Hey folks. I’m really green in the CNC world and am just beginning to build my CNC table. After discussing it with a friend who is already and avid CNCer, I want to build a vacuum table for piece holding.
Now I have limited space, and I have the 48 x 30” model. So I’m designing the table to be stored vertically. But could I permanently mount it vertically, and still utilize the vacuum table for holding the work piece in place? Has anyone tried this yet?
Odds are that I’m sticking with the vertical storage, horizontal running, but if there is some logic to keeping it on the wall, why not?
My thoughts are these - but I’ve never used a machine vertically, so beware!
I would put a slight backwards incline from the top, perhaps 5 degrees or so, and have a fixed guide on the bottom of the spoil/baseboard to rest the workpiece against it and help support the weight of it. I see no issues using a vacuum table (near) vertically, but be aware the Y axis (assuming the Y axis are going to be the vertical ones) will take some effort to move the X gantry (including the milling motor) upwards, so you might need to invest in stronger stepper motors and have one on both the Y1 and Y2 axes.
As I said, I’ve not done this and I haven’t got a LongMill to test it out.
@Forge Welcome to the group.
For info on running the Mill vertically, search on this forum and look at both the Sienci blog and their Youtube channel. Chris has several posts and plans. You do not need to invest in stronger stepper motors. There are a couple of ways to counter gravity. You can add counter weights to the XZ gantry and/or keep power to the Y motors all the time.
For a vacuum table ideas, you may want to look at CNCNutz Youtube channel. Peter has 4 videos on his experiments with vacuum tables. There are lots of other plans online, too. None of them that I have seen are used with a vertical table. Clearly one of the issues that will affect how well it works is that gravity is no longer your friend.
I played with a couple of designs and gave up on all of them. First, you need a good vacuum source. A standard shop vac will not last very long since it will heat up and fry the motor. You can buy a vacuum that has a bypass for cooling air. They are very pricey, but will do the job. I have a Gast vacuum pump that I use for the vacuum chuck on my lathe. It does not move near enough air for a vacuum table. It would hold large pieces in place, but did virtually nothing for small pieces. There simply was not enough surface area on most of the pieces that I cut out to make it work. At the shop, we have a commercial CNC machine and the vacuum pump is just smaller than a Volkswagen. Even then, small pieces fly off.
Instead, I made vacuum “pucks”. They work very well with my Gast. You can find store-bought ones on line. Rockler is one maker.
If you go ahead with this, please post about your experience.
Thanks gwilki! That’s great advice. I’ll look at the pucks and see how they work. I might be able to make them too. I think I’ll create the vacuum table and just work horizontal though. I did some measurements and I can still store it vertically without issue (it’s being run close to my over head door hangers and I was worried it wouldn’t get by, but I don’t think that’s a problem now).
I’ll look into the bypass vacs you’re talking about. I haven’t bought my table vac yet so maybe since I’ve already spent the money to get into CNCing and this is a company project, I might as well go all in.
Thanks again for the advice!
Hmm, that’s a good idea! To be honest, I didn’t know how powerful the stepper motors are on the LongMill, hence my comment, but counterbalancing sounds like a good (and cheaper?) alternative.
@Forge Fein and Festool are two that I know of. Both very pricey. There may be others. The issue with using “ordinary” vacs is that the air coming through the vac hose is used to cool the motor. When you reduce that flow to almost nothing by trying to suck things down onto the table, the motors heat up. Fein and Festool have some sort of bypass that brings air to the motor directly rather than through the hose.
I don’t know Fein, but Festool I’m a fan of. I have the CT MIDI dust collector, a plunge saw, router, sander and jig saw. I love their stuff and when connected to the MIDI there is nearly zero dust.
I was considering the Festool CT SYS for the suction but I didn’t know if that was a good use of the money. Now I think that’s exactly what I’ll do. I’ll just double check the cooling on it since it is a smaller unit.