[cybeeria]

Hello everyone!

I have been lurking for quite a while and learning, learning, learning. Now it's my turn to give something back so here goes.

I have wanted a 3/4 axis CNC mill for some time but I could not afford what I wanted nor the shipping to get it here as I live in southern New Mexico and everything I saw for sale was on the East or West coast and shipping would be outrageous. I finally found a old CNC mill close to me. It is a Hurco Kmb-1m in great shape but with an ageing control system and was therefore pretty much obsolete. I bought it on e-bay for $1000 and since it was only 200 miles away I just borrowed a big trailer and went and got it myself for $70 in diesel. The mill is bigger than I really needed but I'm sure I'll use the capability someday. Since it weighs almost 5000 pounds is was a bit of a chore getting it into my garage but with a couple of friends and a rented forklift we got it in.

I have 3 phase power less than 50 ft from my garage but the electric co. says that since I won't ever use enough power to pay for the cost of installation they want $7000 to hook me up. OUCH! That will never do. It turns out the the Hurcos use a very special motor made just for that mill and the actual motor shaft is part of the variable speed drive system. No single phase motor is available. After much research I decided to simply use a 3 hp single phase motor and drive the old motor with it, useing the old motor as a jack shaft. I made a bracket to hold the new motor and put a pulley where the fan on the 3 phase motor was and voila! works perfect but look a bit odd.

The controls were problematic and the cost of a Hurco upgrade was $4500 to get 10 year old controls. No good. After reading and learning on the forum (thanks to everyone!!) I decided that I really wanted to stay with a closed loop servo drive system and use the nice servo motors that I already had. After more research I decided to purchase the Ajax system (hence posting in this section). I ordered the system and also the upgraded encoders as the 200 line units in my mill were not enough.

I can't say enough about how nice Ajax has been. They were very helpful in deciding what I needed and getting me the right stuff. When it arrived I was very impressed with the whole package. I am just starting the electronics install and will update this as it goes along. I will post pictures too.

I plan to run OneCNCXR2 and they have been very helpful as well. The fact that they have a centroid post already was a major factor in choosing the Ajax/OneCNC combination. I am very computer literate but I don't want to write the interface or post. I want something that will pretty much work right out of the box.

I built a dedicated computer for the mill using a Gigabyte 2004RZ motherboard with an AMD 2.4 GHz CPU and 512Mb ram. I plan to install the motherboard right in the mill as there is plenty of room and I'd like to keep it self contained. I installed the control board and the flash drive from Ajax and it runs perfectly right from the onset-a huge plus! I was unsure that this board would work with the Linux but it does! Easy, Easy, Easy!

I installed the new encoders and they fit right on without any modifications to the encoders or the mill. Again, very easy. I gutted the old controller and am now ready to install the new controls from Ajax.

I will post an update as I get further along.

Bill

[TR MFG]

Sounds good to me. We too have an Ajax installed and agree with you! They work great! We are thinking of doing a lathe next.

[Dan Falck]

I've got a Bridgeport that was converted to CNC by Hurco in their early days. When I bought it the Hurco control had been removed and a Centroid M-40 was installed in it's place. I really like it too. The Centroid/Ajax system is easy to understand and use.

Dan

[cybeeria]

Update on the retrofit project. I finally got the mill fired up over the Thanksgiving holiday. I had to disconnect the limit switches as they are proximity types and therefore not compatible with the controller directly. I will have to make an adapter board using pull-up resistors or an inverter IC.

The interface to the spindle control relays was a bit of a challenge as they are nothing like in the wiring diagrams provided and I had to make it up as I went along. I got it sorted out though and they work well.

Next came the spindle brake. On this mill it is air powered and releases when you apply power. I ended up just using some of the extra contacts in the 24V spindle control relays to activate the brake whenever there is no power to the spindle. The Ajax controller wasn't used for this so the braking is automatic. I may change this later but it just seemed simpler at this point and it works great. The spindle now stops in about two turns if the you send a spindle stop command or even if the power fails. Good for safety.

Once I fired up the system I had a problem with the table moving only a little way and then giving an error. The troubleshooting guide supplied said to reverse the power wires and like magic it started working beautifully! The system setup was pretty straight forward and went very smoothly. I ened up printing out the entire manual (about 300 pages) instead of trying to use the CD version. I still think the printed page has its merits and is overall more useful.

After running all of the diagnostics and setups, the system is telling me that I have excessive friction in the X and Y axis. I'm not sure what to do about this. I guess it means that the servos are drawing more current than the drives are comforatable with. It works just fine so I'm not sure if this is a problem or not but I will do some research on it and go from there. When turning the ball screws by hand they do seem pretty tight but I have no references to judge from. Anyone have any thoughts?

After completing the setups I put a block of aluminum in the vice and set about making some cuts. I used the canned cycles to perform some basic operations and was impressed with the results. It sure was a kick to watch the mill go through the whole cycle automatically! Now the real work begins-learning how to program it!

I still have a bunch of wiring to complete and "neaten" up as I was anxious to get it up and running and I left stuff just hanging. I will post some pictures soon.

[HuFlungDung]

Sounds exciting.

Did you overhaul the machine at all? Some of the slideways could be gummed up with old dried coolant or whatever. If you don't want to do a complete disassembly, you should clean off whatever grunge you might find on the slides and/or ballscrew. Solvents are good to penetrate dried up oily grime, but don't neglect the water based cleaners for loosening dried up coolant residues, particularly in the slideways.

Soak the slides and jog the table back and forth, wipe off, reapply new cleaner, repeat until the rags come off clean. Then apply oil and run it back and forth some more.

[cybeeria]

The mill is pretty much fully useable now with only a few small loose ends to tidy up. I ended up having to dis-assemble the lead screw assemblies and clean the grunge off the screws where they hadn't been used. I guess the previous owner only made small parts!

Here are some pictures of the installation.

I designed some simple parts on the computer and had the machine make them. Having never done any CNC before, the thrill of going from a computer drawing to a finished part automatically was incredible! I am still evaluating CAD/CAM software combinations and have not settled on one yet as each has it's pros and cons but at least I'm makin' chips!

Bill

[patrick71100]

I HAVE HURCO KM3P SAME BASIC MACHINE AS YOURS MACH 3 ,G100 SERVO BOARD,RUTEX DRIVES,OLD POST BUT I THOUGHT YOU WOULD SEE 200 LINE ENCODERS WOULD GIVE ABOUT .00025 ACURRACY WITH ARE BALLSCREWS,YOU CAN USE ROTORY PHASE CONVERTER FOR 200. TO MAKE 3 PHASE POWER OR 3 HP DC BRUSH MOTOR AND GATES TIMING BELT IF VARIDRIVE PULLEYS ARE NOISY WILL RUN ON 220 VOLT SINGLE WITH TONS OF LOW SPEED POWER AND EBAY TOUCH SCREEN FOR CONTROL ROCKS LINUX HAS DRIVERS TOO I GOT MINE 15 LCD FOR 120.00 I HAD MINE WORKING WHEN I WAS PLAYING WITH EMC,CADCAM IF RUN POWERMILL AT WORK AND VISUALMILL BUT FOR US HOBBIE GUYS STUDENT VERSION OF RHINO 3.0 AND MADCAM PLUG IN FOR 400.00 TOTAL CANT BE BEET EMAIL IF ANY QUESTIONS [email protected]