What Size CNC Table Should I Have?
Larger tables offer versatility and material savings for a moderate increase in the investment. February 19, 2011
Question
I am seriously considering going CNC. I have been researching which machine will suit my needs without buying too much machine. I would like to get some advice on table size for nested base panel processing.
We currently cut with a horizontal sliding panel saw. The saw has just slightly over an 8' stroke so all the material we use is 4 x 8. I am so used to using only 4 x 8's that I think in "4 x 8" when calculating materials, even if I could possibly get a better yield with 4 x or 5 x 10.
I have spoken to a couple of salesmen about their CNCs and I was told by both that I should definitely go with a 5 x 10 table for nested base. One explained that I could continue to process 4 x 8's, but the option would be available to process 4 x or 5x 10's if I could achieve better material yields for a specific job. The other said basically the same thing, and mentioned I could set up two work zones on the table if I wished. Any recommendations on the optimal CNC table size?
Forum Responses
(CNC Forum)
From contributor R:
I have an 8ft x 4ft table and have not really needed anything bigger. The cost of the machine is less and it requires less vacuum.
From contributor J:
Since you are working with 4 x 8 material and that is all your saw can handle, you can save money and buy a 4 x 8 machine. A 5 x 10 machine will give better yield when nesting most of the time, and the price for the sheet is usually cheaper. This is because the mill charges for the material they have to cut off to make a 4 x 8 sheet. A 5 x 10 machine would also give you more flexibility compared to a 4 x 8 machine for running longer custom parts.
Do you have the space, and can you easily get the 5 x 10 material where you are located? Right now you have your supplier for 4 x 8. If anything, you can buy a 4 x 8 machine and then later upgrade. This would make it easier for your current product.
I would really run some numbers and see how much more cost effective running 5 x 10 panels would be. I assume you currently optimize for your panel saw? Run some tests using 5 x 10 material to see how much gain you get in yield. It would be different on a router, as the router bit is bigger. But it can give you a rough idea to compare. This with the price difference in material and the numbers will be the best way to determine this.
4 x 8 was the standard and now it is shifting to 5 x 10 material. But if you are comfortable with 4 x 8, I would stick with that.
From the original questioner:
Thanks. Your comments make a lot of sense. I have more than enough space in my shop for a 5 x 10 machine, and 5 x 10 product is readily available in Miami. 5 x 10 product would require some sort of material handling system to get the board on the router table, i.e. vacuum lift and jib crane. That is an expense I did not anticipate.
From contributor M:
I bought a 5x8. I have not used the 5x as much as I expected, but I am glad I have it. I have ordered another machine and will go 5x10 this time.
From contributor E:
The actual cost to produce a 5x10 is not that much more than a 4x8. Aside from a bit more steel at about $1.50 a pound and a few feet more rail and ballscrew/rack, the fixed costs are the same. All of the electrical components including all of the CNC hardware are the same. The added flexibility and capacity is well worth the cost. Additional Z axis travel is also a good investment.
From contributor P:
We process closet parts using 5X8 melamine sheets. Our table is 5X12, though I've only machined as large as 5X10 material. The 5X10 capability was beneficial in some of our applications as well as running materials for local cabinet companies. We do have the ability to run smaller sheets by blocking the table top or isolating the vacuum, so it's extremely versatile. Additionally we have found that 5X8 material is only marginally higher than 4X8, thereby reducing our cost per part. As for loading the table, we positioned our scissor lift table at the end of the CNC and can simply slide the material to the table top.
From contributor T:
I agree with all of the above. Go for at least the 5x10 if you can. When we purchased ours years ago, I thought the larger was going to be overkill. To the contrary, it has been wonderful. Our casework items yield much better on 5x9 sheets and there are times I wish I had a 5x12. As stated above, it's only more iron at that point, as you already have all the high dollar items accounted for. Go for it, you won't be sorry.
From contributor O:
Bigger is better. We recently purchased a router and I thought 5x10 would be best. The owner wanted bigger, so we have a 5 x 12. In my 6 weeks of using our new router, the owner was right. Generally I have the table sectioned off for 4x8, but there have been many occasions already where I needed 10'+. We are a millwork company so we get into large pieces frequently. Whatever size you get, it will change your shop for the better.
From contributor M:
Most materials are available only in 4 by 8, the main exceptions being melamine and MDF which are available larger, up to 5 by 12. Hardly any veneer stock is available in larger than 4 by 8 easily. In the end it may not make sense to run 5 by 12s unless your volume is relatively high and you do jobs large enough to justify the extra hassle of dealing with multiple size sheets. It is a real logistical concern both in handling and in your software for nesting. For example, I cannot forklift a 10 foot sheet to my machine due to space restrictions, but can forklift an 8. I have to know when I nest if I am using a 4 by 8 or a 5 by 12 or 4 by 10. Is the extra yield in density worth the larger scraps? A thousand variations on the theme.
I prefer a 4 by 8 table, but if I had a 5 by 12 it would come in handy, but only very occasionally. I would insist on zoning in your table to take the 4 by 8 automatically. If you go this route though, placing sheets of scrap on the open areas of your table is a real pain if you do any amount of volume, as I needed to do with an otherwise fantastic Omnitech Selexx Pal I used for a while.
