Erics 6DOF Ride Simulator - Ride-u-lator

Hi Wannabeaflyer
J-DOME is the site from the spanjard ,he patented it a year ago
My windscreen i made it this way
Take a pice of MDF from 115x75 cm(pice 1) its gone stand right up
second pice Mdf 115x50 cm(pice 2) ,this pice is gone be placed horizontal (perfect to fit your steer up)
These 2 MDF plates are fitted in a 90 degrade angle.
But before that you need a second 115x50 pice(pice 3), This pice is to fit your screen to your wishes
When your sitting in youre car, you see a line between the dash and windscreen.
This line must be sawed out, and this pice will later clamp the screen in your sawed form,when fitted
plat up they other 115x50 pice
The upstanding MDF plate(pice 1) :You do the same as above, saw it out in form from roof and door style (ROD)Its gonne be youre standing window frame like in youre car.
Now comes Mdf 115x73,2cm (pice 4)and is gone do the same as pice 3,But saw it a fuw cm out bigger than pice 1 , it's also gonna clamp the screen ,only a little bit futher and looking tru pice 1 ,it's gives the illusion youre realy looking outside
Now fit pice 1 and 2 together in a 90 degrade angle ,make the angle stif with some wood on the sides
from the pices.
Now put pice 3 up to pice 1 with screen between them ,and screw it only in the middle
Now put pice 4 up to pice 1 thension the screen and screw it in the middle.
This way you clamping the hole screen ,from center to outsides.
So i made my windscreen
regards Ad

Pice 3 must go up pice 2

Thanks for the post adgun, but I think I'd need to see a picture to understand that.

I think Adgun means something like that: http://www.geo-dome.co.uk/3v_tool.asp

Hmm... I think he was describing something else. The page you linked is pretty much exactly the same as what I've built. Handy resources to have, though. Thanks!

Eric

hi i hope this made it clear

hi i tried it bigger in my simulator
JDome way, but my short trow projector gives to much distorsion
regards Ad

Thanks guys , for me a picture speaks a thousnad words and seeing those made sense of how things work , now dont laugh but could a plain shower curtain type material be used to give a goodish rear projection surface, i like the frame idea as i see the potential to save weight for my Motion platform Flight sim , i already have a projector but due to the location in my workshop , i have the situation where unless everything is blacked out, the image is washed out and not too clear .. :

hi
i dont belive a shower curtain will work
but youre able to buy projection screen/cloth
regards ad

Frustrating weekend on trying to get my last actuator up and running. I have 5 matching actuators (designed to be driven by Emerson/Control Techniques servo drives), and they all work great. I have one oddball actuator designed to be driven by an Allen Bradley servo drive. In theory, the two different models are compatible when you map the 20-or-so connections properly, but I was unsuccessful in getting the thing fired up all weekend.

This actuator is the last big item that needs to be completed before I can get a simple demo running, I think. Unfortunately, I can't rush it because I can't afford replacement actuators or cables (these things are crazy expensive). Or service.

This is one problem with using really good industrial parts (purchased over time via salvage). Can't afford service and they are too expensive to have any non-pros using them, so there is no online community whatsoever. About the only reference to Exlar on x-sim, for example, was from an employee, and he wasn't even sure he could get them himself at a reasonable price.

Oh well....

I'm psyched: I've managed to get my last actuator up and running. I had to take it apart and look up the datasheet on the encoder, at which point I realized that the servo drive unit was using the wrong parameters for this motor. The motor also didn't have its thermal switch hooked up to the designated pins, which resulted in a continuous Motor Overtemp error.

I think that was the last major hurdle, though there are still an ungodly number of of minor hurdles remaining.

I also tested my new dome projection scheme. I had to relocate the projector outside of the dome to get the proper focal length. I should end up with about a 60 1400x1050 dome-shaped screen. If you are willing to give up legroom, it could probably grow to 72+.

here is a sketch of the dome projection system (in reality, it projects higher on the dome than my beautiful illustration shows):

Have to ask ? what type of Mirror or reflective surface is the convex element of your setup? Cheers.

It is an 18 Indoor/Outdoor Acrylic Mirror (used for parking, security, etc).

http://cgi.ebay.com/ws/eBayISAPI.dl...753303&ssPageName=STRK:MEWNX:IT#ht_500wt_1022

The size of the mirror is dependent on your projector. I have a Dell 2400MP (1024x768) that focuses just fine on an 8.5 mirror (truck rear-view convex mirror). The larger Dell 5100MP (1400x1050) requires more distance to focus, hence requires a much larger mirror and more space. But I wanted the additional resolution, so I am ok with it.

The smaller projector and smaller mirror could fit completely inside the dome, but those projectors are loud and create noise, so I am happy to eject it

Eric

http://vcsims.com/index-2.html saw this whilst browsing Dont mean to hog your thread, just for Info for anyone interested in the idea Thanks Eric just scroll down the page for more views

Not a problem... These are all the products I was trying to find before I built my own... Fortunately, I haven't found any other one that's (1) available and (2) affordable.

Keep 'em coming!

Eric

Notes on Modbus control:

It seems that the Modbus standard (or perhaps Emerson's specific variation) defines that you must wait 10ms when changing your target address. In other words, if you chain all of your units on the same RS232 port, you will spend at least 60ms to send a message to every unit in the chain.

To avoid this, I purchased a USB to 8 serial port device for $99. There is no minimum wait time if you are addressing the same device in Modbus, so this should allow me the highest possible bandwidth to my 6 actuator drives.

I'm still not convinced that modbus is the way to go, because I have still have not found a command that can move an actuator to a particular spot, but allow it to be interrupted along the way with a new set of instructions - AND not have to decelerate and accelerate prior to acting on the new instructions.

Normally, when an indexing drive arrives at an index, it will decelerate-to-zero at the defined rate and await a new command. Emerson Epsilon Ei drives have a concept of chained compound indexes, which allow you to define a number of indexes (a chain) and have the drive move to each of the indexes in the chain without decelerating to zero. If I can change the definition of the index chain _while_ part of the chain is running, this would be a terrific control scheme.

If Modbus doesn't work out for real-time control, I'll probably switch to pulse control, with something like 256 pulses for the entire stroke. The actuators are much noisier in pulse mode (probably because they start and stop hundreds of times along the way), but they would be pretty easy to control.

Re: Erics 6DOF Ride Simulator - Ride-u-lator (new pics)

The blood is in the water now.... I'm missing a couple of yokes, but otherwise the basic platform is ready. Cables are ready (no mean feat: over 600 pins involved). Time to start back on the software!

The platform is 3' x 5' on a 3' x 3' base. Actuators are Exlar roller screws with 6 travel (in 0.2 seconds!). The pictures are also in the gallery if you want more detail.

serious stuff my man and project is moving along nicely keep it coming

I really like the way you used the caster wheel mechanisms!!! Did you used ball-bearings on every joint?


Thanos

Thanks! I am really glad I thought of castors, because it eliminates a lot of parts, and they are cheap and the bearing are weight-rated.

Re: all ball bearings. Not quite: the lower shafts have ball bearings (though they are a little dodgy after welding so close to them when creating the ears for the actuators - you should have seen the grease vaporize). The upper shafts are just a polished yoke on a normal steel bolt shaft. And of course the caster swivel bearings are all ball bearings. Bottom line, everything moves great (non-powered... I haven't powered the platform yet).

My feeling is, its not like these joints are rotating 60 RPM like a wheel - they will have 600 lbs of force to move them a few degrees. You could probably use a rusty nail as a shaft and get reasonable results 8) The main thing is probably to keep them from being noisy, which remains to be seen.

Eric