Cheap motion using junk, things about jimspage Questions etc

[jabomeister]

just an idea here...could you simulate motion without really moving?
Say you get a set of harnesses which can tighten to simulate pitch up- i.e. pushing you in your seat, or go loose, to simulate pitch down.
Along with those, your seat cushion has two sections that can inflate, front and back. Front inflates to simulate pitch up, bottom inflates to simulate pitch down. Thus in pitch up your legs would go up a bit, while the seatbelts push you tight against the back of the chair.
In pitch down, the back cushion pushes your butt up, making your torso lean forward and literally hang from the harness.
Well, this is my idea for simulating pitch changes...just an idea

[Jim NZ]

Hi Jabomeister .. Sorry for the big delay .. Been in Australia wrestling some kangaroo's , chasing snakes and drinking beer ... on return, sent away for a week with work.

I suppose your idea has credit but I think it would be big job just to get it to go ... and then you would probably be disappointed with the sensation. Motion in any sort of simulation is a compromise and the amount of money or effort put into can get you closer to the real effect. Your "motion seat" concept reminds me of the "force feed back" joysticks etc that when they first came out, some people though they were amazing, others thought they were just ???
I do know of a guy that is using that same seatbelt idea to add to his motion platform to mimic the effect of an arrestor cable when landing on a aircraft carrier. Anyway, its really, what ever turns you on ,, go for it !!! It would certainly be better than no effects at all !!!

To those waiting on an update on my website ,, I have thrown in a few pictures of the new motion base.
They are in the "Where to from here" page.
http://www.jimspage.co.nz/where.htm

See ya's
Jim NZ
www.jimspage.co.nz

[Roland]

Hi Jim,

Just had a look at your updates on your page: Hats off, it's looking great!! Looks like you are taking care of more driving power (dual motor wiper units).
A couple of questions / comments :
You mention that you are developing a new interface, faster than CHcomm. This really is good news as the 0.2msec update speed of current CHcomm is indeed an issue. You also say that you want to use visual basic iso gwbasic because of speed limitations of gwbasic. I'm not sure where the limitations of GWbasic (in the RS232 data receiving PC) are, as my experience with portdrv utility (update speed 40msec) have not shown any speed limitation with gwbasic in the receiving PC; actually I had to limit the speed of the platform to make sure I don't feel the digital noise of the FS data. GWbasic can update my parallel port DAC's ( http://www.simprojects.nl/parallel_port_dac.htm ) within 40 usec. on a pentium 200Mhz. But maybe I'm overlooking something. The parallel port dac's that I'm currently using are working really well. Didn't need the isolation after all. Now using 2 dac's but the concept is good for totally 4 dacs, so you could drive pitch, roll, yaw, heave all independently. The interface is dead cheap I expect component cost would not exceed $25 ~ $30 for 4 dacs. homebuild that is. The PWM power drive ( http://www.simprojects.nl/electrical_drive.htm ) is another matter. Probably better to buy than to build.

Just some thoughts.

Presently working with the portdrvr utility maker on some interesting modifications.

Cheers,

Roland

[Jim NZ]

Hi Roland, great to hear from you again and thanks for the comments on my progress.

Yes Chcomm is a bit slow (but still very useable) at about 220 msec's on my test's so I took the bull by the horns and developed my own (I call it Jimcomm) everytime I have a fiddle with it I get it faster .. currently about 90 to 80 Msec's but I might be reaching the limit of speed going thru FSUIPC ... don't know ???? Will get back to it one day.

Once I got that running, I hooked it to a much revised and added-to gwbasic program and I kept getting "buffer overflows" after a while, so I assumed the loop speed was too slow to keep the serial buffer empty. ???
You are getting great figures with your loops so I might revisit this and see what I have done wrong. There certainly seems plenty of speed there and one great advantage with Gwbasic is its easy to modify "on the fly".

I had a re-read of my updated page and deleted all the "I'm gonna" things ... (hate pages that say that .. it tells you nothing) but when I wrote it, I just thought I would toss my plans in as, (I gotto admit myself) I have been keeping a low profile mainly because of work.

Now... Roland .... you got a brilliant site and full of real good info ... how do you find time to do it all ??? I know websites are a **** of a lot of work !!! but your updates are the end result of hours fiddling with soldering irons, spanners etc !!! Great stuff .. you are a credit to the cause. !!!

Keep us in touch with that DLL thingy..

See ya ... Jim
www.jimspage.co.nz

[Roland]

Hi Jim,

You definitely are more software savvy than you had us believe. I'm not sure what GWbasic causes to give you buffer overflows, could it be the speed of the PC, or the amount of data that you're trying to send? Never did a baud rate calculation, but the 4 byte data the Keith is sending via portdrv has not given my setup any issues. I have the baud rate at 9600. That should be ample for sending 4 bytes per 40 msec, which is around 800+ bits per second. The GWbasic code itself is probably PC clockrate dependend. Maybe try a faster PC would give some clues. Also running the code compiled gives considerable speed increase. For the FS interface, I know that Keith did a lot of tricks to make his utility so fast. I you want to get in touch with him, let me know. On the FSUIPC you could get in contact with Pete Dowson, he is very helpful, has a special forum where he answers all kinds of questions. http://forums.simflight.com/viewforu...534f96bbff6c8c

Whatever you put on your website will be interesting. I personally love your metalworking tricks and smart use of car parts. Ideas and future plans are always vague, I also try to set some targets, only to fail miserably, but the good thing there is no boss pointing to some fixed deadline you have to meet.... That's why it's called hobby!! Though the wife may sometimes wonder.....

Keeping the website up to date is not such a hassle: I'm using Frontpage which is not a bad program to work with. It's almost like writing a report in Word. Uploading is a breeze, as it automatically looks for updates. There is some extra overhead, but who cares....

For my motion electronics I can imagine there is some difficulty for people less familiar with using electronic components. I could try and make some decent PCB layouts and partslists, so they would be easier to build, but so far no special request, I guess most motion builders are using different approach.

Anyway, likewise keep us posted on the Jimcomm. It has lots of potential.

Rgds Roland