[MDubII]

I built my 4x4 table about 3 years ago (I think) and I have been considering upgrading. It has served me very well, but I find myself cutting material that hangs off the table quite often. It is inconvenient to reposition, but it also takes up more space than a larger table would. Allow me to explain... When cutting a 10' sheet, I have roughly 6' hanging off one side of the table. I cut 40", reposition left and cut another 40", and then repeat one more time, resulting in roughly 6' hanging off the other end of the table. The question is: Would I be better off starting from scratch with a new build and new gantry kit, or simply acquire longer rails and reuse my existing Precision Plasma gantry and Bladerunner electronics? I may also consider a rotary axis for tube cutting... anyone have much experience with one? Maybe Ron can weigh in on this one.

Thanks,
Mike

[MDubII]

Thoughts anyone??? I also plan to convert from hand torch on the machine to a "machine torch" I have found that I can buy the main torch body, and the replacement lead far cheaper than the Hypertherm T45M torch assembly. Anyone know if the replacement lead comes with quick disconnect that plugs into the machine, or are you supposed to reuse an the old one? Jim Colt? I am confident that I can make the rest of the torch holder, rather than buying it. I do not have any dimensions of the T45M, but I am not convinced it will fit on the Z axis of my Precision Plasma Gantry without modification. Another avenue I am considering is buying the T45V hand torch assembly for hundreds less than the machine torch, removing the handle shell, and fabricating my own holder. The only difference I can see from the illustrations of the 2 torch bodies is the position/angle of the gas tube. A hypertherm Tech told me that the machine body will not fit the hand torch lead. I am skeptical. Has anyone altered/fabricated their own torch assembly from parts? Ideally, I'd like to have a torch dedicated to the machine, and another 50' hand torch that will reach anywhere in my shop. I know there is a safety concern if the torch can be remotely fired, but I will probably incorporate a selector switch for hand/machine control.

[JB4x4]

Well, I'll throw my 2 (or 4) cents in.. I also own an older PPLLC 4x4 machine with a CandCNC Blade Runner unit. I would probably look into seeing if there is any market for your used table, and build a larger one. On one hand, you might save some by reusing your gantry and electronics. On the other, you would not be wasting the 4 foot rails, and it would give you a chance to get into newer electronics (maybe even servos).

As for the torch mod, I own a PM65 and both torches. It is very handy to leave the machine torch mounted permanent and quick swap the hand torch for cutting scrap. I too started with a hand torch clamped to the Z axis, and the machine torch was money well spent.

[MDubII]

I think the dedicated machine torch is a must. That will be my next investment. how is yours held on JB4x4? looks like my z axis will not hold the top of the Hypertherm machine torch sleeve without modification. Has there been major advances in technology over the last couple of years that would be worth upgrading to? I am really happy with my investment so far, but I know I could do better by building on what I have learned. I also know I have lots to learn yet. I do not know anyone else who has similar equipment or does what I do, so learning directly from others is out... We do laser cutting at my day job, but I am a maintenance tech, not an operator. Is there anyone out there who can weigh in on rotary cutting? Is it worth the hassle without a specific need for it? Can I upgrade my bladerunner with a 5th axis for rotary?

[Torchhead]

You can add a 5th axis (motor and driver) to any BladeRunner, Rotary cutting is valuable if you need to do pipe fitting or hav e afab shop where you use alot of pipe or round tube (like in a building hot rod parts or roll cages) It is fun to watch but fun does not pay the bills. We will have some interesting developments in pipe cutting in 2014. You can find users with equipment just like yours on our Suppot Forum at CandCNC Support Board ? Index page
TOMcaudle
www.candcnc.com

[MDubII]

the rotary axis sounds cool. I don't have an immediate need for it, but I have thought of projects I could use it for. There are other options I cheaped out on before that I may consider upgrading to or utilizing in my next build. Are the gear reduction drives and 2 start Z axis screw worth the investment? I would like to shave some time off pierces, and better maintain arc gap when cutting thin warping material at high speeds. Would the more-aggressive screw help these issues?

[Torchhead]

The 2 start does help with a stepper system but there is a practical limitation to the response time of the THC that having a faster Z won't help with. It beleagures all MACH3 based THC solutions. It has been resolved with our new DTHC IV that closes the THC loop at the DTHC itself and with the PI tuning )true servo loop tuning) allows Z rates 10 times that of the MACH based THC with stepper based Z's. We still have the tight integration with MACH3 for doing DCC and all of the advanced automation....we just do it a lot faster. The speed of a piere can be increased with some basic parameters in SheetCAm and MACH. The first is to increase the Plunge rate
and if the material is thicker you can decrease the frequency f touch-offs by increasing the RefDistance value in the SheetCAM Post you use.

TOMcaudle
www.CandCNC.com
"Excellence in Engineering"

[MDubII]

Thanks for the info. I will tweak the RefDistance and see what that does for me. I use a higher than recommended pierce height for thin material because I cut a lot of 20 ga, and the weight of the torch just pushes the material down to the grates when touching off.

[MDubII]

I am going to try to figure this out, but will post the question anyways, but I am having difficulty understanding the RefDistance adjustment. The post reads
"dist=9999999
Refdistance=10*scale"

What do these values represent? Also, my plunge rate is currently 12 ipm. What do you recommend for single start z screws?

[Torchhead]

The REF distance is in total travel of XY. the number is in mm. scale changes it inches used for calcualtions. 10mm is not much. Something like 500 would be better for thicker material. the smaller the number the shorter distance it has to travel to do a ref on the next pierce.

Plunge rate needs to be close to the max Z velocity (say at least 60 to 80 % of the Z velocity set in motor tuning That goes not change based on the type leadscrew but you may find that you can only get 60 to 80 IPM of max Z velocity with the single start 10TPI LS. The motor just won't spin any faster and at the RPM has REALLY low torque.

If you need more speed (especailly under THC control) you might consider an upgrade to our new high speed DTHC IV. You can get almost double the raw speeds from the Z and the actual cut speeds (set on the current system by THC Rate as a percentage of max Z) go up to the full Z speed! It is all because the DTHC IV controls the Z directly under THC moves and the "loop" from the arc volts changing to the motor moving is run by a 64MHZ chip in the DTHC IV.

We have an upgrade trade-in program for DTHC II owners. See www.candcnc.com/DTHC_Trade-In2.html

TOMcaudle
www.candcnc.com