Showroom **RIP** - 6DOF project using 12v DC Motors, Sabertooth 2x60's (was MM's) and Arduinos + OSW

ok sorry

That's probably the cause of power being drawn on idle as ball screws are easily back-driven, so the actuators are continuously battling the weight above them. It would seem likely that the addition of gas struts would help in that regard. In terms of holding power a lead screw would be better but then the trade off is higher friction.

Hope to start building my own actuators as this rig of yours looks like a heap of fun!

No they don't move, I can sit on the rig with no power and the rig is solid it doesn't move.

The problem is the power is constantly there because of the reason I explained above

The cruise was great as always - actually on leave until early January, so hopefully can finish off allot of projects that I have on the books. I use 3 x 1100mm/100N gas struts which only lift 10kg each, but I think they are a good compromise for balancing the rig without dampening the movement too much. Talking about motors - don't know if this is relevant but, I did tests on one of Motion Dynamics industrial spec motors early on when I was building my actuators (see picture below from my thread), which were quite a bit larger (size wise) than the motors I ended up going with, but found in testing that they would not track properly - from what I could tell it seemed to be how the motor was wound and there seemed to be a bigger gap between the magnetic poles when it turned (it could not turn in small increments like my other motors - so would stop either just past or before the target). Don't know if that may be relevant to your motors or not - but figured worth mentioning?

Hi Silentchill
You have 1.9mtr hight, did you spred your actuators to lower youre sim.
There is much more force needed to create heave from the lowest point when actuaters are allmost horizontal,than if they stand on a 45 degrade angle.
I am only looking mechanical.
Sorry for the bad english.

Hi @SilentChill - just noticed from @wannabeaflyer2 comment that you used rose joints on the lower frame - are they also on the upper frame - if so, do you have issues with the actuators twisting? From your video the actuator on the right is twisting quite a bit - not good for tracking.

These motors have 4 brushes rather than the usual 2 I dont know if that would affect it or not? Perhaps taking 2 opposite brushes out may smooth it out ? I dunno lol

Yes it is twisting, I need to weld my UV joints on to the bottom.

Yes I did when in the centre position the actuators are at 45 degrees, this is a limitation I cannot get past unfortunately.

You could look with some wight upon seat ,lower it slowly and look what the current does.
Look at this http://www.simprojects.nl/diy_motion_platform_v.htm

-Mmm don't think it would be a good idea to remove the brushes - Yea I thought you had purchased UV joints. Funny thing I have noticed some so called professional sims coming out of many countries which have used rose joints on both top and bottom of their actuators - they twist so much that you can sometimes hear them smashing into the joints stops - says so much for the quality of the engineers behind them.
One of my favorites - @noorbeast will remember him - I did mention it too him before we worked out he was not a DIYer , he did not understand what I was talking about...


- his later 'professional' sim still uses this setup


I know, I know only an engineer could find this funny...

Oh well after a good few stages on Dirt another of my couplers sheared in half. I have ordered new ones to replace all of the cheapo ones that I bought.

Always something else grrrrr it was running sweet too

Ah. I read that like, with your finger, you are able to move the rig up and down.

Hi mate what type of couplers u using flexi or cush drive ?

Definitely keep all four brushes. Four is always better than two anyway and two would be less smooth, not more. Besides, when a motor is designed for four brushes you can't take any out. This would leave power being applied to only 180 degrees on the armature or in other words just half of it. On two brush motors the opposite brush is the opposite polarity but on four brush motors the opposite brush is the same polarity. So taking two out would leave two brushes at 90 degree angles to each other, not 180 degrees like in two brush motors.

Sh!t ones !!!!!! hahaha I had these installed


I have now sheared 2 of these lol I always go cheap first and no I will never learn

I have replaced the first one with one of these and I have order 8 more just in case

Yeah I decided against it, my stupid mind works in stupid ways

Haha sorry I should of been more specific, I can turn the ballscrew with my finger and thumb

hi @SilentChill yep the 2nd one would be the better option , the 1st will quite literaly unwind itself which is what you found .. just made for lighter loads ..

And if the brand name of those couplers is any indication you will be very satisfied with them.

Hi @SilentChill
you have a fantastic project lots of ups and downs, but it's great to see that you have more ups
i could learn a lot, so thanks for being so detailed.
atm i have one question. did you use sound transducers in your first version? did you install them also in your recent build? I know, that they shake with another frequency, than the actuators ever could, but do they add another step in realism?