but guess this means it brakes when not spinning? If so then that is good news!

This motor together with AMC board, a good 2DOF motion base could cost no more than £800 to assemble including pcb production cost and steel fabrication! Who wants to see that happen on this thread? Promise me support here and i will go buy the motors now :highfive:

Chris

hmm, i am assuming from reading that the 240v motor setup can work fine using AMC -> AMC-Mod -> VLC2800 -> Motor ??

The only issue I am concerned about is the reversible thing. There was a quote in your about single phase not being reversible? Although i am not expert, i believe this to be untrue a i seen lots of reversible single phase motors whilst looking.

thanks
Christopher Lamealot

As far as I know you are able to reverse a 1 phase motor, just not by switching the phase and neutral wire. This is Alternating Current and that means it changes 50 times a secound. (if you are in EU, 60 in US)
But a frequenz inverter generates 3 phase from only one and then you can switch them.

I have been looking for a frequenz inverter which is able to use -10 to +10v for controlling it but have not found any yet. The ones I have don't support reversing through the analog 10V signal only by a 12 or 24 digital signal
Ferrari_man

Where did you find that?
EgoExpress said ,I am new to the AC motors stuff as well. But I can tell you, that only 3-phase AC motors can drive bi-directional.

i am getting very excited about this now so hopefully Thanos wont get annoyed with my pestering and see this through to the end. While i am here allow me to introduce myself to the community.. My name is Chris from Essex UK, Southend to be more precise- not far from the airport :yippiee:

i am not the most technical savvy fella but have worked as a perl programmer for several years and managed the development of several interesting projects. Here are some projects I have worked on in the past couple of years, all non commercial

After having several bikes stolen I decided to go crazy and create a small GPS tracker that would fit a cycle. It is based on the Telit GE863-GPS module and works like a charm with some custom mapping apps made for it also. It is programmable via python and sends gps data to my server via gprs or sms if gprs is in trouble. Programmable via mini usb thanks to Silabs CP2102 chip


More on the subject of Flight Sim, with relation to the motion base I have begun work on some software that will hopefully look good in the cockpit and replicate the G1000 glass visual system. It has many screens to choose from including the overhead MFD map. Just using it on a laptop is great but ofcourse there is a lcd screen mount in the making as we speak for the cockpit.
http://www.youtube.com/watch?v=VaKLGdpxAHA

and also i am working on the amazing SVT (synthetic virtual terrain) view. I have based this on NASA GOTOPO survey data and next week will be placing in airport graphics and nav points


oh and I do some great scenery building for FSX also. Here is some stuff I have been making for southend airport




so there you go. It is important to note that although I am technically involved in lots of things, i am not really that clever. Some would say i am 'not the brightest spark in the box' so please just be patient with me and in return i promise lots of good thing :

Chris

Bloody hell mate you dont do things by half do you .. thats excellent stuff damm boy that is good .. er and you call yourself a novice LOL having had my Motorcyle stolen a few years ago , could have done with your GPS tracker NICE One ... 8) im up in london at croydon so not a million miles away, you have definitley peeked my interest, the guys here on this forum know me by now loads of big dreams spending the money but never quite finishing the projects but for me thats part of the kick looks like you'll be a great contributer and i for one will be watching this space : D'oh forgot to ask ...am always on the lookout for decent actuators for my sim, do you have a link to the AC motor that you posted earlier ??

Yeah lol! I never finnish anything but this time the 9/10 devil is gonna be behind me. That big motor is on ebay now. Not bad postage price but collectable from Chatham. Worth a trip there to laugh at the chavs :brows:
http://cgi.ebay.co.uk/HELICAL-WORM-...3|66:2|65:12|39:1|240:1318|301:0|293:1|294:50

I would be more inclined to go for the 53 rpm version because dont fancy the motor spinning full beans just to get a quarter turn.

As for running this motor, the Danfoss VLT 2800 is 10v analogue input (good news) but will need to poke more to see if it is 3 phase output so can be reversed. I think a guru is required here to summon divine wisdom on this matter

Chris