Design Advice

I know I have already started a thread in the project area, but I quickly realized I was getting ahead of myself ... way ahead.

After reading over even more threads, I am planning on investing a bit more money to follow (copy) some other builders.

I am planning to use:
12v Gear Motor from eBay (sold by pgsaw)
Jrk 12x12's
Modified server power supplies
Pot: uncertain at this time.
Seat: looking for suggestions

If I have motors, jrk's and power supplies, I could "play" with the motors, correct? The pot's are only necessary for communicating with the software?

Could someone give a quick and dirty explanation between the 25:1 and 50:1 motors? Is it just a trade off between speed and strength? The unit is for fun only (not a serious racer or anything) and I am curious about a roller coaster sim I saw somewhere as well. Are the parameters easily changed - I am thinking more aggressive for a roller coaster type sim and less for driving game. I know I have read threads where people have been helped to dial in their settings, but I do not know if it is something that you don't mess with once it is done.

Any feedback on the roller coaster sims? Worth worrying about?

At this time I am planning a 2dof seat mover with shoulder mounted motors. I recently read a comment about adding traction loss? Is that something best done at the beginning? What would be involved? I would prefer to keep it simple at first, but make sure I keep my options open. If I could wave my magic wand, I would copy the unit by @jem45472. I am not a welder plus it just looks cool.

Last question: Does anyone have an enclosed unit? I have a closet area that is not used and have been thinking about putting the unit inside. It wouldn't be great for observers, but I think it could really let the player get lost in the game. Yes? No? Maybe?

Thanks in advance for you help and suggestions.

Coach Kalk (Steve)

I can only help a little bit;

You will need pots to play around with the motors/software/JRKs as they provide position feedback to the software/JRKs.

The RollerCoaster sims are AWESOME, and well worth getting. I have No Limits Rollercoaster, have not yet purchased version 2 yet but I am certain that I will eventually.

Personally I would start the design with traction loss in mind, it is easy to add a third axis at this point but much harder later. I rebuilt my 2DoF in order to add traction loss, wish I had done it initially. Although, it is not a herculean task to add it later.

I started with an enclosed static simpit (MechWarrior Online Pit) but decided, because of the weight, not to utilize it and built an open pit instead. The motors that you spec'd would not be able to move an enclosed cockpit (just my opinion, I could be wrong and would be pleasantly surprised to find that I am indeed wrong on this).

Good luck and I look forward to seeing your progress.

David

David,
@Historiker

Thanks for your feedback. So just to get a feel for the motors (no software yet), I would probably just need the modified power supplies and motors. The jrk's and pot's to talk to the software.

Glad to hear the roller coaster sims are fun. Do you use your same setup regardless of the activity (coasters vs driving)?

I will do a forum search for traction loss. I am just not sure what it involves and the wife still hasn't approved all of the necessary 2 dof purchases! If I cannot find any threads, I may be bothering you for help.

As far as the enclosure goes, I was just thinking about enclosing the unit, but it would still be a seat mover. Basically just so you feel like you are inside a car. But, I wasn't planning on moving the entire enclosure.

Thanks again for you insight.

Steve

Hello @CoachKalk , I will dig up some photos and links in a few hours when I am near my PC
yes the pots need to me mechanically moved by the motors, and yes the pots provide feedback to the controllers , JRKS, so the controllers "know" where the motor lever position and where it has to go next.
JRK are the simpler board out there even if they are a bit more costly than arduino-hbridge , and you will get better performance from the JRK.
25:1 and 50:1 , one faster than the other so the slower one provides double the torque.
Most of the time with a shoulder mount seat mover with 10kg seat and up to 120kg driver , 25:1 they will toss you around no problem. Any heavier than that , use the 50:1.
And with the JRK, you have the ability to save different feedback settings files and reload them at will so you can have big throw or short throw.
I suggest start with a 2DOF and look at traction loss later, especially if money is tight.
Immersion is the key of course and a few people have done enclosed pits in the past (need to find the links) , however with a 32" tv in front of me I get good immersion for cheap cost. A good set profile and you really feel more in game. Its a mind trick.
With a good profile , and I have a 2DOF seat mover, no traction loss, I feel the sensation of the seat swinging out when it does not.
3 screens is good and also the new oculus rift is coming along well.
Cheers, David.

T ere is more different between a 50;1 and 25:1 gearbox than only speed and torque!
The factory cast one gearbox housing for different ratio,s,This means the distance between the ingoing and outgoing axis are the same.
They play with wormwheel and worm to create different ratio,s,
The tooth from a 50:1 gearbox are half the size from a 25:1 gearbox,and the tooth angle is different.
50:1 gearboxers are allmost locking and a 25:1 is not ,this does the tooth angle.
A 50:1 gearbox will ware out sooner than a 25:1 gearbox because smaller tooth and tooth angle
sorry for my bad englisch
regards Ad

the 50:1 and 60:1 gearboxes I have seen and used are metal gears inside, while the 25:1 is hard plastic. Sorry @adgun , but 25:1 will wear out faster, only if you really push them hard. ive seen a few fail, but once the sim was better designed, it stopped that problem. No such problem with 50:1 boxes at all.

Hello everyone,

I have a few more questions.

I have a question about the tie rod ends that are used to connect the rod to the lever and seat back. Do the ends allow for rotation (like a shoulder bolt) as well as some flexing? Or are the end tight to the lever and seat back?

I was a bit discouraged when my junkyard wiper motors were really "junk" so that is why I had started looking at the new motors mentioned above. But, after reading over more threads, it seems many people have had success with reused wiper motors. Assuming I can find some that actually work (and modify them for the ground issue), builders seem satisfied with speed/force provided. And it would be a great place to cut some $$ out. Do the junkyards typically bench test them or do you just keep taking them back? Ideally, I would like to know before I start cutting the connect plugs off so I can just return them.

Steve

not sure what you mean about the shoulder mount bolts.
As for bench testing, you would have to ask the place if they can just put 12v on it.

@bsft - I wasn't sure if my shoulder bolt question was very clear. What I am trying to understand is if you have your rod attached to your lever and then remove your lever from the motor - would the lever spin freely or is it tight to the rod end? If it is does not spin, does the tie rod end at least provide for flexing? I am not familiar with tie rode ends at all so I am trying to understand what the connection is supposed to be. I know this may be a very rookie question. Actually, I will try to find some videos showing a closeup of that area while running and it may answer my question.

Steve

rod ends allow for movement as seen in video

David, maybe it is better to build with 50:1 gears just to be sure they will last ?
I also ordered the 25:1 motors but after reading some more maybe i should have changed......

you need to have a design we can look at, and allow for your weight, seat weight, etc.
Then we can suggest the best gear box.

My weight is about 60 KG and my build above the driveshaft is lightweight so I gues the 25:1 motors I ordered have no trouble tossing me around

yep, should be no problem, what sim design are you planning?

This one !

http://www.xsimulator.net/community/threads/al-bundy-s-4-dof-racing-simulator.5704/

Ah ok then, should be ok.

I have components on order now ... Waiting ... Waiting ...

I have started sketching design options - I had to force myself to stop reading through so many threads because there are so many cool designs, most out of my ability level.

I do not have my steering/pedals/shifter yet AND I have never even actually played with one. I plan to have the pedals adjustable, but I am not sure what the typical space is between the seat and pedals. How much adjustment is necessary? There is quite a difference between 7 year old legs and adult legs!

Is the Logitech G27 the gear of choice? I had planned for that, but then started wondering if that is the top of line option for serious racers - of which I am not. My brother told me he has a V3 Interact? Would that work? Did I mention it is free?

Thanks again to anyone and everyone who offers advice.
Steve

I would take the free wheel to start with mate. Upgrade later if needed.
With a seat mover having the pedals moveable toward the pivot is not an issue, but on a Full 2DOF where everything moves it changes the CG point on the sim and can cause issues but thinking out loud its for even a lighter and smaller driver to play , I feel it shouldn't worry the sim movements.

Put the pedal box on a couple of draw sliders so you can lock it in the right position for you and then for your child.

I just received the Jrks in the mail TODAY! Where is the magic button that gets all of the other stuff delivered?

I understand that I want the seat mounted directly on to u joint. I have also bookmarked the thread discussing lever arm length. I have even noted the example drawing recommending the 15 degree angles for the out and back position of the motor.
My question: is the length under the u joint determined by personal preference of desired ending seat height and then the rod lengths are sized accordingly? Or should I also keep the length below the u joint minimal as well and just build up the frame to get desired seat height?

I have a rough design sketch and the seat height is only around 19 inches from the ground. Is that typical? What are some of your seat heights?

Steve