New Motion Sim Project Using AMC

hmmm, well look what we have here. Looks familiar but discontinued
http://www.skyko.com/products/

i am being slowly lurred into the idea of stepper motors :

advantage of that being one can raid old washing machines for motors but this is just a wild thought because i have drunk too much coke this evening

hi guys thanks to that link on e-bay my pocket is now £76.00 lighter found these and had to give them a try if all elses fails i'll put them back up for auction but seemed to good to pass up so bought 3 :
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... %26otn%3D2 have seen this guys work and even though the motors are slower i think they have possibilties for my sim
http://www.youtube.com/watch?v=MxXEOcYY1M0

they look like hairdryers but @ 120w should be ok so long as they got some torque behind them. £13!!! I might buy one just to turn my front door key! :thbup:

yeah know what you mean but at that price i'd rather have em to try and sell on if not up to the Job ... i appreciate speed is not great but i can gear it to increase the spped but may loose out on torque ( no May about it ) mind you the Guy in the You tube clip uses the next size up on his 6dof and not bad looking so eagerly awaiting delivery and at least i'll have a benchmark spped wise to work to ... She's been gather dust while i look for DIY actuators so maybe this might get me back up and running : mind you i use solidworks CAD at work so may get a chace workload permitting to do some simulation after i create a model for these units ... 51Nm torque at 1 meter so figure on 4 times that over 250mm Actuator arm throw .. would be nice

it would be interesting to see where you get the 6DOF position data from for your project unless youo already mentioned that but i missed it?

I now seem to have an option for the controller part thanks to discovering this little baby. Based on the Atmel AT Mega166-A it is the superman of motor controllers but although it is already geared for upto 40v motors i am modifying it to output for larger motors. (or maybe both, lets see how it goes)


Large schematic here, was too large for attachment http://fsuipc.co.uk/img/schematics.jpg

An added bonus is that i have the original Eagle files which is my preffered prog :thbup:
So there is a small chance this thread may take a new direction

Chris

@ Thanos

am i correct thinkig that this set of boards is 99% similar to your AMC?
http://www.dcitech.com/TriPLC/M/T100MD.htm

Chris

sorry to be a pest but does anyone know if this board can be used instead of the AMC? They look similar but i am no expert. It will save me some $$ if i buy this rather than going to print and possiblt screwing up the assembly

http://www.yourdci.com/product.php?productid=1&cat=1&page=1
Chris

Hi Chris,

This controller you link to, is not the same thing as my AMC.

Its a PLC meant to be used with industrial machines. I don't know if you can use such controller for motion simulator, and even if possible, you still need to program it yourself!!!

Thanos

yes, at the age of 30 I have learned the important stuff must be done myself (programming). A friend is looking at the board now and only has concern for the PWM output voltage so far but in general it is looking good. As for firmware I will just need to modify Ian's PICAXE code to use the correct lines.

The thing i like most about this board is the support for stepper motor possiblility, well at least for playing :yippiee:

Chris

ok so the final word on this board http://www.yourdci.com/product.php?productid=1&cat=1&page=1 is that it is suitable for the job but requires an additional 4 mosfets and current sense resistor to run 24vdc motors upto 16amp. That seems pretty simple to me but ofcourse Ian @ BuiltforFun will charge me £50 just to talk to him about his firmware and AMC firmware will be kept compiled forever.

Anywayz, watch this space because there is soon to be an 'out of the box' system materialize before your very eyes. Soldering iron soldiers need not watch this thread lol :thbup:

Something will definitely happen here but hopefully a good thing :clap:

The lure of stepper motors has got me by the danglies! There was a post here about steppers but it faded into oblivion like most posts do with no cigar at the end. For that reason I suggest continuing that investigation until we are all clear I have wasted my time and money.

Here are some benefits of stepper motors
1. High Torque at low RPM
2. No position feedback required
3. Lots of driver boards available off the shelf
4. Can be run directly from PC/serial with no microcontroller required, just send the signal and the motor does what it is told

So today my ebay fingers were itchy and i bought this little baby!
3 Axis 8 Amp CNC Driver Board 4 UNIPOLAR Stepper Motor

and a TTL gizmo based on the CP2102 which is my favourite serial converter chip at the moment.


Although it is 8 amp, unfortunately only pokes 24vdc but this is ok because the first tests here will be to create a small prototype. The driving software is the important step here, sizing up equipment will be later.

btw, soon I will delight everyone here with the sight of a motion chassis that can roll upto 90 degrees. And it has been made professionally by a local fabrication company : Just waiting for a few more welds to be done

Chris

Well stepper motors has 0 tolerance to over power. If you do that they loose steps. It isnt so easy with no position feedback. You need some calibration after every start.
3) and 4) same as DC servos
Steppers are good on CNC machines but only for small ones ! If you use more powerfull motors cost is nearly same as servos.

Thanos board is so far best choise. On ebay are plenty powerfull drivers (+-10V control) for AC motors for great price.

Edit: for example this can handle really big motors http://cgi.ebay.com/Advanced-Motion-Con ... 7C294%3A50

hey man..
I have purchased the motor below (Bosch 24V 9A), and the power supply (Switched Power Supply Stabilized 201W 24V 8A)...not sure if it will work..but I will try..

the power suply will be here this weekend and I will send some pictures of my first test..I hope I dont burn things

my post is:
basic-2dof-configuration-and-faq-t1555-10.html

feel free to drop anything that may be useful

regards
Caue

i would have used the AMC board but I required the -10v,+10v circuit to be added as optional connector before going to print. I PM'ed R-eng about this but no reply and there was no interest in the original sprint files for AMC being published so i could do it myself.

The concerns mentioned about steppers are interesting. No way can I argue them because this is new territory for me and slightly out of my technical league. The main reason for doing this with steppers is that the hardware is very common unlike the deal with DC motors. It is unbelievable that with all the motor control project boards out there that non of them can work with the available motion systems! Surely the practical way to do a motion project is to start with an existing 'off the shelf' board! To create a dc motor driver from scratch around the software seems back to front. The software/firmware should be written around the existing hardware.
Does anyone agree with that?

This test will involve a traditional 2DOF base but smaller scale for testing. It will probably be just big enouogh to take my 10 year old kid for a buckaroo ride :thbup: If the FET's fry then at least we have absolute proof of the stepper theory being busted, no tears for trying.

It will be tested to the max I promise you that. Creating the motion signal app will be great fun because I have just discovered an offset in FSUIPC that allows to calculate the hardness of touchdown : My landings are perfect so will never see that in force but will no doubt screw up a landing to test it :yes:

Chris :

Well all hardware is already here .. AMC + H-bridge for DC motors.
AC motors are so far really expensive but can be done (you can use H-bridge with 10V powersupply to control big servo amplifier(driver) )

yes but needs to be built and no control over logic because the firmware is not open source. Is x-sim open source?

not too concerned about the stepper response now having read that the board I am using is capable of 1000RPM. Thats alot of step signals!

In fact, stepper motors are designed for this sort of application. Has anyone ever questioned the reliablility of DC motors for positioning. Continuous stopping/starting of dc motors in various directions puts a terrible strain on them so i bet they are being replaced very often in existing sims.

Chris