Project Battle

Hundreds of hours of research and nothing........Have you tried a different approach to the problem other that a request here?

Yes I have, but since this was a highly recommend site for good advice I was very positive that I would be given some good advice, guess I started WW3???

I'm sure people will help, but berating somebody (on your first day as a member of this board) for giving good advise didn't help.

You need to give more details. Does the actuator have to stop at precise positions? Do you intend to build the timers yourself? What initiates it? The list goes on but its only you that can give the information.

bet you get asked

a/ whats a PLC

b/ how do i program it

Actually that is a really good question. I take so much for granted. How do I describe Relay Ladder Logic to someone that has no exposure to this means of describing electrical control. To me it is intuitive, but for someone with no knowledge of the fundamental concepts, it may be a challenge.

Once upon a time I was a simple tool maker. I had an idea of a machine that I wanted to build, but I didn't know how to control this machine. That is how I learned electronics and control theory.

In this case, the OP has an idea of what he wants to do. The technology is out there and the basic concepts are simple. I am hoping that he can discover what he needs to know with a push in the right direction. Any more questions and we are here to help.

For the record I know what PLCs are and also know how to program them.

Then why did you need to ask the question in your OP?

most actuators electrical, pneuatic or hydraulic are available with limit switches that detect the position of the actuator.

If you read his previous post ... he already has a LA-30 linak linear actuator.

I'm not clear on what you wish to build.

If you have researched everything for linear actuators, you have probably found these devices, but they are amazing.

http://www.amacoil.com/
http://www.amacoil.com/rolling-ring.html
http://www.amacoil.com/rolling-ring-animation.html

please describe your application more fully, and provide pictures/sketches if you can.

Chris

Thank you for the suggested links, but I already was there and none of there help would be useful. I am also sorry I only gave bits and pieces of info.

ok dude you're 0 for 2 on threads

do you want ideas or not?

If you can't tell us the nature of the problem, how are we possibly going to offer potential solutions?

you want something that goes up & down, after pushing a button

24vdc so it probably is going to run off the battery pack on an electric wheelchair or scooter

we need: the full exact sequence of operation

how far it is going to move

how much weight it is going to move

how fast it needs to move

how often it is going to move

what kind of potential for danger is there?

what kind of overload protection is already included with the actuator? What makes this the right venue for this query?

why are most so critical of this OP - only one person gave any assistance/ advice. Granted the OP may lack certain skills at this stage but how on earth is the OP going to learn. The usual band of brothers are joining forces once more to put down this OP (for no apparent reason). Unlike the band of brothers, this OP and the rest of us mere mortals we were not born knowing everything.

PS I have a different name for the band of brothers but I am almost certain that Admin would delete it if I posted it, however a hint may help: Rearrange the letters in the last word to find the answer "Shower of eesmkrrhocftu"

Because this is his second post regarding the same thing. He says in a previous post.

'This is a projhect for a hanicap person. The details of which I am not at liberty to discuss.' ... NOT AT LIBERTY TO DISCUSS? WTF?

& 'It is a custom project and there is know controller out there that will work so I am forced to build one.' ... yet he has a LA-30 Linak and of course Linak doesn't know how to control them, they just sell the stuff right? WTF? who misspells the word NO? That should give you a clue right there!

& 'I don't have the socket, and was unsure how the blades of the relay could be wired directly into a circuit. I am far from un-qualified, I just haven't done this type up hook before.' ... Using a socket relay but no socket ... but is far from unqualified. FAR FROM UNQUALIFIED? LMFAO

Here we have someone, who is misrepresenting his abilities and is going to wind-up hurting someone else.

News at 11 ... man has head torn off while using homemade wheelchair device. Builder/designer who is 'far from unqualified', blames CR4 members for bad design.

I'm a relatively new member and not in any 'clik' and you should recognized when someone is over their head ... he was advised to get profession help and that is the best advice ... that he shows up with another post, only illustrates his potential to hurt someone. AND HE TITLES THE POST ... PROJECT BATTLE? ... WTF?

Your description of the problem lacks some clarity. However, if you look at vibration isolation tables, you will find a class of tables with self leveling table tops. These tables use pneumatic actuators to control the height of each corner of the table top. Each of the actuators has a small adjustable servo-valve connected to it that measures the table top height above each of the four legs. When a load is placed on the table, the four pneumatic cylinders are compressed by an amount that depends on the weight and its location. The servo valves respond by either adding or venting air from each cylinder to keep the top level. The system is critically damped and used to support sensitive equipment in noisy environments.

Wow, I was referred to this forum by a friend for being a good place to seek advice. For those of you that have given advice thank you. For those of you that have berated me, you should be ashamed. I am degreed Engineer, but have little experience with building electrical circuits, still in the learning phase. The LA-30 actuator I am using is only for the prototyping phase. I am going to use a LA-22 for the completed unit. The 24vdc power supply has built in surge protection. The voltage needs to be constant throughout the cycle. And if I may be more clear the cycle needs to start when a magnetic switch is activated, the cycle begins to move down hopefully with the speed of 28 mm a/second. The at the end of the down cycle when the actuator reaches it fullest extension needs to pause for 2 seconds then have the power switch by a relay into the up cycle until it reaches the fully enclosed position, then the power can be shut off.I have several different timers, diodes and etc but I was thinking by asking I would receive advice of which combination to use. Example use tow 555 timers with two 12vdc DPDT relays and a voltage regulator that would power the time unit by still give the appropriate voltage to the actuator. Be that this is for a disabled veteran I am doing this as a favor and on a very limit budget. This is not a wheelchair mod or anything that will put his life or for that matter anyones else's life in danger, I do have a heart. He would like the unit as small as possible so that I guess is my biggest challenge. I know it can be done. The entire unit, of the actuator, and circuit board need to fit into a enclosure of 4 inches by 3 inches.

On a side note note as far as my intelligence and capabilities I just figured asking for help was more important than using the spell checker. Those of you who cut me down and insulted me. Well all I can say is that if you would have put as much effort into helping me rather than cutting me down maybe i would be a little closer to my objective. As I read the threads this morning I was appalled at how mean several of you got. I really hope you don't consider yourselves to be professionals, because the manner in which some of those threads were worded, were the actions of very little immature childish adults who spent too much time spending mommy and daddy money than actually cutting in in the real word. I served in the military be I myself was injured and became disabled. Before you open you mouth think before you speak and if you don't have any helpful and suggestive comments don't reply. I have every right to be and say what I do because I earned the right with my own blood, sweat and tears. Think about that next time you are unsure who you are commenting to. As for the rest who have actually given some good advice, thank you and I really look forward to more positive input. Please leave the negative remarks for Facebook and Twitter. If more info is needed I'll talk to my client and see how much he is safe with given. Thank you again.

Hi Gene, thanks for providing more information.

you can do this project with out building a circuit board, you can do it with all plug in components here's a Timer relay for your pause mid stroke

but 4 relays, the timer, plug in bases & play around with it until you get the sequence of operations you want

Thank you and I will try it.

Starting from the initial position, how long is the 28 mm/s downstroke? On the upstroke, does this return to the initial position, or does it go beyond? How much force? I am not familiar with the Linak series; does this actuator fit within the 4" x 3" envelope? What is the third (length?) dimension of the envelope? To get the correct speed, does the actuator need the full 24vdc, or does the voltage need to be regulated downward?

A more complete narrative, together with the actuator specs, would be helpful.

Alas ... from his original post ... he is not at liberty to say ... I'm not at liberty to help ... until he has a change of heart and admits that most of the comments were due to his attitude in his original post. You don't just piss off a few people then repost the same thing and not expect some people to remember the previous post.

The actuator has 6 inch stroke. Yes after the complete down cycle it will return fully to closed position. The force of the unit is measure at 400n. The actuator will not fit within the 4x3 area that is where I am hoping to putting the controller unit. The complete measurements will be 4x3x14. Yes the actuator needes the full 24vdc for a complete cycle of up and down.

Okay enough is enough. I admit I got caught up by all the bickering myself. I am very serious when I am asking for suggestions. So once again I thank you to all of those who have given advice or who has asked for more info. I will no longer reply to the off remarks, and only reply to the helpful ones. I may have exaggerated the time spent researching but I know it has been many long days and some nights online looking for a cheap solution. My client had me sign a confidentiality agreement, so before I can give out any info I need to ask him before to find out if he is comfortable with what I will give out. I was asking because he had read something on the 555 timers and how they could be used to control timing sequences. My main question refers to all the elements out there and maybe finding someone who is a guru at electronics and could say7y that two 555 times inconjunction with etc. could be used along with ... to get the required cycle performance. I know the LA-30 is far from the performance of the newer LA-22 but I was given the LA-30 by my client from an old junk wheelchair he had laying around. Since he has a very limited income he suggested that using it for the prototyping would be the cost effective thing to do as a new LA-22 is over a couple hundred dollars. I have played around with electronics but nothing that involves any kind of timer. And I guess you can call me what you like but I guess I am just having a major brain melt. I can see the complete circuit in my head I just can't complete on the actual board.

OK let's start over again.

Initiation (PB or prox sw)

Sequence of operation IE DOWN 45cm or 5 secs, UP 20cm or what ever time, delay X seconds.

This is what we need to help you!

We can't help if we don't have the full information!

You've annoyed every one on this board with your attitude, there's now a lifeline in front of you, if only you take it up!

Hey Tony - speak for yourself

I'm not annoyed at the OP, nor would it appear is Garthh or a few others, by the advice given so far.

"confused" maybe - at the reactions to a post no different to all the other "I don't know how to do this part of my project" ones - which, oddly - always seem to be written by people who don't know about the field, so don't know what' relevant to ask.

However - to the OP - it seems to me this is a 'rate of change' goal rather than a simple timing exercise. You need to describe what sort of action the thing is aimed at achieving and the load characteristics, so folks can grasp what kind of controller you actually need.

But if it is a straight timer you want - there are many inexpensive integrated relay types - as Garthh said.

You're right, I'm not mad at the op.

But I do notice when things don't add up & will point it out

this is the nature of CR4 It's going to be nearly impossible to come up with a solution, to a problem that we can't be told :D

Less is more, there are tons of off the shelf 24vdc devices, that are easy to program, with dipswitches or jumpers

If you have any ideas of any off the shelf items that may work please pass them on, ie. the websites there available or even a item description. I am human and might have overlooked something, thank you for your reply.

OK I'll rephrase that to "a lot of people".

It still boils down to we need to know the sequence of operation.

I once found myself in a ridiculous situation where I was asked to repair a machine, but couldn't be told the sequence due to "The Official Secrets Act". That one I walked away from, "get someone in that can be trusted with the information then".

In all my replies I must of missed that. The cycle will start as a latch switch or other kind of switch is activated. This will then allow the power to drive the actuator in a down cycle at the full speed of that actuator being used, in the LA-22 case it would be 28mm a second. The when the actuator reaches it's fully extended position of 6 inches the unit power will be pause for say 2-3 seconds to allow the power to be transfered in such a way that it will reverse the positive and negative back into the actuator and this will then allow the unit to begin it's retraction cycle of 28 mm a second again. It then will proceed with this action until it reaches it full closed position in which time the power will then be cut or turned off. I hope the explains a little better as to what I am trying to achieve if more info is need please ask, and I'll do my best to be as informative as I can in order to receive the suggests that might be able to help me to come up with a resolution to my brain farts, thank you for your reply.

The actuator will move as long as power is available won't it ? So when you say "power will pause" what you probably mean is that it is cut-off. After the delay you want (2 sec?), the supply to Linak needs to be reversed to make it go the other way ...

i am sure you will be able to find some hardwired relay logic or PLC to do this easily.

i also think that all Linak actuators have safety limit switches built-in to prevent damage...

I'll try to walk you through, what I'm thinking

S1 {NO [normally open] push button}, sends 24 to R1 [relay 1], power goes through a NC contact on S2 [switch at the end of up stroke]

R1 latches on, M1[motor 1] runs until S2 NC breaks

S2 NO sends power to T1 [timer 1], which engages R2 , power goes through NC contact on S3 [home switch]

when the return stroke is complete S3 breaks...

Parts list

2-relays

1-timer relay

2-position switches, w/NO, NC contacts

1-Start switch

1-E-stop [emergency stop switch, S4], to be wired in series with the power to the motor or entire circuit]

1- fuse [& fuse] holder or circuit breaker it can be more elaborate

depending on the current of the actuator, you may need to wire some of the contacts in parallel

depending on the duty cycle, you may need a quench arc or other device to extend the life of the contacts

you need one NO contact on each relay, so it will latch on once it starts

I suck at drawing & don't have any cocktail napkins handy.....

thank you. I have found similar schematics online. My issues though are how to achieve what you suggested with only the one switch to start off the power cycle. I apologize if I sound stupid. As I have said I am most likely over thinking this or over looking something very simple. Thank you for your reply and I will look at your suggestion and see what I have done in the past, so that I am not duplicating my efforts.

why are you trying to reinvent the wheel?

Linak has a control box [cb8] for the actuator..

there is also an option for an 8 pulse per turn encoder

what is it that you are trying to do that linac doesn't have off the shelf parts for?

if the cost is the issue....

Yes cost is the big issue. If you had a budget of under 200 dollars how would you go about it? Spend all of the money on one item or think outside the box and try to make the money go as far as possible so that more aspects of the project can be encompassed at once?

if there were a budget, I would say that

Further, I would actually fully describe what it was I was trying to do

& I would probably not have most of the budget locked up on an actuator that may or may not be appropriate, for whatever the task might be

but you did register, so I have a better idea of where you are coming from in the future

back to 0 for 2

In several of my last post I explained what I am trying to do, I guess I am confused as to what details you are looking for?

In several of my last post I explained what I am trying to do, I guess I am confused as to what details you are looking for?

we cannot design anything based on the information you have supplied

all we have so far

operating voltage 24 vdc

its size

the speed of the acuator

2 second pause

reverses

you would do better to say what its intended purpose is.

ie an actuator to open a door outwards for 2 seconds then close door until actuated again. and the unit must operate at 24vdc and be no more than 6" x 3" in size

now this description would be better than what you have provided.

you may not want it to open a door but at least we know what function its supposed to perform

You dont have to specify exactly what its supposed to do.

telling us its for a disabled person was the wrong approach. and whats a war vet got to do with it?

you know what its meant to do so think of some other thing it could do, and describe that action, ( that way we wont be able to steal the end project)

http://www.e-motionllc.com/MailingList_subscribe.asp

http://www.e-motionllc.com/MINIATURE_12V_LINEAR_ACTUATORS_s/59.htm

http://www.e-motionllc.com/12V_Actuator_Controller_p/mc102l.htm

on the right of this link is a section to ask them for a solution

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555 timers

http://www.google.co.uk/search?q=555+timers+circuits&sourceid=ie7&rls=com.microsoft:en-gb:IE-SearchBox&ie=&oe=&rlz=1I7GGLT_en&redir_esc=&ei=u8-bTInoKIKQjAeDoK3DCQ

what is the project it may help if we know

If you had a budget of under 200 dollars how would you go about it? .....

I wouldn't. Not for the type of scope given.

See that is where you and I differ. I think it can be done with a little help and ingenuity. It is a big task but that is why I am seeking advice and taking my time so that I can choose the best plan of attack.

You're quite right in taking your time and looking at all the options, but if you want help with the best plan of attack, you're going to have to give more information.

You can keep the details your secret application to yourself, but the more detail you supply about what force you actually need, how far and fast you need to move and so on the better the chance of getting suggested solutions optimal for your application.

The LA-30 produces up to 6000N - do you really need that, or is it just that you have the LA-30 (and a 24V PSU that you "need to use"), and you're doing a proof-of-concept lash-up?

possible, since your doing it pro'bono, I do look at it as a seemingly straight forward project, but when I see 100's of hours research and zero returns, some other things come to mind with the info given. I basically stopped reading all the posts.....too many posts. Good luck.

Genie75 started this thread but it looks like Tolstoy took over, it's got more chapters than War & Peace!

drill a small hole in the shaft of the acuator and insert a magnet. then position a reed or hall effect switch at the points on the acutator body where you want the shaft to stop.

a 555 tmer coul then be used for the delay and at each end stroke reverse the field widings and the motor will reverse

simple really

That sounds very simple. Part of my problem is as I am looking at the issues I have a very bad habit of over thinking the situation. And the simplest things sometime are right there in front of me and I can't see it until after I have done something way over the top. Thank you for reply and I'll try it.

or

http://www.trossenrobotics.com/store/p/5189-Dual-Linear-Actuator-Controller.aspx

looks good