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16  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 05, 2013, 11:01:11 pm
I missed the second image at first.  Is it some kind torque gaining, speed reducing doo-dad?


It looks like the upper larger gear is the driven gear, and the lower two are speed reducers? Or do I have that bass ackwards?
17  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 05, 2013, 10:40:50 pm
Hey, man; thanks for having taken the time to work that out on paper for me. I think I understand the concept, or at least I thought I did. In the gizmo I'm building, there are 2 identical gears each engaged with the other. The output gear turns clockwise which means the driven gear turns counterclockwise. The driven gear is fixed to the large pulley, and via a belt, turns the small pulley. As desired, both pulleys turn counterclockwise.

In your drawing, there is a point that confuses me. Your output gear rotates counterclockwise. As drawn, it is engaged with pulley A which turns clockwise. I'm with you to this point. Then pulley A the driven gear is engaged with pulley B, the idler gear, which appears in your drawing to also be turning clockwise...and visa versa when the lever is toggled, and the idler gear engages directly with the output gear. I guess what I'm unclear about is that before the toggle, both A & B are turning clockwise, and after the toggle, both A & B are still turning clockwise.

That said, I think I found enough in the way of gears, and shafts to attempt to make something work. I'll stick close by so you can help me understand better what confuses me now.
18  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 05, 2013, 08:30:54 pm
Well, first, I tore apart a laser printer, retained all the screws, PCBs, 2 motors, a bunch of gears, cams, rods, rollers, wires, springs, switches, and bits that moved that I don't know how to name. Next, I re-read these last two posts of yours. I brought the ritual to completion by wiggling my finger in front of my lips while humming softly. "Two more printers to go", I said, and then continued my autistic mannerisms by staring at nearby lights.

Several posts up, you said:

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I'm sure you understand exactly how this works, but to someone unfamiliar with the process you are going to have to explain it like you are talking to a toddler. lol

I get the idea that you know how to do what I want to do, but after numerous Google searches, I'm not finding anything to help me catch up to you. It does make sense, just not enough to jump start the old engine. A photo, or drawing, or diagram would be great.
19  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 05, 2013, 12:37:59 am
Yes, you do have it now. Sorry it took so long to explain it coherently. There are several variables, and you named one of them; that as the yarn gets thicker on the drum, it takes more yarn to make a single revolution around the drum. However, unless the thickness of the yarn increases or decreases, precisely the same number of revolutions will be required to move from point A to point B on layer 1 as it will take to move from point B to point A on layer 8.

Another variable is the thickness of a single ply.  In GB, AU, NZ, and most if not all of Europe for that matter, ply has a specific meaning. So, the yarn we call "baby yarn", or "sock yarn" here in the states, is called "4 ply" in much of the rest of the world. We call it "worsted weight", most everyone else calls it "8 ply". Same word, same topic, but very different meaning. To further complicate things, there is no exacting standard. One mill might produce a worsted weight yarn that another mill down river a mile calls DK weight.

Folks in the US have invented a new wheel. It's called wraps per inch, or WPI. Ostensibly, it dares to set a standard. By wrapping a yarn around a ruler, and counting the wraps between any two inch marks, worshipers of the WPI standard can tell you in no uncertain terms what the weight of a yarn is.  Unless they're pissed, wrap a little more tightly than usual, and cram an extra couple of wraps in there, or unless the individual who did the wraps was your demure gramma who wraps considerably more loosely than the average fiber artist because she knows not to ever wind yarn too tightly lest you stretch the life out of it.

Because precision on that level is impossible, I wouldn't mind if there was a half a yarn width gap between revolutions, or if there were an overlap of half a yarn width or more. Consistency is the goal, and it's also a very good reason to mechanize that aspect. You hit on a very important point when you said,

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As you change the speed of the drum, you want to also increase the speed of the side to side movement.

Exactly right. And since the crank that turns the drum needs to be done by hand to respond immediately when something is amiss, creating an electronic component may possibly be counter productive. I wish it were as simple as adding 2 more pulleys and a belt connected to the existing power train, but I don't think it is because of the direction change that is required.

Anyway, thanks; good thinking!
20  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 04, 2013, 11:05:41 pm
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rip the drive mechanism and motor out of an inkjet printer and use it as-is, using an Arduino to replace the part of the printer that controlled it.

I like that idea; thanks. I've also considered using the worm gear from a mechanical sewing machine, and also checking out the mechanism from a typewriter, either of the sort in which the entire carriage moves, or the sort in which the type head moves back and forth. The question I have about the typewriters is that they are designed to operate in one direction, from left to right. That's solved with the printer, though, since it operates in both directions, and I think I still have one around here somewhere.
21  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 04, 2013, 10:57:52 pm
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1. What determines when a hook needs to slide, and what do they do when the determination is made?
2. Are the hooks expected to move independently of each other?
3. Are we sliding side to side along the shaft or rotating around the shaft?

1. Ideally, they would slide very slowly but continually back and forth as the crank is turned. "As the crank is turned" suggests a purely mechanical device might be better suited. I mean, I might need to answer the phone, pour more coffee, take a leak, and forget to turn off that motor. When I move them manually, it's in response to certain visual cues; the yarn is getting deep in a particular slice of the drum, and the "V" shape of the split yarn starts to move towards the place where it's mounding more deeply.

2. As it is right now, yes, they move independently. Whether they are moved by purely mechanical means, or with the assistance of electronics, they would slide back and forth in unison. I anticipate a nearly perfect distribution of the yarn around the drum, and zero breakage.

3. They slide side to side.
22  Using Arduino / Project Guidance / Re: Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 04, 2013, 10:13:29 pm
Right. Very sorry about the confusion. The vid was "pre-hook"...there were no hooks yet when that was made.

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I've made a fairly important change since the video was made. See this (image) The rod and sliding "hooks" replaced the screw eyes so as to distribute the yarn more evenly on the drum.

On most spinning wheels, there is a gadget called a flyer. The flyer has two arms, one on either side of the bobbin. Traditionally, these arms have had screw hooks, or cup hooks fairly close together. Without the hooks, the newly spun yarn would pile up in one place, rather than evenly distributed throughout the whole of the bobbin. In the last 5 years or so, small, modified spring-like devices called sliding hooks began replacing the traditional hooks because they are faster, and distribute the yarn more evenly on the bobbin.

In the image, you'll see a metal rod with 4 of these sliding hooks attached. Neither the rod, nor the sliding hooks were in the vid. They replace the row of static screw eyes, and that's a marked improvement. However, every time I need to stop to slide the hooks, I'm not cranking. The cranking mechanism needs to remain a manual operation because one's hand can feel when something needs immediate attention.

In the video, for example, there is a yarn ball hanging from an inverted U at the top of which is a sealed bearing which allows it to rotate easily so as to keep the plied yarn's twist from accumulating. The yarn travels from there to a screw eye, and then is split into it's 4 plies by the other 4 screw eyes. From there, it is wound around the drum. Plies were breaking with this method, however, because the yarn didn't wind evenly around the drum. In some places, it was thicker than others, and where it was thicker, more yarn was needed to wrap around the total circumferance at each revolution of the drum. Sooner rather than later, that ply would break. That doesn't happen with the sliding hooks.

Yes; I have thought about a number of different mechanical mechanisms to move those sliding hooks back and forth. Little levers from model railroading which are used to switch tracks could also be used to switch the rotation of the motor. Place one at each end of the rod, and you have an endless looping of rotational changes of the motor. I haven't considered an oscillating mechanism, but it sounds intriguing. I'd like to hear more of your thinking with that.

There's something I find very satisfying, and rewarding about simple, basic mechanical devices. Cars, and household appliances like sewing machines worked beautifully before printed circuit boards. Quite a number of them are still in service. Jane & John Homeowner didn't need a degree in electrical engineering to service them, either. That said, I'm looking for practical applications to learn Arduino, and about electronics in general. This contraption seems like one of those practical applications.
23  Using Arduino / Project Guidance / Arduino, and Mechanical Movement of Objects - a Newbie Question on: February 04, 2013, 07:36:42 pm
I'm working on a prototype for a machine that splits the plies of commercial yarns. These yarns are reclaimed from hand-me-down, and thrift shop sweaters. A model of this machine can be seen here , but I've made a fairly important change since the video was made. See this image.

The rod and sliding "hooks" replaced the screw eyes so as to distribute the yarn more evenly on the drum. When the yarn is even distributed, the operation works smoothly, and it didn't work well with the stationary screw eyes. At this point, I've decided that I want that distribution to happen automatically. The sliding hooks work as I hoped except they're a bit fiddly.

I am a newborn to both electronics, and Arduino. My question revolves around a joint mechanical / Arduino approach. I could use a little 12v. DC motor, and a reducing worm gear to turn a threaded rod on which these sliding hooks could ride. Alternatively, the worm gear might operate a rack directly under the rod, and the rack could be fixed to the sliding hooks. I would need for the Arduino program to reverse the rotation of the motor at specific intervals. Sometimes, 2 hooks will be used, so the motor controller would need to turn in one direction for a longer time than if 3 or 4 hooks would be used. What kind of sensor might make sense to help me accomplish that? Is this something I could accomplish, or would I be wiser to pay someone to do the eagle PCB layout, and Arduino programming?

If I've hastened through a point that needs clarification, please feel free to ask. I'll try to find a way to make it clearer.

Peace,

Dave
24  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 30, 2013, 06:45:01 pm
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or you can often find good sized ones out of older appliances

That sent me on a scavenger hunt into corners of my house looking for anything that might contain a PCB to see what components I might find to salvage. Just a bit ago, I found a multi channel amplifier, a NAD 906, and it's just loaded with stuff in triplicate. It doesn't power on. I swear I never saw it before, either, and I haven't an idea where it came from. Several in working order have sold on eBay for around $100 in the last month. I may see if I can figure out what's wrong with some on-line tutorial help, but if not, I'll have loads of fodder to practice un-soldering components.

In the process of snugging the components down close to surface of my project board, I broke the wires of a 10uF Capacitor at the level of the solder. Now, I had a mess; how to remove the solder, and how to get the broken wire out of the hole. As it happens, I have 8" stainless steel double pointed knitting needles in all sorts of sizes from .7mm to 5mm. These holes are tiny, so I pulled one of the .7mm needles, heated it along with the solder until I could push the needle through the hole. After a couple of seconds, I pulled the needle back out of the hole, and on the back side, a small straw of solder remained. That easily knocked off, and revealed an open hole. Because there was an identical capacitor right next to that one, I knew how to align this one to keep polarity. It didn't explode when I connected it to the power source, and turned on the switch, and the motor turned as always.

Back to the amp; there are 3 aluminum angle irons about 1.5" x 1.25" x 12", and each of these is screwed to heat sinks about 1.75" x 3" x 9". To each of those angle irons are screwed many of what looks like 5V. Regulators. Everything inside is extremely dusty, and covered with lint, pet hair, and I don't know what else. When it's light tomorrow, it's going to get a good hard gust of wind from the air compressor.

What might I find in there that's worth keeping?
25  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 29, 2013, 09:49:01 pm
The diodes get warm, but not hot.  The L298N, the larger of the two chips with a metal tab gets warm, but not at all hot. The ATMega168 also gets warm, but the 5V Regulator LM7805, the smaller chip with a metal tab gets hotter than is comfortable to touch in just a few seconds, and it stays hot while the PCB is connected to the power supply, even if it is switched off. Is that normal?

The wooden box is not entirely closed, either. There is an opening about 2" x 4" to accommodate the belt; the PCB is fairly close to that. Maybe I don't need a fan.
26  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 29, 2013, 06:42:38 pm
Since several of the components of my project get hot, and since both it, and the motor it will control will be housed inside a wooden box, I'd like to put a 12V. PC box fan in that box as well.

Can my project board support the fan as it is, and if so can I make solder connections with it's leads somewhere?

I found that I could connect the leads to two of the pads at the AC connector, but of course, it's not switched there. Allowing the fan to run all the time the unit is connected to the power supply is an alternative that works just fine, but I would like to connect it in a way that is controlled by the power switch.
27  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 27, 2013, 05:17:16 pm
Thanks, Larry! You have a very supportive way about you that's uncommon in tech forums.

I can easily add a tiny bit more solder to the corner push button pad as you suggested. I see that in the image now that you point it out, and I can see it on the board with a magnifying glass now, too. 

I used a toothbrush with isopropyl as was suggested by the designer of this board. I gather by your having mentioned it that I didn't get it all. I'll study the enlargement to find and clean up the rest.

The marks at pin 1 of the micro controller are a good idea. I had been using the little notch, but the mark will be even easier to see.

Shoot. I intentionally kept some of the components away from the board just to try to keep them from getting too hot. With at least some of them, I think it won't be hard to drop them to where they should be. The resistors, and diodes are 3mm to 5mm above the PCB surface; should they be closer do you think? The crystal, and most of the capacitors should be easy to bring down.

Thanks very much again...those are some very helpful suggestions.
28  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 27, 2013, 01:14:59 pm
I spent a couple of hours yesterday soldering my PCB. No one should be allowed to have so much fun when they're by themselves. At this point, without the software for this motor controller, the motor comes on, and spins at full speed in a clockwise direction, even when the potentiometer is straight up. It'll be a little while before I can spend more money on this, but I've decided to get the genuine Arduino UNO R3 Dev. board. I'm going to use the open source Arduino software, and this is a small way of contributing something back.

If you have a couple of minutes, anyone, I covet your constructive criticism of my soldering, etc., especially when I can improve on what's been done:

http://www.meadowcroft-dyeworks.com/PCB%20001.jpg
http://www.meadowcroft-dyeworks.com/PCB%20002.jpg
http://www.meadowcroft-dyeworks.com/PCB%20003.jpg

Click on the image for a closer view.

edited to correct a misspelling
29  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 26, 2013, 08:09:36 am
Thank you again for all your helpful information. I have a lot of reading / watching to do, a decision to make, and another part to order.

This past summer, I wanted to do a small html / css project, and while I had messed around with both for years, it was usually with the crutch of an editor. I wanted to write the code for myself using a text editor. With the vast amount of information, examples, and tutorials on the web, it was not all that difficult to do, but it was time consuming. In the process, I learned...about divs, about connecting css to html, and about code. I'm hooked. This is starting the same way that did, so you were speaking right to me when you suggested I might want to move on to another project when this one is completed. So, one of the things I want to do is to see what can be done.
30  Using Arduino / Project Guidance / Re: Motor Controller with ATMega168 on: January 26, 2013, 12:15:33 am
Found these with good prices:

Arduino Uno R3 http://www.ebay.com/itm/Arduino-Uno-R3-/300823638330?pt=LH_DefaultDomain_0&hash=item460a7c713a

(Arduino-Compatible) UNO R3 MEGA 328 for Arduino IDE Software USB Cable 01052 http://www.ebay.com/itm/Arduino-Compatible-UNO-R3-MEGA-328-for-Arduino-IDE-Software-USB-Cable-01052-/281052236490?pt=LH_DefaultDomain_0&hash=item417004caca

USBasp AVR programmer Atmel arduino microcontroller http://www.ebay.com/itm/USBasp-AVR-programmer-Atmel-arduino-microcontroller-USB-ASP-ISP-USA-/181065759451?pt=LH_DefaultDomain_0&hash=item2a285c3adb
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