Starting my motion simulator

Hi Peter,

I hope these drawings help you a little bit. They have been a challenge to draw. I am not gifted at using CAD or drawing programs.

OK, this is where the pushrods must connect, you can easily visualize that many movements are possible with this setup. Better to have the front on each side and the rear in the middle. On side to side movement, the rear will move more than the front to simulate loss of traction of rear wheels. I had the front in the middle and terrible clearance problems before I switched. Your's should look similar to this.
I have 2 options for positionning links. This is one and the other will be a challenge to draw. But I will explain later.
By the way, having a flight simulator rotating aroung CG is OK but for a race car, the road is where it grips and maybe the real rotation should be at the floor level but really not practical to make. So I think that below CG is OK. You must remember that it is always how it will feel that must lead in your decision. And I think it is not important to feel all 3g's in curves, just have a good feeling of what is happening with the car. You want to improve your racing skills and records, not take a roller coaster ride.
If you place the links on the side it will look something like this. If you do it this way, remember that the links are pointing slightly in front of your feet and that the bolts that hold it must be perpendicular to avoid binding.
The second option would be to install the links under the seat, pointing in front of your feet also but since they would be placed lower for clearance it would require a 3rd arm and some kind of upright. It is difficult to explain, a drawing will help. This would make a very compact simulator and hide the moving parts which is very important to protect the young fingers that run in the house.

As for cylinders, I have 4 options and I think they are all good.
1 - Under the links with the low connection in the rear. On side to side movement, the support is always the same. However diameter would be larger and can not be calculated without knowning coords of attach points.
2 - Vertical under the links, in this case their diameter would be 40mm. The leaning from side to side would not affect very much their supporting capacity.
3 - Under the seat, on each side. 40mm
4 - At each corner, 4 cylinders of 30mm

I have another one too : use 4 gas struts, one at each corner. Of course they must be of NO DAMPING type. I placed a special order at Destek at 50$CAD/ea plus freight from Turkey. Their specs is 200mm stroke, 10mm rod, 22mm cylinder, 300N and 8mm rod ends at each end. Simply bolt in place, no compressor, no regulator. It is not the 200mm stroke that was important but the total length. However pressure can not be adjusted for a pilot of different weight. The motors must be able to overcome this handicap. (This subject will be another post). But the worst unknown is how long will they last.

One thing upsets me a bit about air cylinders, only the shaft end can take a rod end. The best base only have a bushing for a pin, not great, we need a rod end at the botton too.

I trust your common sense and creativity to decide what to do.

Fern

Thanks for sharing the info, I am interested for sure and may develop a sim like this as well.

You are welcome floriske.nl and bsft and anyone interested in this

Your comments and questions are welcome, I will answer the best I can

Fern

Hi,

It was not easy but I think you can get the picture. This upright and linkages could be placed UNDER the seat to hide everything and have a more compact design. Note that you need more than 20° of rod ends because the links are short. Ball joint linkage like this should be used http://www.mcmaster.com/#rod-ends/=hgmzz1
All 3 links must be either attached to front or to rear part of base. The bottom link must be a little shorter 3-4 mm to minimize the arc movement. No matter where you attach them front or rear, the links all point in front of your feet.

Fern

Hi !

I was little confused that last picture, but now i confuse you too. I think my way to do this sim is cylinders which are under the seat vertical attached brackets and other end is on the rubber buffer. Not sure how it hang on but if it brake, then we know. Supporting arms going outside those brackets. Motors are connected with rods to the seat frame. left to right 400mm and front to back 400mm.

Peter

Hi Peter,

I am sorry I could not answer before but if my understang is correct this is what it is all about It looks good to me. Just remember that side arms are not parallel and try to place mounting points accordingly.
If you plan to use rubber bushings this is where I recommend to place them. I also recommend sandblast metering tube because it is soft durometer 35 and very resistant. You should be able to find old ones from sandblasting shop but not at body shop, this is used on large blasting equipment. Cut lengths of 15/20 mm and place one between seat frame and sub-frame and one bottom at each corner and using nylon lock nuts adjust tightness until it feels right.

You will have to adjust distance between L/R points and also motor stroke.

This drawing shows top at 20° side to side, the stroke is 69.459mm with a radius of 200mm. For 100 mm stroke, radius has to be increased to 287.939 mm. You will have to compromise by increasing radius to max which will help the motor gears and then re-drill the lever arm to the right stroke.
The same has to be verified F/R, but it should be easier on that axis since the length limit is larger than the width limit.

Keep up, I will come up with info about motors, since it is about time to get them.

Fern

Hi!

Long time no see..
Family take sometime all the time, but i don't complain.
Wednesday i finally got some time and go local junkyard. I found 2pcs bosch cylinders 40mm dia 320mm stroke. they are quite long but at least there are enough space under the seat :thbup: . No need to micro mechanics. The minimum length is about 560mm with fasteners. i was thinking another idea for fastener. i try cross-links what are used for socket wrench in . Weekend i try to make some time for the project. I post pictures if those ideas are any good and i get something done.

Peter

Hello!

there is a good reason why i think this project going to last at least one year. Other stuff make my 24 hour day too short.. but maybe i get some time next week(fingers cross..).
This kind of motor pushrod attachment i plan to do. is those place right enough? I meaning that could that work if cg is middle of those f/r placements?



Peter

Hi Peter,

I am in the same situation about available time and my project is really slow moving.

It seems you read my mind on this sub-frame. Take a look at mine :

I still have to make the bracket for the shifter These brackets are available at http://www.out2win.com/catalog/wtbrkt.html
Those motors are 52mm and I think it will be more power than required. I will make tests with them but I think that 43mm would be enough (when 4 are used) The stroke is 70mm and the lean angle is 15° I think 50mm of stroke would be enough and still give 10° each side (D-BOX have 38 mm of stroke) I think 50mm would move enough here too The electronics could attach to the PSU and make a compact simulator

Fern

First test of my proto2

Hi Peter,

This I hope will encourage you to continue with your project
http://www.youtube.com/watch?v=Qa4XwguBKuM&feature=youtu.be
http://www.youtube.com/watch?v=Qa4XwguB ... e=youtu.be
Fern

thats great! moves really well.
sorry if I missed it , but what motors are you using please?

ML-52 24v by Shayang Ye

http://www.robotmarketplace.com/products/ML-52-53.html

Fern

Thanks for that, it converts to about 4nm, fairly low than I expected, but hey, it works on yours.
I am tempted to build one with my motors, they are 12v at 20nm.

Hi!

Thanks for that video!
My project is still in trying one thing and found that its bad decision and try another way to do that. But its better to do those mistakes by myself, then i know what is the right way before i show it to others.
I'm glad you prototype looking functional maybe my version going to work someday.

Happy new year to you all who try to make sim by themselves.

(Sometimes the journey is more important than the destination)
Peter