Vacuum Table revisit - CNCnutz Episode 243

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Revisiting my Vacuum table build. This time I want to do it properly, or at least better.
For additional information about this build please visit:
www.cncnutz.com/2020/02/vacuu...
It was almost 2 years ago that I made my first vacuum table and even today I still get questions about the table. people want to know how it is going and requesting drawings to make their own.
My thoughts were that the old table was a bit more complex than it needed to be and I wanted to make another. This time I wanted to use a base material that would not leak as plain MDF does. I searched around to see what I could find and managed to get some melamine coated MDF. MDF is porus as I found last time but with the major surfaces sealed by the melamine coating I only need to seal the edges. To do this I gave the edges 3 coats to ensure a good seal.
Next I looked at the seal between the base and the top. Last time I simply screwed the 2 pieces together and it seemed to work but this time I bought 2 meters of 6mm round rubber to act as an o'ring. This will seal the top to the bottom and allow me to machine new tops as replacements and also to experiment with as I still have more to learn.
Next I added threaded inserts to attach the base to the top. This will give me a consistent method to attach the top and allow easy replacement. Something to note I didn't screw the top screws down to compress the o'ring. The screw down until they stop turning under gentle pressure and that is all. I do not want to keep the o'ring under constant compression but will allow the vacuum to do this when it is in use and it can return to it's normal state when the vacuum is off. I hope this will prolong the o'ring life.
This time the top has no pockets cut into it but has been left as plane MDF. While in the video I get more than enough sideways holding I don't seem to get much in the way of vertical holding. Does this mean that pockets will improve the table holding or am I missing something. This I hope to find out in the 2nd part of this build at which time I will also release the CAD drawings I used to make the table for those who wish to make their own.
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I hope you enjoy.

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Опубликовано:

26 фев 2020

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Комментарии : 91

@rchobbynet 4 года назад

Hi Peter, about a year ago, I built a similar vacuum table and found that MDF is very breathable. That means you also have to seal the side edges. Furthermore, the surface which is not covered by the workpiece must also be covered with an air-impermeable film. Furthermore, the suction side of the vacuum cleaner must be optimized. Since a lot of air is drawn through the MDF, the diameter of the suction line to the vacuum cleaner must be as large as possible. As a result, the pressure drops are lower and the suction power increases. The milling strategy must also be adjusted. This means that the last layer is only milled through at the end of the milling process. At the top I only have a 4 mm thick MDF board as a wear layer. I hope you understand me, english is not my native language.

@cncnutz 4 года назад

Thanks rchobbynet. Thinner board is an option I should try. Thank you for sharing.

@IEraiderfan 4 года назад

Peter, a great video I am looking forward to your next videos thank you for sharing.👍👍👍

@grantclarke4713 4 года назад

Thanks for the video.... can't wait to see part 2. I've missed your videos over the passed months.

@cncnutz 4 года назад

Thanks Grant. Time is the problem. Trying to balance work & home life. Cheers Peter

@pngcustomwoodworks3499 4 года назад

Good to see you back online......

@cncnutz 4 года назад

Thanks Paul good to have some time to make both the table and video. Cheers Peter

@jnrmrtn 2 года назад

This is like magic to me. I saw this technique in another video but I didn't get the info as clearly as stated as you've done here. Thank you!

@Radmonkeyboy 4 года назад

Thanks again, Peter!! I really enjoy the continuous learning process. :)

@cncnutz 4 года назад

Thanks Radmonkeyboy

@SimplyWoodenCreations1980 4 года назад

Enjoyed watching and some great information. 👍

@cncnutz 4 года назад

Thanks Russ

@skyphantomvideography8294 4 года назад

Great Video Peter. I see that you were very careful to seal all the edges of your base vacuum table, but not for the top section . On the top piece, I suggest that you seal all the edges and the area at the top nearest the vacuum hose inlet. Then after placing the work-piece, cover all the rest of the surface of the sacrifice board with other material of similar thickness. This will seal in the vacuum to act more forcefully on the work-piece being cut. You want none of the vacuum to escape and be wasted, so that it holds down the material being cut. I've been running two large (600 x 1200 mm) table routers since 2001 (for a sign company), and use MDF as my sacrifice board just as you have. The equipment pulling the vacuum is pretty substantial, and valves are used to open and close sections of the table to receive the vacuum. I simply lift the sacrifice board and push in a rubber seal across the table to confine the vacuum to the area covered by the work-piece. I think sealing and covering may add a lot to the hold down force compared to what you are currently experiencing.

@cryptojunkie5875 4 года назад

We’ll summarised, exactly what I was thinking. Additionally I thought maybe a thinner top plate may allow the air to flow though easier providing mor holding.

@skyphantomvideography8294 4 года назад

@@cryptojunkie5875 Absolutley. Consider the top piece as a sacrifice board that will have to be re-surfaced from time to time. With good suction you can cut right through the work-piece with a final cut being very thin so there is no cutter force to grab on and gouge the material.

@dronesvisionsaeriennes 4 года назад

Excellent Peter, i love yours videos....Philippe

@cncnutz 4 года назад

Thanks Philippe

@dronesvisionsaeriennes 4 года назад

@@cncnutz Hello Peter, i've just built my CnC about 120Kg, 1500cm long and 1000mm wide with 32cm under the gantry...So, i'm building a vacuum table to now with 1100mm long and 850mm wide, it's my first CnC and a very good challenge for me...First tests are very good for the plate with about 600 squares for vacuum...i have to put the pipes now and check another one the plan of my plate....Some videos will be on you tube in about one month....Nice day and thank's for yours channel which is great for me....See you ...Philippe

@tonysfun 4 года назад

Love your ideas and the Vacuum Table.... If you put something in the area where you do not have the VT covered, it will hold your working material well! You can use some kind of smooth material or plexiglass.... Or even flat rubber that will also work well. The second positive that comes out is that the "micro holes in the VT" aren't gonna attract micro-dust! I became a subscriber also and thank you for your ideas and videos!

@cncnutz 4 года назад

Thanks Tony

@vahpr 3 года назад

Hi Peter, thanks for doing these. I've watched a couple times and am a little unclear - how did the big holes and big holes with small center through-holes affect hold-down power vs the unbored, original top plate? Or in other words, what was the best option, exclusive of any other mods?

@hamps856 4 года назад

very informative, good job.

@cncnutz 4 года назад

Thanks Hamp

@perrybrown4985 4 года назад

I made a vac table a while ago. In the design, I didn't want the hose exiting upwards - it seemed like a liability - another object for the machine to crash into :-( Instead, I extended the vac plenum out over the front of the table so the hose could exit downwards. The only use of the vac table is with a home made/designed drag knife and it is nice to eliminate at least one source of destruction for the knife. I like your idea of using the porosity of MDF rather than holes (the undulations from the holes interfere with the drag knife) - it might be worth a try - but I suspect the porosity of paper/cardboard would trump the MDF :-( (love your work - I use so many of your ideas and designs: knobs, hold down blocks, cam clamp, not spoiling the spoil board, parallel ruler setup, v-carved inlays - the list goes on and on...)

@bradbarker4189 3 года назад

Hi Peter, thankyou for all the great informative videos! I have a question about the vacuum you are using... If I recall its a fesstool, how does it go with overheating and is there any better options for dust removal aswell as vacuum hold down? Cheers from Australia

@DodgyBrothersEngineering 4 года назад

What if you made it upside down? Exact same design, but have the vacuum attach to the other side. You have cut out a lot of grooves making the top (current bottom) thinner in spots, but still retaining a fair amount of strength. More vacuum (thinner in places) might aid hold down.

@builtrodewreckedit 4 года назад

i had no idea you could pull air threw mdf. I wonder if cutting it just a bit thinner would let it suck down more? or maybe setting some scraps along side your project would block off some of the wasted suck?

@johnrevill9592 4 года назад

Great video Peter. Can't wait for Part 2. Not sure where you are going in Part 2, but in my experience, each small vacuum hole in the table should have a larger diameter pocket on the top. The wet Dry Vacuum will have a curtain PSI is will generate and with small hole, the surface area is very small and that does not equate to much downward force, but the larger shallow pockets, only 1-2mm required, the PSI remains the same, but the surface area affected by that force is greatly increased, but because the smaller holes in the table below the pockets are the same, you will not loose vacuum in uncovered areas. Not sure if I'm explaining myself correctly.

@cncnutz 4 года назад

Thanks John. That's what I did on the last table but I wanted to see how UN pocketed MDF behaved as this is how the big boys do it. I hope to do a comparison. Cheers Peter

@johnrevill9592 4 года назад

@@cncnutz That is interesting. Most people believe that a vacuum sucks, but the truth is more like the vacuum creates lower pressure and the Atmosphere pushes towards the lower pressure. A "pure" vacuum actually has no force. A vacuum table works by using the atmospheric pressure above the object to apply a downward force on the object. The Atmosphere can apply approx 1Kg per cm2 onto a vacuum. If we take that a vacuum table is about 50% efficient that we might see a max of 500g per cm2. A 2mm diameter hole is only about 3.1mm2 and as such only about 16grams of downward force on that hole. The more holes covered by the object, the more force. Now if be increase the pocket at the top of the hole to 10mm, we now have 78.6mm2 and the atmosphere can now apply 400g of force on this area. The more holes covered, the more force. To have a table using only small holes, you would have to have a lot of them, mean 10,000's of holes. This introduces another problem. Air Flow. The more holes, the more powerful and large hose you will need on the vacuum. I have a 31mm Diameter hose on my Vacuum, and this would allows me to have 240x 2mm holes. My next table will use 1mm holes and a 40mm vacuum hose. This should allow up to 1600 holes in the board.

@johnrevill9592 4 года назад

OK, So some of the industrial tables that use 10,000 of small holes get around the air flow problem by dividing the table up into zones and use ball valves to turn off the flow the areas of the table that are not being used. Here are some photos I found that use this method. mk0cnccookbookgxcner.kinstacdn.com/wp-content/uploads/2017/08/Clampusystems.jpg i.pinimg.com/originals/5c/da/8f/5cda8f29fff3c775b0a22b8491f5b64b.jpg www.cnccookbook.com/wp-content/uploads/2017/08/Vacuum_Table1.jpg

@ringo2398 4 года назад

Nice Job! if you do a few coats of shellac or any type of sealer to the area you cut in the melamine (bottom board) you won't lose any vacuum through your screw holes and t-slot holes. you have contained the vacuum completely in the rubber sealed area, also you then do not need to paint the edges...just a thought

@cncnutz 4 года назад

Good thought. I was going to paint the outside anyway if for no other reason than to make it look pretty. I thought about painting inside but didn't fancy the mess cleaning up the top surface. Shellac would be better as it wipes away easy with alcohol even after drying. Might yet do this. Cheers Peter

@clintonhoines4070 4 года назад

Nice can't wait to see part2 just thinking about building a vac table for a future project. @CNCnutz (Peter Passuello) what vacuum did you end up going with as a replacement?

@cncnutz 4 года назад

I picked up a Karcher wd6 which looks like the top model at least in the consumer marker. I need to do more tests with it and it can't be run full power for long or it gets very hot. Will be testing in the next episode so don't rush out and buy one just yet. Cheers Peter

@moi1480 4 года назад

Hello Peter. Excellent job. I’m trying to do a small Cnc. Could you tell me about your experience. Is it possible put pads on the table and they can stick together too? Thank you.

@cncnutz 4 года назад

I have no idea as I haven't tried that. Cheers Peter

@772777777777777 4 года назад

You need to seal the side edge of the mdf and the top surface that was not intended to be vaccuum surface.. with a thick expoxy.

@Simsy5861 4 года назад

Hi Peter, How do you reckon it would perform if the areas not covered by your piece of project material were coverd by a piece of plastic so as to stop air being pulled through it? All of the vacuum would then be effectively holding down your project rather than "leaking" through the uncovered part of the vacuum table. Hope that makes sense! Cheers.

@cncnutz 4 года назад

I have been doing some tests and it doesn't seem to make any difference. I think that the vacuum can keep up with the air loss. I need to come up with a way to measure rather than feel. Cheers Peter

@fredthijssen7528 3 года назад

I have a vacuumpress, meant for vacuming forms with epoxy and fabriks. would that be better then a normal vacumer ?

@cncnutz 3 года назад

I don't know. You would need to try. Cheers Peter

@RC-Flight 4 года назад

Great video as usual! Hey that vacuum hose on your dust boot is it metal or plastic? How is it for static? My plastic hose on mine, is like a Van de Graaff generator that produces nasty shocks and computer faults. 🙁

@cncnutz 4 года назад

Thanks Glen. The hose is plastic. Haven't noticed static yet but it is a good point. Will keep an eye out for that although it will make its presence felt if it is a problem. Cheers Peter

@johnrevill9592 4 года назад

Hi GlenGH, It is highly recommended that you ground your CNC machine, Router or Spindle and your vacuum to reduce the risk of static discharge and electrical faults. I have my CNC machine, Spindle and Vacuum all grounded and never had a problem. I do know someone that didn't have there machine or Spindle grounded and the static from the vacuum fried the spindle controller.

@tkaudioservices1936 2 года назад

Brilliant. Not sure if I missed it, but how powerful is the hoover you are using.

@cncnutz 2 года назад

1100w

@AlwaysCensored-xp1be Год назад

I didn't know MDF was that porous. What about peg board, comes with holes. Just use news paper to block the open holes.

@sendguns 4 года назад

Hi Peter: Q. Could you have achieved the same results by using a splitter system on your main cnc dust collection system, providing the HP of the motor is sufficient? Best - Michael

@cncnutz 4 года назад

Dust collectors are high volume low pressure so are not suitable for a vacuum table. Cheers Peter

@fredthijssen7528 3 года назад

If one would not use the "rubber O ring" but would seal the upper and lower part with duct tape or so, would that work as well ?

@cncnutz 3 года назад

I Honestly don't know. You would have to try. Cheers Peter

@artgehr7178 4 года назад

Hi Peter, Is that a new spindle on your CNC? I am planning on upgrading from a router to a spindle and looking for options and things to avoid.

@cncnutz 4 года назад

It is the one I installed about 2 years ago. I did a video series on installing the spindle. Cheers Peter

@WouldWorkforWoodWork 4 года назад

African or European? Good to see you back Peter! It's been too long.

@cncnutz 4 года назад

Thanks Doug That is the question. Cheers Peter

@pinkponyofprey1965 4 года назад

@@cncnutz Must be New Zealand.

@user-ty9gc6fm4f Год назад

what kinds of MDF do you use it. I tried making something similar but it didn't work.

@terry8966 9 месяцев назад

At about 1:45 he states that he is using Melamine coated MDF and he is going to paint the edges.

@jamesgreen2060 Год назад

Do you not need to seal the sides of the MDF?

@8BitLife69 Год назад

You SHOULD. Use a good 2 part epoxy would improve the efficiency.

@101akafox 4 года назад

try sealing the edge of top board so as not to loose suction through side of top

@cncnutz 4 года назад

Thanks Andrew. I did it the next day to see the effect. Will cover that in the next episode. Cheers Peter

@paulvandriel2344 4 года назад

14:22 Sound dropped out here for some reason. Peter, you know that there is no sound in a vacuum (like in space). So, when you pulled out the hose you created instant vacuum in your shop, hence no sound. As soon you plugged it back in, the sound came back. The vacuum was again in the vacuum plates. Simple. ;-)

@cncnutz 4 года назад

Of Course! Why didn't think of that? Cheers Peter

@paulvandriel2344 4 года назад

@@cncnutz Possibly because you were in a vacuum? ;-) Anyway, nice work again. Always a great joy to watch your videos. Very instructive and entertaining. Keep up the good work. Looking forward to your follow up.

@bobd. 2 года назад

I like your vacuum table, but wondering how a vacuum cleaner (most of which have universal motors) has held up when used in this manner. I would expect that many of your routing sessions run for an hour or more. This seems like it would wear out the brushes in a universal motor pretty fast. For the price of a good vacuum you can get a lab grade vacuum pump which is designed to run 24/7 and moves 30L/minute or more. That is much less volume than a vacuum I know but if you cover all the open areas on your table there is not much vacuum loss and hence greatly reduced volume required to achieve a secure hold on your workpiece. The other plus is the vacuum pump is very quiet and you won't have to listen to the whine of a vacuum for hours on end.

@petergosney6433 2 года назад

A quite inexpensive workshop vac will work fine, as long as it is ‘wet and dry’. Ordinary vacuum cleaners cool their motor from the vac stream and will eventually burn out, whereas wet and dry vac motors have independent cooling.

@thomasreynolds1530 2 года назад

Bob D, if you don't mind sharing a link or website name?

@bobd. 2 года назад

@@thomasreynolds1530 search Amazon for 'oilless vacuum pump'. You should get at least 6 hits.

@thomasdukes7698 4 года назад

Looking good! Will your plans be available for purchase?

@cncnutz 4 года назад

No Files will be available for free. 😁 Cheers Peter.

@thomasdukes7698 4 года назад

@@cncnutz AWESOME!! I threw one together in vcarve based on your design using the 5/8" hole pattern for the top. I think the answer is sealing the MDF and covering any unused areas with a thin plastic sheet. But, I'm just guessing. I haven't had time to test it out. Thanks!!

@thomasdukes7698 4 года назад

@@cncnutz Also wanted to add, on the top board, using the 5/8 holes, I'd run every toolpath except the 1.1mm hole. Seal it, then run that toolpath.

@claytonrenzi4873 4 года назад

Where do you buy the brunch for the dust boot

@cncnutz 4 года назад

It comes with the dust shoe. Cheers Peter

@8BitLife69 Год назад

So how long did that vacuum cleaner last running it for 2 hrs nonstop during an operation. LOL

@phillbarnes 4 года назад

Bunnings sells a product like this in Australia, not sure if they do in NZ. www.australiantimbers.com.au/product/softboard/

@80211Denver 4 года назад

OK so... WHAAAAT? When you finally fire this up put the board on there..... how???? Is the air actually going through the MDF???? Sorry I'm REALLY new to this and that's kinda blowing my mind. (sucking?). If you describe this property someplace else, could someone point me to the video? I'll look on my own as well. (edit, it's of course his other video. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ioepaP17UpQ.html starting around #11:30 where he's testing and noticing air loss someplace -this is AMAZING) Also, will this burn out the vacuum? Could you do the same with a vacuum pump others are using?

@cncnutz 4 года назад

If you want to know how porous MDF is have a watch of my first attempt. Cheers Peter ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ioepaP17UpQ.html

@phillbarnes 4 года назад

Hi Pete You might want to try some low density fibreboard, (LDF). Here is a link for you locally. www.bord.com.au/products/raw-substrate/ldf-low-density-fiberboard/ Regards Phill