I am currently building a similar table for my mill. My plan is to cut a spoiler the dimensions of my work piece, surfacing that flat, then clamping the spoiler and work piece together. (I will use side clamps to hold the spoiler while surfacing it.) This is practical for me because I will be doing a lot of repetitive cutting, and I don't intend to ever put a work piece directly against the table without a spoiler.
Apart from accidents (ie use a better controller and focus while doing your recipies) - i zero on my bed, and then setup stock in the positive Z. Done right, i can Onion Skin the bottom to perfection. Once you have that nailed, spoilboards become a afterthought. Big mills dont have spoilboards - for a reason - rigidity. But it takes skill and time to get there before you can reliably risk it. Of course, vslot can still be replaced too (;
Retrosmith. I know it looks really cool, but, if you think about it; say you were cutting a circle out of any material, you would normally cut all the way through the material, leaving just small tabs to hold the piece in place. Although you would put the thickness of the material into your program, there is still a likely chance that it will cut just a little lower than expected, thereby cutting a circle in your nice new worktop. Give it six months of regular use and your worktop is going to look pretty cut up, which is why most people use a wooden table, so they can just re-surface it easily. So it is just a practical thing to put a sacrificial board between your work piece and table. I favour the 25mm MDF work table, and use the machine to surface and then cut slots for T slots to be screwed into them, sitting them a few mill lower, so as to allow for at least one more re-surface before replacing the whole thing and re-using the T slots again. Gray
My bad. I'll go take apart the setup I've been using effectively along with my v slot table all this time. So you mill you table down by .001" to level it. Do you really think it will be level? No, so you'll keep doing that until it is level. That could easily be a full millimeter depending on the particular extrusion. Let's say you get that done perfectly (which is very possible), not it's time to cut. "Oh look. I have some foam pars to cut, but I'll have to program my machine like I'm cutting aluminum since I will hit the spoiler. So now you're running at reduced rates which consumes more time. Not only that, but you're digging into your once "perfect" table. Eventually, that table will be too uneven and will have to surface again. Think beyond the now. You can do some really radical stuff "now" that will only screw you up later. What do you think I meant when I said cut slots in the spoiler? Think about what someone is telling you before assuming. Otherwise, no one will even bother giving suggestions. You can do like I did (see 2d picture), or you can make smaller narrow sections of spoiler with exposed slots. The 2d picture was for a specific task, but I have others that cover my entire work bench for both flood and dry machining.
Big mills use vices which operate on an entirely different principle to sheet goods. You can't efficiently put a block on a table, nor can you efficiently put a sheet in a vice. I do agree with everything else though.
Retrosmith. Oh Dear. You opened a can of worms it seems! I'm sorry we all jumped on you there. As you can see, whilst it makes sense to make a table which will allow for easy clamping, as well as antisipating the need to cut with cooling agents, there are also a number of good reasons why the above alternative suggestions have been made. Gray
I appreciate what you're saying on the through cuts of course. I would use a spoilboard if I ever did them but it's a very rare thing with what I do, which is why I want to level the bed, not because it looks cool. Though it does!
I didn't come to argue with you, but you're looking answers that directly align with answers that you already had in head before even starting this thread. If that's the case, why post? No one can tell you what to do. And your questions where answered by more than one person. You asked for situations? We both gave you scenarios. You responded to my original simple statement with pure sarcasm, but somehow got offended when I came back with a full response. You pick apart my post and I'm the bad guy? Ok have a good day. Have you seen the rest of the channel? They get to play with some awesome toys! I don't know if I missed it, but did he mention what vacuum pressure they were using? Stick around to the end of the video for his final thoughts though. I definitely have respect for my seniors and I know you know your stuff, but a lack of experience can lead to very disastrous consequences if Murphy strikes.
Well folks, since Kevon can't keep himself from popping up in my threads I'm going to give a huge thank you to the group for the help and guidance I've received to this point and take my leave. As I mentioned, life is simply too short to waste any of it on the Kevon Ritters of the world. Best of luck to all of you in whatever it is you're making.