new to sim

Hi all,

I'm in Nashville, Tennessee and was googling around and stumbled on this great site for info on the sim. 2DOF I've been researching the info here on my own and would like to move the whole frame building, including the monitor.

I'm looking at the following items on EBAY and would like to know I'm on the right track.
http://www.ebay.com/itm/370915744975?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/271156323784?_trksid=p2055120.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/190594364036?_trksid=p2055120.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.com/itm/380832952345?_trksid=p2055120.m1438.l2649&ssPageName=STRK:MEBIDX:IT


I'm thinking that the 2 motors I have listed above, I prefer the second motor, all-metal gears and hardened as it states, providing I get a thumbs up from you Gents.

Also please let me know if I'm missing anything in the electronics department.

Thanks

Tim

I have updated the original post with links. Thank you yobuddy for the advise.

ok thank you.

Links one and two , the difference of 20-30 rpm is not a problem, just fiddle with profiles.
The crabpot motor is similar to this one http://www.motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque.html , but may not be a as strong as the AU motor in the gearbox. I dont see where it comes in two speeds though.
I suspect the crabpot motor specs are incorrect as well. 30-40nm, maybe with the motor overdriven yes, not standard.
The second motor link looks good as well. I dont recall anyone trying them out, so maybe give it a run.
I did that with these big motors in the beginning, bought and thrashed them. They worked.
The JRK is the simplest controller by far, no code to write, it will run these motors easy. We can advise of settings.
The power supply looks big ok. 15v is getting near the JRK limit, but may be ok. They are a good protected board, but you still need to be very carfeul of reverse polarity and voltage. I run mine at about 14v though.
Current of the psu may be a bit low but as they are 15v, they would compensate for lack of current.
Usually a 40 amp psu is better.
Maybe that helps and @eaorobbie can advise as well.
Cheers, David.

Thank you David for your input. As I stated "new to sim" this is completely new to me and I'm looking forward to learning how these work. I have some more questions that maybe you can help me with.
I believe that the first motor is showing a range in rpm with load (pull) 150 and no load (feed) 160 , not sure how that would effect the sim?
This motor is also a permanent magnet motor, does that matter with the JRK stating for a brushed motor?
What was the reasoning for you trashing these type of motors and what are you using now?
I believe the power supply from this vendor is available in 12v by requesting on purchase and I will check and see if he is listing anything in 40 amp.
Once again your input is greatly appreciated.

Tim

Nice choice in controller, not sure on motor choice and power choice, I use a simular unit myself and so do a few others to the first choice, good motor. The power supplies not sure as I have only run the Jrk12v12 (http://www.pololu.com/product/1393)
to 13.8v makes abig difference in their speed and torque. Must check on the pololu site and see they have overvoltage protection up to 41v, doesnt mean they can handle 41v or output 41v, so please check on the makers site.

Motors I and few use :http://www.motiondynamics.com.au/worm-drive-motor-12v-24v-200w-180-rpm-20nm-torque.html

Edit: Just check looks like 16v is there recommended limits. Should be fine.
Another note to remember is to have a little or big heatsink on the main chip, and use a decent fans as running them at these voltages and amps require excellent cooling in order to drive theses motors hard and fast.

So whats the rig style will you build in, myself I would recommend a seatmover, nice easy quick construction and can be modifed at a later date to a full 2dof unit.

Seat mover as an example.

Ok to answer your questions, 10 rpm diference is not going to affect the sim at all.
Not sure on the motor, Id say yes as others are using all sorts on the JRKS.
I just did a google search on permanent magnet and brushed dc motor, got the same link in wikipedia http://en.wikipedia.org/wiki/Electric_motor
I should say I wasnt so much thrashing the motors, but as far as I know I was the first to try such a motor, a step up from the humble wiper motor, so obviously I was going to push them as hard as I could, despite the supplier cringing about it. They are a 200watt motor and I had them about 530 watts overdriven, maybe higher. They survived well, hence suggesting them.
Rob agrees the power supply should be fine, I had read JRK specs wrong and forgot about up to 41v protection.
Cheers, David.

thanks eaorobbie. I have just a seat unit now, no motion, and would like to convert it. I'm think on the plans of a unit to move seat, feet and steering control along with the monitor. (not sure on monitor as of yet). If I'm understanding you correctly, the list of items I published for purchase is all good? (using first motor listed )

I have also looked at actuators, your thoughts on these and do the require a controller also?

thanks again David, waiting on an answer from eaorobbie for my post above. I think he is telling me that all is well with what I listed, just want to confirm before I throw the dollars at it.

Have you had any experience with actuators?

Rob is just busy and will get to this later, as he is in a different time zone........well.....3 hrs.
The only experience I have with actuators is from this link http://www.xsimulator.net/community/threads/actuator-2-dof-seat-mover.5065/ , they were given to me.
Otherwise the current option is SCN5 and SCN6 , @yobuddy has a link to buy them somewhere. They will cost more than DC motors and the SCN5 is not as strong as the DC motors. Still a good looking unit though. They are simpler to setup as far as I know, a few wires, some commands and you are off.
On another point about actuators, I am currently building a 200mm throw version of these http://bffsimulation.com/linear-act.php , I bought the plans a while a go and thanks to Rob for helping with shorter measurements. I am making mine from industrial plastic as it should be a strong as aluminium and about 1/3 the price. Some stuff here in Australia is stupidly expensive.
They work out at $400 each in parts, motor, bearings, plastic. Control board extra. They should move at 350mm per second loaded with 20 kg or more, but I will test them to see how much I can toss on them. I reckon 40kg each and they should hardly slow.

Just a thought, if you are building a frame to move everything, I suggest not the screen, you need to consider your own weight, design of frame, weight of heaviest planned driver, angle of motion - distance of motor from pivot, mounting point of motors to frame, weight of seat. In fact quite a few things. Frame design and weight will affect what actuators and or dc motors you plan to use.
I have been through a few full frame designs, so I have an idea of what will work.

think I will keep the screen fixed, but would like to move all other. Any info on your full frame design and components used would be appreciated. I 'm liking the design at http://www.xsimulator.net/community/threads/diy-2dof-simulator.4793/

With that link ask @Erwan960 for infor. with mine, not really much details as everything was hand built with no plans. Generally pivot was a cut down driveshaft with plates welded on the ends, motors were 200w big worm gear motors from motion dynamics in Australia (kind of handy when he is 5 mins drive away), the Pololu JRKS of course.
Still post up an idea and we can help.
Erwans sim is a good set up, ideally though motors connecting the the shoulders at the rear will really give you solid motion because they dont have to work as much. Like full framing a seat mover.
I built this a while ago http://www.xsimulator.net/community...placement-sim-updated-photos-19-11-2013.3822/ , the foot placement works really well because its so far from the pivot. In hindsight it would have worked better if I had spaced the motors out a bit wider and made connections to the frame higher up, like at top of the seat level (where you sit on). Not at top of toe level.
This handled 130kg to 30 kg easy with no need to move the pivot. It was set in one place.

Nice clean set up on yours also. I want to enclose mine with sheet metal and paint the same scheme that is on my Open Wheel Modified dirt car.

I think I'm kind of confused on the design principle, please correct me if the following is not correct.

When the motors are placed at the foot position, it is less stress on them as they are father from the pivot point under the seat , but the movement is better when the motors are mounted behind the pivot point (seat ) and at shoulder height. So would I move the pivot point more towards the feet for the better set up and feel?

The problem with having all moving is the weight transfer while a change of motion happens, can be done, but because of the charactristic of the resulting movement the motor may not have the same speed as if used solely as a seat mover.
One suggestion is to design a simple seat mover letting you be free to place any size monitors and wheels, pedals controllers or keyboards , etc on the sim.
See what happens in an all in one sim, you keep adding to them forgetting about weight and having it balanced perfectly on both axis (front-back and left - right), because if its not the side where the weight shifts too will cause all sorts of woes.
To overcome this took me 4 sims and alot of head scratching to get a final product that I was happy with.

A seat mover can be a good starting point to learn Simtools and sim building as in what you have build can be modified and you can test and set it up as you go. Like adding a foot well to the chair support and wheels support, etc , mean while its still drivable and can be done bit by bit. The idea of my above sketches was to give an option for people who were either still suspect of SimTools or did not want to give up there beloved static sim. It took me about an hour to fabricate and another hour to wire and setup the Jrks within 1/2hr was running Dirt3 in SimTools. And all for an outlay of $800 - 900, producing some radical motion, effortlessly. The plan is to finish them when I get a chance to write it all up as a base for newbies to start with and get their hand dirty and enter into the wondrous world of sim building.

If going for a full 2dof , be careful to get it all balanced right , not too much angle, for race 10 deg is plenty, building a seatmover style shows you that. Step forward in small steps but really you could be enjoying motion very quickly and be on your way to modding to the rig you dream of.

Motors at feet result in more roll that pitch, an unbalanced motion to me , at the shoulders is the strongest point mathematically to place them. Worst is directly under the sim.

thank you, I will take both of your advise and start with the seat mover design you have attached above. I'm going to make the unit out of aluminum tubing to help keep the weight down. I own a machine shop here in the US and can get it pretty cheap.

the problem of the big roll was a frame design fault by me. I was working on a compact frame and I placed the motors at about 450mm spacing, combined with a distance of 700mm from pivot, yes it was unbalanced, a good profile fix helped pf course, but the design was part of my research into a suitable compact frame. It worked though. It would have been better to place the motors 550-600mm apart ideally.