1/4" MDF is too thin to skin off the dense layers. (It almost doesn't' even have a porous core like thicker MDFs) And it doesn't offer much protection from coding mistakes. I prefer 3/4" MDF and then mill off about 0.05" off of each sided to open it up. Then you have enough thickness to skim off layers as needed to get a good smooth holding surface after running a few different files. We typically remove only 0.01" when resurfacing the spoilboard. Then replace the spoil board when it gets to be less than about 0.35" thick. We run 3 shifts a day and a new spoilboard will typically last us about a month on a machine.
As to vacuum requirements for a 5ftx10ft table and spoil board I like to have about 300ACFM (200 minimum) and be able to maintain at least 15inHg, which typically takes at least about a 10hp vacuum pump (20hp would be much better.) Todd Zuercher P. Graham Dunn Inc. 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 -----Original Message----- From: Les Newell <les.new...@fastmail.co.uk> Sent: Wednesday, June 09, 2021 9:25 AM To: emc-users@lists.sourceforge.net Subject: Re: [Emc-users] OT: About a chat here on vacuum table ideas [EXTERNAL EMAIL] Be sure links are safe. Yes, 6mm (1/4") MDF works well. It has a bit of restriction so you don't lose all of your vacuum when you cut right through your parts. What sort of vacuum pumps did you have in mind? You'll probably need a minimum of 250 cubic metres per hour for decent hold down. In terms of motor size, that's getting on towards 7.5kw /10HP. Les On 09/06/2021 03:46, Leonardo Marsaglia wrote: > Thank you guys for your answers! > > I've been reading and apparently MDF with a skim cut is pretty good to > distribute the vacuum all around it's surface given its porosity. I > think I'm gonna try that option first to see how severe is the vacuum > loss when the cuts are made. > > Second option would be what Todd suggests, wich is a little trickier > mostly because my surface needs to be 3000 mm x 2000 mm, so that's a > lot of springs... > > I'll keep you informed as the project progresses. > > Thanks as always for your help :) _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
