How do you get a table FLAT, TRUE & SQUARE?

[WSS]

I have started a build on a 6 X 12 table for a Dynatorch gantry. I am at the point of truing up and leveling, squaring and so on. Any thoughts on how to properly accomplish this? I do not have a jig or even a very flat spot to layout something this big. So I will be relying on traditional methods. Thanks for ANY input!

[Geof]

No doubt you know about measuring the diagonals for square.

For flat, stretch thin wires tightly acroos the frame on the diagonal.

Make sure all the ends are firmly in contact with the surface of the metal not held up by a bead of weld.

With everything pulled very tight see if the two wires touch at the center; if they do not touch the frame is twisted with the corners for the top wire higher than the others.

If they do touch reverse their position so what was the top one is now the bottom and again see if they touch in the middle.

If they touch with either on top your frame is flat to withing the diameter of the wire.

[WSS]

I assume I would stretch them as close to the corners as possible (similar to measuring the diagonals), making an "X" and clamping with C clamps or vise grips? This would also show movement as you tack and gusset (providing you can work around the wire).

Thanks!

[Karl_T]

I just finished the welding stage on my table. I used a precision level to make sure the two side frames had no twist. You can get one on eBay reasonable. Then sell it when you're done.

[Geof]

I assume I would stretch them as close to the corners as possible (similar to measuring the diagonals), making an "X" and clamping with C clamps or vise grips? This would also show movement as you tack and gusset (providing you can work around the wire).

Thanks!

That is the idea.

If you are going to have the wires clamped there as a reference while you are welding here is a slight modification. Clamp the top wire on a spacer about 1/4" thick at each end. Now when the frame is straight there will be a 1/4" gap between the wires where they cross; if it is larger than 1/4" your the corners with the packing are high and of course if it is less they are low.

[magma-joe]

WSS, I found that metal saw horses work well. When I built my 5 x 10 table I placed the main frame sections ( 3 x 8 x 3/16 tube ) on top of 6 saw horses and then used shims to level the frame before finish welding. A 6' to 8' level can be used to help get all the frame sections leveled. Once I had the main frame level I welded on the legs with adjustable levelers in the bottom. Mind you the legs were not touching the floor as the the main frame was still being supported by the saw horses.

I purchased the levelors at Enco. I used the 3/4" stud with 3" diameter base.
http://www.use-enco.com/CGI/INPDFF?P...MITEM=990-2062 Each leveler will hold 7400 lbs.

Once the legs were in place I used my fork lift to raise the table one side at a time and removed the saw horses. Once the table was on the floor I used the levelers to re - level the table. You can then finish building the table.

It has been 3 years since I built my table. It is a standard style table. Dynatorch has come out with so many new features I thought it was time to upgrade. I am waiting for one last shipment from Dynatorch and the upgrade will begin. I will be adding the drop side option and if I can make it work with the existing hardware it will be a (dual drop), a new laser locator (their first ones were battery powered), the DASH system and the Dynascribe. The Dynatorch guys have been great at helping me with the up grade parts.

I will post some pictures when I get started. Here is the thread with pics of my existing table. "Dynatorch users"

[WSS]

magma-joe,
I worked this past weekend on the legs and long axis supports. I managed to get them straight and true. The design is almost modular, as the slat supports and the gantry rails will be separate but bolted to the same 5" I-beam. The legs are 5X5X1/4" w/6X6X1" plates for feet. I will get it up off the ground however and use some sort of shimming device to get everything in line (great idea). I will use the wire trick too mentioned by Geof. I have a box straight edge/level that is 8' that should help with some of the flats.

I am most interested to see your build! A dual drop would be pretty cool. You went all the way it looks like. Just the DASH and the dynascribe are a shedload. Will you retrofit or build new? I have looked at pics of your table many times when I was drawing ours. The guys a DT have been very accommodating for us here. I spoke with Mike at DT yesterday and he said it can ship when I am ready. I am hoping to ship in the first week of August

I will post some pics after this weekends round of work. I have been busy this last month with other stuff in our shop, it has picked up a bit (yeah). I think that is part of murphy's law. I wish time really was like money and I could put some in the bank!

[Dustin407]

All suggestions are very good from everyone and very similar techniques that I have used on projects. I dont think anyone mentioned welding techniques. Tak (sp) everything first real good and check for level,twist,square...etc after each couple of taks, things can move so keep checking. If things are not in the correct position cut the welds back off and start over it will only get worse trust me.... Once everything looks good dont keep welding in one area move around to different spots randomly. 6' x 12' is a pretty large table, as the numbers go up the tolerances go down a little, so I wouldnt expect perfection..

[magma-joe]

WSS,
What a great collection of wisdom on the cnc zone! Like you, I spent many hours (days) looking at different table designs and styles. I soon realized that although building the table square and level is important, it is not critical. The main goal is to have a level cutting surface. Once the table frame is built, even if it is out of square or not level, you will still have another opportunity to level the cutting surface when you install the slat holders.

If you have looked at my pictures you have noticed I used 3 x 3 square tube floating x axis rail mounts. This design alows for adjusting your gantry rails INDEPENDANT of your table. This will again allow you another oportunity to compensate for errors in the frame. It also makes it easy to perfectly align the x axis V rails and gear rack in ANY direction.

I am excited to upgrade my machine. I will be modifying my existing table. Your gantry will be the latest and greatest that Dynatorch has to offer so I am playing catch up. I am sure you will be happy once you get your machine up and running. Proper planning now will pay off later with nice precision cuts. I will post some pictures soon.

[Edwardo]

I built my DT table using there drawings, the only difference is i went with 1/4 tubing instead of 1/8, the 2 end cross peices have the gusset welded to them and bolted through the legs, both rails are the same length so like mentioned above i measured corner to corner to square it up then tightened the bolts.. i had made some simple height ajustment legs using large nuts/bolts/washers because my cement floor isn't level, they are crude but they work, i check the squareness of my table from time to time when i am cutting square peices, so far it hasnt moved as the peices are bang on.
I cut the slat support notches in the angle iron using my chop saw, so they arent all exactly the same depth, but close... i off set the center slat support notches to the center of the 2 outside ones which give my slats a nice bow running from one side to the other.
I think squareness is more important than level, your table can be perfectly level but the sheet you are cutting might not be meaning the thinner material thats is warped or becomes warped when cutting... but the thc takes care of that..
On a after thought i remember now wishing i had welded the leg height adjustment knobs on first, it would have made my life alot easier at the time instead of trying to shim them with whatever i could find.

EDD

[WSS]

I hope this thread will continue to add tips and tricks! This type of knowledge really speeds the build. I managed to (with the help of my wife) get it all laid out and true! It was certainly quicker once I had an idea and direction. I am posting the dxf converted to a jpg of the end and back (high) side. I will post some build progress later this weekend.

Thanks again!!

[CNCDevil]

Some simple idea I got...


Materials you need:

4 transparent tubes (acryllic/glass)

Waterhose that will fit to the tubes

1 piece of 4-way distributor

1 piece of 3-way distributor (optional)



Mount the 4 transparent tubes in a vertical position at each corner to your base and interconnect them with hoses, with help of the 4-way distributor. Now fill water into the "system" and at point you will see the water raise in all of the tubes. You can be absolutely sure that the waterlevel in the tubes are in perfect level with each other (thank you nature). As you may already have guessed, the goal is to make the top of the base corners, level to the water in the tubes.

The 3-way distributor may be inserted to the system, making it easier to let water in and out.


Brian