linear actuator degrees to full length

[glowytheglowbug]

just a simple place to deposit how many degrees it takes from the input to fully extend and contract a linear actuator (ill be posting them soon)

Edited September 19, 2023 by glowytheglowbug

[glowytheglowbug]

7160 degrees seems to be the limit for a small linear actuator, (7 to 10 studs)   71.6 degrees per millimeter (50x0) (remember to have something tensioning the output or else u get backlash)

9649 degrees seems to be limit for large actuator (11 to 16 studs)   241.225 degrees per millimeter (33x3)

 

 

i cant find my XL :/

Edited September 22, 2023 by glowytheglowbug

[Davidz90]

Interesting. For small LA, 71.6 degrees per mm translates to 0.7955 rotations/mm. In my (less accurate) measurements, I got 0.7911. I couldn't find any technical data sheet that would specify the thread pitch of LA, but the number (1.25698 mm/rotation) is a bit odd; does not give a nice, even number in inches as well (0.04949 inches/rotation). Maybe the actual value is 0.8 rotations/mm and 1.25 mm/rotation, respectively? That is one of the standard thread pitches

Edited September 21, 2023 by Davidz90

[glowytheglowbug]

53 minutes ago, Davidz90 said:

Interesting. For small LA, 71.6 degrees per mm translates to 0.7955 rotations/mm. In my (less accurate) measurements, I got 0.7911. I couldn't find any technical data sheet that would specify the thread pitch of LA, but the number (1.25698 mm/rotation) is a bit odd; does not give a nice, even number in inches as well (0.04949 inches/rotation). Maybe the actual value is 0.8 rotations/mm and 1.25 mm/rotation, respectively? That is one of the standard thread pitches

measures small again its 7157 degrees so its pretty accurate

[MAB]

9 hours ago, glowytheglowbug said:

7160 degrees seems to be the limit for a small linear actuator, (7 to 10 studs)   71.6 degrees per millimeter (50x0) (remember to have something tensioning the output or else u get backlash)

9649 degrees seems to be limit for large actuator (11 to 16 studs)   37.69 degrees per millimeter (33x3)

 

 

i cant find my XL :/

I thought they all have the same degrees per mm extension ratio. As shown in the speed section of Sariel's video...

 

[glowytheglowbug]

6 hours ago, MAB said:

I thought they all have the same degrees per mm extension ratio. As shown in the speed section of Sariel's video...

ooh thats interesting i have to check how many degrees to LA length again for the large actuator (i might have gotten a different reading from using a slightly damaged actuator)

Edited September 22, 2023 by glowytheglowbug
Removed quoted video. (more words now)

[Milan]

53 minutes ago, glowytheglowbug said:

ooh thats interesting 

Please do not quote videos and images from the same page, and please use proper punctuation and capital letters.
Thanks.

[Lego Tom]

14 hours ago, MAB said:

I thought they all have the same degrees per mm extension ratio. As shown in the speed section of Sariel's video...

That would stand to reason since I believe they all use the same size thread. Thus, it wouldn't matter how long the actuator was, it would expand/contract at the same rate. A nut on a 5mm bolt will travel the same distance with 10 turns of the nut whether the bolt is 15mm long or a 150.

Edited September 22, 2023 by Milan
Please do not quote images and videos from the same page.

[glowytheglowbug]

4 hours ago, Lego Tom said:

That would stand to reason since I believe they all use the same size thread. Thus, it wouldn't matter how long the actuator was, it would expand/contract at the same rate. A nut on a 5mm bolt will travel the same distance with 10 turns of the nut whether the bolt is 15mm long or a 150.

by that logic im guessing a XL actuator's degrees per mm can be gotten from that measurement ill continue to test my actuators and see if they work that way



small actuator = 7112retract , 7226extend, 7144retract, 7187extend, 7169retract, 7151extend

 

large actuator = 9703 extend, 9694retract, 9689 extend, 9709retract, 9689 retract , 9665 extend

 

these are 5 readings i got from testing (theres prob like 10-20 degrees error since it relies on me waiting till the actuators clutches provinde enough torque for me to see movement on the output)

Edited September 22, 2023 by glowytheglowbug

[recklessGlitch]

On 9/21/2023 at 4:06 PM, Davidz90 said:

Interesting. For small LA, 71.6 degrees per mm translates to 0.7955 rotations/mm. In my (less accurate) measurements, I got 0.7911. I couldn't find any technical data sheet that would specify the thread pitch of LA, but the number (1.25698 mm/rotation) is a bit odd; does not give a nice, even number in inches as well (0.04949 inches/rotation). Maybe the actual value is 0.8 rotations/mm and 1.25 mm/rotation, respectively? That is one of the standard thread pitches

excuse me ... what? Last Time I checked a full rotation had 360°,
so if (accuracy?) it has 71,6° per mm that means 71,6 °/mm / 360 °/rot = 0.2 rot/mm.
You calculated with 90° that is a right angle, as in a quarter rotation, even in the US and UK!

Anyway, LONG linear actuator 40918c01
measured by manual rotation:
43,75 Rotations = 15750°
64mm = 8studs =>
5.5 rot/stud = 0,68 rot/mm
1969 °/stud = 246 °/mm
 

Edited May 9, 2024 by recklessGlitch

[Davidz90]

5 hours ago, recklessGlitch said:

excuse me ... what? Last Time I checked a full rotation had 360°,

Of course you are right. I don't know what I meant here, tbh.

Tested it again now, small linear actuator did 19.75 rotations for full extension (3 studs = 23.4 mm) so 0.84 rotations/mm.

[recklessGlitch]

On 5/9/2024 at 8:45 PM, Davidz90 said:

Of course you are right. I don't know what I meant here, tbh.

Tested it again now, small linear actuator did 19.75 rotations for full extension (3 studs = 23.4 mm) so 0.84 rotations/mm.

well with a symetrical part, like the connector at the end of the actuator's bar - maximum rotational offset would be 90°, so then it's rotated ;)
anyway, thanks, that was the information I intended to get.