Many questions from a first timer

[Jason38]

I am new to the whole CNC thing but not to the fabrication aspect.
I was in a friends shop watched his CNC machine and had to have one. Being a Carpenter by trade, I conjured up many uses for one in my shop Ah the justification of a new item. I went online and found that The shop bot was a little cost prohibitive. Further research I stumbled upon a jgro Free Plans, I downloaded and looked over the plans and the decision was made I could build this and I will with some mods here and there.

I built my base from aluminumn extrusions in order to eliminate the torsion box the gantry was per jgro the dimensions of the whole unit are a little larger than the plans.

(2) days I built the base, and gantry it performs flawlessly on all axis. Now I am entering the difficult part.

where do I get the acme rods what size and pitch? good price?

The electronics, I found a package which included nema 23 stepper motors on buildyourcnc.com are these good motors/ strong enough? is anyone familiar with the package that i speak of?

Is Mach3 the program to use? I wanted to run this machine off of a lap top that I have but I just saw that laptops are not supported by mach 3 is there another option? I have only this laptop that is a pc everything else is mac.

Last question for this post:

I built the Machine, order the electronics, install and wire electronics, load software, connect electronics to computer, run program, CNC will function?

Is it that easy? I suspect not.

Any help will be greatly appreciated as I am pretty sure that I will need quite a bit of it.

Thanks

[ger21]

I wouldn't buy motors from a website that says they'll send you one or the other, whatever they have in stock.

The best performing drive for hobbyests is the Gecko G540. Check out the kit with the 381oz-in steppers from Keling.
http://www.kelinginc.net/CNCNEMA23G540Package.html

As for screws, go with either 1/2-8 2 start acme (150-200+ipm) or 1/2-10 5 start acme (250-300+ipm). Available at www.mcmaster.com or www.mscdirect.com

Get antibacklash nuts from www.dumpstercnc.com

You can download Mach3 and see if it'll work on your laptop, but it doesn't work on most. It's free to download and use for up to 500 lines of code, so definitely download it and learn how to use it now.

Actually, Mach3 will probably run OK, but it may not run you machine OK. I tried using my laptop, and the motors run extremely rough and stop and start. With my $20 1Ghz Dell desktop, they run great.

Last question for this post: I built the Machine, order the electronics, install and wire electronics, load software, connect electronics to computer, run program, CNC will function?

It should. :-) But you'll need a CAD or design program and a CAM program to create g-code for Mach3 to run.

[Jason38]

Okay,
This is what 3 days of work got me, Look at it and let me know what you think. It is the basic JGRO design but I did deviate from the plans a bit, I had allot of aluminum lying around and I just cant stand mdf I had marine plywood left over from my boat build. I am going to make the router clamp out of HDPE. I used Skate bearings. All the Axis's are very smooth and have no slop what so ever (I was shocked how tight and smooth this thing turned out. I plan on using a vaccumn table for a clamping method which will build above the aluminum. I eliminated the adjustment blocks on the pipes and threaded them solid (i am not sure if that was a good idea I just figured what am I gonna adjust with mdf blocks and threads with crazy glue?

Keep in mind I have no idea what I am doing here, I am just a carpenter who would like to have a CNC on the cheap to see if it could be a viable investment for my business to build a large scale one. I still need to acquire my lead screws and nuts, make my anti backlash block and get the electronics oh yeah and figure that out.

I you can see that I have done something wrong with my build where it will not function properly or blow apart please let me know, I will need much help as I suspect this may have been the easy part. oh yeah that piece of ply on the center is just to represent the approximate height of the vaccum table below that plywood is a aluminum extrusion to exist as a torsion box, I still have to tig up the 45 braces.

All input appreciated

http://www.cnczone.com/forums/attach...1&d=1262837374

[zeeway]

Jason,

I am a bit ahead of you in my build...just have received the drive (Gecko 540) and the power supply, but still waiting for the motors (from CNCrouterparts.com).

Your build looks pretty good, but you may want to go back and add the adjustability back into your design. I am a reasonably good woodworker, and have built a number of cabinets, etc. I have always prided myself on getting everything square and plumb. But these machines have so many elements determining fit, that it is almost impossible to get your machine square enough with just the usual cabinetmaker skills working. Just my $.02.

Angie

[Jason38]

Zeeway,

Thanks for the input. If the adjustment blocks are there only for the reason of squaring up then no worries there dont need them. I tigged up a jig shot my centers with an instrument and my corners and assembled from there. I would say since nothing is perfect it may be 1/2 mm out if at all. I do know the importance of squaring up and used some tricks I learned while employed at Mcdonald Douglas.