How about our community Kickstarts a Linear Actuator

Hi All

Our community helps each other with their experience and knowledge which is great, so how about we put our heads together and come up with a design, drawings, and the eventual manufacture of the parts so that our members can source and assemble a DIY linear actuator?

To kickstart this and get the ball rolling

My initial specs would be

1 a universal design to suit 2dof through to a 6dof

2 adaptable motor mounts to suit various motors

3 quiet operation


I have seen a few linear actuator designs on the net, bff, Rolands, and the one that to me that has the most potential, as an easy to assemble diy project is this one.

http://jippes.home.xs4all.nl/hi6sim/MK_IV.html




what do you guys think?

regards Terry

Good idea Telfel!

Let's think about this!

This belt design looks simple indeed. I wonder if the belt can cope with this amount of effort, and how big is the backlash?
Mat

Hi Mat

One of the pictures on the Douwe site I linked to, is a prototype actuator from

http://www.motion-sim.cz/index.php/en

using a toothed belt drive, they have very good motion judging by their videos.

also with Douwe's design the air cylinder can balance the weight which should even up the loading on the belt.

regards Terry

A couple of us are actually in personal development of exactly what you propose, I have one working unit as a test unit, just ramping the speeds to match or better the SCN5 but wont be a DIY project, they will be sold complete, its the end of 2 years of research and development I have endured.

But would strongly back a diy community developed Linear Actutor, but really needs to beat 700mm/s I push out of DC motors with Jrks to worth it I feel.

Ah Matt there is no backlash on ballscrews mate.

in the first link Telfel has posted, you can see the following picture:


and yes, there is backlash on screwballs!
Only specific screwballs or double nuts screwball has no backlash http://www.ebay.com/sch/i.html?_trk...kw=screwball+anti+backlash&_sacat=0&_from=R40

as @eaorobbie says, I am working with him on DIY actuators currently. And I will post ALL details on the site soon. Just got to get the time to finish them...hopefully within a few weeks

From my DIY CNC router table experience I can say that there is indeed backlash on ball screws. You can of course greatly reduce backlash but like anything else, you have to throw more money at it.

Thanks Guys.
I stand corrected , I dont bother looking at cheap stuff, gunna do why would you compromise the units by adding backlash, poor design to me, most I have looked into didn't have any, my test unit has zero backlash and actually was only $19 from china, lol.
This is how we all learn.

Hi Robbie

I thought a community project would have ideas, contacts for supplies, and manufacturing facilities on each continent, thus you don't have high shipping costs.
The other advantage of diy parts and self assembly kits is the injury or accident liability is with the builder.

regards Terry

If a ballscrew is having backlash ore not,depents on his precision class.
c1/c3/c5 class ballscrews have no backlash and c7 class and higher have backlash.
c7 class is mostly sold on ebay and have 0,05 mm backlash
regards Ad

We have planned to share , well its been a 3 month project to come up with a method and principle that would work for most DIY builders , don't want to post something thats a white elephant and never works well.

Sorry @RaceRay the unit I spoke about I can not share it was built for another person on a commercial level, I got it running and he disappeared to be fair to his personal investment I had shelved it to protect his interest only. This is not a BBF Clone but an industrial quality linear actuator. I had built in china for him, he paid for but never returned.

Here a complete video explaining how to build a belt linear actuator:


and a 6 DOF running with 6 DIY linear actuators:


very nice, indeed!

Hi Mat

I have been following Rolands work, very clever ideas, just seems a lot of work x 6,

I think the Douwe actuator looks a lot more diy friendly, and using adjustable air pressure to balance the weight seems an easy way to adjust for different weights of users, equipment. using the air cylinder as the ram is genius.

I don't feel the the drive belt slack will be a problem, the image on the Douwe site is an early prototype, once tensioned. Car cam belts dont really stretch, and the design would allow easy replacement.

I did read the history of Motion Sim cz, and the development of their belt driven actuator, using powerful ac drive motors.

regards Terry

Hi Telfel!

Can you tell us what do you intend to design: an actuator for flight sim or for racing sim ?
as the specs are not similar
yours

Hi
Just bouncing a few idea's around, to see what feedback we get.
I thought for a
1, seat mover short actuator no air balacing (racing)
2, 3dof short actuator air balancing (racing or flight depending on motor pulley gearing
3, 6 dof long actuator air balancing (flight)

regards Terry

I am in the process of building these as per Ian at BFF http://www.xsimulator.net/community...s-by-ian-bff-shortened-by-me.5279/#post-51818
I will keep everyone informed.
But using that basic design a ball screw could be added instead of a chain, but I am going as per the plans. And mine will be 200mm long, not 400mm long.
@telfel , are you the "airbag" sim builder?

Hi Dave
Nah I'm the dirt bag builder lol

Look forward to seeing your prototype,

At the moment i'm building a 6dof wormgear, crank arm sim,

I will give the linear a go after that, I was thinking of getting the parts manufactured and then the diy parts just have to be assembled

Regards Terry