[supahonkey]

Keith,

That is an awesome idea. I will definitely do something like that if I can't get Mach to read my encoder. If not I might move to EMC. I hear EMC can handle rotary encoders. I really like your idea, have you seen this used in other applications?

Skippy - The point of this thread is to display what I have done, get user input, and possibly help answer questions pertaining to my project along the way. You need to create your own post about that tube bender. If you know you are hijacking, why apologize for it?

[NEATman]

No, I can't think of a place where I saw this exact set up used in this manner, but I come up with stuff like this all the time - it's my job as an ME :-)
I may have to build one of these now - I am thinking of building a couple go-carts at some point - like this:
http://www.ridgerunner.biz/

I'll watch this thread - let me know if you do use the idea.

Keith

[skippy]

"If you know you are hijacking, why apologize for it?"
If you check all my posts you'll see that I'm always considerate of others. Most people I know wouldn't consider one question as being "hijacking". Hijacking is multiple questions or multiple posts about someone else's project. Why did I apologise? Because one in a thousand people can be touchy.
I still think your project's a great which is why I'm following it and sorry for upsetting you.

[supahonkey]

I wired my relay and breakout board last night. I didn't get a chance to hook it up to the PC because the parallel port on the computer and breakout board are both male connections. My cable has a male at one end and female at the other.

I am going to give Mach3 a chance, but after reading into EMC2 and it's ability to read rotary encoders, I believe I will install it. Plus, the thought of a Linux distribution driving my machine sounds awesome. I hear of Mach3 having trouble with 100 PPR manual pulse generators. One fella talks of it skipping pulses on just 100 ppr. I want to run a 360PPR in quadrature mode, meaning I will get 1440 discrete events per revolution. As many have suggested, Mach3 seems to be out of the realm of possibility. I will post pictures of the board later tonight.

[supahonkey]

It's been a little while since my last update. I've been busy with finals and work.

I installed Ubuntu 8.04 on my PC for the tube bender. One hard drive has Windows XP and the second has Linux (Ubuntu is just a distribution of Linux). EMC2 is a cool piece of software. It isn't quite as user friendly as Mach3, but (1) it allows the use of rotary encoders and (2) its free. Plus, its just cool to have a Linux PC controlling my tube bender. I worked on installing and configuring Linux and EMC2 all day. There is a surprising amount of documentation available on the web.

I used pins 1 and 2 on my breakout board as outputs going to my relay board. The relay board energizes the coils on my directional control valve. On the EMC2 main page, I can energize the relay board's relays by hitting the CC or CCW buttons. I am totally lost now and need some guidance in the right direction. I finally got a rotary encoder, but have yet to hook it up. Correct me if I am wrong, but I have a general idea of what I need to do. I assume that I will need a to have EMC2 record the input value of the encoder, and constantly check to see if it is equal to the input value of the user. How can I accomplish this? I just need a step in the right direction.

[supahonkey]

My rotary encoder has 10 wire inputs on it. It is of the screw design where you loosen the screw, bend the wire around, and tighten the screw. On the side of the rotary encoder says:

1: ENG
2: GND
5: MET
6: CH A+
8: CH B+

What is ENG and MET? I want to wire it up soon, but I don't want to take the chance of screwing it up. The rotary encoder was purchased on eBay. It is made by Dynamics Research Inc, and it's actually made in the USA!

[Al_The_Man]

That must be an oldie if it has terminals on it!
I believe DRC is no longer around so you may have a problem finding info.
Renco are selling NOS encoders on ebay for $20.00 right now, they are not the completely shrouded types so they may need a bit of a protective cover, but the price is right.
Al.

[supahonkey]

Yeah, the build date is 6/95. ENG means encoder ground. I still can't figure out what MET means.

[NEATman]

My guess is that MET is some type of index mark - one pulse per revolution. Most rotary encoders have such an output, but why it is called MET I'm not sure.

Keith

[Al_The_Man]

Also is it open collector? 5,12 or 24v supply?
If MET is the marker, what is the +supply terminal?
Al.

[NEATman]

Al-
Good point. He does mention that there are 10 connections, I assumed that he didn't list the positive connection - only the ones that he didn't know what they were. Perhaps a picture of the terminals on the encoder would be best.

DRC still exists - perhaps they can be of help.
http://www.microesys.com/drcEncoders/data.html

I took a look at a couple datasheets, but I didn't see any connections with the same abbreviations for the terminals.

Keith

[supahonkey]

Hey fellas. I finally got a hold of DRC. They sold their encoder division to GSI seven years ago. I called GSI and they gave me a data sheet. Unfortunately, what the data sheet lists as ground and power is not the same as what the sticker on the side of the encoder lists. The output circuitry is a single-ended squarewave output. How does this affect me and my ability for EMC2 to read my encoder's signal?

Pin 1: Spare
Pin 2: Channel B
Pin 3: Channel B-bar (B with a bar above it... don't know what that means)
Pin 4: Common
Pin 5: Channel ZR
Pin 6: Channel ZR-bar
Pin 7: Channel A-bar
Pin 8: Channel A
Pin 9: Spare
Pin 10: +Vdc

I have absolutely no clue what any of the X-bar pins do. I assume that pin 10 is the voltage in pin. It appears as though I just need to hook up to pin 2, 8 and 10. Unfortunately the sticker on the side of the encoder doesn't coincide with the data sheet. I will post the data sheet on my FTP server when I get homel; work has blocked access to my website.

Thanks for your help.

[supahonkey]

One more thing…

Last night I actually cycled my valve using EMC2 and my relay board. I am using a 300W Antec computer power supply for the relay and breakout boards. CNC4PC recommends using a PC power supply. After about 15 seconds of engaging the directional valve, the power supply shuts off. I have to unplug the power supply, wait for the capacitors to de-energize, then plug it in again. It works again but turns off after a brief period. I have checked the wiring and I have no shorts in the system. My room mate suggested that the power supply wasn’t up to the task, but I find that hard to believe. The relays on the C15 relay board probably draw less than 0.5 amps. My power supply is rated at 31A @ 5V and 28A @ 12V. Any ideas?

[Al_The_Man]

The /A /B etc on the encoder output is the complement of the A B etc. this is used if using the encoder in the differential fashion for noise immunity, if your control device that the encoder is fed back to takes single ended, just ignore the complement outputs.
The ones marked Z are the 1/rev marker pulse.
You need to trouble shoot the drop out problem methodically, IOW monitor the various voltage points to see where the drop out is occurring, starting with the power to the relay itself.
Is the command signal from the port to the relay switching device being maintained?
I doubt also that it is anything to do with the P.S.
Al.

[supahonkey]

I ended up using power from the power supply in my computer. Previously, when I was having the trouble, I was using a separate PC power supply. Since switching, I have had no problems. Either something is wrong with the power supply or the load from the relay is so small the power supply thinks nothing is on and it shuts off.

I actually blew one of my relays on the relay board. I had a few wiring issues that I spent a good part of the day sorting out. I bent my first piece of tube under computer control. EMC was fairly simple to setup. Linux sure has come a long way since the last time I used it back in 2001. Ubuntu is a nice operation system with a lot of features not currently present in Vista.

EMC has a handy wizard called ConfWizard. It simply asks you what pins you wish to address and how you want to use them. My breakout board is interfaced to the PC with a parallel printer cable. Currently, I can hit F10 to make my tube bender extend. Hitting F10 again makes it stop. Alternatively, while the cylinder is extending, I can hit F9 and it will instantly retract. I don't have limit switches installed yet, but I bought really cool photo microsensor switches made by Omron. I haven't decided whether I wish to control die stop/start position with limit switches or with the rotary encoder.

The next step is to hook the rotary encoder up to the breakout board and configure EMC2 to read it. I then have to modify the JD2 bender to make the center die pin follow the movement of the die. I have to mount the rotary encoder and limit switches. I will then have quite a bit of programming to do. We'll see if I can actually get this done by December 15th.

PC being built



Beautiful!





EMC2 Screen. Notice the Spindle Postition buttons? All you do is hit the CW or CCW buttons move the valve.



Rough wiring of my breakout and relay boards.



Bender



Bender



Bender

[skippy]

"I bent my first piece of tube under computer control"

Well done! You might not have all the programming done yet but just bending a tube under computer control is a big step on its own. I'm enjoying this thread and thanks for sharing.
Congratulations!

[supahonkey]

"I bent my first piece of tube under computer control"

Well done! You might not have all the programming done yet but just bending a tube under computer control is a big step on its own. I'm enjoying this thread and thanks for sharing.
Congratulations!

Oh, I can only imagine the required programming ahead of me. I was hoping to use Mach3 so I can program in VB. Now that I am using EMC2, VB is, for obvious reasons, out of the question.

I managed to fry one of the coils on my tube bender. I was trying to get a USB wireless adapter working on Linux when I heard a sizzling sound. I looked down and both relay indicator LEDs were on! The valve's coils were fighting each other to draw the shaft over. I have each pin assigned as Spindle CC and Spindle CCW. There is no way EMC2 will allow both buttons to be active at the same time. I am using pins 1 and 14 on my breakout board. I would love to know why EMC2 made both pins active! I odn't know what to do; this can't happen again, new coils cost $50 a piece.

[Al_The_Man]

This is why DC coils are a best bet for solenoids, not only are they more efficient, if the spool sticks or both are activated together,(which should be prevented at all cost!!).
The current in the coil does not increase as it does with AC solenoid.
The loss of the armature in an AC sol. when under power reduces the inductive reactance to close to the wire resistance value.
Result, Immediate fry. (chair)
In common boolean logic control, the output to each coil is interlocked with a NOT statement for the opposing coil.
Al.

[keebler303]

I just realized you had a thread going over here too.

you would need more than a NOT, you will also need an AND or something so you can have a neutral position as well as push and pull. I've attached a schematic which would work. It would disable the retract relay whenever the extend relay was powered. Let me know if you need part numbers to actually do this.

Matt

[supahonkey]

Thank you both Alan and Matt for all of your help; I truly appreciate it. Matt, I was thinking I would need a provision in the software to prevent both coils from energizing. I can see how hardware would be much better, as we can see the errors of software. I am POSITIVE I didn't press both F9 and F10. I haven't tried it, but I can't imagine EMC2 would allow both Spindle CC and Spindle CCW to be active, you can't turn a motor two directions at once! Matt: part numbers would be great. The last time I worked with logic gates was freshman year of high school in electronics class. I have a Vickers valve wtih DC coils. It has two bridge rectifiers in it to convert 120V AC to 12V DC. When connecting the wires I accidently thought I was connecting the neutral wire to the rectifier, when I actually connected a hot. I destroyed a few components on one of the boards. I might look into getting new parts and resoldering them, so as long as the board itself isn't damaged.

Alan: I see what you mean about the proportional valve. I bent a stinger for the front of my Jeep (a U shaped bar that has a 126 degree bend in it). Once I zeroed in on the target bend I had a difficult time hitting the actual number. The bender is slow, but bending just a few degrees isn't possible, as the valve gives it all it has. I, unfortunately, can't afford a $1000 valve!

PS: Matt, I like the name of your picture! "Coil BOOM BOOM" or "Boom goes the coil" are also adequate.