A little project that I am working on what do you guys think? Should be really nice on the X-carve the lower flange is 75 mm on center so it will bolt up to the Stock Inventables waste-board I screwed up on the cam in Fusion 360 lol
So the first 3hr bottom cutout might be all for nothing but I am going to cut the top tomorrow it will have 3 different tool changes though
74,000 + lines of gcode in just the bottom alone 
Looks great! I did one a bit smaller and a thinner neck leading out from the machine for the vacuum. The first one I did was tiny and worked but I didn’t have support so it started to sag from the pressure. I cut milling time down by over 75 percent by using rectangles instead of small pillars for the most part creating a pathway for the air to flow.
Looking forward to seeing how this turns out.
oh really hey what program did you use to design your table? did you use fusion 360?
I am just curious on what machining strategy you used for doing that center pocket? you said squares work good? did you use 2d adaptive clearing?
I just used easel, I was going to share the files but then I forgot I messed everything up and deleted a bunch of stuff on accident. Not sure exactly what 2d adaptive is (even after I looked it up! haha).The squares work really well. I took pictures so here is a picture of it before the drill holes. Now that I am a little more learned I would have had the machine do all that long horrible work.
oh man yeah you gotta have the machine drill all those little holes in the top lol I think mine has like 350 or something but when using easel it kinda sucks for that job because you can’t cut the a .125" hole with a .125" bit you have to go like .135" and if you do that the bit will not plunge straight down and thats what you need
but yeah that table looks good for sure
how are you going to seal the 2 halfs together?
Not the best quality video- .125 bit set to cut .126 holes. You can also see the dust collection in action. https://youtu.be/dsRCusTQnN4
I just mated the pair and used couter sunk holes for 1/2 inch drywall screws. I then coated the outter edge (with the joint of the two) with silicone. If I could go back and do it again, I would lay a bead around the edge before screwing them together. When I make a new one ill have to share and save everything haha
Why all the holes? I thought the point of using MDF for the top was for it be a bleeder board. Or are you also using a bleeder board?
hmm i am not sure what is how the bleeder board differs from with I was doing?
my base board would be my bottom
the little standoff circles in the bottom boards would act as my plenum
and all the little hole in my top board will act as the bleeder board
correct?
The bleeder board has no holes. The air moves through the MDF itself (you plane the sealed surface off both sides of the MDF, and being Medium Density Fiberboard, air flows through it). Some people use LDF instead for more airflow, but MDF is most common.
This means the entire surface area under the piece is being held via vacuum through the MDF. If you drill holes, you get a lot of air flow through them and not the MDF itself, meaning small pieces of the piece you’re cutting (if not covering a hole) will have nothing holding them down. It also means you need a significantly more powerful vacuum because it’s trying to create a vacuum in a sieve.
hmm so I will be the first to admit that I am no engineer lol that being said the vacuum table will not work to hold parts down as I have designed it?
my vacuum table will be cut out of particle board and then sealed with a poly or wood hardener and then the 2 half’s will be mated together and sealed with a thin coat of clear silicon. will this not work?
I plan on running a 5 gallon shop vac to provide the vacuum for the table the total area of the part that will actually be holding parts down is about 14 x 14" square
Unless your piece covers a majority of the holes I think you’re going to get a very poor hold. The holes have a much more dynamic air flow volume than straight MDF. Meaning a covered hole will not have much flow while the flow through the open holes can take up a lot of the slack.
However, this is just my intuition, and I’m just an electrical engineer, so it’s not my field.
If you do get poor results, you’ll just need to cover any open holes not already covered by your part.
The setups I have seen just use a small shop vac.
There is a video demonstration how you can pick up a sheet of 4’ x 4’ 3/4 MDF with just a small shop vac. And they were using masking tape to block of the unused holes.
But those were not using a bleeder board. I don’t know if the small shop vac has enough draw for that. 
One big advantage of a bleeder board is it doubles as a sacrifice sheet and facing it insures your work surface is level. Though you do have to face both sided for it to be able to pull air though.
There is a type of mdf that is lighter which allows air to flow a bit more. I can feel pull where the holes are not but it would not hold anything.
I use sheets of paper or magazine to cover the holes not being used. You want to have almost all of the holes covered to have the hold.
oh yeah I plan on just using something to cover the additional holes in the vacuum table but the part that I designed it for will take up the majority of the holes
Hi
I also made one over the weekend. Table was longer ready but was waiting for the small stuff.
Works very nice.
Now intergrade in the xcarve.
But thinking on make it bigger. have 1000x 1000mm version but want to go 15000 x 1000.
I divided the plate in 9 sections with each has own tab. The vacuumpump comes from a retired aircon mechanic.
The groove is 4mm wide and 3.5mm deep. I use moose rubber 4mm. Only need a filter between the plate and the pump.
Koen
Quick question, How much luck are you having using the shop vacs? I made a quick 24 x 30 inch table that works wonderful, but I’m sure that I’ll burn up my shop vac using it. I was wondering if there was something affordable to use instead.
Mine works great, I have yet to burn it out but I also dont use it for super long carves. I need to get another one for dust collection so that I dont fill the one for the table up!~ 
