Lightning CNC ......any good?

[michmetalman]

Does anyone know anything about this company or tables?

http://www.ebay.com/itm/5-x-5-M4-CNC-Pl ... 3cd372defa


I desperately need to upgrade from my 2x2 table, but cannot afford $10,000 or more for a table.

[jimcolt]

It looks like it is priced pretty low. There appears to be a motorized z axis as well.....but no mention of arc voltage feedback height control. I would suggest finding their website and reviewing their macine very carefully. The biggest issue with many of the small machine manufacturers is with training, after sale support and parts availability. And in my opinion a cnc plasma without a decent height control is a relatively non productive machine.....you cut parts one at a time while babysitting the process. With a decent height control system you can program a hundred parts and walk away from the machine while cutting. Typically a good height control system will add between $2k and $4k to the cost of the machine....which is why the reputable machine brands such as PlasmaCam, Torchmate and others are pricier that the machine in the ebay ad you linked.

Jim Colt

[trucutcnc]

With Torchmate and PlasmaCAM a decent THC is "Optional". I agree that the THC is a critical component which is why it should not be an option. Kind of like your car salesman asking "So did you want to order the optional engine with that?"

[jimcolt]

Agreed. In my opinion a cnc plasma is non productive without a THC. It is a machine that can cut one part at a time, with operator supervision. Still....better than ccuttin by hand, but certainly not adequate to cut many parts with precise tolerances.

Up until a few years ago all PlasmaCams were equipped with a very nice height control. Because PlasmaCam and Torchmate are always competeing in the market place...and Torchmate was offering stystems without height control for a lower price....PlasmaCam changed tactics and offered systems without height controls as well....in order to be price competitive. I'm sure the lower prices increased system sales and made them more competitive for the budget concious buyer....however I spend a lot of time helping users with low cost cnc plasma's...with no height control...understand why their productivity, accuracy and consumable life is not as good as others (with height control) report!

You cannot buy an industrial cnc plasma without a height control!

Jim Colt Hypertherm

With Torchmate and PlasmaCAM a decent THC is "Optional". I agree that the THC is a critical component which is why it should not be an option. Kind of like your car salesman asking "So did you want to order the optional engine with that?"

[trucutcnc]

Agreed....We get requests now and then to delete the THC so they can save money. We've never built a machine without a THC and never will. IMO, the THC is just as critical a component as the controller software. The machine is not much good without either.

[tnbndr]

That ad also states they "do not accept PayPal" a big red flag and I believe against ebay policy.

[michmetalman]

Thanks for the reply guys. Believe it or not, I've built a pretty thriving business on a 2' x 2' table with no height control...lol I wouldn't know what to do with a larger table WITH height control! To me anything looks better then what I have!

[SpartanKen]

you can get their table with THC and you don't have to go through ebay.

Ken

[beefy]

Agreed....We get requests now and then to delete the THC so they can save money. We've never built a machine without a THC and never will. IMO, the THC is just as critical a component as the controller software. The machine is not much good without either.

I fully agree.

I suppose it is possible to operate without one but it would be a pain. You'd have to make sure the top of the slats were dead level / parallel with the X & Y axis, but then what I've found is you always get caked on slag on top of the slats so that stuffs up any perfectly level slats. The metal would have to be thick enough so it doesn't warp with the heat. With my Hypertherm for instance you are talking about maintaining a precise height of 1.5mm while cutting so everything would have to be mechanical perfect to maintain that without torch height control.

I like to buy the engine with the car.

Keith.

[CNCCAJUN]

The only way you can operate with any success without a THC is if you are cutting only thin material and use a "RollerBall" system like MultiCAM uses on their sheet metal shop units. . . .

The guy that owns DACC here in Baton Rouge equips a lot of his machines that way.

Steve

[jimcolt]

A plasma torch needs to stay within the range of its physical cutting height as listed in its operators manual.....within about +-.005". There is no piece of steel on this planet that will set on any plasma table slats and will be within .005" over the cutting area of the table...not a 2 x 2 table, and certainly not one that is larger. Further, onece you add heat input and start cutting...you will release kinetic stresses on any plate, and it will move, guaranteed more than .005". Cutting too close will cause coliisions, double arcing (nozzle wear) and dross. Cutting too far away will cause poor angularity, dross, warpage and a wider kerf.

Yes you can cut without height control. No, you will not be as productive, you will not have cut quality as good as with an well operating height control, and you will buy more consumable parts as compared to one with a well operating height control.

All of the above issues cost either time (rework, grinding, machine babysitting) or money (more consumables, more labor. This is why all industrial quality (more expensive, built to hold up under high duty cycle conditions and a tough environment) cnc plasma's have height control.

A good quality height control can set the pierce height, pierce delay time, indexes to cut height before moving in the x or y direction, then after the x or y travel approaches the programmed speed starts to monitor arc voltage and maintains height. Better height controls need to interface intimately with the machines motion control to eliminate diving during corner slowdown, during kerf corossings, etc. Even better height controls will automatically set the voltage/height relationship at the beginning of every cut, compensating for consumable wear, operator speed changes etc, these height controls do not require that the operator sets a voltage, rather, he just sets a physical height. The best height conrols are fully automated and required no operator settings.

Jim Colt Hypertherm