New Machine Build- Your evaluation and help please.

[Deskin]

Great community in the zone. Soooo much to learn.
So I get this crazy idea - build a CNC Machine in my basement! I don't know where to start asking for help, but I'll tell you where I am.

I purchased parts piecemail on e-bay, (read enough but not enough to stop with plans "in my head".)
Here's what I have:
A welded steel frame and gantry of 2" square tube.
Supported 16 mm rails in x and y, unsupported 16mm z
3 - 5mm pitch ballscrews and antibacklash nuts
260 oz steppers, TB6560 controller/driver Mach 3 Demo.
motors are tuned correctly at 1/16th and I'm getting about 180 ipm
Setup is very solid. Z slide is 1/4 plate aluminum.
Mounted a cheapo harbor freight panel router for testing only.
I can cut basic stuff in Mach 3 (circles and squares using the wizards or direct g-code.)
This is where it ends.............now the hard work and questions. All help comments and referrals for counseling accepted!

Given the above, is my 180 ipm a decent speed?
I assume I have a rugged CNC for any wood or plastic. I'm hoping aluminum too? yes/no? (I am aware much becomes spindle and tool dependent and before I ever move to a serious spindle, I'll be mounting a porter cable 690)

Current major heartaches - I have Rhino 4.0 CAD/CAM/ART - can't get the post processing files to open in the Demo version of Mach. I can export simple dxf stuff to Lazycam and load from there but thats not the long term solution.

I havent installed my limit or home switches yet. Do these have to be installed and set for soft limits to work? Can't get those working

I would really value your comments. THIS has been a great learning experience but I know I have .004 of the knowledge base I really need and want.

[ger21]

Given the above, is my 180 ipm a decent speed?

I'd say that's very good, from what I've read about those drives.

I havent installed my limit or home switches yet. Do these have to be installed and set for soft limits to work? Can't get those working

You don't need to have them installed. But you do need to reference to a repeatable position using the ref all button, or ref'ing the individual axis.

Before I had home switches, I would jog up against the stops, and ref there.

[Deskin]

Originally Posted by ger21 I'd say that's very good, from what I've read about those drives. You don't need to have them installed. But you do need to reference to a repeatable position using the ref all button, or ref'ing the individual axis. Before I had home switches, I would jog up against the stops, and ref there.

Thanks ger - I have referenced all at the correct table positions. I can be elsewhere and hit go to zero and it will home. The table is 900 x1000 mm I know where the limit toggle is but get messages like soft limits out of table range. I think I just don't understand the values and proper signs to load in the max and min soft limit config fields. Is one always minus and the other plus? One always less than another? Is it like 30 and -30 or 25 and 975 given the table size? Sorry for such basic questions.

[ger21]

I have referenced all at the correct table positions. I can be elsewhere and hit go to zero and it will home.

Goto Zero and going to home are not necessarily the same thing. Assuming 0 is the lowest you want to go, you're softlimit min should be slightly less than 0, depending on how much room you have past 0. Your MAX settings should be just less than your max travel.

Max must always be greater than Min.

If you're getting an error, than your current position is either less than your Min, or more than your Max.

[Deskin]

Set as follows again for a 900x1000 mm table

X max 950 x min -15
y max 850 y min -15
Z max 100 z min -15

I "think" I referenced home at 25 mm from the home min axis intersect point.

I jog to mid table, hit the soft limit toggle switch and get,"machine out of limits for soft limit activation"

I don't think I am properly setting or going to home now based on your earlier comments.

After this last question, any basic book you could recommend for a rookie? May just look for a local class at technical school.