Vacuum table kit for ShopBot Machines

[gbradley]

I am testing the waters here with a complete kit for ShopBot cnc routers and machines that are similar. We are currently doing a vacuum table conversion with a retro fitted Gast pump set up for a non-profit organization in Providence RI called AS220 that has a 4X8 ShopBot. We will be documenting from the tear down of the existing table to the install of the grid gasket. The vacuum conversion kit is something that we are looking to produce as one of our products. This kit will be complete table, pump, pvc pipe, and all necessary hardware to install on your ShopBot. Let me know if this is something that sound of interest to the ShopBot community.

Thanks for looking

[Brady Watson]

George,
You will need to post specs of your system in order for there to be any interest.

Voltage/hp of pump?

CFM?

Hg" max?

Ballpark price of system?

-B

[gbradley]

Ok will do

[gbradley]

This is a picture of a 24 X 32 table for an older ShopBot
http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=567

The Gast pump for this table is 1/4 HP 110VAC-60hz-single phase, silencer, street tee, vacuum gauge female hex, long nipple, inline plastic vacuum filter with clear plastic bowl, hose barb x ½”

[Brady Watson]

George,
This might be OK for non-porous parts with minimal kerf width, but it lacks the CFM to be a buffer for leakage when you cut all the way through, or for porous materials like MDF and some woods.

You want something with at least 200 CFM and say 9 or 10 Hg" to be suitable for a universal type system that uses an ultralight MDF bleeder board. This type of setup is great for sheet goods, but no so great for smaller parts.

-B

[gbradley]

All Star Adhesives is aware of vacuum vs CFM. Like the picture I posted yesterday, a customer that buy's a small router 24 X 32 table is not going to be cutting cabinet parts. He will not need a high cfm pump. All Star has been in the gasket business and trying to teach the ways of fixturing and how to cut small parts for a long time. We are trying to branch out to make our own table kits this is why I said "I want to test the waters" because everybody has their own opinion on how it should work. All Star has consulted with several of our close customers that have worked in the industry and we have consulted with Gast for our vacuum table application

"We are here to SAVE vacuum not create it" :)

[Brady Watson]

Hey George - I had no idea you were with AllStar - tell John I said hello.

-B

[gbradley]

Ok I will tell him. I am just putting this out their to see if this is worth doing. I will be posting our video on the vacuum conversion with the non profit organization. We are waiting for the materials to come in and we are going to install at the AS220 shop in Providence RI

[dana_swift]

The Allstar products make high vacuum work trivial! But not only that I have found other uses for the gasket tape, such as making "o" rings for tunable marimba resonators. I have also used it for small cushions to prevent non-musical parts from "talking".

Those uses dont use it up very fast so I have rolls of it around. Anyone trying to make high vacuum hold downs for small or production runs, this stuff is highly recommended!

D

[gbradley]

Dana what size o rings are you making we have tons of different sizes on the shelf.

[dana_swift]

I am slipping 1 1/4" pvc inside 1 1/2" pvc. 1/8" tape making about three wraps of the 1 1/4" works. Real o-rings would be nice tho. I have comptemplated using 1/4 x 1/4" tape and getting a tighter wipe on the inside of the 1 1/2 pipe.

The tape is laid immediately against the previous wrap, so it synthesizes a 1/8" thick 3/8" wide ring. Not a great wipe, and the resonance is not as strong as a fixed tube cut to the correct length. My hunch is some air motion or damping is occurring on the joint.

The tape slides a wee bit on the pvc, but gets support from the next wrap. A real o-ring might be a better choice.

I looked at the website, no mention of O rings.

D

[gbradley]

Dana I will get you a list of o rings that we have. Give me a bit and I will see what we have

[Brady Watson]

FYI - Those of you not familiar with AllStar Adhesives - should check out their selection of vacuum gasket materials for part hold down. The spoilboard cover product is fantastic for a number of applications.

These guys have already worked out what materials & durometer are suitable for holding stuff down - so don't reinvent the wheel trying to make stuff from the big box stores work.

-B

[Simops]

. I am just putting this out their to see if this is worth doing. I will be posting our video on the vacuum conversion with the non profit organization. We are waiting for the materials to come in and we are going to install at the AS220 shop in Providence RI

George I would be interested in a vac table for my Buddy......I use 48 x 48 table and finding that really need vac to cut alluminium properly!

I already planned a vac table for it but abandoned it for now due not being able to find suitable vac motor here at a reasonable price.

I only need to split table into 2 zones and have pipe running to each zone between the rollers to a manifold then flex piping to two motors underneath table.....should work fine. Something simple.

But no point reinventing wheel if you are considering a kit.......but our power supply here at 1 phase is 240VAC at 50Hz!

Look forward to seeing the video...

Cheers

[gbradley]

Michael our pumps are and wired for 110VAC-60hz-single phase. Gast recommends "It is recommended your customer provide a dedicated 15amp circuit with switched outlet" I expect our materials to be in within a week or two. Let us get the one installed and get some video and All Star can get the vac table kit ball rolling.

[chiloquinruss]

I would be interested in a portable 48x48 piece that I can place and remove easily from my 48x96 bot. Most of what I cut in the smaller size stuff is full cut through, sometimes with tabs. Please keep us posted and if you can some ball park pricing. Thanks in advance. Russ

[gbradley]

Thanks for the reply's we are doing the cost and setting it up in our system so by the second week in January we should have it all worked out

[Simops]

Michael our pumps are and wired for 110VAC-60hz-single phase.

Unfortunately that power requirement will not work here in AUS! Finding a suitable pump priced similarly to that found in the States is proving difficult. I'll Keep looking.....

Cheers

[gbradley]

Michael I am going to send your info to our gast tech and see if we can get you what you need

[gbradley]

Dana I looked at what we had nothing that measures out to .375. I thought we would have something like this http://allstaradhesives.com/cart/product_detail/g_cr_25_305/57 that would work. But the grommets are .25 increments

[Simops]

Michael I am going to send your info to our gast tech and see if we can get you what you need

Thanks for your interest George......our power supply here for single phase is 220 - 240V at 50Hz. Standard domestic power points rated to 10amps. 15 amp power points easily interchanged with the 10 amp points.

See how you go.....?

Cheers

[gbradley]

I may have an alternative for your issue we have a product CR 18 38 http://allstaradhesives.com/cart/product_detail/cr_18_38/50 this is .1875 X .375 wide maybe this may work better for you?

[gbradley]

Here is a sneak peek at our base and grid on our vacuum table


http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=578

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=575

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=577

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=576

[gbradley]

Here are some more images

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=581

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=580

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=579

[pappybaynes]

George, I also am interested in a 48"x48" that I can take on and off my 48"x96" table.
Thanks,
Dick

[gbradley]

Dick

I need to ask why would you do only half of the table and what is the purpose of removing the 48 X 48 from the table?

[Brady Watson]

George, I also am interested in a 48"x48" that I can take on and off my 48"x96" table.
Thanks,
Dick

You already have that available. It's called a BradyVac & it's free...aside from whatever material or scrap you use.

RE: BradyVac I (http://www.shopbotblog.com/index.php/2006/11/a-removable-vacuum-plenum-that-maximizes-hold-down-potential/) & BradyVac II (http://www.shopbotblog.com/index.php/2007/07/the-bradyvac-ii-%E2%80%93-a-production-vacuum-fixture-on-a-shoestring-budget/)

-B

[pappybaynes]

that is true Brady...I certainly interested in the AllStar System - they helped me design a job specific vacuum table for a coaster project I was working on a few years ago...When I get to spend every day in the shop and not in my day JOB, I'll obviously have more time to fabricate jigs and fixtures...I'll review the BradyVacs again...
Thanks
Dick

[Simops]

Here are some more images

George the vac motor shown in first pic......what are the specs....the label is not clear on the side? Does it take 240VAC at 50Hz?

Cheers

[gbradley]

Here is what the manufacture had sent to me

• Includes foot plate on vacuum pump, 6 ft. power cord 14 gauge and wired for 110VAC-60hz-single phase, silencer, street tee, vacuum gauge female hex, long nipple, inline plastic vacuum filter with clear plastic bowl, hose barb x ½”, tested for operation prior to shipment
• Assembled in two sections – pump with fittings (gauge) and vacuum filter and fittings and are packaged in one box for shipment.
• It is recommended your customer provide a dedicated 15amp circuit with switched outlet

[Simops]

110VAC-60hz-single phase

Bugger!:rolleyes:

[gerryv]

We're planning an ongoing product that will use nominal six quarter (1.5") X 8w" hardwood lumber in 8' and 6.5' lengths. I'd like to use the 'bot for as many operations as possible even though some can be done faster with conventional equipment. This will allow us to do other things while the bot is working.

After quite a lot of reading, and finding out the hard way that interchangeable, powerstick vac. tables with spoil boards are HEAVY, I'd like to try using vacuum pucks/pods mounted directly onto the powersticks (I have 4', 6, & 8'). I'd probably make/buy quite tall ones to minimize the potential for cutting into my powersticks if something goes wrong. My plan is to bolt them into the tee-bolt slots and move them as needed (not a lot). I don't expect to ever need to cut through, only trim the outer edges off, perhaps with a round over and do carving on one side. The process would be something like this:

1. Joint one wide face of the plank so that the vac pucks would seal and hold properly.
2. Mount the plank on the pucks for the rest of the facing & cutting operations which would include:
a. Plane the remaining wide face
b. Carving that face
c. Trim off the edges to size the plank, and
d. Hopefully, then use the air drill attachment to do top and edge sanding

Obviously, several tool changes and some experimentation but;

My question really relates more to what the other Buddy owners experience and thoughts might be on using vac pucks/pods for this application.

Also, what vac source you'd choose - high vac lower volume likely - that won't break the bank.

We don't need to worry about "what else" I plan on doing with it because I already have spoil board tables of different sizes made up.

[bobmoore]

Gerald;
If you are going to use a high vac low volume source for vacuum with multiple pods daisy chained together, like wiring in series to use that metaphor, be careful to avoid any knots with your puck locations. Even a solid knot at 25" mercury will pull air through and loose a substancial amount of vacuum. Low volume of course won't be able to make up many such leaks.
Bob

[Joe Porter]

Gerald, I don't know if you have seen this or not, but seems to be the type of system you might be interested in.http://www.joewoodworker.com/veneering/downloads.htm
I keep meaning to build one of these and a set of pods and use it on my Buddy also. I hope my link shows through, as most around here have figured out, my computer skills are considered the Lowest Common Denominator. Good luck with your project...joe

[gerryv]

Bob,
Thanks much for the heads up on that, I'd never have thought of that.

Joe,
Thanks much for the link. I'll check it out this evening.

Because I'm paranoid about cutting into my powerstick and because I have lots of clearance with mt 12" Z axis, I'm pretty sure I'll either make some tall, custom pucks or install machined spacers under commercially available ones. I should also have enough room to install upper and lower position sensors to prevent any kind of diving error - very likely mine:-)

Once I have it all setup I'll post a video on the Buddy forum. :)

[gbradley]

Here is a 24 X 32 test table with a 3/4 Gast PSI pump. This table has 2 adjustable zones With our Vacuum Levee.

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=589

This is the reading at half the table

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=591

and this is the reading at the full table( about a 12% drop from half to full table)

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=591

You can see more pictures here

http://www.talkshopbot.com/forum/album.php?albumid=87

[gbradley]

We have modified our 4 X 8 table to accommodate two ends of the vacuum fields 48 X 48 is dedicated to CFM (air flow) and the other end 48 X 48 is dedicated to PSI ( small parts/ fixtures). This is a two pump set up 48 X 48 is set up with a Gast 3/4 rotary vane pump with 1" pvc pipe, and the other is set up with a 1 hp regenerative blower with 2" pvc pipe. The zoned portion of the table is universal, you can have a 6" X 12" zone all the way up to 48 X 48.
http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=626

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=627

http://www.talkshopbot.com/forum/picture.php?albumid=87&pictureid=628

Take a look at my albums for vacuum numbers on the fixture end of the table
http://www.talkshopbot.com/forum/album.php?albumid=87

[Simops]

George can you give me the specs on your Regen blower? I'm looking for one and doing some homework. I'm looking at a Chinese 2200 watt (240VAC 50Hz) unit.

Cheers

[gbradley]

Here are the specs on the regenerative blower. If you can not find anything that fits your power supply maybe you can contact Gast they should have something.

http://www.gastmfg.com/support_documents/LTD142rD.pdf

[Simops]

Here are the specs on the regenerative blower. If you can not find anything that fits your power supply maybe you can contact Gast they should have something.

http://www.gastmfg.com/support_documents/LTD142rD.pdf

George, it seems you are using a 1 Hp Regen blower...am I reading that correctly? The unit I'm looking at is 2.2Kw - 3 Hp......so I can assume then that will be sufficient to do a 4 x 4 foot table?
Cheers

[gbradley]

I think that having a 3 hp unit on a 48 X 48 table will work very good.

[Simops]

Thanks George......
Look forward to where you end up with your kit?

Cheers

[gbradley]

Here I made up a vacuum table for a Desktop model using 3/4 HDPE for the base and 1/2 HDPE for the fixture cutting 1.5 circles out of .25 HDPE. Using a 1/4 HP Gast psi pump.

25457254562545925458

[scottp55]

George,
1.5" circles out of .25" stock:)
Now you've got me interested!!!
Still got cover gasket you gave me at Shopbot camp last year/ .75"HDPE all surfaced/ and just took my vac pump for it's VERY first test ride today on a down and dirty 2x4" puck just to see if my 3cfm cheap pump would spew oil and surge, or if I needed a vac reservoir.
WAY better than I thought, and NO oil:)
Going to finalize my most common size button and give it a whirl thanks to you!!!
What exactly are the hose and fittings I see?
I Gommed mine together with .51" OD braided hose and it's way too thick:(
What size cutter used on cutout, and how aggressive was cut?
Did you toolpath all aggressive and leave a skin so sheet remained whole, and then go back and take skin off in a second toolpath?
Or do each one all the way?
NICE:)
scott

[gbradley]

Scott

I ran 2 passes .125 each no skin cuts or anything like that. i got some quick connects at Lowes 1/4 od and 1/8 in MIP with 1/4 inch nylon hose. I used a Onsrud 65-026 is the number I think, .25 super "O" flute. I am going to go for a 1" circle in the same manner. Let me know how you make out when you get the buttons held down.

[scottp55]

Thanks George!
Probably be at similar to 1" once I leave gasket for buttonholes.
Using a .25" 60degree VBit for cutout. Will probably make a last pass of .01" to minimize cutting force.
Thanks for quick connects. Going to go to Lowes anyways to pick up some other fittings and valves I forgot anyways.
Good to see another example of cover gasket and waste hold down.
Interesting... base and THEN the jig, got me thinking.
Post 1", even if it doesn't work...please.
Did you say that AllStar makes a cover gasket that has extra high friction properties so parts don't slide?
Or was that a separate product I have mixed up?
scott

[gbradley]

Scott

Yes the product is called grab, http://allstaradhesives.com/cart/product_detail/zbc_03_lf/53 this is the link to it. I am confident that the 1" will hold. I will post more when I get the chance.

[scottp55]

Thanks George,
Going to try scuffing my surfaces first with 80G(they were both 320G and one was shellac).
May try "Onboard" next with that thin roll you kindly gave us at the Portland Shopbot Camp.
This Vac stuff is exciting once you try it:)
Bookmarked!

[scottp55]

George,
What is CFM on your Gast (or G. if your Gast is identical)?
Just getting around to playing with design of my base and trying to stay away from needing a surge tank like Gert uses for the moment.

[gbradley]

The CFM on our pump is 4.0. here is a link to the specs http://www.gastmfg.com/product_detail.aspx?ProductID=117&ProductTypeID=20

[scottp55]

Thanks George.
At least I'm in the ballpark with 3 CFM and a smaller jig.