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DLee123

Newbe, just seeking 'back and forth' control

14 posts in this topic

Hello - First, huge thank you for any and all assistance can provide as I'm just a bit lost (very lost).  With other things in my life forums have been so great and helpful and I do contribute hugely on subjects I actually know about (I'm not just a forum 'consumer', also contributor when able to).  I've tried to educate myself but all of this is so very out of my wheelhouse!!!  I've been searching and searching and honestly had issues just knowing the direction to head.  I fear I'm heading in the wrong direction though as I'm creating a device that has very simple operation, basically it's an arm that will go back and forth and have features like be on a timer and safety features like if there's something blocking the path, it will wait until the path is clear.  I've been looking at CNC type controllers but not sure if that's the right direction to head. 

So where I'm at is a bought a few things to build a prototype and found a "Ball Screw Linear CNC Router Slide Stage Actuator Lead Rod Stroke Nema 23 Motor" which seems about perfect but for my application but there's nothing really 'precision' about my needs and by that I mean it could be as simple as the motor sends the unit to one side, when hits the limit switch reverses it to go the other way and when hit that switch it stops (that would be one 'cycle').  No stops in between unless perhaps there's a cut off in case something blocks the path...

One huge question is if the motor type is right or do I just need a basic motor which as mentioned, goes in one direction and really the limit switches play a big part with just some sort of basic controller...  One thing that is funny and purely coincidental is I recently installed an automatic gate at my house and all the sudden it occurred to me that the gate controller functions with a lot of the features that could use (inputs to stop operation, triggers to start operation...).  This is honestly what made me question if I'm heading in the right direction.

Thanks again for any input have and even if it's as simple as suggesting to research this type of motor, that controller... I'm not looking for other's to spoon feed me info, I'm not afraid to spend  hours doing my own research but again, just not sure of the directions to head with this.

Cheers

David

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well start by selecting actuator to meet your stroke, force/torque and speed requirements (with some reserves of course). if there is safety concern, what is to be protected, what is the hazard, and what is potential severity....?

does it have to be a motor? did you think about using pneumatic cylinder?

how do you need to sense obstacle? is it a point, line, plane or volume?

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Thanks for the response!  There's not any great 'requirement' for torque and speed and what will be mounted/moved is very light (a few ounces would imagine) but I do want to over engineer a little bit.  There's not really a safety concern for people or anything like that, more a concern over it operating and hitting something/someone and breaking or just interrupting the cycle...  This is very linear so my idea was just use small photo optic beams.  The unit needs to be pretty self contained, and compact so don't see using pneumatic.  The screw drive really seems like a perfect solution if I can just find the right motor for it but am still open to other ideas/systems.  My very first thought was some sort of rack and pinion system.

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help can only be offered when something concrete is specified. since all specs are secret, i guess you will be on your own then.

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Sorry I seemed to have rubbed you the wrong way, it's not my intension in the least!  The precise application is secret but other specs are not secret at all, there just really aren't any as there can be great flexibility.  In other words, it does not matter if a cycle takes 10 seconds or 45 seconds.  I have to develop the 'attachment' to know the exact weight, developing the attachment somewhat depends upon the mechanism...

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no offense but the thing is - i value my time and... well, here is the third attempt to help someone struggling to formulate a question. so far you hardly started stating what you need and you are not answering any questions.

let me assure that nobody cares about your secret application. make it abstract like a question students would get on an exam. use model if you like and obfuscate any details that may expose your real application - watering roses or moving sex toy or packing cocaine does not need to be part of problem description. it is enough to say that you need to move an object of mass X, distance Y, in time T, travel is vertical or horizontal.  that would help propose actuator and drive type. there are so many motor types, AC, DC, geared or not, steppers, servos, linear motors, and the list goes on.

Same goes for  then sensors and control circuit.

if you are asking for help anonymously in a public forum, be prepared to present SOME info. if that is not possible, be prepared to hire a contractor and make him sign non-disclosure agreement. your choice...

 

 

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I'm not all about secrecy as I've developed many products and never bothered patenting them just because that means have to then defend a patent and I also value my time and everyone's time...  I've been copied but never let it slow me down too much.  I also know ideas are easy to come by, putting them together is where it's at and that's my strength as I'm too stubborn to give up!!!  :)  I'm not sure what other info can provide on the description than provided initially, "basically it's an arm that will go back and forth and have features like be on a timer and safety features like if there's something blocking the path, it will wait until the path is clear.  I've been looking at CNC type controllers but not sure if that's the right direction to head."  Ok, so it's back and forth horizontally so I can add that.  There's no stops in between which has me drawn away from stepper motors and the need for drivers... and at this exact moment looking at reversible DC voltage motors.  I mentioned the ball screw mechanism in my original message and I still like that as a mechanism (I've done a good bit more research since posting).  The length of the mechanism will vary per application, in some cases may be 3' and go up to maybe 15' (100% that is based on the specific application so the design needs to be 'adaptable').  My thought is the 'logic' for the length (travel distance) and control would simply be limit switches, it runs until the end and hits the limit switch, a controller/relay then tells it to turn around and go back.  I do understand the need/application for a controller as motor is one thing but need to figure out motor type first and then think controller which I have vendors in my current biz that can develop a custom one once I know what technology we're dealing with (basic DC reversible motor, pulse, that whole list mentioned as options).  I'm also wondering if couldn't just use relays or even look at a swing gate controller which seems to include most of the features are looking at (motor operation and safety features).

A few more details, the 'arm' is light (just probably a few ounces) and no clue on what speed would be optimal which that would be something to test once get closer to a motor type and I guess that's just in the gearing (as of now a 90 degree configuration would be best for mounting to the mechanism which would save on space).  I think the issue we're having is if a spec isn't mentioned that means it's not critical or simply hasn't been determined.  Like a big issue for me is how much torque may be required but I just have to get something to test to get a feel for that and the speed.  Another consideration is that want this to be durable and ultra reliable but, in a day it will probably 'cycle' (go back and forth) probably just 20 times on average and not every day...

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you could get arduino and two relays shield and a push button to control small DC gearmotor. 

or couple of relays will also be able to replace controller. but this is more  tedious to wire or troubleshoot. or use small programmable controller like Zelio etc. such things are mini PLCs and commonly called "smart relays".

brushed DC motors are reversible, can be cheap, can be obtained as geared but the commutator is subject to wear, which should not be an issue for low duty applications like yours. 

on the higher end of the spectrum you could get motor with built in controller like QuickSilver. they are compact and everything you want but they are not cheap.

 

i also think you are too quick to dismiss steppers. they could easily be the perfect solution as they have no commutator, are quite high torque, don;t run fast, can have driver and controller built in, and cost some ten times less than QuickSilver.

for example check: 

https://www.anaheimautomation.com/manuals/stepper/L010363%20-%2023MDSI%20Series%20SpecSheet.pdf

https://www.anaheimautomation.com/manuals/stepper/L010273%20-%2023MDSI%20Series%20Users%20Guide.pdf

 

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Huge huge thanks and I agree that I've dismissed steppers a bit too quickly.  So you definitely got me to reverse course as honestly didn't find previously the integrated units so that's a bit of a game changer.  I checked out your links and that got me off to the races.  It seems like may be the same thing but perhaps I just understood the wiring on this one a bit better and can see how relay control could potentially work, what do you think of this one?  https://www.omc-stepperonline.com/integrated-stepper-motor/nema-23-integrated-stepper-motor-126-ncm-178-4oz-in-w-controller-isc04-12-38vdc.html.  While I can see it still doesn't mean know exactly how to do it but at least seem to be moving in the right direction!  Thanks again!

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Looks nice but that unit will still need external logic controller that will select direction and control start/reversal/stop. But no programming is required. 

the example i shared should have everything built in. The only external components here should be two travel limit sensors and button to start. 

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Thanks one more time, I'll circle back around to your links!!!

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After a night sleeping on this probably the first and best question I could have asked is where/how to find someone for $$$ to develop the functionality for this?  I say functionality because I can deal with the mechanism so just thinking the motor and control...  While I love to learn new things I just think I could learn much more quickly what I need to know once someone was to put it together and then explain the mechanics of it all although now I at least understand stepper motors and the drivers and control, conceptually understand that is...

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so you are in Florida?

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Sorry for the delay, holidays...  Yes, in Florida and actually found a company/manufacturer (China) that's been very responsive and thus far have received an initial sample and they say can provide an integrated stepper motor/unit and I'm awaiting some of the details but may be on the right track.  They have said no problem on the features I've mentioned but I don't know how much of it is programming versus needing a separate controller for the different inputs...

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