[Fastest1]

I cant see cncing an RF45, it could be done but I dont think it is the best candidate. No real rush on the 0704 but now that I have tasted manual milling, I miss my cnc. My Sherline/A2ZCNC and my Dyna DM2400 have such small work envelopes I just want a bigger machine. I have no problem doing manual machining via my shuttle pro!

Thanks for the info... altho I cannot imagine why anyone who has an rf45 would want an 0704.... I guess to each his own.... peace

Pete

[hoss2006]

Thanks for the info... altho I cannot imagine why anyone who has an rf45 would want an 0704.... I guess to each his own.... peace

Pete

Well, for me, because the RF45 isn't going to fit in my spare bedroom, not really a hard concept to understand I don't think.
Hoss

[pete from TN]

Well that is funny you mention that, I used to have my rf45 in my spare bedroom before we moved here. I know the 0704 is obviously smaller than the rf45 but when you get right down to it they need a certain amount of space to be able to run and the table travel of the 0704 in the X axis is not terribly far from that of the rf45 so the space required at least from side to side is similar.
Not sure what you mean about the best candidate for CNC either. I guess IH build them CNC for no good reason? They are an excellent candidate for CNC if you ask me. At least with the RF45 when you are finished you have something that can take a decent cut in steel without crawling. I know you like the 0704 hoss and you at least offset your living making parts and CDroms for it and from what I have seen on here it is not a bad little mill but again I dunno why anyone who has an RF45 would want to buy another machine to CNC it. The only real negative about CNC ing the RF45 is the weight of the head and there are ways around that too.. Both machines need a belt drive or similar setup to get any real spindle speed and both machined would need some decent components to run properly. In the end the RF45 is a much more capable machine.... but as I said that is why there are so many flavors of ice cream right... peace

[Fastest1]

Pete I just had a brain fart and came back here as quick as possible. I have a RF30 not the RF45. It is a round column mill. If I had the 45, I would be happy. Especially cnc'd. Sorry, maybe now you see why I dont want to convert it. But it cuts well and had very little use or set up either.

[pete from TN]

Well that does make sense... altho my pal Art might argue with you still.. Yeah I thought you had an RF45 dovetail column mill and wanted an 0704 which as I said does not make much sense to me but oh well.. The RF31 I used to have is a great little mill and I kinda wish I still had it but I would probably keep it manual if I did. Good luck man.. peace

Pete

[44 Echo]

This is my final try...

I've had a TMC-1000 (old ProLight 1000), for a few years, even posted here a couple of years ago, but no luck. If I don't figure it out this time, it's going in the trash, or wherever these things go when they become giant paperweights (on the sale list and/or E-Bay) Anyway, here we go:

1. It used to work, I used it at work almost every day.

2. One at a time, the axis drive motors quit working.

3. When in Manual Mode, I can get the Spindle Motor to rotate.

4. If I give it an axis motion, I can hear the hum change pitch. The contoller counts as if it is moving, yet nothing moves. If I hit the "space bar" on the screen, it sounds like a hard stop is being hit.

5. If I open the cover, the indicator tells me, so that seems to be working.

6. Yes, I pulled the "E" Stop.

Again, one last try...

Any help would be MUCH appreciated.

Thanks,

Jerry

[pete from TN]

I have seen you post about this a couple times now and would like to help but I do not know anything about that mill. It sure looks like a nice little machine and I would hate to see it thrown in the trash. I would be inclined to say that if you cannot get the original control working it would be relatively easy to convert it to run on modern step and direction control with stepper motors either the ones it already has or some new ones of the same size and power. You could easily run that whole machine off a G320 or some of the keling inc. drives and get probably more speed and power than it ever thought about having when it was built and of course modern software and capabilities. It really comes down to either finding someone who is an expert on that particular machine or upgrading it to modern control. I would opt for the latter because in the end it might actually be cheaper and result in a more capable expandable machine that a lot of people on here can help you with. Have you tried to contact the manuf. name for a discussion group or something....? Peace

Pete

[44 Echo]

I have seen you post about this a couple times now and would like to help but I do not know anything about that mill. It sure looks like a nice little machine and I would hate to see it thrown in the trash. I would be inclined to say that if you cannot get the original control working it would be relatively easy to convert it to run on modern step and direction control with stepper motors either the ones it already has or some new ones of the same size and power. You could easily run that whole machine off a G320 or some of the keling inc. drives and get probably more speed and power than it ever thought about having when it was built and of course modern software and capabilities. It really comes down to either finding someone who is an expert on that particular machine or upgrading it to modern control. I would opt for the latter because in the end it might actually be cheaper and result in a more capable expandable machine that a lot of people on here can help you with. Have you tried to contact the manuf. name for a discussion group or something....? Peace

Pete

Pete, Thanks and sorry for hijacking the thread. I am just at my wits end. yes, I tried contacting the manufacturer and they want an arm and a leg just to look at it. Also, I don't have the money to convert it, but I might have a few bucks if it was a simple fix.
Thanks again,
44 Echo

[Nth]

Don't ever trash it. If you live anywhere near Ohio I'll take it off your hands but I'm going to guess you'll be keeping it .

When you try to move an axis does the axis motor sound sort of like a grinding that changes pitch and the axis may twitch a little and possible jump a tad? How good are you with electronics/soldering specifically.

[44 Echo]

Don't ever trash it. If you live anywhere near Ohio I'll take it off your hands but I'm going to guess you'll be keeping it .

When you try to move an axis does the axis motor sound sort of like a grinding that changes pitch and the axis may twitch a little and possible jump a tad? How good are you with electronics/soldering specifically.

I just want to fix the little guy, and get him working again. I used to use it to fabricate prototype parts at work. I brought it home, after they decided to get rid of it. It was having sporadic issues, with the X axis whenever I brought it home, and then kaput, they all went!

Anyway, if you tell me what to do, I've got MAD skills. I have a small solder station, and know how to solder PC boards, without leaving cold solder joints. I have a "solder sucker" and know how to remove old components. I have a can of flux remover...

Yes, when I fire the unit up, the axis motors have like a high pitched hiss to them, and then if I tell one to move, I hear a chug, and then the hissing noise changes pitch.

[Nth]

Do you have an oscilloscope?

[44 Echo]

That I do not have. I have a VOMeter. I have access to an oscilloscope at work, but know not how to use it, nor can I bring it home. I assume that I would need the unit fired up, so taking it to work is kind of out of the question, too.

[Nth]

Ok, I'll tell you what I think is wrong but without the scope can not actually diagnose.

The only test you can do with a multimeter would be to test the 40v/5v power supply and make sure nothing is faulty with it. In the following image I've marked a few components. The 5 volt regulator is a good place to test the voltages. The leads should be marked ICU. Input ~40v, common ground and output which would read ~5v. Test them at idle and when the table is trying to move to make sure the PSU is good. A little variants would be expected.



What probably happened is your l298's(full wave driver) have blown possibly taking the l297's(stepper controller) and maybe the 40a diodes with it. Causes can range from age/use to heat to a loose axis cable. If the drivers are driving and a connection isn't tight and opens it will hurt the driver. Any added resistance is just extra heat for them. and they run hot as is.

Luckily the components are all cheap and swapping them out is not too hard. The l297's are, at least in my controller, in IC sockets so you don't have to solder to replace them. Use an IC puller and you can have them replaced in 15 minutes. They run around $3 - $4 on ebay.

The l298n's are a bit cheaper at $2 - $3 but more work to replace. They're housed on that big heatsink.


After you remove the sink cut the leads of the IC with small snips and remove them individually. It is by far the best way. You'll risk damaging the board if you heat all the pins at once.


When the l298 is out test the 8 schottkey diodes downstream to it one by one with your meter. Set the meter to ohms and put the positive and negitive on each side of one of the diodes. Then swap the positive and negitive terminals. Ideally you should see no resistance one way and infinite the other. Realistically there will be a little resistance one way and a ton the other. Just look to see that all the diodes have about the same resistances forward and back. While the meter won't tell you how fast they're acting it will let you know if any are leaking substantial voltage. If you do find that some diodes are leaking I'd replace just the bad ones.


When you put the heatsink back apply thermal grease to the l298's and make sure they're seated well.

Keep in mind this is just a guess. It is possible the motor's themselves have burnt out, an optocoupler has went out, or something else like cable's and connections have severed. Test the voltages first, check wire continuities, fuses, look over the traces and other electronics on the controller board for obvious damage, etc. As you see in the pictures the x/y/z drives are distinct. U7 (the one replaced in the pics) is the x axis, U8 is y and U9 z on my board, YMMV. You can replace just one set of l297/8's and see if that fixes one axis before investing the time and money to replace them all. Also I wouldn't recommend replacing just the l297 and firing it up. If the l298 it drives is bad you could burn out the new 297. The 298 is also the most likely to fail of the two.

[44 Echo]

Wow Nth! Thanks a bunch! Yes, I know exactly the socketed IC's, the three (3) located in the big heatsink, and the diodes located in front of them that you speak of. I will get started on trying to find the IC's.

Just for the record, if I were to get my hands on a scope, and someone to drive it. What would we then be looking for?

Thanks again, you don't know how much this means!

44 Echo

[Nth]

The short answer would be to download the datasheets for the l297/l298 and use the data in them to test the chips.

For the l297's start with the enable pin and make sure it's high. There are a lot of chips (4 or 5) in between the enables on the l297's and the enable signal from the control card. There was a hex buffer bad on my control box when I got it. But your axes went bad one at a time so I don't think that's your problem. Step pulse input would be the next pin. Make sure it is getting a clear signal from the optocouplers. Then check the four ouput's and make sure they're correct.

The l298's you simply check the inputs vs the outputs. They're just full wave h-bridge drivers.

I'd also scope out the PSU since somehow all the axes went out at different times. That sounds strange to me. Unless you didn't tighten your connector's down.

[44 Echo]

The short answer would be to download the datasheets for the l297/l298 and use the data in them to test the chips.

For the l297's start with the enable pin and make sure it's high. There are a lot of chips (4 or 5) in between the enables on the l297's and the enable signal from the control card. There was a hex buffer bad on my control box when I got it. But your axes went bad one at a time so I don't think that's your problem. Step pulse input would be the next pin. Make sure it is getting a clear signal from the optocouplers. Then check the four ouput's and make sure they're correct.

The l298's you simply check the inputs vs the outputs. They're just full wave h-bridge drivers.

I'd also scope out the PSU since somehow all the axes went out at different times. That sounds strange to me. Unless you didn't tighten your connector's down.

Again, Nth, thank you ever so much. I'll give this to one of my EE friends, they ought to be able to square me away, in terms of the scope and undertanding what I'm reading.

I'll let you know how I make out.

Sincerely,

44 Echo

[44 Echo]

The short answer would be to download the datasheets for the l297/l298 and use the data in them to test the chips.

For the l297's start with the enable pin and make sure it's high. There are a lot of chips (4 or 5) in between the enables on the l297's and the enable signal from the control card. There was a hex buffer bad on my control box when I got it. But your axes went bad one at a time so I don't think that's your problem. Step pulse input would be the next pin. Make sure it is getting a clear signal from the optocouplers. Then check the four ouput's and make sure they're correct.

The l298's you simply check the inputs vs the outputs. They're just full wave h-bridge drivers.

I'd also scope out the PSU since somehow all the axes went out at different times. That sounds strange to me. Unless you didn't tighten your connector's down.

My EE bud's (who doesn't know anything about milling machines) eyes lit up, when I mentioned L297 and L298, as per your post. Without seeing the device, he had originally told me that chances are he couldn't help me, without a schematic. In the past, however, he had designed a stepper motor circuit, using the L297 and L298, in order for providing motion for another application.

Anyway, he mentioned that it might be something wrong with the input voltage to the L297? I think he is driving at the same angle you are concerning the power supply, or whatever is providing the power that gets "chopped"?, as NOT being provided. Did I understand you correctly to say that power is coming from the opto-coupler? He said that without that power source, it would cause the motor to lock, but not move, since the power is not being chopped, which is the condition I am seeing. Without the schematic, he doesn't know where that power is coming from.

As a result, he also asked that I bring the control box in. He still has his breadboard, and said we can put the L297's directly in that and test them, and then scope out the L298's.

Maybe someday I'll understand what is going on. Until then, THANKS AGAIN!!!

44 Echo

[44 Echo]

I am my own worst enemy...

I went to check the 5V regulator, and it is marked IAO, or something to that effect. Anyway, I checked the 1st pin, and got a little over 1.5V. The second pin I measured 0Volts, which I am assuming is the GND pin. The last pin, I let the multimeter lead slip and wedge between the 2nd and 3rd pins, which sent sparks flying out of the center L298. Anyway, I put things down, taking a breather. Too many things going on at once. I'll have to wait until this weekend, when I have time to sit down and look at it, without being in such a hurry.

I also noticed beforehand, that I have a large capacitor near the 5 V regulator that you do not have. Also, it looks like it has a factory cut land in the board, in that it is not discolored as though it were burned through. I noticed this before my little fiasco.

Now all I smell is charred electronics...

44 Echo

[Nth]

The input voltage to all the logic IC's come from the 5v regulator. If it is bad then all kinds of weirdness ensues. The step pulse signal comes from the optocouplers which will put out a nice pulse if they have proper voltage. The machine uses the chopper from (i believe) the x axis to feed the others. The l297's are made to daisy chain one's chopper to the others to sync the drivers. Also helps reduce noise.

If you shorted out the 5v reg and sparks flew from an l298 then I'd think that it was bad to begin with. Five volt regulators are cheap and easy to replace. Don't sweat it. There is nothing on this board that can't be replaced.

When testing an IC with a large open probe you might want to find an open test point in the trace connected to that IC like a via or a component with a lead.


As for the difference in the boards it is to be expected. My is from '05 and yours was pre-Light Machines. Even mine has components soldered between traces in places. After production 'fixes'. I've added some on my own components too. A few filter caps, a couple more biasing resistors, a 12v regulator to run a fan mounted on the l298's heatsink, etc.

I have no idea how the stock software will react to the controller not being hooked up to the mill but I'd bring the computer a long to your friend's house. Having the computer send step pulses to the machine while on the scope is the only way to go.

Let me know how it goes. Also double check your fuses

[44 Echo]

The input voltage to all the logic IC's come from the 5v regulator. If it is bad then all kinds of weirdness ensues. The step pulse signal comes from the optocouplers which will put out a nice pulse if they have proper voltage. The machine uses the chopper from (i believe) the x axis to feed the others. The l297's are made to daisy chain one's chopper to the others to sync the drivers. Also helps reduce noise.

If you shorted out the 5v reg and sparks flew from an l298 then I'd think that it was bad to begin with. Five volt regulators are cheap and easy to replace. Don't sweat it. There is nothing on this board that can't be replaced.

When testing an IC with a large open probe you might want to find an open test point in the trace connected to that IC like a via or a component with a lead.


As for the difference in the boards it is to be expected. My is from '05 and yours was pre-Light Machines. Even mine has components soldered between traces in places. After production 'fixes'. I've added some on my own components too. A few filter caps, a couple more biasing resistors, a 12v regulator to run a fan mounted on the l298's heatsink, etc.

I have no idea how the stock software will react to the controller not being hooked up to the mill but I'd bring the computer a long to your friend's house. Having the computer send step pulses to the machine while on the scope is the only way to go.

Let me know how it goes. Also double check your fuses

Oh, it was such a Rookie mistake, you just don't know...

Very little sleep, lots of cups of coffee, little time before I had to be somewhere. Wanting to take a look at this after gaining the information, like a kid with a new toy... I even told myself to wait, but NOOOOO!!!!!

Anyway, I already tested the fuses, right after I fried the center L298. And yes, I even KNEW to pick another point, rather than the one I went after...

Just for my edification, what is an optocoupler, and where would I find one?

Like you said, nothing on there that can't be replaced.

Thanks, as always!

44 Echo