Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: WRMorrison on May 31, 2007, 11:58:30 PM

Title: point me in the right direction?...
Post by: WRMorrison on May 31, 2007, 11:58:30 PM
Hello all!

I'm here seeking advice, but first, a bit of background info:

I'm a CNC mill operator (aerospace), and have a little experience writing gcode (but not a lot).  At work, we normally write all programs by hand, as the boss was too cheap to buy CAM software..(until now, we just ordered FeatureCAM, but that's another story).  I've always used manual mills at home for the personal projects, or a bridgeport manual at work, but recently decided to try and convert an X1 to CNC.

So, I've got the mill built, motors installed and everything works, so now for everything else.  What exactly do I need to operate my 3 axis CNC?  I downloaded the trial M2, but haven't had a chance to install it yet.  Once I can see that it will do what I need, I'll probably purchase the M3.  Is this software the only thing I need to go from .dxf to finished part?  For the time being, I'll just be milling 2D (some flat plates with holes...simple stuff).

Is there any other software/extras that I'm going to need that I'm unaware of?  I tried searching, but to no avail...my searching skills are a bit lacking I suppose.

Thanks in advance,
-WRM
Title: Re: point me in the right direction?...
Post by: Hood on June 01, 2007, 02:15:03 AM
First off I would suggest you download Mach3, no point in starting with Mach2 when Mach3 is so much better .
 If just doing simple things then there are quite a few wizards which will write code for you, have a look at them once you install Mach. If things are a bit more complicated then Mach comes with LazyCAM which will convert from DXF, there is also LazyCAM Pro which you pay for but not sure of the differences between that and the standard LazyCAM.
Hood
Title: Re: point me in the right direction?...
Post by: WRMorrison on June 01, 2007, 07:51:57 AM
Thanks for the reply!  I guess I read the page wrong...I was assuming that the M2 was the free download and M3 the paid version. 

-WRM
Title: Re: point me in the right direction?...
Post by: newbie on June 01, 2007, 05:22:51 PM
I am new to the cnc world.  sounds like im in the same boat as WRMorrison.
At work i would like to upgrade a xy table that uses pc that runs pascal.  i downloaded M3 and love it , i think it will work great for my needs.
i dont know much about encoders and drives. 
i guess i dont understand how my encoders hood up to my pc, or do they go to a interface board first ?
Do my motors hook up to this board also, or does it all hook directly into my printer port?
i have a ribbon cable coming out of my encoders.
any coments will be helpfull, thanks

Title: Re: point me in the right direction?...
Post by: Hood on June 01, 2007, 05:33:11 PM
i guess i dont understand how my encoders hood up to my pc, or do they go to a interface board first ?

They just go to your servo drives, the servo drives get told by the computer to move a certain distance and they read the encoders to see if it gets there, if not then they fault out.

Do my motors hook up to this board also, or does it all hook directly into my printer port?

The servo drives can connect direct to the parallel port but it is best to use an optically isolated breakout board, there are many boards to choose from but the two I have tried are the PMDX122 from www.pmdx.com and the CNC Building blocks board from www.cncbuildingblocks.com

Just one question from me :) does your X Y table definitely have servo motors or could they be steppers?

Hood
Title: Re: point me in the right direction?...
Post by: newbie on June 01, 2007, 06:18:40 PM
im not for sure , they might be steppers.  what are the differances so i can find out? 
From the encoder the ribbon cables goes to a card they call LRM.  this card also has the home sensors wired to it and has a ribbon cable that goes to the servo dirve card.  then there is a rs422 cable that concects to the computer.
it has 3 home sensors and two more sensors for the head up/down.  will i need more that one port?
thanks



Title: Re: point me in the right direction?...
Post by: Hood on June 01, 2007, 07:11:15 PM
can you post a pic of the motors, that will be the easiest way to tell whether they are steppers or servos. Servos need encoders, steppers dont , as you have encoders its likely they are servos but it could just be that the control requires feedbackthus the need for encoders. You can probably get away with 1 port but as PCI ports are so cheap its not a problem if you do need another.


Hood
Title: Re: point me in the right direction?...
Post by: WRMorrison on June 02, 2007, 09:46:47 PM
Alright, I downloaded and installed the Mach3 demo, and I read about half of the 170+ page tutorial.  I understand pretty much everything, until it starts talking about the limit/home switches and setting up the ports/motors for Mach3.  If I had an electrical engineering degree, maybe I wouldn't have such a hard time understanding all of it... :D

Basically, I just want to get this thing up and running some small parts to see if it will do what I want.  Do I absolutely have to add home/limit switches right now?  I'll probably add them at a later date, but for now, I'd like to just machine from an origin on the part.  With these small parts, the tables won't even come close to their limits of travel.

Also, I just don't understand how to set up the inputs/outputs to get everything working.  I don't suppose there's someone here that can tell me exactly what to click?  Like a "Complete Retard's Guide to Mach3?"  (BTW, sorry if that offends anyone, but it's just a joke... :D).

Thanks,
-WRM

ETA:  It would probably help to know the specifics of the hardware that I'm trying to use. 

I'm using this 4 axis kit from stepperworld: http://www.stepperworld.com/FET3dynamo.htm

I just want to know how to assign (what ports/pins) the motors.  I have no limit/home switches at the moment, but I think that I will eventually buy at least homing switches (maybe make the Z axis home switch adjustable for machining different height parts to reduce time in homing that axis?).  Eventually, I would also like to add an E-stop switch and a MPG/feed rate override switch/4 axis switch (similar to older FANUC boards).  Where is the best place online to find all these goodies?  Since I only have one parallel port, I assume that I need to limit my options due to lack of inputs.
Title: Re: point me in the right direction?...
Post by: Hood on June 03, 2007, 04:54:26 AM
You can run Mach without limits etc no problem, obviously its better to have them but when I first converted a manual Bridgeport I had it running for a long time before I got round to making the limits. I would however say that an E-Stop is a necessity and would highly recommend that you put one on.
 I know what ou mean about reading the manual, when everything is new it is a lot to take it but onceyou  start to use Mach it becomes clearer and is a good reference source. I am not sure if you have seen the videos, you will get to them from the Downloads tab at the top of the forum. Have a look at them as there are ones on most subjects and may help you out quite a bit. If you still have problems post again and we can get you sorted.

Hood
Title: Re: point me in the right direction?...
Post by: Hood on June 03, 2007, 04:57:43 AM
Also forgot to say that you can use one limit for each axis, it will act as a home switch and a limit switch for that axis and saves on pins.


Hood
Title: Re: point me in the right direction?...
Post by: WRMorrison on June 03, 2007, 10:35:20 AM
Thanks for the advice Hood, I'll check out the videos and see if I can find something that helps.  Is there a good place online that I can find an E-stop and other related switches?  If I order the E-stop, I may as well get the other switches and things that I want, and install them all at once.  I'd like for the home positions to be in the middle of the X/Y axis, and have the Z home on an adjustable track of some sort.  How about where to find an MPG wheel?  Lots and lots more reading and searching to do...

-WRM
Title: Re: point me in the right direction?...
Post by: greg on June 03, 2007, 11:23:22 AM
go on ebay & search for item #330114559353. that is a e stop switch. go to the home page &on the left you will see different catagories ther is a catagorey for e stop & limit switches. i have made several buys from him  & he is always right on with good items , combined shipping & supper fast shipping. good luck greg ;D
Title: Re: point me in the right direction?...
Post by: Hood on June 03, 2007, 02:32:11 PM
Any electrical/electronics supplier should be able to supply E-Stops, limits etc. I live in the UK and am not sure where you are so cant really recommemnd suppliers. As greg has said, eBay is an excellent place to get bits and pieces and bargains can be got quite easily. For an MPG I got mine when there was a bulk buy on the Mach Yahoo group a few years ago but I know Ron Rogers sells them http://www.rogersmachine.net/MPG/heatsink.html and also I am sure ther is a guy making them up, have a look here http://www.artsoftcontrols.com/forum/index.php?topic=862.0
 Regarding the limits, iIf you need more inputs its a simple and relatively cheap thing to put in a PCI parallel port card, ebay can also be a good source for them, in the UK I would expect to pay only £1 or £2 for a new one on eBay.
Hood