4'x8' vacuum table build questions - Page 4


Page 4 of 7 FirstFirst 1234567 LastLast
Results 61 to 80 of 139

Thread: 4'x8' vacuum table build questions

  1. #61
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    So I was able to get the vacuum gauge & pressure relief valve installed and with all zones closed & with 1 motor the gauge is reading 11 (HG - inches or whatever the gauge measures. Then as I turn on more motors the gauge doesn't increase, I'm assuming the relief valve is opening up. Does that sound correct? Should I "tighten / close" the valve to increase the number on the gauge or is it at about the right spot? How do I know when to turn on an additional motor(s).

    Thank you
    Gary



  2. #62
    Member
    Join Date
    Jan 2015
    Posts
    194
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    I don't have a relief valve but that is possible, don't know. I just open another valve just barely if I need to give the motors a little more breathing room. In your case you could do that as well or if you're using all of the zones, you could then control suction by turning on/off motors. With the idea of keeping engineering simple, I would recommend removing the relief valve until you understand how the system operates since the relief valve is somewhat of a black box in how/when it operates.

    David Gage
    Deep Sea Sound


  3. #63

    Default

    Quote Originally Posted by Gary-Wiant View Post
    So I was able to get the vacuum gauge & pressure relief valve installed and with all zones closed & with 1 motor the gauge is reading 11 (HG - inches or whatever the gauge measures. Then as I turn on more motors the gauge doesn't increase, I'm assuming the relief valve is opening up. Does that sound correct? Should I "tighten / close" the valve to increase the number on the gauge or is it at about the right spot? How do I know when to turn on an additional motor(s).

    Thank you
    Gary
    Gary if we have the same motors, that is too much vacuum. 11” of mercury is approx 149” water. That is the maximum vacuum that my motors can pull. I currently have my relief valve set to start opening at 8” of mercury and I add motors if the vacuum drops below 7” when in use. Another good way to tell how hard your motors are working is by the temperature of the exhaust. My exhaust is warm, but not hot. I can leave my hand in the exhaust stream without any pain
    Cheers
    Sean



  4. #64
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    So I was able to get the vacuum gauge & pressure relief valve installed and with all zones closed & with 1 motor the gauge is reading 11 (HG - inches or whatever the gauge measures. Then as I turn on more motors the gauge doesn't increase, I'm assuming the relief valve is opening up.
    Multiple motors won't pull higher vacuum, they just move more air.

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  5. #65
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    David - wouldn't removing the relief valve just make it harder to figure out how many motors to run & when?

    Sean - I have 4 of these 220 / 240v motors https://www.centralvacuummotor.com/Ametek/122178-18.htm
    I should set the valve with all 4 zones closed right?

    Gerry - So if the extra motors don't draw more vacuum, just more air what are your feelings about setting the valve?

    Thanks
    Gary



  6. #66
    Member
    Join Date
    Jan 2015
    Posts
    194
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    I do fine and I don't have a relief valve. How do I do it? The sound of the motors, even through very effective hearing protection. But I would not run the vacuums with all zones closed as you could burn them up quickly due to no air flow. And I have the same motors.

    David Gage
    Deep Sea Sound


  7. #67

    Default Re: 4'x8' vacuum table build questions

    Gary, This is how would setup your check valve. I would set all 4 zones initially closed and only one motor running. Slowly open your zone valves until you get around 8”Hg steady holding on the gauge. Then adjust the check valve until it just starts to flow.
    On an aside, you won’t get anymore vacuum that 11” Hg because this is the maximum vacuum that your motor can provide. So once you have reached 11”Hg, no additional amount of parallel motors will achieve any appreciable additional vacuum.
    Cheers
    Sean



  8. #68
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Davd - that's what the relief valve is hopefully going to prevent case I do something stupid it will be a little bit of insurance for my motors & assurance for my mind. And let's face it doing something stupid is fairly possible.

    Sean - that was the answer I've been looking for. How do I set the valve. I wasn't sure if I should start turning the adjustment screw while all zone gates are close or what. Can I adjust the valve with it screwed into to system via the Phillip's screw on the end of the valve? Do I need to remove the valve after the initial setting to tighten the lock nut on the inside? I don't want that lock nut getting loose & going through my motor. I'd assume there is plenty of adjustment there but I just want to make sure.



  9. #69
    Member routalot's Avatar
    Join Date
    Dec 2003
    Posts
    1206
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Do the vacuum pumps come with a warning not to exceed any particular figure?Eleven inches of mercury (thats what Hg is) isn't enormous but should certainly be enough to hold the job in place.There are other applications that would require upwards of 28 inches and pumps to suit the application,the important things are holding your workpiece and doing so without damaging the hardware.Perhaps you ought to contact the supplier of the pumps to see if they can assure you.



  10. #70
    Member
    Join Date
    Sep 2005
    Location
    United States
    Posts
    1740
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Why would it make a difference if the vacuum was greater? As long as the motors did not overheat and I think I understand they are cooled by a separate air flow. If you had a way to measure the motor amp draw then you would know. Of course why run more motors than needed to hold down the material.

    1000x750 Workbee CNC - Mach4 - PMDX USB - Windows 10 Pro


  11. #71
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    WmGeorge -thats kind of my thought. I don't want to run more motors than necessary and shorten their life but the bigger issue would be not running enough motors and the piece loosing vacuum & destroying the material & or causing a dangerous situation.



  12. #72
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    If you try to use the minimum vacuum required, you won't have enough. A general rule with a vacuum table on a router, is that you'll never have enough vacuum. More is always better.

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  13. #73

    Default Re: 4'x8' vacuum table build questions

    Gary, I’ll have to check my valve tonight to see.
    Wmgeorge and ger21, yes more vacuum is better. But, Gary and I are using vacuum cleaner motors, not vacuum pumps. These motors are not designed for continuous operation at maximum vacuum. So the idea is to have the operation point that gives good results on the table, and allowing the motors to provide a reasonable lifetime. If money wasn’t an object,I would have used a real vacuum pump in the 10-20hp range
    Cheers
    Sean



  14. #74
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Sean - David (DGAGE) uses the same motors as we do (as well as a lot of other people on this forum) I talked to Warren from central vacuum today, he says 11" of Mercury won't hurt anything & he said we should make any & all adjustments based on motor temperature. If the whole table is covered he recommends using 2 motors if part of it is open use 3 motors. He said as long as the motors are running at 170° or cooler it will be great keep them under 180° because they will shut off at about 185



  15. #75

    Default Re: 4'x8' vacuum table build questions

    Gary, this is good information -I’ll put a temp probe in the exhaust and crank down on the relief valve a bit.
    On an aside, to adjust the valve hold the screw and turn the nut. Also make sure that the arrow on the valve is pointed towards the plenum.
    Cheers guys
    Sean



  16. #76
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Sean - So unless I'm not remembering correctly or just wasn't paying attention, the relief valve has to be removed to be adjusted? Also asked Warren where to check the temperatures exhaust or motor case (body) and he said to check the motor case (body) he didn't seem to care as much or even any about exhaust temp.



  17. #77
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Well I got it all finished up today & while I haven't used it to cut a job yet I'm very happy with it from testing it. All zones open & 3 motors running it will pull about 7in. of mercury while it was surfacing the spoil board. Then I placed a 7.5" x 27" piece of oak on zone 1 & opened just the 1 zone & with the 3 motors running it draws about 7.5" - 8" of mercury without using anything to block off the rest of the zone & it takes A LOT of pressure to push it.

    That brings up the question. Should I be able to move the board at all by shoving against it? Keep in mind I'm 6'7" 320# so when I shove against it... I shove against it!

    Also has anyone routed a couple grid lines so I can square up material quick & easy? I'm thinking 1/16" or so deep with a v-bit.

    Also I have a question that is probably pretty general. When I didn't have the vacuum table I would just cut through the material by .1" then I would just resurface the spoilboard. Now that I have the vacuum table set up I don't want to cut to deep & have to keep resurfacing. I know that material thickness fluctuations but how much deeper do you cut than the material? Is .025" enough?

    Thank you
    Gary



  18. #78
    Member
    Join Date
    Apr 2016
    Location
    United States
    Posts
    841
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Quote Originally Posted by Gary-Wiant View Post
    Also I have a question that is probably pretty general. When I didn't have the vacuum table I would just cut through the material by .1" then I would just resurface the spoilboard. Now that I have the vacuum table set up I don't want to cut to deep & have to keep resurfacing. I know that material thickness fluctuations but how much deeper do you cut than the material? Is .025" enough?

    Thank you
    Gary

    Watch this video. You don't need to cut into your spoilboard at all. I use this technique. Works like a charm. You just need to ensure your Z-Axis steps per are set perfectly. If you use a touch plate, your offset also need to be dead on.




    Gary




  19. #79
    Member
    Join Date
    Jun 2017
    Posts
    369
    Downloads
    0
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    Thank you Gary, that makes a lot of sense. Yes I'm using CNC Router Parts new touch plate with edge finding so my offsets should be exact right? Also if I tell Aspire that I'm setting my Z from the table height would I still need to enter the negative amount into Mach 3?

    Does anyone have any thought on if v carving registration lines will effect my vacuum? I'm only thinking of going 1/16"?

    Here is the video I should have given the vacuum more time to build up before trying to move the wood



    Gary

    Last edited by Gary-Wiant; 01-26-2019 at 06:33 AM. Reason: Added video


  20. #80
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: 4'x8' vacuum table build questions

    On our 5x12 table, I have a 4x8 outline engraved in so I know where to place 4x8 sheets, and I use this outline as my origin when running smaller parts. About 1/16" deep, and I color it with a sharpie. I can usually surface the spoilboard 3-4 times before I have to redo the outline.

    On our vacuum table, we cut .003"-.005" through, depending on the material. Some materials require slightly more depth.

    On my machine at home with no vacuum, I usually cut .005-.01" short of the bottom, and sand off the "skin" with a sanding block.

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


Page 4 of 7 FirstFirst 1234567 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

4'x8' vacuum table build questions

4'x8' vacuum table build questions