[panozeng]

About a year ago there was a company offering a CNC plasma gantry on Ebay that utilized a cantilevered Y axis. They claimed it was the easiest one to load material into/onto due to having 3 sides clear. For some reason I cannot find it any more, and don't remember who made it. But, I would like to see pictures of one again as I am considering building a machine with a similar design. Can anyone help me out on this one?

Thank you,
Jason

[millman52]

I have seen several cantilever design machines manufactured by someone like ESAB. They were all of the optical tracer type machine. If designed similar to theirs one will take up twice the floor space as a gantry type machine. However I would think you could build a cantilever machine somewhat like the rough sketch below.

[panozeng]

Yes, I have seen some of those industrial ones as well, and they are huge! The one I remember seeing on ebay often was in the < $10k range (might have been closer to $5k) and was similar to your sketch. If I remember right it was right around 60" x 60" cutting area, and seems like it was mostly aluminum. I may be off on the time frame, though - it would have been 1 -2 years ago that I saw it.

Thank you,
Jason

[JerryFlyGuy]

I know one such machine was called a Ezloader but I hear they were crap. We just about purchased one for R&D but after talking to some other users realized it wasn't worth the time or money.

Fwiw

Jerry

[millman52]

The optical tracer design tables have a table the same size as the burning area. The table has to be the same size to use full size drawings. They are usually set up with about a 2' aisle between the tracer table & the burning table to allow room for the operator. You still have to build your own burning support table.

http://products.esabna.com/index.htm...tegory_id/3472

[blackhollowmfg]

Is this it?

http://cgi.ebay.com/CNC-4x8-PLASMA-C...QQcmdZViewItem

[JerryFlyGuy]

Thats sure looks like the one I saw.

Jerry

[panozeng]

You know, I am not sure if that is it or not now. I was thinking it was in the <$10k range, but maybe I'm just not remembering it right. I emailed the company with an inquiry about 2 weeks ago and got a read response, but never heard back from them.

I am thinking about building a machine somewhat along the same lines, and was hoping to get a bunch of close-up pictures of it. There are a few on thier website - http://www.pcsplasmacutting.com/. Actually, they seemed to have updated it when I went just now to get the link, not sure if all the pics are still there or not.

Thank you,
Jason

[panozeng]

Looks like the website is mainly a series of broken links.... At least all of the product links give errors...

[Lee cnc]

Hi People,
this is my first ever post. I really want to deisgn & build a cantilevered, single side drive 8'x4' table. I have purchased a machmotion servo system. if there is anyone out there with an idea or two they'd like to share, i really woukld appreciate it. ART make a machine called a smart 4000. i've used that machine and it is awesome.

[jimcolt]

Cantelever machines were an old design that was necessary before the modern day cnc controlled machines. Most of them used a photocell tracer to trace a full size drawing....and then a torch (oxy-fuel or plasma) mounted on a cantelevered arm would do the cutting.

These machines had serious speed limitations (could not trace/follow lines at speeds much faster than about 50 ipm)....so they were best suited for oxy-fuel....simply were not fast enough for plasma. Many of these older machines have been converted (remove the photo tracer head, install a cnc control) to cnc....and while the cnc control added higher speed capability...now the mechanical backlash (inherent in a cantelevered, single side machine design) caused issues with accuracy...especially after some cutting time was accumulated on the machine.

Today it is generally considered more cost effective to design and build gantry or bridge style machines as they take up less floor space, are more rigid, and can be made far more accurate.

There are thousands of old cantelever machines still in use....the majority are upgraded to cnc control, and most of them use multiple oxy-fuel torch heads as the cutting tool...very few use plasma due to the limitations listed above.

These machines were built by C-R-O, MG Industries, Koike, Airco, Heath, Linde and Esab to name a few. (CRO later became MG, now is called Messer, the Airco machines became Koike machines....and Linde and Heath are now Esab.

I would recommend building a dual drive gantry....vs a single drive gantry or cantelever....if plasma is to be used for cutting. Plasma requires good acceleration, a wide speed range (5 to 250 ipm at least!), and should have a z axis for height control.

Jim Colt Hypertherm

About a year ago there was a company offering a CNC plasma gantry on Ebay that utilized a cantilevered Y axis. They claimed it was the easiest one to load material into/onto due to having 3 sides clear. For some reason I cannot find it any more, and don't remember who made it. But, I would like to see pictures of one again as I am considering building a machine with a similar design. Can anyone help me out on this one?

Thank you,
Jason

[johnohara]

panozeng~

Not sure if these links help. They are for portable plasma cutting. The gantries are cantilevered.

Portable CNC Cutting Machine,Plasma Cutting Machine-ArcMate Ltd.

SteelTailor portable CNC cutting machine, CNC plasma cutting machine,oxy-fuel cutting torch, plasma cutter

~john

[Beefy]

Ever since I first set eyes on a picture of a cantilevered design I did not like it. The mechanical part of my brain instantly sets off alarm bells regarding rigidity, especially when operating at fast cut speeds with a complete change in direction, and even more so when the weight of the z-axis is at the far end of "the cantilever" (hold your arm out straight with a weight in your hand, and move backwards and forwards fast. Not easy to keep your arm rigid with your body is it).

The build rigidity required would indicate to me that the weight of the gantry would be increased to attain this, something undesirable in a plasma table. Then there's the extra "solidness" needed in the rail system. The cantilevered gantry is like a long lever trying to deflect the rails holding it.

Why take the risk, I'll always go for rails at each side and each side independantly driven with a master and slave motors. As long as the table is built with the gantry perpendicular to the X-axis then homing switches on each side of the table ensure the gantry is dead square when you do a homing operation (as long as your homing switches are accurately positioned of course).

That's my 2c.

Keith.