6dof motion platform ‘lite’

[tzuvela]

Hi ucasdiulbern,

Thanks for the link, but using twice as much motors is exactly the kind of complexity I'm trying to reduce.
If I really have to have more powerful motors, I'll just buy stronger motors.
I think lever has a lot of benefits, so far mostly been used in 2dof simulators.

In theory you could make 2dof by mounting seat directly to a motor shaft and 2 motors would do the job, but pivot point makes it possible to use much smaller engines, I just plan to use the same tried technique from 2dof wiper simulators.
In 2dof setup, two motors share the same pivot point for movement in 2 directions, for 6dof I plan each motor to have it's own pivot point, which should take on some of platform weight.
Also 1/3 lever should help motors as they will always feel just one third of the platform weight.

[esmadja]

I came across a great post yesterday, which goes into all kinds of details on calculations for designing a 3DoF system. In this case a spring is used to take on some of the load.
http://x-sim.de/forum/viewtopic.php?f=3 ... tion#p8184

I was wondering if instead of using a lever or s sping you could use a gas shock;
Either one shock positioned in the middle of the platform;

Gas Shock.jpg (12.87 KiB) Viewed 5562 times

One shock in middle of platform

Or three shocks which would be positioned in between two motors

Gas Shock3.jpg (13.45 KiB) Viewed 5562 times

3 shocks one per pair of motors

The shock could be adjusted based on the expected weight of the platform.

Would the shock dampen the system too much?

[ferslash]

what is a gas-shock, where do you buy it?

best regards

fer

[tronicgr]

what is a gas-shock, where do you buy it?

best regards

fer

http://www.newegg.com/Product/Product.aspx?gclid=CjgKEAjwzIucBRDzjIz9qMOB3TASJABBIwL16oSly15bgJQCS4Uqfmwx6PB4sy7eWO2j2ijzuhTsV_D_BwE&Item=9ATBCKM00C8694&nm_mc=KNC-GoogleAdwords&cm_mmc=KNC-GoogleAdwords-_-pla-_-Shocks%2c+Struts+%26+Suspension+-+Replacement-_-9ATBCKM00C8694&ef_id=UjnaAQAABYPycu5H:20140526204722:s

Look in motor bike store maybe...

[esmadja]

You can also look on Amazon

http://www.amazon.com/SUSPA®-Spring-Strut-Shock-C16-04270/dp/B0041EBSTS/ref=pd_sxp_f_pt/178-3649189-7675532

what is a gas-shock, where do you buy it?

best regards

fer

[Edwardo]

Did this go anywhere? I think the Lever argument was a great idea. I've done a proper study on the Force and Torque side, and my calculations show that with a 370mm lever with a fulcrum at the 300mm point, using one of those beefy 200w, 20Nm gear motors, you can lift 130kg and get total travel of 140mm. That would be taxing the motor but if you could keep your 6dof around ~120kg, it eminently possible to build a 6dof with good travel, that works off a standard powerpoint, with great performance for not much more than 1000 bucks. Maybe a bit more....
I've got a couple of those motors from Motion Dynamics, so tomorrow i'll test if one can lift me (88kg) with a 370mm lever.
Cheers
Ed

[guaridagt]

Nice work buddy!

[tzuvela]

Thanks Edwardo and esmadja,

Sorry for a lack of replies, but I think the project is getting closer to completion now.

I've decided to go with chain and sprocket system, and the prototype I made last year has worked out quite well (ignore the bad welding ):
https://tinyurl.com/mdyrjtg



Does anyone know if I need to buy Supporter Edition or Single license for x-sim.de ?
http://www.x-sim.de/software.php?lang=e ... commercial