IH Build

[SMW Precision]

I have just finished the Mechanical installation part of my Industrial Hobbies CNC retrofit kit. In this case on an Enco RF45 mill/drill. I am going to try to give a fair evaluation of the kit as I complete major sections.
This kit is Aaron’s latest version. First element of these kits is number of boxes delivered in my case it was 7 different packages. When opened each different part assembly is packaged, labeled and specialized instructions are included within many of those bags.
I had originally thought too build my own system there are lots or mill/drill plans out there. I purchased this kit after examining everything I could find. Along with going through groups and studying the technology. For me it has been a several year process with a long way to go before I will feel comfortable in CNC operation.
Kit installation directions are excellent in providing information needed. They reflect a lot of experience with many users. Parts included in this kit are meticulous in both machining and quality control. After installing the mechanicals it became clear to me how silly a complete system build would have been for me. I would have exchanged 1000 to 1500 dollars in possible cost savings for a 150 to 250 more build hours. What I would of ended up with would of been a much lower quality of system.
It is very obvious that Aaron has thousands of hours of thought and design experience in these kits. There are no weak spots that I could find ¾” ballscrews, powerful motors and heavy duty installation brackets. System is beautifully designed to operate in a fluid coolant environment.


Ken

[wildcat]

Have to completely agree with Ken on the kit. Wished some Loctite had been included but that was the only thing that I needed to pick up from town. A couple of items were not included but Aaron took care of that fast (one was shipped before I know it was missing). Also he replaced a couple of items where I had screwed up. That's service!

Below are some pics of what $4200 gets you. A little dissappointing on the quantity perhaps but I am very happy with the quality. The transformer arrived a little later (not shown here) mounted to a wooden support in a big box.

[SMW Precision]

Wildcat,

Great pic's I did not take a set. Have you completed your installation yet? I found an a lot of parts in those bags. There must of been close to 250 fasteners. Encoders and covers alone had 13 screws each.
At least for me a key advantage of this kit after putting it together is knowing how to repair and service it. As most of us are aware most Chinese tools require some tweaking.

Ken

[wildcat]

Ken - I have everything together and on except for the limit switches and shields which were shipped separately. The power supply/controllers/breakout board are mounted on a piece of MDF until I can make or locate a suitable enclosure. This weekend I trammed the mill which required shimming the column or the head. I have the old style head though and tightening those boles is a pain. Anyway, it was great to mount a test indicator, zero it out against a stop, rapid away and then back and find the test indicator dead on zero for all axis. Doing very small movements (<10 thou) was a different story but still good. I did goof-up in a few spots. I cut the Y ball-screw .25-.5 inch shorter than I should have. The ball screw must not have been completely slid into the Y assembly when I measured. Also, the Y-axis ball-screw is at a slight incline but this does not seem to affect the Y-axis movement. [If necessary I will remount the Y-axis assembly - no way am I going to try to shim the Y-axis bracket. It baffles me why Aaron suggests on the IH mill to cut the back of the bracket off and insert a bolt from the top side of the slide. If you ever want to remove the bracket the table has to come off. Also, if I had left it full size my undercut ball-screw would have come past the wiper.] I cut the base a little to increase the Y travel which turned out to be completely unnecessary. I forgot to put the chip guard back under the saddle (though I don't see it in Aaron's shots either - perhaps it can jam?) Cut the X-axis motor wire short (that axis moves And I forgot the cut the strut out of the front of the column and had to do that after mounting the head and find that it was not possible to get the head down to the table. Also, the SIIG card I got kept locking XP up for some reason - the built-in parallel port on this Dell seems to work fine though. Seems like a long list but nothing too tragic. Cutting the ball-screw short is a little sickening at the time though. Been cutting a lot of shapes into MDF to get the hang of everything and have really been enjoying it.

[SMW Precision]

Sounds like you are getting close to completion. I think on electronic's box I am going to just form it myself likely light gage aluminium. Ordered B/O board today with VFD and fluild control. I purchased a C11 board at CNC4PC.
Talked too Aaron about these boards and he did not like any of them. So I guess I will see if board will work. This week I need to complete mill enclosure or at least make some progress. Stand is done and I need too form an aluminium pan. Likely use 1/8th inch plastic for walls; I need to be able to pull enclosure apart. So it will be built with ability to be disassembled.

[wildcat]

Ken - did you get a sense from Aaron why he dislikes the breakout boards? Not knocking his kit but the suggested wiring seems a little limited on safety features (not to mention hard to read). The geckos reset after a fault without shutting Mach down, there is limited isolation, no charge pump protection, emergency switch, etc. It is nice to keep the price down but I would not have minded paying a little extra to have the electronics well packaged and safe.

[SMW Precision]

Wildcat,

It was several months ago I talked to Aaron about boards. He mentioned he was going to offer boards for VFD and pump. I asked him to let me know when they were available; I have not yet heard back from him. I know they are not listed on website.
From our discussion I got the feeling from Aaron various boards have caused him support problems. He was not big on opto isolation either.
I wish he would find a set that works well and at least reccommend them. Kit is designed for VFD and fluid pump. It would be nice if a box and the rest was an available option. Frankly electronics are not one my expert areas though I have support if needed.

[Richards]

Let's discuss opto-isolation a little. In my designs over the last thirty years, I've almost always used opto-isolation. With well over 100 designs that ended up as fabricated circuit boards, that's a lot of design time (well, some of the designs were simple little ten-minute things). When I hear that someone doesn't like opto-isolation, it usually comes down to them not wanting to install extra power supplies - or even worse, using the same power supply on both sides of the opto-coupler, which defeats the opto-isolation. If we understand it, it is a wonderful and wonderfully easy concept. With opto-isolation, there is NO copper connection between the computer and the controller. There is only a light going on and off to transfer the state of a signal from one device to another. With opto-isolation, when used properly, most of the electrical interference problems that plague industrial electronics can be eliminated. The common opto-couplers like the TIL-111 are available for a few cents each. Granted, there is a signal delay involved, usually about 5us, and there are some current requirements, usually about 10ma, but both of those factors are common with a lot of TTL circuits.

They're very easy to use. For instance, with a TIL-111, you can connect pin 2 to your active LOW signal line. You connect pin 1 to a resistor (330 ohms is a good starting point). You connect the other end of the resistor to +5VDC. When the signal goes active (LOW), the internal light turns on. On the other side of the circuit, you connect pin 4 to ground. You connect pin 5 to another resistor (2,200 ohms to 4,700 ohms usually work fine). The other end of the resistor is connected to a separate 5VDC supply. You also connect the device you're sending the signal to, to the junction of pin 5 and the resistor. In a typical TTL circuit, you're ready to run. Assuming that everything in the circuit works off an active LOW signal, when the input circuit goes LOW, the internal light turns on. When the intermal light turns on, the internal light detector turns on. When the internal light detector turns on, the internal transistor turns on, and the voltage on the Collector drops to zero. Thus, an active LOW input signal produces an active LOW output signal.

The beauty of the system is that if something happens on the controller side of the circuit, like fluid splashing the electronics or metal chips shorting out the electronics, you might burn up the controller, but your computer is safe. On the other hand, if your computer decides to take a dive, it might fry, but the controller is saved.

Some breakout boards have opto-isolation built in. If they do, you won't have to add your own circuits. To me, one of the main advantages of using a breakout board is that I don't have to build high-current step/direction circuits to drive the Gecko's step/direction lines. The documentation that I have states very clearly that the Geckos need 16ma of current to work properly. In the TTL world, 16ma is a lot more current than most TTL circuits need. In fact 4ma to 10ma are much more common than 16ma. Parallel ports, in my opinion and with my experience, can't be counted on to supply 16ma. That means that the step/direction signals might not pulse when they're supposed to. That also means flakey behavior and possibly missed steps. Do yourself a favor. If you're spending the better part of $10,000 to buy a mill with CNC controls, a computer and some tooling, buy a good quality breakout board for about $100.

[wildcat]

Richards - points and experience well taken. I thought of making my own isolation but after reading the Sound Logic documentation that pointed out the danger of not being careful with the power supply (as you pointed as well) I decided that isolation is an area best left to experts instead of those like myself that know enough to talk about electronics but obviously not enough to build something from scratch. I also did not know about the current requirements of the input lines on the Geckos. Perhaps this partially why some have so much trouble with built in PPorts and laptops?

Thanks

[Richards]

Sometimes it's difficult being the owner, operator, bill collector, maintanence man, designer, and errand boy all wrapped up into one person. When I started my first business, I was totally overwhemed by all of the 'little' time consumming tasks that kept me from doing the necessary things. After talking with a friend, who had an MBA and worked for one of the large utility companies, he just laughed and said that most companies have whole departments for each of those 'jobs'. Welcome to the world of the small business person.

The amount of knowledge that we have to have to make these machines work and work profitably, is almost overwhelming. Many who have the answers are just a little timid in sharing those answers with the rest of us. Hopefully, that timidity will pass and we'll all benefit from the vast experience that is out there.

[IndHobby]

Personally I like optical isolation, so lets look at the basic issues.

Geckos and Limits.

Geckos are optically isolated onto themselves.
Optcal Limits are optical isolaters, take one apart and look.

If you follow the basic schematic and steal the control power from the PC you will be isolated.

Insofar as the motor and coolant. The SS relay I use is optically isolated as well and can be driven right from the PC. Solves that problem as well.

We do use Bob's VFD controller board, it can be used by itself, and to my knowledge can be isolated as well just by using a seperate PS on the VFD side.

I have helped troubleshoot more than one breakout board problem over the phone and it starts getting real old real fast, so have a hard time reccomending them to a customer.

The other problem I have with a breakout board is the real estate it takes, they are huge. If we are concerned with chips or coolant getting in the wrong spot lets not see how big of a target we can provide.

My first machine is all wire to terminal connections, just hard wired, nothing fancy. And it looks so bad I would never post a picture of it, it was just a concept and I always figured I would go back and rewire it later. Later never came. But she just keeps chuging along, about once every 6 months I blow out all the stray metal chips and leave it alone.

The point I'm making is that simplicity is a quality onto itself, simplicity usually brings robustness another quality I like.

Just my 2 cents worth.

[Runner4404spd]

i make it a point to mount my break out board upside down in the case as well as other electrical devices. everything mounted on the floor of the case is either shielded or covered to prevent shorts from chips.