MWB 4 DOF Simulator

Also a quick question, I've seen two MM's have been put together to double the power, has anyone done this with the IBT-2?

I did use gas struts for quite some time, but now I'm not much of a fan - Even though they do a good job of supporting the weight of the sim and taking some load off the motors when it is stationary, in this world there is no free ride - as when the rig is in motion, especially when it is trying to move fast for a reasonable distance, they will do what they are designed to do and dampen/stop that fast movement - try moving one by hand - you will see what I mean (you may struggle with 500 Nm struts ). Unfortunately this will actually load up the motor and drivers and possible even cause them to trip out as they max out trying to stay on target. Also the failure mode that I had was terrible with zero support and a suction on the rod that actually retarded the rig from rising . From the information I was given by the supplier each 100Nm will support 10Kg. So you are pushing up and dampening with 100 kg there . Anyway that is just what I have found - the proof will be in the pudding .

Sorry the struts are 300Nm not 500Nm, my mistake! But I tend to agree with you, I'm going to remove them and see what difference it makes. May be tempted to try 100Nm ones.

Got my steering wheel and pedals fitted. Remade the front tie bar, triangulated it and put M8 rose joints at the front, it's much stronger now, when sat in the seat the hole things a lot more rigid.

You can see that I bent the old bar!

So bit of an update, my feedback system is inherently floored, if my arm tries to rotate past the bottom everything hits. I've always known this was going to be a problem and planned to do it a different way.

So I've been working on trying to drive the pot with a belt instead. With the help of a 3D printer I started working on making a cog that would slide over the back of the hub.

Eleven attempts later, I nailed it. lol


I've used a T2.5 belt and pully from RS. 52 teeth on the hub and 40 on the pot, I did this to make the pot that little bit more sensitive, don't need the arm to rotate the full 180.

I'm using a 180 hall affect pot, there's no stop on the pot so if my rig throws a wobbly the arm can rotate as much as it wants without damaging anything. Also printed a bracket to hold the pot




May rework the bracket, but it works for the time being! So now I just need to try and get the new Simtools working!!!

I forgot to say, there's no backlash on the belt at all!

video in action soon ?

really curious to see weight bearing tests. I dont trust the strength of the arms you have extending to the frame from your motor arms. I also feel that you sideways lateral movement is going to lack power to bring you back to center. THose appear to be somewhere around 25:1 motors based on the speed and I would think you would want to be closer to 60/90:1 for the weight and momentum you will be trying to rebound from. Looks cool so dont think im just bashing here, just calling out from experience.

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Hi @shannonb1
The arms are anti roll bar drop links from a Ford KA, £8 a pair from good old eBay
My thinking is that when you hit a pot hole at 50 mph this little link stands up to it no worries! All its strength is in push and pull, I'm not getting out the calculator!
But so far they've held up pretty well!
My father has been helping with the test driving and has been putting it through it's paces rather enthusiastically!!!

The motors do lack a bit but I think I may need some better controllers IBT-2 are meant to be good for 43A but I have a 35A fuse supplying both and it hasn't blown yet, so I may well be able to throw some more current at it yet, after about 30mins the motors are only marginally warm. Also I'm only running the front two motors at the moment, when I'm happy I'll start with the back ones, will post a video very soon.

Magnifique travail qui devrait conduire à un système performant !
Magnificent work that should lead to an efficient system!

Anyone doubting power I had 13.5amp 125w 12v motors on a 15:1 gearboxs running my 6DOF. Maybe you possibly will need a couple of 100nm gas struts at most but deffo try without first.

Althoigh I think you will have plenty enough power in the motors/gears but you really seriously absolutely need to look at getting some sabertooths.

I detest those IBT's they couldn't lift rat sh1t off the floor. That's just my opinion which doesn't mean much lol

Really good build BTW quality work

Are you going to post any videos of a user on while testing? Love to see that.

@MWB Those pots will fail i had a similar hook up in testing and the bearing in the pot fails everytime. instead try this aproach.
https://www.xsimulator.net/communit...w-arduino-and-mm-smc3.8479/page-5#post-111392

Those are the Hall effect's we all use, they don't have a bearing but rather a Bronze bushing.

semantics

As promised, some footage of my rig in action!
I'm only running the front two motors at the moment

"Couldn't lift rat sh1t" lol love it

I haven't been able to mesure peek current being pulled through the IBT's yet. But am very tempted with the Sabertooths. Is it these ones you're using on your rig?


Sabertooth Dual 60A. I've been looking at the 2x32A ones, but then I'm thinking should I future proof and just go 60A

Anyway thanks for the compliment, means a lot coming from you mate, your rigs immense!!!

Is that a GT2 belt your using? I found with the larger pulleys, you only need very little tension on the belt, because there are so many teeth in contact at one time, also I found the T2.5 belts to be made of almost an elastic material, so although it looks like it, there really isn't that much tension on my belts, but thanks for the heads up, I will keep an eye out, and let you know how I get on.