Beaver MK.2 retrofit - my first cnc project

[bseibenick]

Today I bought my first cnc mill, a Beaver MK.2 vertical knee mill. Currently the mill has a Summit/Dana controller on it and it appears to have 220V 3phase AC Servos with what I believe are resolvers on the back end. I won't know until I get the mill back to my shop whether the current controls are functional or not. The mill also has an oiler and a coolant system on it.

When I get the mill I have the option to purchase 4 Ormec MAC-DA055G/I AC servo drives (220v/3ph 12A, 56 in-lbs) with encoders but I am undecided on what I will do there as I am not sure yet whether I will be able to find an AC drive for them that I can use with Mach3. I may have to pass and bite the bullet for some good DC servos. Part of my issue with the AC servos besides the drives is i will be running a 3phase rotary converter to make my 220v/3ph power and from what I have read it may cause issues with the motors pulsing. I have posted some questions to the servo/drive section of the forum and I will see what kind of info people can give me.

I have already been reading a bunch of the other builds on the forums so I am very excited to get going.

For those who have done similar projects can anyone give me any advice?

Is there anyone who sells 'packages' of dc servo motors and gecko's for a mill conversion? I have seen some of the conversion packages like the Ajaxcnc, Centroid, etc but I have not found any packages for DIYers.

Thanks!
Brian

[123CNC]

Brian,

10 bucks says you have steppers there. Of course you will have to get it to your shop to reveal the inside of the cover. They could be DC brushed servos, but you usually can see /access the brushes (not visible in any of your pics). I'm pretty sure all of the Bandits pre-dated AC Servos, but I'll bet 100 bucks that these are not AC Servos.

There are older threads and a current thread on replacing the Bandit (Summit/Dana) you may want to read as well.

If you just want to get the old gal up and running in the shortest time possible with the least amount of money, I think you will find the steppers the easiest, simplest, and cheapest.

For the life of me I cannot think of or find what I thought was a decent 'kit' or complete package, if I find it I will repost.

Bob Campbell also offers a decent looking kit and various components. CNC4PC is an excellent choice for components, but don't know if they sell in packages (don't think they sell drive motors).

Welcome Brian! It may be appropriate in your next post to let everybody know how long youv'e been afflicted with the CNC bug (somehow its supposed to help you toward recovery, I just haven't figured out how).

Good luck with your project, and have fun.

[bseibenick]

123CNC, thank you for pointing me in the direction that my controller is really a bandit. I will start reading on the Bandit and the retrofits. If my motors turned out to be dc servos that would actually make me happy. Then I could purcahse some encoders and gecko's and not even have to replace the motors. Once I get the machine home I will have to look closer at the motors and try to find some numbers on them. Something about standing out in 10degree weather makes you forget to look at things...

As far as my cnc bug/addiction, it started when I purchased my first manual bridgeport about 3 years ago. From day 1 I wanted to be able to convert it into a cnc machine but the ways were just too worn out plus the cost of ballscrews and a quill feed made it impractical. when this machine became available I jumped at it.

brian

[DennisCNC]

Those are old slo-syn steppers on that mill. As for buying dc servos keling sells dc motors and geckos.

[bseibenick]

Dennis, if those really are dc steppers then to get the mill up and running I should be able to buy a couple stepper Gecko's, a breakout board and build a power supply for it and I should be in business and then upgrade it to servos once I gain more knowledge.

The biggest issue I see is if I cannot find any info on the stepper will be figuring out the motor's voltage/amperage to get the right power supply for the motor. I am hoping for some model number but if I can't find any is there any way to figure out the requirements for the motor? I already know how to map out the motor's wiring (4, 6, 8 wire, etc)

Thanks,
Brian

[DennisCNC]

I see a lot of people worry about stepper motor specs and such. The way I do it when I get a unknown stepper is get what ever stepper drive is available crack up the amps on it with ~50v power supply and wait to see what gets warm first, if the motor is first reduce the voltage if the drive reduce the current. Never fried a drive or motor. I'm sure the old control should have a good power supply.

[bseibenick]

Dennis, which break out board and drives do you prefer?

I am getting anxious...I should have the mill delivered to my shop by the weekend.

Thanks,
Brian

[DennisCNC]

I say go with geckos can't go wrong with them and for the break out board the CNC4PC.com, I use a C1g and C11g boards both work nice and the price is right.

[123CNC]

I second Dennis's opinion, but would also recommend you consider the Gecko 203V drive. The 203V (Vampire) is aptly named and therefore more friendly to experimenters (intentional or not).

[bseibenick]

Since I am definately an 'experimenter' I just placed an order for some Gecko 203v's and the c11g b.o.b. from cnc4pc.com.

I'll report back once the mill and parts get here.

Thanks for all the help! I'm sure there will be more questions to come

Brian

[bseibenick]

Well, yesterday the truck showed up with my mill. It only took about 3 hours to get the mill into the garage and put back together. It is definitely heavier than my Bridgeport. Last night was spend checking everything out on the mill. I did determine that the motors are steppers. Unfortunately it appears something in the regulator board of the Bandit is fried as the steppers power on and hum but I get nothing on the front panel of the Bandit and there are some nice charred marks on the regulator board. The model on the Bandit is 218-300-02B built in 1979. I just have to do more research to determine which model Bandit it is.

On a good note I found that the Bandit has a 45V power supply and on the two stepper drivers inside they actually have a tag hanging on them saying the driver was set for 5.5A. Even though there is not model/manuf. info on the steppers it sounds like I have a good place to start for a power supply voltage and a current setting for the steppers and the Geckos. The other nice thing is that the stepper wires are tagged where they meet the Summit driver with A1,AA-Com,A2,B1,BB-Com, and B2. It sounds like it already have my wiring setup for the steppers. A1,A2,B1, & B2 should be my phase wires. The only thing I am unsure about is from the Gecko manual where to hook up the 2 common wires of the stepper up to on the Gecko. Any ideas for the Gecko 203V?

My break out board from cnc4pc showed up the other day and the Gecko's are scheduled to be delivered today. If all goes well I am going to try and get the motors turning tonight. Does anyone has a 'quick start' guide on getting Mach3 setup with the C11g break out board from cnc4pc and the Gecko's?

Progress is a good thing, right???

[bseibenick]

With both my breakout board and Gecko's in hand I started unhooking the old Bandit control last night. It took about an hour and I had the c11g breakout board and the gecko wired up along with the x-axis stepper. For now I setup the stepper as parallel connected. I loaded up Mach3 on my pc and configured it per the setup guide. Of course all my progress came to a halt at that point because I could not find a male-male db25 cable to connect my pc to the breakout board.

Since I was determined to make a stepper move last night I resorted to disabling the charge pump on the c11g and then manually issue 'step' signals on the step wire to the Gecko. Amazingly the stepper moved!

Tonight's plan is to find a cable on my way home from work and then attempt to get the stepper to make a few revolutions and the put the stepper back on the mill and see if I can't get the x-axis to move some.