Linear Actuators

[dutchcedar]

Hey, there are a few of us on this forum looking to make things in our 'puters move and I was wondering if anyone has found any good linear actuators that are reasonable, decent looking and can operate on 12V. :blink:

[fillip]

Define reasonable.

and what length stroke/throw do you want?

[dutchcedar]

^^^ Good questions... no good answers. The best prices I've found are on eBay, but there aren't many small units there. Less than $100. would be a good starting point.

A 2" stroke that can push 30# could be made to do the job... <_<

[fillip]

Check back in a couple of mins while I raid my bookmarks...

Almost bang on spec' but just a little pricey @ $105 - http://www.aeicomp.com/Detail.asp?Product_ID=301.100_6179E

IMD3 meet your requirements though it's a European company, but you're looking @ 40 EUROS - http://www.transmotec.com/product.asp?cat=6

40mm stroke @ just over £10 so pretty cheap, but no idea about the load. Would need to email them. - http://www.robotstoreuk.com/MOTORS/MOTORS/MFA/MOTORS-page4.htm

This is far too long so unless you can cut it down in some way it's prb useless, plus it pushes a huge load http://wizdforums.co.uk/images/smilies/ph34r.gif but it's a reasonable price for what it does - http://www.bullnet.co.uk/shops/test/channel_master_linear_actuator_m.htm

Norgren.com have loads but didn't get to check prices



Hope that sets you off.

[dutchcedar]

Hey, big thanks... that first one is spot on!!! B)

[fillip]

Hey, big thanks... that first one is spot on!!! B)
Glad to be of assistance

[Vis]

Hmmm. Are you thinking what I'm thinking? :cool:

[dutchcedar]

^^^ That all depends on what you're thinkin'... :lol:

[Da_Rude_Baboon]

[pinky and the brain]where will we get a pair of rubber pants that small? [/pinky and the brain]

[fillip]

[pinky and the brain]where will we get a pair of rubber pants that small? [/pinky and the brain]
ROFL!! http://wizdforums.co.uk/images/smilies/laugh.gif

[scopEDog]

Autoloc Linear Actuators (http://www.autoloc.com/products/linearactuator.lasso)

I picked up 2 of these for my project, 8 inch stroke and supposed to be durable as hell. I even created a simple sketchup (http://www.scopeworks.org/files/autolocla6-la8.skp) of them a while back, should be pretty accurate..just a bit crude :)

[Vis]

This may be a stupid question, mechanical engineering isn't my strong point, but would two linear actuators working together lift twice the weight?

[Starbuck3733T]

In theory and providing that the weight they lifted would not exceed their capabilities as a team.

[Vis]

Ok thanks. My problem is that if I decide to go down this route I'll have the actuator attachment points being very close to a pivot point lifting almost the entire assembly. What I really need is short stroke and high capacity which presumably would translate to a very fine threaded screw on the actuator.

[dutchcedar]

^^^ Vis, I'm tapping my old day mechanical engineering prowess here, so it may be a bit tainted, but...

The load capacity of an electric linear actuator can be doubled by reducing its speed by half through gearing... so selection of a short throw actuator is critical... you're speaking of a situation similar to my own here, so the equations are kinda fresh on my fuzzy brain.

In my case, I want to lift a hinged, 13" long object 90 degrees in about five or six seconds... with a throw on the lever that's as short as possible... the load is roughly five pounds, which gets multiplied by a factor of the ratio of the stroke length over the load length, at least at first (it will reduce as the load is put in motion)... the challenge seems to be to find a short throw actuator that's slow enough and small enough and strong enough.

I'm still head scratching, but the actuator won't be needed right away, just have to make sure there's room for it and all the linkage schtuff. B)

Getting two actuators to run in synch would be a tough one. I would suggest that you avoid that like the plague. If one gets ahead of the other, you may have a binding up problem... not fun. :wacko:


scopE... them's are nice... B)

[ỒĊBłůē]

... the challenge seems to be to find a short throw actuator that's slow enough and small enough and strong enough.
Couldn't you hide/disguise a counterbalance weight the other side of the hinge to reduce the load?

[dutchcedar]

Couldn't you hide/disguise a counterbalance weight the other side of the hinge to reduce the load?No... but it appears the weight is not really a problem... most of these actuators are quite powerful.

[Vis]

I'm assuming you're going for something like a "gullwing" side panel, Dutch? I'd have to lift a hell of a lot more than that. Right now it isn't looking very feasible. Unfortunately I don't think my mech will be standing up when I hit the power button. Maybe next time.

[Starbuck3733T]

Dumb question, how are the actuators triggered? Just apply 12V?

Cuz if thats the case and you need to slow it down, just PWM the bastard.

[BigBen2k]

Dumb question, how are the actuators triggered? Just apply 12V?

Cuz if thats the case and you need to slow it down, just PWM the bastard. Right on.

Also, you'll need to isolate the circuit, if you plan to use the same PSU as your PC.

edit: need more info?
Here's a couple of diagrams for a DC pump, with the protection circuitry:
(the diode is an 1N4001, the caps I used are 0.1, 0.01 uF and 1 uF.)
(the second diagram has a fuse, in case the pump jammed)

[Starbuck3733T]

The model that he's looking at buying (he PM'd me) doesn't look that simple.

http://www.ultramotion.com/products/actuator_info.php?ac=1&mt=14&ls=2&st=1&nm=10&bm=0&tm=5&ma=0&sw=0&pt=1&ab=1

http://www.ultramotion.com/products/digitApp.html

[Vis]

I may not know much about engineering but I know that wont work. You have to reduce the speed by gearing. If you halve the speed with gears then the actuator is working half as hard but for twice as long and hence doing the same amount of work to move from point a to point b. Same principle as a pulley. You still do as much work as if you lift the weight directly but you don't have to do it over so short a distance.

[redfox]

hey dutch, did u make the badass1 and 2 cases? those are completely outrageous. awesome design man !

[ksuechuc]

couldn't he use a pneumatic actuator??

I was thinking of doing a gullwing today and was wondering where I could get an acutator as well...pneumatic should be cheaper and smaller right?

[ỒĊBłůē]

So long as you have either a suitable compressed air supply available near your case, or some kind of rechargable gas canister to run them off, then sure :D

Welcome to WizD ksuechuc :magic:

Can you fill in your Country in your profile, please? :thumb:

[dutchcedar]

couldn't he use a pneumatic actuator??

I was thinking of doing a gullwing today and was wondering where I could get an acutator as well...pneumatic should be cheaper and smaller right?You'll have one heck of a time controlling the speed of a pneumatic cylinder (actuator).

[ỒĊBłůē]

I think you'd possibly just about get away with it using low pressure, some of those mini regulator-fittings and a cushion on the cylinders :shrug:

[ksuechuc]

well i wasnt thinking of something with an external source... something contained like a gas shock or like what some cars have to keep the hood or trunk open...

[2JSC]

well i wasnt thinking of something with an external source... something contained like a gas shock or like what some cars have to keep the hood or trunk open...

THat is quite possible, and most of those are gass filled, the only problem is though. Most are rated for 25-40lbs of lifting force, and they would pop the hinge open so fast it might hurt something on the case. If you were to find some that work for a window off a truck camper with a lighter lift capacity then it might work, you'd just need some latches to hold the case down so that it doesn't rise on its own.... but I think the electrical/mechanical noise is a LOT better than a pshhhhhhhhhssshhht. :lol:

[drnedatsnov]

I have been researching micro acuators and have found www.firgelli.com (http://www.firgelli.com)
they specialize in micro actuation and will make custom applications. They are pencil size or smaller.

[wallydogking]

40mm stroke @ just over £10 so pretty cheap, but no idea about the load. Would need to email them. - http://www.robotstoreuk.com/MOTORS/MOTORS/MFA/MOTORS-page4.htm


I've just tried to order one of these, and had the misfortune to have to take it up with PayPal as a dispute. Don't even bother trying to use these jokers. Its been a nightmare from start to finish. :mad:

[mroing]

The company Artektron AB from Sweden have some nice actuators.

http://base.google.com/base/s2?hl=en&gl=us&view=List&authorid=4406546
(http://base.google.com/base/s2?hl=en&gl=us&view=List&authorid=4406546)
Linear Actuators from Artektron (http://www.artektron.se/)

Click for pic (http://www.artektron.se/images/E500actuator.jpg)

[donkeyot]

I'm trying to build a laser scanner and require a low cost linear actuator with a track ideally and ball screw, or maybe just a stepper motor controlled linear actuator, I've checked out your threads but am looking ideally for a stroke length of about 1 metre can anyone help?

[mikeiver]

You might be better off using a toothed belt for that duty. They are going to be far cheaper than a ball screw. If you don't need super high accuracy you can try looking for a acme screw, they are fairly cheap and of reasonable accuracy. Here in the USA we have McMaster-Carr. http://www.mcmaster.com (http://www.mcmaster.com/)
If our government ran like they run their business we would not be in the mess we are in now. Very fast shipping and the prices are reasonable considering the depth and breath of stock they have on offer. Both the acme and tooth belt parts can be had form them as well as just about every other thing you might need for your project.

Mike

[donkeyot]

Thanks for that mike interesting site, there is a place in the uk called IGUS that do linear actuators running on a belt cost £380 for a metre stroke, I will have to weigh things up, but should keep me going for a while thanks!
reminds me of roadrunner for some reason acme ? lol

Nick

[mikeiver]

Yep, that was what I thought the first time as well.

You also could use a pair of toothed belts on toothed pulleys at each end tied together with a common shaft on each pair. This is VERY accurate and Repeatable and is in fact used allot for high precision positioning.

Best of luck with it.

Mike

[NhocCuteGirlUK]

Define reasonable.



and what length stroke/throw do you want?
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