Suggestions for a plasma table

[treemuncher]

Seems like I do quite a bit of repetitive cutting with my Hypermax 1000. Normally, I make patterns out of 1/8" aluminum flat stock, oversized to accommodate the size of the torch tip, in order to trace out common cut parts. This works reasonably well but there is always variances with the hand held torch.

Rather than send all of my money into to the tax (and spend) government system, why not purchase a plasma table for my business? It will save me time, open more opportunities for builds and business, and make for better parts than hand cuts. Lots of times when I'm making tools for pullers, bearings or fixtures, I could see a CNC plasma table saving me lots of time.

I'm looking for suggestions as to what system to look for. My Hypertherm is designed for a machine torch but I'm not sure if it will work with these newer systems that are available. I was going to build my own table years ago but I stay way too busy with my normal work to even think about that anymore.

 

[Tags]

So I have a friend that bought a PlasmaCam 4x4 table about a year ago. I belive all in with the software he was somewhere close to $20k. He had never used a table before but he has gotten quite good with it over the last year, the hardest part is learning how to run the programs efficiently. He has cut up some parts for a static screening bucket I was making, 3/4" plate, it did an amazing job once we got the profile right. He has been getting more and more more small jobs from local guys. This is not his primary business so the plasmacam table seems to work perfect for what he does with it. I would imagine if it's primarily for you and a small side job here and there it may work out for you. If you get one I would suggest a water table or a very good down draft system to get rid of the smoke.

 

[DirtyHoe]

I have used a variety of CNC plasma tables for over 20 years. PlamaCAM, ArcLight, Burny, and one other I can't think of the name. If you can afford it get a dedicated machine torch. At work a few years ago I went through the process of getting several quotes to replace the ArcLight(problem child). We purchased a Koike Aronson ShopPro 4x8 for around $26,000. Absolutely the best machine I have operated and maintained. It uses a Hypertherm PowerMax 85 plasma cutter with a machine torch. Touch screen and a water table. Downdraft tables get expensive because you need to catch the sparks with a spark rated dust collection system. The system will cost more than the plasma machine. We have had zero problems after cutting hundreds of sheets of material on the ShopPro.
Realize you will need to learn how to draw your parts in CAD, then program your cutting paths. Plus learn how to correctly set the machine up for cutting amps, cutting speed, pierce time, and different types of consumables.

The most important part is clean and DRY shop air. You really need to install a refrigerated air dryer to do it right. Any moisture will half-life your consumables.

https://www.koike.com/shoppro

Let me know if you have any other questions,

Steve

 

[Welder Dave]

I don't know if there's a bad CNC plasma??? Torchmate are popular but not sure if they can hook up to a Hypertherm machine. These JD Squared seem like a reasonable price. I worked with a guy briefly that was associated with Kickass Machines plasma tables but they have since gone out of business. I would think you might find a good used plasma table with the downturn in the economy.

Torchmate 4000 Series CNC Plasma Tables | 4x4, 4x8, 5x10 Plasma Cutting Machines | Torchmate

JD2. MAD MP CNC TABLE

 

[lantraxco]

If you normally don't cut big pieces, try getting your feet wet with a Langmuir like the Crossfire Pro. Then after you are much better informed maybe write that $10K plus check for a real production unit.

 

[treemuncher]

I ran into a guy with a local welding fab shop at the metal sales place the other day. He told me he purchased a GoFab unit for well under $10k with everything needed and he is staying VERY busy with it. I doubt it is a very high end unit but it looks like something that would fit my needs. I plan to stop by and look at his if I can ever find some free time or happen to be close to his shop. I've already got the air compressor and my Hypertherm 1000, not to mention the schooling for CAD and CAM from years ago.

I've looked them over on the web site and some others. My budget will be $10k max as I don't plan to use it very often. I'm not looking for big production but just for my occasional needs. I would rather spend money on something like this that is a write off rather than spending it in taxes that gets wasted by some government tool. If it saves me 10 hours per year, it is a justified tool in that price range. I see the potential to save much more time than that and allow me to get involved in other projects as well.

This is the way I justified my lathe and vertical mill. Those have been some of the best purchases that I've ever made because I can make many of my own parts when time is of the essence or factory prices are outrageous. Just last year, I saved well over $750 because I could make 2 Menzi Muck bushings out of a stock $65 bushing in my shop. I make a lot of custom parts as the need arises or when I have a better idea.

 

[DirtyHoe]

Welder Dave,
Yes, there are bad CNC plasma's out there. Most manufactures are building the frame and using 3rd party for all the hardware, linear bearings, controllers, torch height control, and drive motors(servo or stepper). Then they put it all together to make a working machine. The problem I have first-hand experience with is when the machine doesn't work. This machine would cut fine most of the time, then it would lose its Z height position and fire the torch 3 inches off the plate and air cut the part. The manufacturer would not accept responsibility or find a solution. It's your ground system they said. So I had the electrician install a separate 8-foot ground to the frame. That didn't work. Try these parts...that didn't work. It's your Hypertherm unit. Sent it to Hypertherm under warranty. Nope, that wasn't it either. Change the parameters, no wrong again. We offered to pay for their wages, travel time, lodging, and meals to come fix it. They said we only offer phone support! We are both in Oregon. We got rid of the machine.

The more expensive machines do a better job of protecting the linear bearings and other moving parts from the cutting splatter. Regardless, all machine need to be wiped down and lubed regularly.

Treemuncher-
When you select a machine be sure to read their reviews and find out about technical support and warranty support. You will need strong support for a new machine. I would lean towards a machine that has an active user forum. It will speed up the learning curve.

Steve

 

[Welder Dave]

What brand was yours?

 

[digger doug]

I have qty (2) of them, looking to sell my small one. It was home made by someone else, I only run oxy torch on it.

I repaired a torchmate 5x10 for a friend, learned allot.
Seeing how I fixed this one, another friend recommended me to get a torchmate 4x4 "Growth series" up and running.
I would NOT purchase any Torchmate.

I just bought a "mini gantry" from alibaba, (NewLin Machinery) and built the table portion, getting it up and running presently.

Can you draw the parts you need on CAD ?
The Fangling controllers are getting popular, and have 50 standard shapes loaded into them you might find allot of your work can be done using them, right on the controller.

 

[digger doug]

Update, sold small one (oxy only no plasma) had to clean out shop....to make room.
And got the imported one up and running.

 

[digger doug]

More pix, the machine made it's own slat table combs:

 

[colson04]

@treemuncher

Did you end up buying a CNC plasma table?

 

[treemuncher]

@treemuncher

Did you end up buying a CNC plasma table?

No. Not yet, at least. Floor space in my shop is more important right now and I really don't have the time to brush up on my CAD/CAM abilities. Cheaper to go without right now for the amount of work load that I currently have. Sure would be nice to have but only so much time in the day.

 

[nowing75]

I keep thinking of pulling the Triger on a Langmuir.

 

[treemuncher]

This came across my feed. Fairly close to home. Not enough time in the day right now. Trying hard to learn FreeCad 0.21 for our house plans. That would be great knowledge for a table though!
https://www.facebook.com/marketplac...wse_serp:22f0a35c-18dc-4132-a7ea-b295fd23be8a

 

[Entropy1]

Two basic ways you can do this.

1: buy a turn-key cnc plasma table ($$$$$)
2: buy the cnc parts (controller, rails, stepper motors, etc - a kit) and build your own table ($$)

Recommendations:

Look into getting a z-axis also. Desirable for piercing operations - works with plasma and oxy-fuel cutting. Don't need much z-axis travel. Just enough to lift the torch for piercing.

Another variable is how quickly the table can move/respond. Ultimately this boils down to how thin of material you desire to cut. Cutting thick plate - no problem - table needs to move slowly anyway. But cutting decorative parts from thin sheet steel (for example) requires quick table movement. More specifically, imagine cutting a star pattern from 16 gauge steel. The tips of the star will be burnt (rounded over) unless your table can both traverse quickly and change directions quickly. These fast responding tables will have larger stepper motors and/or combined with reduction gears - to achieve more applied-force for rapid response. Needless to say, these fast-responding tables cost more, and are (generally speaking) only required for cutting thin materials with fidelity.

Also look into obtaining/building a water-table for your CNC plasma. They are relatively easy to build. A void under the table holds water, and compressed air displaces the water to the tray above. You can precisely control the water level with the air valve. Simply open the vent valve to drain the water back down below. In the above example (cutting the star from 16 gauge) - when water is positioned about a quarter-inch or so below the steel sheet, the plasma air-jet will splash the sheet from underneath with water - providing a cooling action. This will not only reduce thermal distortion of the part being cut, it'll almost completely eliminate the burnt (rounded over) edges - enabling detailed/fine decorative cuts on thin sheet.

Another big advantage of a water table under your CNC plasma, is a rather significant reduction in dust/smoke during cutting (cleaner shop - cleaner lungs).

Downsides to the water-table. Corrosion is a known problem, especially within the air voids. You can either paint everything well (almost impossible to pre-paint everything if you're also welding the table together). Or you can make the table from stainless ($$$$$). Or you can use thicker material to account for corrosion allowance. Bolting in marine zincs will protect the steel that's always wet, but the air space within the void is where the majority of the corrosion will occur. If I were to do it, I'd probably do the pre-paint everything as best I can then weld together, in combination with marine zincs.

***Caution*** cutting aluminum with plasma over a water table can generate & trap hydrogen gas under the plate being cut, or even worse - trap hydrogen within the air void under the table - resulting in a dangerous explosion hazard. It is generally best to NOT cut aluminum over water with plasma. Simply leave the water under the table and cut it dry. Unfortunately you're back to heavy white smoke & dust everywhere without water under the plate/sheet. . . .

 

[Entropy1]

Or if you've got really deep pockets - water-jet tables are amazing. . . . .

 

[Welder Dave]

There are also plasma tables that the plate is completely under water. I think unless you're doing continuous production cutting a standard table with good fume extraction would suffice. I'm curious if a fume extractor nozzle with the flexible hose has even been incorporated right at/on the torch of a CNC plasma table? It could go through a wall mounted extractor or even just the exhaust fan style to vent outdoors.

 

[Entropy1]

The biggest headache with downdraft (fume extraction) CNC plasma tables, is that you have to cover the majority of the table with something - plywood, sheet-metal, etc. If there's too much cross-sectional area of the table exposed/open, there will be inadequate downdraft velocity, and smoke will jump the table and fill the workspace (unless you've got a very large suction-blower). It's not that big of deal to keep the table adequately covered. But again - if you desire to cut ornamental-type artwork pieces from thin gauge steel, a water-table is almost a must - primarily to prevent warpage, and to increase fine-cut fidelity.

Another cool feature of a water table (particularly with oxy-fuel CNC cutting of thicker plate) is you can submerge the parts when you're done cutting - to quickly cool them for handling. With downdraft tables you're waiting quite a while for parts to cool before handling (or wearing very heavy gloves). I suppose it's not that big of deal for making one-off parts. But if you're lofting out a bunch of thick-plate pieces for profit, there's measurable time-savings to be had with a water table.

 

[Entropy1]

Large capacity industrial downdraft CNC plasma tables will have selectable/automatic air dampers/baffles.

Example: when the torch is over the first quadrant of the bed, the first quadrant air damper is open, and the fume extractor is sucking air from the just first quadrant. When the torch traverses over to the second quadrant, the first quadrant damper closes & the second quadrant air damper opens - then so on. This eliminates the need to cover the bed to maintain downdraft velocity, as the blower is large enough to evacuate any uncovered quadrant of table.

For a smaller home/shop downdraft table, the assumption is that the entire table represents a single downdraft void. You'll either need a large suction-blower, or run a smaller blower while keeping the unused portion of the table covered during cutting operations.