[rchacich]

After having a frame sitting around for 6 months, I decided it was time to complete the mechanical assembly of my 3 x 4 table. The design consists of an upper and lower frame which would allow for a water pan to sit between the two if desired.

Advantages of this table design:

• Small footprint of 4' x 5' for a table travel of 40" x 50"
• Split frame design allows for a water pan
• Can be moved in a pickup truck
• Parts can be cut from a full 4' x 8' sheet of material
• Can be moved through a 36" door in 2 pieces

I will be detailing how I set the rails providing the gantry to ride square and smooth.

[rchacich]

My brother fabricated a frame based on the Precision Plasma LLC 3 x 4 table print. I had it powder coated before I drilled the upper holes to mount the rails. The holes are not shown on the print because variations in welding the frame could cause the rails not to be parallel if they were previously drilled.



Here are some close up pictures of the welded corners.

[rock4xfab]

Ok I am subscribed, seeing How I cant seem to find the time to finish my 3x4table... LOL

[rchacich]

Rock4xfab,
I have been watching your build and it does appear that your progress has slowed as well. Maybe my progress today will inspire you to get your table finished.

It was quite easy to get the rails mounted parallel. The first thing that I recommend is to invest in 4 spring clamps if you don't have them already. I have used c-clamps in the past, but the spring clamps worked much easier. They cost $10 for a set of 4 and they allow you to slide the rail around without having to loosen and tighten the clamp.



I first clamped both rails on the frame.



NOTE: AT THIS POINT, INSTALL THE STOP BOLTS ON THE RAIL!



These shoulder bolts will prevent the gantry from accidentally rolling off the end and falling onto the floor. I learned this the hard way on my first build....twice.

[rchacich]

Precision Plasma LLC sells 2 different gantry kits, a standard and economy version. The wheels on the economy version are fixed, and they are adjustable on the standard version. When the economy version is used, the rails must be parallel and an exact distance apart. When using the standard version, the rails must be parallel, but the distance between can vary by 1/8" and everything will still work just fine. Just set the rails parallel and to the dimension on the print for the standard gantry.

I set the rails on this table using the economy version, since it is more difficult, even though I plan on running the standard gantry parts.

First, set the gantry on the rails and adjust the rails so that the v-guide wheels set exactly on the v-guide rails.

Here is an example of a good fit.



Here is an example of a poor fit:



Slide the gantry to both ends to set the rail along the full length. Also, be sure the rails are centered on your frame.

Note: There is a gap between the step on the bottom of the rails and the tube of the frame. This allows room for making adjustments when mounting the rails.

[rchacich]

Now that the rails are positioned correctly, it is time to bolt them to the frame. The first step is to tap the 1/4-20 holes for the mounting bolts.

Rail position verified.



Note: Use 1/4" bolts to attach the rails even though the holes in the rails are 10mm. The extra clearance will come in handy for adjusting and for any wandering of the tapped holes.

There are 3 methods I have used to tap the holes.

1. Mark the holes using a sharpie, center punch, drill, and tap.
2. Transfer punch, drill, and tap.
3. Use a drill bushing, and tap.

This time I used method 1, which didn't take long since it is in 16ga. material.

Holes tapped.



Next, use 2 bolts on each rail and verify the gantry fits properly. Adjust the rails as necessary.



Install all of the rail bolts.

[rchacich]

If you are using the interlocking slats rather than the welded grate, it can be a bit tricky to install them. Put a top slat in the center of the table and then add bottom slats from one end to the other. Slip the bottom slats in beneath the top slat and rotate into place. You will need to lift the top slat slightly for each slat added.



Note: You can use plastic corner protectors for your home on the frame to protect the paint from being scratched by the slats. Hold them into place temporarily with scotch tape.

Once all of the bottom slats are in place, add the remainder of the top slats.

Finished assembly.

[rchacich]

Here are pictures of the table mechanically complete and resting on the bottom frame. The gantry is the standard kit and not the economy kit.

Main table



Closeup of upper and lower frame



End plate



Z axis

[rock4xfab]

Well I am at the shop today so Hopefully I will get some more progress.. I did find that one of may rails is crooked at the end.. (Tube is /) so I can see the where the V-roller rides up. I will have to adresss that soon to.