Linear Actuator Designs ...

I've just got this FB pot idea for "linear motion tiny available space use" and wanted to share it ...

Components :
-2 m. spring measuring tape .
-10k Ohm 10 turns pot .
-Suitable dial knob for the pot axle attaching .
-Hot glue gun [epoxy resin is preferred] .

Concept :
converting the linear 2m. tape movement into a circular rotation that can be measured by the 10 turns FB pot ...

step 1- after taking apart the tape ... make a big hole of a bigger diameter than the knob on the "spring free" plastic side .
step 2- spare the plastic center hole for reattaching the "center spring screw support" back in place .

step 3- [ The tricky part ] cover the center with a little grease [ Vaseline ] ... Glue the knob centered on top of the rotating wheel " Note that the center screw is fixed to main stationary body and will not be glued with the knob " ...
step 4- Attach and Aline the metal tape start point to the actuator mechanism and calibrate the FB pot turns to the motion range correct length ...
Then tighten the FB axle to the knob side set screw ... then you'll have a linear to circular F.B. that can be used in any place ...

Edit :If you like going into corners in your actuator design use an old adhesive wheel support to corner the metal tape .

FAQ : How to connect potentiometer? ... updated

Hi @yobuddy ...

Wow ... Very inspiring and definitely solves a lot of problems ...
A combination between these two ideas is always a good move guys .

Hi guys ...
this Theo Jansen mechanism S/W might help you in the future when designing any complex linked motion even with gears and chains ... a CAD design S/W is available for download and use here ...
http://blog.rectorsquid.com/linkage-mechanism-designer-and-simulator/



I think something like this next video mechanism could be done easily with it ...

Hi guys, does anyone seen this linear actuator design before? I was wondering how cheap, easy and ultra fast the setup looks like. Does anyone have more information about this build? I can only find videos about...

Yes sure you're right, and the build thread of seattimes Carbon actuators I'm well known.

But his version is more than big and for his 6dof setup. I'm searching for a smart version of diy linear actuators, which are fast, don't make same noise and are not expensive...

Like the ones in the video. So I'm wondering that there is no buildlog of this actuators in our forum... Maybe someone know this guy or company (psi motion)??

Best regards

Ah, the search for the holy Grail... You could try the 'X-Sim' website.

haha, a 6DOF isn't a low cost, no noise, no weight or ghost design. But probably you will find a solution, who knows.

Hi @WowaDriver ... So, If you're not happy with @SeatTime design ...
you may search for more ideas on how they make the z-axis of the CNC ...

@speedy, funny you should mention the Z-Axis of a CNC machine as I am using exactly that for the Heave on my G-seat in my flight simpit. [it is slow...very slow, but works great for flight]

Yah @Historiker ... all based on a screwball threaded rod with different housing ...
for your slow ones you might gain some more speed if you've chosen longer rod bitch or faster motor .

Some affordable designs...



And the Sarrus...

time goes and goes and im be more and more an "expert" in building linear acctuators ... actually i'm searching for motors and find these ones:

http://shop.mat-con.net/E-Motor-Unite-MY6812GR-150W-12V-DC-Walze

For the control i would use 12v12 jrk's and here is me problem... the jrks can handle current amps of 13-14A
These motor will have a rated amp of 14.3 A, ok this should work .... the jrk's can handle peaks of 30A but
this should not be all the time i think...

So i think i would get probs if i will use motors with 200W and a rated amp of 23A or what do you think?

The next step are the pots.... I will need linear multiturn 10kOhm pots with 10-20 turns .... do you have an idea
which one i should use? Does mutliturn pots exists like the hall effect pots without a mechanical stop after the 10-20 turns?

Thanks for reading my problems and for the help!!

Best regards

Has anyone tried using quadrature encoders instead of a timing belt / pot for feedback?

@WowaDriver - the bridge on the JRK 12v12 can actually handle up to around 50A peak and 30A continuous. What limits the 12x12 to 12A continuous is the board size and cooling. (https://www.xsimulator.net/community/threads/jrk-12v12-overheating.10327/#post-133655). There are also potential issues from inductive kickback. While the 12v12 is an amazing circuit, you may want to go another route depending on motor draw. I use the 12v12 and have had great luck, they run cool in my rig with pgsaw motors, and they work great with SimTools.

Also, regular pots and multi-turn pots are expensive and not really designed for these kinds of applications. They can wear out and open up/fail. Limit switches and other protect mechanisms get very important when using standard potentiometers. For whatever it’s worth, I’m a big fan of Hall sensors or encoders. Non-contact pretty much eliminates a lot of other failure modes.

@haribole - https://www.xsimulator.net/communit...starter-announcement.10517/page-6#post-145901 There are other ways but @Thanos has those purpose built for tracking encoders and interfacing with 0-5V feedback systems.

@speedy - That Disney video is amazing!