Hey guys,
I am new to CNC routers, but I have been doing a lot of research lately, and received a lot of great info from this site. I just finished up school, and I am starting a small custom ski and snowboard manufacturing company based in Lake Tahoe. I just received some initial R&D funding to create my CNC router, pneumatic press and produce some prototypes. I have taken autocad and solidworks classes, and am looking to build a high quality cnc router to produce the parts I have designed.
The primary use for this router will be cutting out the outline of ski/boards and creating the thickness profile of my wood/bamboo cores as well as some UHMW plastic pieces that are used for the sidewall/tip/tail construction. However, I would like to make the machine as versatile as possible, and will be using it to create more CNC routers and parts in the future. I would like it to be able to machine aluminum, and will probably fabricate a plasma cutter attachment for it at some point down the line.
I am looking to build the machine with a cutting area of approximately (slightly more than) 2' x 6'. I have a budget for the build of approximately $2000 for the machine and electronics (I already have a windows xp computer with parallel port, autocad, solidworks, bobcad/cam and Mach3). I have a full shop at my disposal and am an accomplished MIG welder. I am on a bit of a time crunch and need to have a working machine within 2 months. Here’s a basic overview of my plans so far:
Spindle: Bosch 1617EVS 2.25hp variable speed router
Z AXIS: K2 CNC's 5" travel z axis assembly and 3.5" router mount:
K2 CNC Router 5" Linear Slide Actuator - ZA500QR Z Axis- Nema 23/34 motor mount | eBay
GANTRY & TABLE: I will either be fabricating the gantry out of 2" square steel tubing or possibly 3060 extrusion w/cncrouterparts.com gantry risers. My plan for the table is to fabricate the table frame from 3" tubular steel with a 2.5' x 7' opening to allow an 8" thick 2.5' x 7' MDF torsion box to be mounted as a work surface/surface to mount my jigs. The gantry will mount to the steel frame and allow the torsion box to be removed.
X AND Y AXIS DRIVE SYSTEM: I am planning on purchasing three of cncrouterparts.com's NEMA 23 3:1 belt reduction Rack and Pinion drive systems. Two for the x axis, and the other for the y axis. link here: CNCRouterParts
I will be ordering (2) 7' 20 pitch racks for the x axis, and one 3' 20pitch rack for the Y axis from Moore Gear. The x axis racks will be mounted to underside of the steel tubular table frame I am fabricating.
Please let me know if I am on the right track so far and if you have any other suggestions. I am looking at these prefabricated parts partially due to my timeframe for completion, and they seem to be well designed and offered at a fair price. I am more than open to other suggestions though.
QUESTIONS
Electronics?: I have been looking at the NEMA 23 setups available, and it seems most places offer essentially the same kits at roughly the same price. I will be needing 4 stepper motors for my current design, 2 for the X axis, and 1 each for Y and Z. What TQ steppers do you recommend for my setup? I figured the 425oz/in NEMA 23's would be fine. Can i get away with the lower power 287OZ/IN steppers availible? Seems like the best price i can find for a 4 axis 425oz/in kit is about $500, and the 287's are about half that.
Linear Motion? I have been debating back and forth numerous times on what to use for linear bearing rails. The Z axis is taken care of, so I just need to answer the X and Y dilemma. For the X axis I am thinking of using the extended carriages from cncrouterparts that run on 1/4" cold rolled steel. I may also use them for the x axis, but am undecided. please let me know if you have any thoughts or suggestions.
Thanks guys, I am exited to get started on the build. I would greatly appreciate and advise you guys can give!
-Ryan