Can 't seem to find the combination of phrases to find what I am looking for so decided to ask h...

[G+_Rud Dog]

Can't seem to find the combination of phrases to find what I am looking for so decided to ask here. Looking for a small power motor that can wind a small gauge cable on a spool. The dimension of the spool is to give and idea of the over all size I am searching to find.

 

[G+_Black Merc]

What kind of load? Are we talking lb. or oz.? 3d-printer or winch?

[G+_Paul Hutchinson]

You are looking for a electric motorized winch, AKA electric winch

[G+_Rud Dog]

The load will be a window 3 x 4 feet. Standard sliding window found in most modern homes.

[G+_Ben Reese]

I used to wind wire for power transformers. My boss built the contraption we used. Consisted of a 1.5 HP electric motor stepped down using a Model A or Model T transmission.

 

Not what you're looking for, but your description brought back memories.

[G+_John Sullivan]

You want to wind a cable on a spool to do what? open a sliding window? How will you close it?

If you want to open / close it, you might want a chain and sprocket, similar to when people have electric gates at the end of their driveway.

[G+_Rud Dog]

The idea is to have 2 spools one for winding in one direction and the other for winding in the other. The main thing here is to find the basic motor and spool materials allowing the next step; picking the item up and testing on a mock window.

[G+_Paul Hutchinson]

If there is any chance of visitors, especially children and seniors, getting near this you should add an automatic safety shutoff so that fingers and hands can't get crushed.

 

I suspect it's that feature making the commercially available devices so expensive (lost fingers can make you liable for huge bucks so a few hundred extra looks like good insurance).

[G+_Michael Hagberg]

Go to an auto junk yard and take a look at the mechanism for motorized windows.

 

Hard to explain, but it uses a motor attached to a spool that has a sprial groove. As the wire enters one side it exits the other.

[G+_Rud Dog]

Paul Hutchinson Agreed there must be a means by which when resistance is encountered the motor must shut down. Thinking maybe sensing current would do the trick but that is down the road once I get this actually working.

[G+_Rud Dog]

Michael Hagberg Looks like a visit to the junkyard is in my future.

[G+_Michael Hagberg]

Look what I found. This is a Doorman 740-664. The motor mounts on the bottom hub.

>

[G+_Michael Hagberg]

Here's a photo of the spiral hub. I popped it out of the housing so you can see how it works.

[G+_Rud Dog]

Michael Hagberg So frustrating with Google search. Unless you already have an idea of what it is you are looking for you won't find it.

 

Maybe what I should do, now that the idea of what I am looking for is known, is ask for search phrases people come up with and try those.

I tried:

Take up and feed.

Motor slide forward and reverse.

Motor for window open close.

Linear actuator

 

Ideas for a search please add here. Thank you.

[G+_John Sullivan]

Rud Dog I believe the word you're looking for is "capstan". Google for "capstan drum" to see some examples.

In your case, I would attach one end of the cable to the window, route it to the drum and wind it a few times then secure it to the middle of the drum.

[Edited]Now continue the cable around the drum for an equal number of turns finally exiting the drum and returning to the other side of the window.

Now turning the drum in one direction opens the window, turning in the other closes it, which is probably what the device that Michael found does, although I can't be sure from the photos.

[G+_Chris O'Riley]

If the window slides smoothly enough, you might be able to use a small stepper motor like the ones used in 3D printers. Recent printers that use motor driver boards like the Trinamic TMC 2130 can sense motor current and use that as safety and end stops vs. physical limit switches. Since these are used in DIY 3D printers, there's a ton of information on them. Basically, you'd use a stepper motor, one of those driver boards and an Arduino to control it, read the current, etc.

[G+_Rud Dog]

cosmic Ray Had a cursory look at capstan motors and appears at first glance they are mostly suited for tape drives. Not sure they would have the ability to slide a window back and forth? Placing the found returns from google search in my folder of possibilities, thank you.

Found this and wow this guy went all out:

[G+_Rud Dog]

Chris O'Riley Sounds promising. One requirement it will need to fit in the wall in the final version. The dept of the wall is about 3 1/2 inches.

Will see if I can find a motor fitting this requirement. After which a load test can be conducted.

Interesting driver:

https://www.trinamic.com/products/integrated-circuits/details/tmc2130/

[G+_Paul Hutchinson]

Rud Dog unfortunately capstan is a generic term so it is hard to locate the right sized capstan. It applies to devices ranging from tiny mechanisms in a micro-cassette drive (diameter in millimeters) to the the giant windlasses that lift the multi-ton anchors on super size container ships (diameter in meters).

[G+_Michael Hagberg]

Have you considered a linear actuator consisting of a long treaded rod connected to a stepper motor?

 

Most handles are located in the center of the window. If you were to attach to the top or bottom of the sash this could rack the window causing a jam or increased torque on the motor.

[G+_Rud Dog]

Michael Hagberg Yes linear actuators are looking very good. Excellent point, binding if attached to the bottom or top of the window, would occur. At this point looking at the crazy array of motors available. Found one but it only had a threaded rod of 12 inches. The search continues.

BTW the reasoning behind the push pull cable has to do with the ease with with the cable could be threaded through the window frame and attach to the slider. Small holes for the cable and the motor could be hidden in the wall. On the other hand the ease of using the linear actuator is looking pretty good.

[G+_Michael Hagberg]

Rud Dog a stepper motor can be coupled to a threaded rod of any length. Don't worry about finding a motor with built-in threaded shaft.

[G+_Rud Dog]

Michael Hagberg No sooner do I find threaded rod sold separately and return to announce this fact then I see your post stating exactly that. Great minds. Now back to searching not only for the motor but also the selection of lead screw rods available. So far the longest I could find was 400mm or about 15 3/4 inches.

[G+_Rud Dog]

Hmm, this gives me the configuration of the entire setup.

ebay.com - Details about T8 600mm 3D Printer Lead Screw Rod Nut Coupling Shaft Mounting Bearing Motor Kit

Need to find the dimensions of the motor now.

[G+_John Sullivan]

What Michael said about binding might be a concern if the window fits tight in the frame. I'm thinking that I would prefer something out-of-sight rather than a rod right in the middle.

Going back to Paul's concern about injuring someone, I think I would try a counterweight hung in the sash or wall, with a cable attached to the window to close it. You could adjust the weight of the counterweight so that it closes the window effectively, but would not harm anyone who happened to get in the way. I would use a motor with a spool and a cable attached to the other side of the windows to open it. Reversing the motor allows the counterweight to begin closing the window.

As long as the window doesn't bind in the frame (you can test it by pushing it with your finger) I would attach both cables to the bottom of the sliding window, one on each side, and they would be out-of-sight to the casual observer.