NEW CATEGORY

[Matt Olieman]

Thanks to a suggestions from Jim @ www.jimspage.co.nz

Here we are, just a category for the Motion Platform builders. Which I personally will keep a close eye on...., I like motion:)

If you haven't been to Jim's site.... check it out. Jim keeps his design simple and inexpensive.

Thanks again Jim :)

[CWFlightsim]

Gidday Matt0 I can vouch for Jims motion platform I have a working model in my garage!

http://homepages.paradise.net.nz/cwarner/flightsim.htm

[Matt Olieman]

CW, absolutely wonderful.... "Nice Job" impressive :D

Btw, what's the gross weight of your platform?

[bishoff7]

Hi to all I have a question for roland if I may
In most of your graphs I have noticed after the initial output in your graphs there are a number of small after spikes is this a result of the raw data supplied from portdrvr and if so is there any way of filtering it out without just clipping it which would also clip out most of the smaller signals and the start of the larger ones to my driver circuits.
I ask because that is the problem I face at this present time with my sim
I love the fact of having the dynamics that you have afforded us, I linked the output of your D toA back in through the variable speed circuits that jim used as I am using hydraulics . This instantly improved the characteristics by a long way but I now need to get rid of the unwanted signals do you have any suggestions for me
Regards
Bish.
Australia :oops:

[CWFlightsim]

Giggay Matt0 the weight of the moving mass without pilot is 155 kg. This includes a truck battery under the co-pilots seat (to run the wiper motors) to partly balance out the pilot. I also have two computers and three CRT displays, one will disapear when the projector gets mounted. I am working on the visuals at the moment, it is going to be a back lit screen in front of the sim reflected with one mirror. the projector is going to be mounted underneath the sim at the front with the mirror sitting out in front. It will all move with the sim (of course) screen size to block all non view parts while looking out the front will be 2000 x 800 mm.
Cheers

CW

[Bob Reed]

Hi guys... Just a thought.. Shouldn't the screen be stationary?

[dodiano]

What will be the Useful load of your platform??

Regards,

Roberto

[Tibob]

Most sims in general have stationary screens. However i have a brainstorm for the pit that i am building once i clear up my garage, is to have a screen that tilts in the opposite direction of bank. That would definitely promote greater motion cues to my belief.
I will try to replicate something similar to MATT OLEIMAN'S curve screen with three projectors. the puzzler is how is the image projected going to be affected during a bank.

[Roland]

Great to see a lot of activity going on here lately!

Sorry for late answer, as I was 3 weeks away for business. Always seems to get in the way of the important (motion) stuff.


Hi to all I have a question for roland if I may
In most of your graphs I have noticed after the initial output in your graphs there are a number of small after spikes is this a result of the raw data supplied from portdrvr and if so is there any way of filtering it out without just clipping it which would also clip out most of the smaller signals and the start of the larger ones to my driver circuits.
I ask because that is the problem I face at this present time with my sim
I love the fact of having the dynamics that you have afforded us, I linked the output of your D toA back in through the variable speed circuits that jim used as I am using hydraulics . This instantly improved the characteristics by a long way but I now need to get rid of the unwanted signals do you have any suggestions for me

---> Indeed if you take de differential signal as I did, you will end up with some lsb noise due to the coarseness of the roll/pitch output. I have not yet driven my platform with the software directly (currently busy building the isolation interface with optocouplers). In my interface, I have have control over the motor speed. Small low amplitude spikes will therefore hardly influence the platform movement, while spikes with larger amplitude will make things move more voilently. In the servo circuit I can tweak the servo gain, and set some null-zone in which there will be hardly any movement. Note this is still not tested, but should be feasible. Currently I'm also in contact with the guy who wrote the Portdrv utility, and together we are going to do some tests hardware and software related, to get a good solution for dynamics, noise etc. It may take a while as we all have fulltime jobs and other things that seem to get in the way of this addicting hobby. But as soon as there is any news, I'll let you all know.

You seem to be quite far with your platform. Please share with us some of your findings, if possible.

Rgds

Roland

[bishoff7]

Hi to all
and thanks Roland for your reply . It will be really great to see some of the results you come up with between the two of you no doubt you will get this thing fine tuned very effectively .
For me I like jims idea of using that particular type of reduction as it lends itself very easily to get 3 dof out of it with only the addition of one extra steering box and a spline added to his tailshaft found in most two piece tailshafts.apart from that it does not take a lot of data manipulation to get right feeling going and that is the most important part to me .
I have been using old ford radius arm power steering not the rack and pinion type and have found that in order to get them to to react quickly enough to drive a fighter type sim has been quite a challenge one of the main drawbacks of this is that you have to use a separate pump drive for each steering box as using just the one pump and a series type hydraulic circuit is far to restrictive in these older boxes and this slows the action and the lifting capacity down too far to be viable . As you stated once before Roland only about one in every ten good ideas that you have actually works . So true
I am not going to use rack and pinion for my next attempt I am now putting together the same type of steering box as jim
used with no power assist but driven by a gear reduced servo motor setup which should do the trick very well and do away with some relays at the same time . I never realised how much torque you could pull out of those motors .
There are still many hours in front of me but with a comunity like this to converse with how can I fail
Regards Bish

[Manfred]

Hi guys... Just a thought.. Shouldn't the screen be stationary?

Hey Bob,

I would say definetly no. If the screen did not move with the platform, it would counter the motion platform's attempt to simulate motion. If you don't have a motion platform, your screen does not move about, so neither should it move about when you are on a platform. Hope I am explaining that clearly :P

[wannabeaflyer]

Hi Craig
Been away but lurking everyday to see whats happening on our scene :D i have posted a picture of my soon to be started flight sim based on yours and jims plans thoughts and ideas, like they said in the Jaws Movie it got to the stage where " I Think im gonna need a bigger Boat " only in this instance it turns out i had to make a Workshop at the bottom of my garden to house my new project .... been thinking about building a proper workshop and the little lady hinted as women do :lol: that the house ain't big enough for both of em LOL:-) ... anyways will post mor pics as the building work is all but done now down to finishing touches have a look see on the gallery page under missc ... had another look at your site and was trying to see wait material you used to make the Base and cockpit support platform out of :?: look like 4" x 2" wood or is that box section Metal ???

[Matt Olieman]

I love the addition to your home..... :) That's the way to do it!!!! Love the pic :)

[CWFlightsim]

Gidday, wannabeaflyer. Well if that is the sim's home I am waiting keenly to see the sim itself! Good effort so far.

My wife said to me once, "Either that sim goes or I go!" Oh well I didnt need a wife anyway!.... Just kidding, she is right behind me and the kids love flying it, I just wish she wouldnt hang the washing on it!

I am using 4 x 2 on the bottom, it was originally sitting on castors on the floor, but when I decided to go for motion, I picked the whole lot up and rebuilt it on the base, in hindsight the 4x2 and 18mm particle board make for a heavy base, but it aint gonna flex!

I am having a whole lot of trouble (or challenges for the optomists within us!) I blew up the motion computer, was a bit economical with diode protection on the motion circuit! So the parallel port fried along with the computer, anyway a rebuild of the motion board with lots of diodes and a couple of softstarts/speed controls added and a new computer with a seperate ISA parallel port card and we are moving again, oh wait theres more! It only moved for a while then the Pitch motor decided it had enough and stopped, and then the micro switch assembly for the roll axis jammed up and the power steering ram destroyed that too!
The good news is that while this was all going on I have a workable flightsim on top that I keep 'airworthy' so I can use it anytime!
I have managed to get away with one softstart per axis I can change the speed to create slow return to centre and also change the return to centre speed on left or right to compensate for my weight on one side, all fully adjustable. I have programmed braking and acceleration in as well, anyone interested in wiring diagrams or program files just let me know, I havent updated the website for a while because there has been no visual improvements.

Cheers,
CW

[NicD]

Material for the base-frame and shell-frame is my biggest decision at the moment - so I'm interested in your experience thus far. I'm trying to decide between timber like you guys have done, or to go welded steel tube (or box section).

Reason is that I'll probably have to move my sim to a different location next year and want to move it as a complete unit. I'm not thinking of doing motion anytime soon (if ever), but wonder if I should do a strong base/frame anyway just in case.

Advantages of wood are low cost, easier to build/change. Disadvantages are weight, strength required for overhead (?), flex, and tricky joins in some places.

Advantages of steel are strength and low-flex, disadvantages are cost, someone else has to do it, and difficult to change once done.

Any other thoughts / advice?

cheers

[CWFlightsim]

Gidday NicD,
I used 40 x 40mm timber as a frame and 3mm MDF as cover, my last sim was steel tube with aluminium as a cover.
As a cost saving this time round I am using wood, I think whatever you are happy working with you should use, the timber is strong and the MDF is flexible enough to mould into shapes. I have seen some awesome sims made of wood around the web. So, in a nutshell I havent really been any help, dude!
As a foot note to my other post, I have repaired all the motion system problems and everything is running again, in fact with the addition of the softstart/speed controllers, adding some trampoline springs and a change in pivot points, I no longer need the power assist! My wiper motors running the power steering racks is enough to move the whole sim (155KG)
It has been a good day, I hope everyone has a productive sim building day too, that is what makes this fascinating hobby worthwhile!

CW

[wannabeaflyer]

Hi Craig as always you guys came good but you just opened the door and am goona step through :D you mentioned updates to your sim after your minor grounding and as always want to learn from these things .. You mentioned Diode protection and the hindsight need for an parallel port card which is pluggable onto the mother board as a prudent step to safeguarding the system ... i kinda like that option as its something i did when i made my DIY CNC machine.. Got the Parallel IFC card from a company in the States ... They are on the CNCZone website ..Anyways you mentioned a wiring diagram and Program files .. any chance of shipping them over to me via E-mail . Because im just finishing the workshop ( Hanger ) as i insist on calling it i am just lurking, scouting, Beg borrowing and down right blatantly using any info i get from the net to decide the best and easiest elements to get my project going , as soon as i manage to post more than one picture i'll create an Album so you guys can see that i am getting on with this and it's not wishful thinking :) My E-mail Address is Calvin.hall@muirheadaerospace.com the other big plus for me was that you said your able to drive your sim without the need for the Power steering pump working :wink: thats made life a lot easier are you happy with the performance of this setup.. got me some beefy motors as used on an electric bed and even if the motors cant be used becuse of their continuious use rating the leadscrew setup looks the business... Cheers guys keep it all coming and this sponge will soak it up :D in a helpfull sorta way

[NicD]

Thanks CW - that is a help. Glad to hear you're problems are getting fixed.