Does a sturdier and stronger system really benefit hobby users?

[Garth Snyder]

Hello, Creekers - CNC newb here, and I could really use some advice regarding CNC router systems. This is really just another "which CNC should I buy/build?" thread in disguise, but I think I've done enough research to get the basic concepts already. So my question's a bit more specific.

My application is nonprofessional woodworking: furniture, cabinets, architectural elements, just for me and friends. So I'm looking at systems with mid-to-large cutting areas, say 2' x 2' and up. (I am a non-CNC woodworker already, with a fairly complete shop.)

I've noticed that virtually all these systems, from the lightest-duty X-Carve models up through professional machines, seem to have similar geometric specs: accuracy of ~5 mil and repeatability of ~2 mil. It doesn't seem to matter whether the systems are based on routers, palm routers, dremel tools, or pencil sharpeners. And of course, those various types of spindles all drive pretty much the same bits.

So, I have the impression that -- for a given work area -- what you get by going to a heavier/sturdier system is really just the ability to cut more aggressively and thereby lower your routing time. Is that pretty much it, or is there some other reason to spend more?

I guess a related question is, for those of you who started light-duty and then traded up, what was it that you couldn't do?

(Keep in mind, this is for hobby purposes - I know the bigger machines can run all day, but that really doesn't matter to me. And software doesn't matter, either. I am fortunate to have access to the Autodesk CAD/CAM suite.)

[Gary Campbell]

Garth...
There is another item to consider, even tho many seem not to. And I don't believe it is a hobby/professional choice. Simply stated the more rigid machines, by definition, have the ability to withstand more lateral force. That gives the ability to use larger and longer bits AND cut dense materials with less deflection.

Once you get above 1" thickness in dense hardwoods the game changes. You will (should) be using 3/8 or larger bits at 3" or longer OAL. And unless you wish to spend your time sanding out "waterlines" you will want a machine that can withstand the forces that accompany the cutting conditions that materials require, not just the ones that you may think you will encounter.

[Phil Thien]

Garth...
There is another item to consider, even tho many seem not to. And I don't believe it is a hobby/professional choice. Simply stated the more rigid machines, by definition, have the ability to withstand more lateral force. That gives the ability to use larger and longer bits AND cut dense materials with less deflection.

Once you get above 1" thickness in dense hardwoods the game changes. You will (should) be using 3/8 or larger bits at 3" or longer OAL. And unless you wish to spend your time sanding out "waterlines" you will want a machine that can withstand the forces that accompany the cutting conditions that materials require, not just the ones that you may think you will encounter.

Yep. With my small desktop CNC machine, I have to make clean-up passes and even taking very small bites in the thousandths, the bit will deflect in deep material.

The more ridged, the better.

[Garth Snyder]

Thanks for the comments. As much as I enjoy tinkering and technical projects, it would be nice to focus on the woodworking design rather than on torturing the CNC system into behaving. :-)

[Ted Reischl]

The real issue for most prospective cnc users is the cost vs performance. I have been around and working with CNC machines for almost 40 years now.

When I decided I wanted one for my home shop about 8 years ago I had the attitude that I did not want to "tinker" around with a machine so I bought a ready to go solution. Luckily for me the machine was a Shark. After two days of trying to get it to make a decent cut I hauled it back to Ohio for a refund. I did not want to spend $$$$'s on a more rigid machine so that led me into building my own. My first one was "ok". Certainly better than the Shark, but I learned a lot. The next one I built was mostly parts from CNC Router Parts. That is what is known as an 8020 build. Aluminum extrusions, rack and pinion drives. They have a great solution for the electronic (which I am NOT good at) so that helped out a lot.

I currently run that machine, it is 4' X 3' X 8" Z travel. I have actually cut at 800 IPM on it. Though I normally cut in the 100 -250 IPM range. Recently I added a rotary axis to it for about $200. I am going to increase the Z by another 4" which will cost about $32 (a couple of extrusions).

The moral of this is that if you have a shop it is very easy to build a rigid machine with a standard router for about the cost of a flimsy one running a trim router. AND, get much better cutting results. A huge plus is that it is very easy to expand these type of machines.

The problem with "store bought" machines is that it always seems if you want to modify one it either cannot be done, or it will cost an arm and leg. Of course, if I was running a production shop I would by a commercial machine and spend the bucks. But for hobby use? I am too cheap.