New CNC Build

The CNC router parts PRO machine is a fine kit and their instructions will walk you through the process. Search YouTube for the Frank Howarth video of him assembling his. You will not need a powerful computer for running the machine, but it should be dedicated, and stripped of all unnecessary other software. Keep your CAD and CAM software on another computer.

A vacuum table is very nice to have in production situations, but may not be necessary otherwise. It will probably add substantial cost and power usage ( for 4' x 8' typically 25-40 horsepower, usually 3 phase). A $10,000 budget is probably not enough for a 4x8 machine with a vacuum table. Spend money first on dust collection, a 3 hp cyclone would be very effective.

Remember that buying your own copy of Aspire, or Rhino and Rhinocam will run another $2000 at least. Look into Fusion 360 as an alternative (free for students, hobbyists and startups). Rhino does have student prices as well. Aspire is still being regularly updated, version 9 is due out soon, don't know what version you have been using if you consider it outdated. Investigate Linux cnc, UCCNC, WINCNC or Mach as options for your control software.

Along with the machine, software and dust collection, you will also need to buy tooling (bits, collets, clamps, etc.). Is $10,000 your total budget?

I chose to design and build my own machine. With some lucky deals on on materials, I was able to build a complete 50" x 60" machine for less than a third the price of buying the CNCRP 4' x 4' kit, so that is another option, especially if you still have access to a campus shop to help you make parts.

Great info. I do have access to a CNC machine, so building my own parts would definitely be an option. I would say around $8k is total budget on CNC-specific parts but I would be willing to create my own parts if it meant saving some cash (I am certainly not made of money, this would be considered a business expense of sorts). I am also capable of welding and can frame up a table. I would be adding a dust collection system to run with other machines so that could be considered separate, and I agree spending money there is always a great idea. I think vacuum would be the biggest bear. Would I be able to add a vacuum table later if I didn't go with one right off the bat? I honestly didn't even consider not using one. Having that nice suction to the table without drilling holes all through my workpiece is a plus, and it also helps to keep the edge clean by not allowing the material to bounce around.

I had no idea Aspire would be that expensive, I only assumed ours was outdated because I think we're still on 2009.

For bits and collets, what are you guys running for 3/4" material and the like? I have found our collets slip with the 1/4" stuff so I usually use 3/8" or 1/2" end mills at least. And I am willing to spend the extra money on bits, I've seen why you spend more for higher quality steel.

4DThinker said:

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One "bad" thing that happens now is that students use the large CNC just to break down plywood sheets into smaller rectangles. Yet we have several more efficient less expensive tools to make a large sheet into smaller sheets..
4D

Click to expand...

Lol.... guilty as charged. But man they aint cock :nerd: eyed

@RainMan 2.0
Ok Rick... as you seen whats put into it. Im sure you'll go Franks way
with a video. At least insulate the machine if you haven't done the walls etc.
Cold machines don't perform well. Capes are optional.

@jgrant6 - What will you be cutting and making? Would a 4x4 suffice and
you could do the half/half tile method. Ya know, slide the material over?

On our Multicam I'm able to cut 22' in length w/ tools removed from ATC holder.
It works fine as long as you setup everything 'perfect'. PITA tho.

@4DThinker - I would have to have a 4x8. I intend on making full sheet cutouts that really can't be split or re-indexed. It would be possible, but it would be so frustrating that I would eventually upgrade to a full 4x8 bed. I definitely understand what you mean when you say the machine is wasted on straight cuts, but if you have it the equipment and you don't want to have to worry about crooked factory edges, you really can't beat it. I guess it just comes down to what are you willing to pay for it, and I believe mine would be able to pay for itself in a year or two. That being said, I would be doing much more than straight lines.

As I'm looking more and more into this, I think I would be willing to do a lot more myself than I had originally thought. Is there a reason people are using aluminum instead of steel? I feel like steel would give you tighter tolerances as the table does not shift at all, and not to mention is more easily fabricated from scrap. I get the weight, but who cares. I don't plan on moving this thing more than once every 10 years or so.

@UglySign - I would be cutting full sheets of 4x8 3/4" softwood ply, and probably a lot of birch veneer ply as well. Mostly doing irregular shapes and dados into pieces roughly 7'x3.5'. A lot of inside cuts, and all stuff that would need to be repeatable. Also, likely some very thin 3-4mm marine grade plywood "skins" that would then be adhesed to the structural pieces.

Trying to get a better understanding of how you'd actually go about building a table and the XYZ constraints, I decided to play around in Sketchup and in about an hour I came up with this. None of the dimensions really mean anything, it was more me just trying to take a representational stab at it. I based it on a 2x2 steel frame which is likely overkill and could come down to 1.5" if braced properly.

Now for the parts that would actually have to be sized and whatnot, please help me understand this. So the the x,y, and z axis "controllers" basically attach to a threaded rod (lead screw) on which they are able to move back and forth on as directed by the computer. What are these controllers exactly? Just simple motors?

And after doing a little bit of research on vacuum tables, it seems you really would have to have an aluminum bed grated out and then have the fittings milled in, however I think it would be worthwhile and could be retrofitted at a later date. Having that rigid aluminum base below the spoilboard would also make it deflect less, but I suppose with a steel frame it wouldn't be particularly weak as long as there is enough ribbing below the cutting area.

For a 4' x 8' table you will probably not use "threaded rod" or even ballscrews. Read around on the DIY CNC Router Table Machines forum. There are hundreds of posts you will need to digest. The main difficulty with a welded frame is distortion due to welding. The linear guides need to be mounted on a very flat surface. There are ways to do this that can be done DIY (self leveling epoxy, etc.). There is also a lot of thinking involved in making sure everything is or can be adjusted square. Pay attention to contributors wizard and ger21.

What type of router table is in the school shop?

At a first glance , your table concept is definitely not overkill, the gantry and supports are undersized.
The "sticky" thread on a "CNC router for hardwoods" has a good discussion. Wise contributors there suggest gantry should be a minimum of 8" x 8" steel tube with diagonal reinforcement , especially if you ever want to consider milling aluminum at a reasonable speed. A router will never replace a mill. Most hobbyist routers use stepper motors, some use servos. Both can work well if the system is well engineered.

I used aluminum because I found it at a very good price. The extrusions I used are much larger than the CNCRP kit, and were extremely straight and stiff.