6DOF Costs?

Do you mean they wear out?

I think the way to go is DC brushless motors...I just have to find some that aren't too crazy expensive. The big thing is I'm not exactly sure how much torque is needed...I guess if I get one through a worm gear then depending on the gearing the motor can be significantly less torque. But those are seeming to be too terribly cheap as well? I want to do it right, and I don't mind spending the money it just might have to be over a longer period of time then I want.

Even doing a 2DOF setup with the SCN5's isn't too cheap. Those SCN5's can be 300-400 a piece it seems. It would be nice if you could find wiper motors with specs on them lol.

Brushless DC motors are indeed nice but their extra price and complexity doesn't justify the marginal benefits.
I haven't seen brushless motors used in a closed loop positioning system.

As I said before, you can make compromises with speed and torque. Increasing the gear ratio will give you more torque, but speed will suffer using the same motor. Same thing with the length of the arm in a servo application. Longer the servo arm, faster the end moves over a greater distance, but the torque will be reduced. Further more if you don't have enough torque, your acceleration will suffer.

If you consider what you get with the SCN5's, they are not that expensive for $400. They already have the stepper driver, encoders, positioning system, and also the mechanical construction, all ready to take serial commands. Any of the other home built solutions will cost nearly as much per axis by the time you collect all this.

But the SCN5's aren't recommended for a 6DOF setup right? I think I read they don't do so well with horizontal force.

Right, they cannot take loads from the side. Having said that, with extra precautions, lot of testing and proper geometry, they could work well for lighter loads. There have been discussion about this and the research is ongoing.

i checked out the site that was mentioned earlier http://www.progressiveautomations.com and i was able to have them manufacture me a faster unit. 1.5 inches a second, works well and haven't run into any issues with them thus far.

forgot to mention it was a 200lbs unit with 25% duty cycle

Hi there

I was reading your board for some months now, but today i register.
Currently, I am in the more or less same situation as the thread creator.
No childs, but the wife is angry about it anyway

So i am also in thinking about a 6dof plattform.
I evaluate all the prices now for a few weeks.

1. Out of this board, it seems pneumatic is crap
2. For me, hydraulic is just to expensive. I am not willing to pay that much. Because then really i could buy a force dynamic 301 or something similar.
3. Then e-actuators, i just dont find anything fast, strong and cheap enough

Basicly i decided to give a try with a wiper motor and some onw build linear actor.
Right now, i thinking about buying one set of this things
http://www.maedler.de/Article/24166632.aspx
http://www.maedler.de/Article/24102800.aspx
http://www.maedler.de/Article/62522000.aspx
http://www.maedler.de/Article/63002000.aspx
http://www.pollin.de/shop/dt/MDQ1OTg2OT ... P_24V.html
and some onw metal stuff around. It seems to be one of the cheapest solutions i have right now.

I might be a lucky guy that i have some metalworker as my friends. I have an 4 years education as a carpenter. Then did a change and working as a software developer for about 8 years now. So hopefully I am not in such a bad position to be able to do that

Just to give you my results of the last few weeks of digging into that stuff

Hi!

I only just discovered this forum. I thought you might like to see a mini stewart platform I made recently.

http://www.youtube.com/watch?v=xCn-Wjr-4c8

Have you considered using electric stepper motors instead of linear actuators, as I've done? Stepper motors are a more readily available (read: cheaper and easier to work with). You can get all the mechanical parts from an auto shop and all the electrics & motors from anyone who specializes in CNC machines (probably online). As long as you're not scared by a little math, the challenge is doable.