4X4 to 4x8 CONVERSION!

[Joe Jones]

This was my FIRST 4x4 to 4x8 conversion, and it was a LOT easier than I anticipated!

We used standard DHC2 rails with Samson 510 gear racks inside to give us the additional travel. The legs were deliberately tucked in at the far end, so the gantry can travel BEYOND the end of the table for PIPE CUTTING! The way this table is now configured, we can place a 22" diameter cylinder onto rollers next to the far table legs, and cut the tube (pipe/cylinder, etc.) By extending the torch DOWN via a custom backing plate extension, we can cut patterns or text into OIL DRUMS!

We only ran into one small snag, when it became evident that the lower spring and hardware nut on the far lower end of the gantry crashed into the center support we made. So with a bit of redneck engineering, and an alternate plan, we corrected the error.

The table is actually 48" x110" now! All we need to do is build a pipe roller to place beneath the gantry when it is extended beyond the table frame, and rotate the pipe beneath the table's existing gantry and carriage, using an AUX gantry motor and a belt. NO NEED to disassemble the table to configure a pipe cutter! We will add center legs as well, and a cross member for the frame to retain squareness.

This went SO WELL, I am excited to get home and do the same to a few of the auction tables I have purchased, so I can sell them with the proper CSU upgrade and the "Big Three" upgrades as well. I will be purchasing a lot of upgrades from PlasmaCam!

Either that, OR I can sell these auction tables as the extensions, and if you already HAVE the CSU upgrade, you are good to go!

We are nine hours into the project. The only thing left to do is to add the swinging boom arm, and replace the PlasmaCam grates with a herringbone slat grate, using 3" x 1/8" flat bar, just like the new GENESIS tables are set up!

My client is really pleased with the results. http://flic.kr/s/aHBqjBX97w More photos will be added soon!

I will probably do some video to explain how this was accomplished.

Joe


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[05Duramax]

Pretty slick Joe! This would be a very popular upgrade for many I am sure.

[Joe Jones]

Many people do not have the room in a small shop for a 5x10 table, which requires 12x17 feet of floor space at a bare minimum.

I can help people convert their tables to 4x8 or 4x9 and it won't require an additional DesignEdge software license.

Wait until I make the 4x4 tables with my grate elevator system. You KNOW I am going to make one out of a 510 too, someday!

Joe



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[acourtjester]

Here is a boom setup I used on the 8' tables I built, I has a swivel at the end of the boom. This allows the cable to move the boom to swing when the cables get shorter as the torch moves to the full length of the table. Images are of 2 different table the swivel is slightly different between the tables.

DSCN1668.JPG

4X8 table for sale (2).JPG

Cable boom with swivel.JPG

new wire boom (1).jpg

new wire boom.jpg

[adbuch]

The Plasmacam 4x4 (or 2x2) to 4x8 conversion is pretty common and very simple to do. All parts are readily available - most directly from Plasmacam. Doug started out with a GoTorch 2x2 and did indeed expand it to 4x8. If using Design Edge, the Customizable Size upgrade ($998) is required in order to make full use of the table. I believe that Robert Johnson offers longer wiring harness kits at his store. I have also seen rail riser kits from John Derby in the past. So lots of parts and kits already available to accomplish this table expansion.

David

[adbuch]

Tom - this one looks very interesting. Very nice design! Is that a coil spring at the top of the arm?

David

DSCN1668.JPG

[acourtjester]

The spring allows the end of the arm to pivot as the torch moves with change of torch direction, and the arm follows it then. When I just had the cable to the end of the arm it would bind and not follow. With this each time the cable changes direction or nears a bind it pivots the end and the arm smoothly follows the cable. I found this was only needed for the 8' tables and I put the arm swivel base in the center of the tables length.

[Joe Jones]

We got the pipe cutter working too!

Joe

IMG_6584.jpg

4X4 TABLE WITH PIPE CUTTER.jpg

[acourtjester]

So it looks like you are using a drive to turn the pipe like the one JD Garage showed. Drive belt around the pipe with a Motor under it. I assume you used drive control from another axis from your controller with an optional cable. Nice Job

[Joe Jones]

No. I used an AUX gantry motor mounted to the triangular plate on the pipe cutter. The main gantry motor cable was moved to that motor. Instead of moving the gantry, it rotates the pipe.

Joe

[acourtjester]

Ok so a separate motor but cabled by one of the tables other axis cable. I'm sure you needed to recalibrate the steps per for that drive assembly.

[Joe Jones]

Ok so a separate motor but cabled by one of the tables other axis cable. I'm sure you needed to recalibrate the steps per for that drive assembly.

Nope! The PlasmaCam table gantry motor with a belt drive is a 1:1 ratio. Wrap the pipe and cut. The torch tip doesn't know if it is hovering over flat steel, or riding over the top center of a round rotating pipe. The cut surfaces are treated the same.

Joe

[adbuch]

Ok so a separate motor but cabled by one of the tables other axis cable. I'm sure you needed to recalibrate the steps per for that drive assembly.

Tom - the Plasmacam mechanical drive ratio is not 1:1. The "turns ratio" needs to be set in the system configuration table just like any other plasma table or cnc router table. Mach3, Centroid, etc. all have these sorts of settings for calibrating the table so that 1 inch in software translates to 1 inch in actual motion along the axis.

Plasmacam has already set these ratios (factory settings). See attached image.

Plasmacam Pipe Cut Attachment 2.jpg

Plasmacam Pipe Cut Attachment 1.jpg

[Joe Jones]

Notice (in the photo above) that the belt does not ENGAGE or DRIVE the 60-tooth aluminum belt cog or the 24 tooth pinion gear when using the pipe cutter. The belt is REMOVED from that 60/24 combination. The belt drives the pipe rotation directly. So that 60-tooth belt cog and the 24-tooth pinion gear do not come into play when using the pipe cutter.

The belt wraps around the 15 rib belt pulley and the pipe circumference only, with a small pulley wheel on a slide to take up the slack and tension the belt.

Joe

[acourtjester]

Thanks for the diagram and explanation I now see how it works. the JD Garage was setup differently in that the pipe more or less replaced the 60 tooth sprocket in Joe's diagram. This would require a different calibration for each pipe diameter change. The way you shows it is much easier a setup. I will take this info into when and if I develop a pipe/tubing cutter for my table. The one I built years ago is more in line with the JD Garage setup.

[adbuch]

Thanks for the diagram and explanation I now see how it works.

Tom - the new Plasmacam table simply rolls the pipe along the table. So no need for additional motor or worrying about calibrating with the correct turns ratio.

David

genesis pipe attachment.jpg

[Joe Jones]

Thanks for the diagram and explanation I now see how it works.

Tom - the new Plasmacam table simply rolls the pipe along the table. So no need for additional motor or worrying about calibrating with the correct turns ratio.

David

genesis pipe attachment.jpg

Easy enough to reproduce for the DHC2 and Samson 510 tables too.

Joe

[adbuch]

Thanks for the diagram and explanation I now see how it works.

Tom - you are quite welcome! The red belt and gear rack I show is for the standard configuration running the table. For the pipe cutting attachment the red belt is removed and the long black belt installed as shown - it wraps around the pipe. Even though the mechanical ratio is not 1:1 for the gantry, Plasmacam had the foresight to use a setup with the proper turns ratio such that there is a one to one correlation between the incremental circumferential distance moved on the drive motor pulley and the actual distance moved in the Y direction for the table (gantry incremental movement).

So when the motor turns such that the incremental circumferential distance moved is say 1/8", this translated into an incremental movement of the gantry or 1/8" in the Y-direction. By using a setup like this, Plasmacam was able to drive the tube cutting attachment by simply wrapping the drive belt around the tube/pipe being cut. So in that configuration - there is a one to one correlation between the circumferential distance moved along the outer edge of the drive pulley and the circumferential distance moved along the outer edge (circumference) of the pipe/tube being rotated for cutting.

Had they not had this foresight, then the turns ratio would have needed to be adjusted every time the table was converted from conventional operation to pipe cutting operation and back.

David