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View Full Version : What do i need.



manofgresley
29-07-2012, 06:37 PM
Hi every one.

I am new to this site and the world of CNC. I am a timed served Toolmaker, but i left the trade before CNC controlled machines took a hold on British engineering. I have a 1918 Drummond Lathe and a Hobbymat BFE 65 milling machine, it is this Miller i wish to convert to CNC control.

I have done a lot of studying about what equipment and parts i need, but it is quiet bewildering out there for a retired mechanical engineer when it comes to Electronics.

I understand I need the following :
X,Y, & Z Stepper motors, but what size?
A Stepper driver board for each Motor (or all in one?)
A Breakout board with Parallel connection for PC (or can you get an all in one board along with the Stepper Drivers?)
A suitable power supply (Although i have seen some advertised as USB connectible, or am i reading that wrong)

The mechanics I understand like Ballscrews Leadscrews Flexible couplings etc.
The software, well i think i have it covered - Mach 3 for the G - Code, Sheetcam for CAM, and Draftsight for CAD. Unless anyone knows better, please feel free to advise.

Can anyone help and put me on the right path for the electronics.
Many thanks in anticipation of your replies.

Ray

Ricardoco
29-07-2012, 08:28 PM
Hi there and Welcome to the site, it is a daunting task to undertake but converting a mill with the help of the guys on this site has been educational and a lot of fun My first was a Boxford VMC 260 Impossible without all the Stupid questions ai asked the guys on here, Then i converted a similar size mill to yours some time back and i wanted to see what was going on inside the machines when i got it working so i opted for this Breakout board on both occasions

:-http://www.cncdoctor.co.uk/opto-bb-v1_61.html

There is a manual there for download before you even make a decision, there may be cheaper boards out there but i opted for this one as it has plenty of features and with the LEDS on the board i could see when and where the signals were going. It has given me no problems what so ever. I chose to have seperate drivers as that was the general concensus of opinion at the time.

I used nema 23 3nm motors for the X & Y and a Nema 34 for the Z

Power supplies Hmmm cant help you there as i made mine from bits i had around, but im sure there will be someone to help you with advice there..


Have fun and Welcome to the Forum

Rick

Ali Kat
30-07-2012, 08:10 PM
Hi, and welcome to the world of CNC. Like yourself, I was totally bewildered by the elctronic side of things when I started and even paid someone to wire together my first little CNC machine! Oh what a fool I feel now when I realise what help there is on forums such as this one and how simple it really is once you have done some basic homework.

There is no single correct answer for your question "What do I need". A dozen people could respond to this thread, all giving different options and all would be correct from a certain point of view. For my own recomendation I am going to go with the Gecko G540. This is an "all in one" break out board and 4 axis driver unit that will comfortably drive NEMA 23 motors for the mill that you want to convert. There is an established xml file already in existence so Mach 3 is simple to set up. It is contained in a nice small aluminium enclosure which is fairly easy to mount anywhere you fancy. I think the maximum voltage supply is 48v for this unit so motor speed should be fine.

Next week I might recommend something different but I have just retro fitted a Denford novamill with a G540, using the original NEMA 23 motors and a power supply from ZAPP Automation. A few evenings of wiring and I ended up with a nice setup that is currently cutting anything that I can throw at it (repaired an outboard last night with a small machining job that took 10 minutes but would have cost me over £50 from Johnson / Evinrude).

Hopefully others will contribute to this thread so that you can get a feel for the different options that are out there. But most importantly, remember that we all started somewhere and I would bet that most of us have made our choice of system work to a greater or lesser degree. I wanted to get into CNC to make more accurate parts quickly but now I find that I enjoy building or converting machines as much as I do machining parts.

Good luck and continue to throw your questions at us -I for one will be more than happy to help and I'm sure that there's a lot more out there with a similar feeling.

Ali Kat