Hey all--
I bought a couple of the DM440's over the last holiday, so thought I would post a build log, even though I'm partially into it already. I got them from a shop near where I work in the Phoenix area--here's a couple pix, getting loaded to move to the rigger's yard temporarily:
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I left one in storage with the rigger and had the other moved to my garage another 35 miles away--here she sits:
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Since that picture I've done some cleaning up. Many people have already extolled the virtues of these machines, so I won't say a lot, except wow, what a cool little machine. It takes up less than a quarter of my 2 car garage, but it's built like a brick outhouse, a full on industrial cnc in a nice compact package. Needs a lot of work, though, and when I found these I had no idea about the SKIP controller. If I had known beforehand I might have passed them up, but by the time I realized I was already charmed by them.
One of the first things I did was start hunting down as much information as I could about these--got on CNCZone and quickly discovered this Dyna forum and read through all the posts. I already knew that the one I had in the garage had an oiler problem, and the forum quickly helped me find out the culprit. I removed the covers over the Y ballscrew and found the disintegrated lube line that everyone else with this machine discovered. That was an easy task--I used the technique 'olfoundryman' did (I think it was him) and wrapped the tubing around a mandrel and heated it with an air gun for a few minutes, which gave it a nice spiral to go around the ballscrew like the original. Worked out nice. I didn't take any pix because I hadn't thought of a build log at that time, but there's plenty of similar pics on this forum, nothing unusual about mine.
The next thing was to get it up and running and check out all the operations to see what else might need to be done. I only had single phase 240V but I went ahead and connected two of the transformer coils and got some life out of it. At the time I assumed that my only option was to eventually get three phase, but thanks to a couple other members (Jim Dawson and Marty Escarcega) I discovered that wasn't so--everything on the machine except the spindle amp used single phase, and even the amp would run the spindle motor on single phase, but I could not get the spindle to initialize even though everything else would, including the ATC (yes!). There's a lengthy thread (http://www.cnczone.com/forums/dyna-m...converter.html) that goes into a lot of the details, but it came down to a ground fault between some component and the frame. I finally tracked it down to the coolant pump--once I left that unplugged the spindle amp finally stopped showing a ground fault and the spindle would initialize. After my initial excitement of getting the last item running the excitement was quickly tempered by really loud spindle bearings. So another item on the to-do list.
So what am I gonna do with these? Well, it wasn't originally in my mind to do a retrofit, but after I discovered the SKIP controller and trying my best to get a handle on it (I've used conventional G code for too long now) it's turned into a retrofit project. Apart from that, I have an amateur astronomy (my other hobby) product I've developed and hope to eventually commercialize, and most of the parts would fit nice on this machine. I had a cnc router I had built myself a few years back and I was able to prototype a lot of the parts on it (acetal and aluminum) but it really wasn't up to any kind of production runs, and of course the accuracy of a home built isn't going to come close to a real metal cutting machine.
So down to brass tacks (whatever that means, but it sounds nice). I've already stripped out all the electronics from the cabinet and started doing some research into what I would need. I've divided the project into three main areas in my mind, in the following order:
1. Axis motion
2. Spindle operation
3. ATC operation
The first item I feel pretty comfortable with. Since my experience with building the router I've learned a lot about stepper motors and drivers and limit/homing switches, so I'm pretty comfortable with that part. I plan to use the existing steppers for now since they seemed to be in fine working order, and I'm not so desperate for really fast rapids since it doesn't have far to go. I've already ordered a Gecko G540 which is due to arrive tomorrow (Saturday) so my weekend is going to be taken up with that. I plan to use the existing power supplies from the machine, which seemed to be in good working order. I haven't decided on what controller software to use, but for my router I used LinuxCNC so I will use that to get started until (if) I run into any insurmountable snags with it. I'm thinking of getting a full motion controller of some sort, and some additional I/O board(s), but for now this will get the machine moving. I found an old PC with a parallel port and fired it up, and discovered I already had LinuxCNC on it. I finally recalled that there was some issue I was having with that machine and had replaced it with another, but I don't recall what the problem was. I guess I'll soon find out and may have to find another PC--I just sold the router and included the working Linux box with it.
The other two items after axis motion are going to be daunting for me. As evidenced by the other thread I'm no expert on electrical/electronics matters, so it's going to be a tough row to hoe for me. But, I love to learn new things, so I feel pretty good about forging ahead with it. As far as the ATC is concerned, even if I don't get the full system operating (I hope it doesn't come to that, what a waste of one of the nicest features on it) I need to at least get the 'presser bar' working in order to change tools manually. That's the AC reversing motor/worm gear/presser that pushes on the drawbar at the top, with two sensors to track the presser bar. One thing I don't like about it is you have to use two separate buttons to clamp and unclamp, and I have to make an effort to make sure I don't leave it in the unclamp position and pressing on the drawbar washers. It would be nice to re-work it to use one button like most machines I've used so that the presser moves back after releasing the button.
I think that's enough to get started--I'll report on my progress with the Gecko soon I hope.