New Build-12x6ft Plasma Table

[Davek0974]

This is my first build - it was an educational exercise that got pressed into mini-production It worked really well on my Powermax 30XP but that was a hand system and difficult to use on CNC, I then upgraded to a PM45 and now the table cannot go fast enough !

I am now building a new, bigger table to match the PM45.

[Boyan Silyavski]

Hi,

I am almost ready with my mixed universal machine which will do plasma also, usually at the back side of the table. That for the moment untill i have time to build me a dedicated plasma machine. So i investigated this and that.

here are my thoughts on building a dedicated plasma machine, especially one your intended size. I can further elaborate on the "why" if you have any questions

Preliminary:
- study commercial designs that size
- decide on a budget and don't cut any corners cause that machine size is not for hobby

Machine:

-make machine and table SEPARATE

-build left side and right side as beams only , supported by legs, leveled by screws that screw on integrated in floor plates

-for left right structures, use sth like 120x120x4mm at least, better would be sth like 140x140x4 at least, best would be beam like 200x200x4. The bigger the better, the longer could be the element, the simpler.

-RP obviously, use proven design with community support , don't go for belt to belt drives following a hype, unless you have made previous working machine, you want top make money, not test ideas . Avoid expensive RP, special shapes, special gear boxes, etc. In other words maybe go for the CNCrouterparts design and i would even buy from them the pieces for a piece of mind

-spend time on the design and make it truly modular, cause one day even this one could be short for you

-rails - on such a machine no doubt i would use at least Hiwin20 rail, but best would be the low wide rail / MGW15 size/ which is stainless by the way , so are the carriages and the balls. Other benefit of using the slightly more expensive MGW is that you could make the gantry rail only 1, same with the Z. One rail only.

-motors- no need to tell you to use servo motors, i hope you have that clear already. you will need the speed for cutting thin stuff without bending. If you have doubts forget them and use servo motors, at least for the closed loop, cause i dont want to think what would happen to a geared , even light, RP gantry flying at tremendous speed cutting thin stuff that suddenly racks due to lost steps. i will tell you- it will be bad.

- ATHC, one thing that is clear to me is it must be "real" , no semi THC with simple arc controls there. meaning it must control the motor on the Z somehow, a motion control. I bought the Neuron THC. Its a new one, more or less is same or even better compared to the CANDCNC , who by the way is not my favorite guy to deal with. If you dig deeper you will see some ridiculous statements made by him, here and there, even at his web, talking about chinese machines and warranty and so...
Now i still can not tell you how good the Neuron works, but i can tell you is made in EU, Andrei is very helpful and knowledgeable guy. I received mine without any hassle and Andrey said at the moment the machine is running we will make Skype contact and he will adjust whats necessary remotely for a first run. What more do you want as a support?

-Plasma is not 100% necessary to be Hyper therm . Now here many will cry, but they are the best. Yeah, but ...if i was buying from USA in $$, maybe. Not with that EU price. First of all consider Thermall Dynamics/Victor or re branded as ESAB and other, here in EU. The magic word is CUTMASTER/ . 20-30% cheaper and original consumables are much readily available everywhere and much cheaply.
Secondly consider German-Chinese machine from eBay with quality control better than pure Chinese and with 5 year warranty. I have such and confirm that the MIG, ARC and Plasma work like a charm. Now change the Chinese plasma crap torch with universal Thermal Dynamics torch like SL60 or SL100 and you have a winner.Still not tested though but soon will report. Now even cheaper if you find Radnor which is the sam
Andrey who makes the Neuron told me in some conversation that many people in Russia change the torches with Binzel torches and all works like a charm.


Hope that helps. I am talking a bout a superiour build, that does not necessary has to be very expensive.

[F1transportationserv]

wow guys thanks for the replies there great so far.

silyavski I was thinking of something like the image at the end of your quote build my table first use it if I need to then progress to cnc it asap. I'm new to this whole scene but I willing to try anything as long as I'm learning from it and it has something to do with my industry.

I'm thinking of a bench approx 12'6 x 6'6 so I can sit a 12x6 sheet onto it with finger or hook room. Might even place it in a room 20x8 ish with a little overhead gantry to keep it all tidy away.

The table will probably be 75x75x5 square tube and 50x50x5 square tube with a water tray similar to this.

And the left/right sides will probably be the 140x140x6mm at least. What will I make the gantry out of?

[Robin Hewitt]

The table will probably be 75x75x5 square tube and 50x50x5 square tube with a water tray similar to this.

Hang on a mo', stop drawing and start thinking...
You have to support the slats that support the work piece and you have to support them through the water bed. I don't see slat support. A water table 5' x 8' is 40 square feet so every inch depth weighs slightly over 200 lbs. You have to support that to, add some triangles perhaps.
When you weld this thing up it is going to bend. Suggest you do not weld the gantry supports because you will only end up trying to correct the misalignment with a THC. Best if you correct misalignment with screw adjustment or, let the gantry assembly rest on the table so it conforms.
More if you want it...

[F1transportationserv]

Hang on a mo', stop drawing and start thinking...
You have to support the slats that support the work piece and you have to support them through the water bed. I don't see slat support. A water table 5' x 8' is 40 square feet so every inch depth weighs slightly over 200 lbs. You have to support that to, add some triangles perhaps.
When you weld this thing up it is going to bend. Suggest you do not weld the gantry supports because you will only end up trying to correct the misalignment with a THC. Best if you correct misalignment with screw adjustment or, let the gantry assembly rest on the table so it conforms.
More if you want it...

That was an idea i came across for the table, I have this one also as an idea separate table to the gantry with maybe a 4 hole base plate for leveling up (or is this too much)??

[Davek0974]

Wow, some heavy-duty ideas there:)

I was also advised never to weld the thing 100% and i am not doing so now.

The base frame will hopefully be welded and gusseted/triangulated as one piece, right up to the support pads for the motion beams.

The beams for the Y-axis will then be bolted on so they can be adjusted, paralleled and shimmed level to each other and the bed area. Once they are set, the X-axis/gantry will be easy to fit.

That is my plan but my machine is far smaller at only 1250x1250mm cut area. I am thinking of using 50x50x5mm for the whole build including the single gantry beam.

[Robin Hewitt]

Here is another idea. You will need a torch height control. Once you accept that as a design feature it becomes obvious that the torch needs to be raised and lowered by a DC motor driven by a power op-amp. This hugely simplifies the THC and greatly reduces the weight of the torch assembly which, in turn, greatly reduces the weight of the gantry needed to accelerate it. It also reduces the wiring and without electronics at the torch head it makes you immune to interference from the arc.
If you think of torch height as an obvious job for a DC motor it is not hard to get cut and pierce heights using micro-switches rather than using a computer and vast hardware to do something absurdly simple. There are more ways to kill a cat than building an Arnold Schwartznegger, terminator look alike, cat stomping machine.

[F1transportationserv]

This is my first build - it was an educational exercise that got pressed into mini-production It worked really well on my Powermax 30XP but that was a hand system and difficult to use on CNC, I then upgraded to a PM45 and now the table cannot go fast enough !

I am now building a new, bigger table to match the PM45.

Is that the Machine on the you tube video??

https://youtu.be/vETkf1sqo3M

[Davek0974]

No, thats not my machine on youtube.

My one is belt drive not chain as well ;)