[johndjmix]

Finally broke down, droped the $2100 and bought a hypertherm45 with machine torch for my plasma table. Up until now ive been using the everlast plasma. The everlast kept losing arc, going through consumables rediculously fast, and giving bad readings on tip volts so my DTHC was useless.

Let me just say it this way, 100000% improvement from the everlast. There is no comparison. Jim from hypertherm is dead on with his posts, the cuts are perfect...no slag. Theres no losing arc-ok signal, no loss of arc, no going through a tip in 5 mins of cutting, etc. The hypertherm just works! Cut quality is very good and consistant throughout the cut, but like i said, the most important thing to me is there is no no problems with the cut that interrupt it.

That said, for the money, if you want a machine for hand cutting (not cnc), the everlast for ~ $700 is priced so low you cant go wrong. Its not going to work like the hypertherm but its a good machine for $700.

Candcnc has all the settings setup in it allready for the hypertherm! I basically just mounted the torch, and used the settings in the book that comes with the hypertherm in sheetcam. Perfect cut, first time! The fact that it comes with a book with amps, torch height, torch volts, etc for just about every material is priceless. These guys did their homework.

Looking at the consumables you can see right away, its a HUDGE difference from a Chinese machine....pics below.



Hypertherm tip on left, everlast/harbor freight/Chinese on the right.



The torch mount I made out of 1.5" alum square solid. Took me all day, (It was a 2 hour job, but it was one of those days...break taps in material, break drill bits, etc....grrr!).


The EXCELENT manual that comes with the hypertherm, shows settings for everything! AWESOME.


There is is, in its glory under my water table.


The first cut i did with it, 1/4" Aluminum. Almost perfect. Like Jim always says, there is no slag. Basiclly there is just an edge left that u can scrape off using a sharp object.

[xalky]

John, you're absolutely correct. Hindsight is 20/20, but had i known what i know now, i would never have bought my Longevity machine for machine cutting either. The chinese machines are a good value for hand cutting, but everyone heed our advice, don't buy a chinese machine for machine cutting. If you can't afford a hypertherm, wait till you can. I'm sure John will agree here: the time lost in attempting to get a cheapie plasma to work with a top notch electronics package will more than pay for the hypertherm. I don't know about you John, but I have a solid $4000 into my plasma table, when counting the PC and the CandCNC electronics, It really makes no sense to save $1000 or $2000 for an inferior plasma cutter that'll give you nothing but headaches and frustration.

John you had less problems than i did. I couldn't even fire the chinese plasma without seizing the computer or burning out a board in the controller. I fried a PC power supply the first time. And this was with heavy shielding and grounding.

With the hypertherm I was pretty much able to get rid of most of the shielding, and simple grounging was all that was needed.

It's really a no brainer.

Marcel

[johndjmix]

Yea, i got to tell you...everyone keeps talking about grounding, and shielding. I didn't ground ANYTHING. Yes, you head me right....NOTHING. Never had a problem!

Time wasted in an understatement. Things like when cutting a 4' piece of material the torch going out, or hitting the material and moving it destroying the entire piece. GRRR! It would get me so frustrated!!! I did a job for a buddy where i had to cut 30 9" circles out of 1/2" steel. That everlast went through 9 tips and 9 cones on that job, along with the torch going on and off in the middle of cuts on every circle. I spent MAJOR time, as in 4 hours a night for 2 months trying to get it to work. No good. Waste of time. The chinese machines look cool, but its simple they just dont work with CNC well. Not bad to keep in your truck for emergency jobs, or somewhere where things have a tendency to "walk". Heck, I might buy one of the chinese combo machines to take with me on ATV trips. Just not for CNC.

xalky, what hypertherm did you get?

--John

[xalky]

I bought the powermax85. It was certainly more than i wanted to spend but after using the machine for a few weeks, i don't regret my decision at all. I wanted to be able to do heavy brackets and things out of 1/2" steel. I also bought it with the machine torch package. After using it on the plasma table I ordered the hand torch too. I'll be paying this one off on payments but who cares, it's only money....I'll make more. I'm having fun now, you can't put a price on that.

[duramaxer]

hey john did yo use any relays for the hypertherm i just ordered mine and want to have all the electrical ready . i know i have to jumper the hand torch but what relays do you use and how many ? thanks

[johndjmix]

Nothing needed. Just ordered the cable to connect from candcnc. That's what's I love about the candcnc!

--John

[xalky]

Nothing needed. Just ordered the cable to connect from candcnc. That's what's I love about the candcnc!

--John

Thier prices are really resonable when you consider how much time and effort and money you save "trying to reinvent the wheel". They did all the research and development, that's absolutely worth every penny difference between building it myself and getting thier Bladerunner Kit. I would venture to say that if I built it myself , i would have wasted a lot of money on unneeded and destroyed parts. (chair)

[BBchevy396_]

Here, here! One more vote for Hypertherm, and Tom at CandCNC!

[johndjmix]

One issue im having guys, is the angled edge of cuts....its thinner at the top....but the catch is, only on thinner material. On 1/8" its very noticable, but I just cut a piece of 3/8" and its almost perfectly straight. Doesnt make sence to me.

I used all the recomended settings from the hypertherm book....

Dont get me wrong, the cuts are good, but why im getting the bevel is beyond me.

--John

[xalky]

One issue im having guys, is the angled edge of cuts....its thinner at the top....but the catch is, only on thinner material. On 1/8" its very noticable, but I just cut a piece of 3/8" and its almost perfectly straight. Doesnt make sence to me.

I used all the recomended settings from the hypertherm book....

Dont get me wrong, the cuts are good, but why im getting the bevel is beyond me.

--John

First make sure your torch is square to the work. If you currently have the cut height set the same for all materials try changing the cut height in sheetcam for the thinner stuff. Make the arc gap a litlle bigger. the arc cone comes out of the torch small then it gradually enlarges and then it gets small again. The arc cone taper will be more obvious on either end of the length of the torch arc and not so much in the middle. The idea is that you want the cone of the arc to be centered on the material. The .060 torch distance might be working perfectly on thiicker material for that reason. I noticed on my machine that my arc voltage on thin material is much lower than the preset values in the cut profiles when i run a manual test cut set at .060, which leads me to believe that my arc gap is too close to the material on thin materials. Play wtih the arc gap manually and run a manual test with THC off with a larger gap to see what happens. Try to get the gap set to where the voltages match those in the cut profiles as closely as possible. I use a feeler guage to set the gap manually. Also make sure that your floating torch switch offset is set correctly.

Once you get your settings nailed down for a given material, save them in sheetcam and make a custom cut profile in Mach for the same material and try to name them the same for obvious reasons, so you can pick them out of the menus easily in the future.

Are you using fine cut consumables for the thin stuff? Fine cut might be too small for 1/8" materials though. That could change things too. There are a lot of variables to consider, i think your realizing this too.

I'm no pro either, and i certainly don't have a lot of cut time under my belt, but my brain is starting to get a handle on the different variables. The more I play with it, the more this stuff starts to cement in my head.

Have fun
Marcel

[jimcolt]

Angularity with any plasma is always greater on thinner materials than on thicker materials. To best minimize angularity on thin materials (and all materials) use the following techniques:

-Match the consumables and power level to the material being cut. Look at the cut charts (in the Hypertherm operators manual) and use the lowest powered process that is listed for your material thickness. The 45 does not provide a lot of choices...but you can use the 30 amp consumables (per specs in the manual) and they will provide a narrower kerf and squarer edge as compared to the 45 amp process.

-There are two speed columns listed in the manual, recommended and maximum. Maximum is self explanatory....will cut fast and clean but with more angularity. Recommended is a speed where edge angularity is better, and low speed dross is mostly non-existant. If you cut slower than recommended...the edge will get squarer, but you will have some slow speed (easy to remove) dross.

-Torch height. I cannot stress it enough....proper torch height during steady state cutting is absolutely necessary for best cut edge angularity. The physical height is the critical height....follow this exactly as the operators manual suggests. If you have an arc voltage based height control....do your first cut at the voltage suggested in the manual....then adjust voltage (down for closer, up for higher) if the physical Cut height is not correct. Too high, and you will get more edge bevel.

-Nozzle and shield. Any out of roundness or nicks in the nozzle or shield orifice will cause increased and varying angularity. Inspect the orifice with a 10x jewelers eye loupe. Damaged nozzle orifices are caused by a. Piercing too close, or with inadequate pierce delay, b. Too many amps for the nozzle design, c. Nozzle is simply worn out.


You are using an air plasma...these are the low cost version of plasma cutters. There are high definition plasma cutting systems that can cut thin materials with much better edge angularity...they are less expensive as compared to laser plate cutters or water jets, but cost much more than an air plasma cutter. You cannot achieve a perfect 90 degree edge angle with an air plasma, however , properly set up an air plasma will cut fast, will be repeatable, and will cut at very low cost compared to virtually any other process.


Hope this helps.

Jim Colt Hypertherm

One issue im having guys, is the angled edge of cuts....its thinner at the top....but the catch is, only on thinner material. On 1/8" its very noticable, but I just cut a piece of 3/8" and its almost perfectly straight. Doesnt make sence to me.

I used all the recomended settings from the hypertherm book....

Dont get me wrong, the cuts are good, but why im getting the bevel is beyond me.

--John

[Torchhead]

There are enough tolerances in all of the settings and the feedback volts that it can be a volt or two off. Even the air pressure and toolpath (feedrate in a given path) can effect torch volts. So treat the charts and the stored library we furnish for the Hypertherm units as a good starting point. Like Jim says...It's all about the proper Arc gap and you need to run at whatever volts it takes to hold that. One reason we made the settings in the Cut Profile editable is you can over time develop a chart that is dead on for your machine. We also have the Smart-Kut (tm) that will "learn" the PRESET volts by make a few inches of cut right after a pierce (where the cut height is still from the G-code) and than set the PRESET value to hold that height.

In the end the secret is learning to control all of the variables (like air pressure, air dryness, feedrates, etc). when you can keep the number of variables low the answer gets easier to arrive at.


TOMcaudle
www.candcnc.com

[johndjmix]

I'm cutting at .06. Tried at .1, looked the same. How high is still reasonable?

Tom, question. The thc delay you have on your settings screen in Mach, it's the number of seconds from what? From after the tng hits the plate? From after the torch ignites? From after the torch plunges and hits the g code cut height?

--John

[xalky]

It's the time after the perce that the THC kicks in and begins to sense the voltage. If it's set to soon, the Thc will pick up the pierce voltage spike which will make the torch dive. It has to be set at a suitable delay for the cut to be underway after the pierce. At least that's my understanding.

[johndjmix]

Xalky: your post is confusing. First you say the time starts after the pierce, then you say it has to be set right to not allow the pierce to affect it. Please clarify.

--John

[xalky]

Xalky: your post is confusing. First you say the time starts after the pierce, then you say it has to be set right to not allow the pierce to affect it. Please clarify.

--John

I'm sorry. When you do a manual test cut you can watch the pierce on the screen and see the voltage spike. If Thc kicks in too soon it'll take the high voltage reading from the pierce and act to counteract that ...to your detriment...You will get torch dive.

This isn't that easy to explain LOL.
1) the torch pierces
2) the torch completes the pierce (There is a pierce delay which is set in sheetcam)
3) the torch begins to cut
4) THC takes over

So looking at the events above, The pierce finishes and the torch starts to move, wherein the THC takes over to regulate the height. So the delay time is the time from when the pierce happens to when you want THC to take over. If you set the delay to 2 seconds the cut will be 2 seconds into the straightaway( for lack of a better description), before THC takes control of the torch height. You can start with a high # like 2 seconds to get a feel for what I'm talking about. As you reduce that time delay, the THC will take over sooner after the pierce.

I hope that clarified it. Maybe?

[Torchhead]

Important note. If you have a DTHCII setup purchased in the last 8 months than you need to set the THC DELAY in MACH to ZERO. seconds. Then open the CUT PROFILE and find the THC (fault delay) in the stting s and set it for the TOTAL time (from when the torch fires) until it actaully is in position and start cutting metal in XY at the correct cut height (as set in the SheetCAM parameters.

I have posted numerous times on this over in the CandCNCSupport Yahoo forum

[johndjmix]

Thanks Tom! Just did that now.

Still having issues with angled cuts on small circles on thin material, although my other post about auto-disabling thc and slowing down on small holes has helped Im slowing down to 30% normal feed rate, maybe i should go even slower???.

Interesting, my everlast plasma did not have this problem (Although, it had a million other issues with cuts vs the hypertherm!).

--John

[jimcolt]

It is not actually the "pierce voltage spike" that causes a dive at the beginning of a cut...rather it is because the machine has not accelerated to the cut speed. When the speed is slower...the plasma burns a wider kerf...meaning the arc voltage has to stretch (increase) to find its pathe to the plate....the height control then tries to correct the voltage by moving the torch closer to the plate...often causing a collision.

The same often will happen in corners (machine slows, torch dives) and in fine features (machine cannot maintain speed). In reality...either the motion control software (and /or) the CAM software needs to recognize speed anomalies and freeze the height adjustment under these situations. Some softwares / machines do this by monitoring speed, others use the part program to recognize features that can cause diving....and a freeze is issued to the z axis. There still are machines and height controls on the market that do not have the ability to freeze height when motion slows.....you will see these machines diving in corners, diving on kerf crossings, fine features as well as at the beginning of the cut.

Jim Colt Hypertherm

It's the time after the perce that the THC kicks in and begins to sense the voltage. If it's set to soon, the Thc will pick up the pierce voltage spike which will make the torch dive. It has to be set at a suitable delay for the cut to be underway after the pierce. At least that's my understanding.

[larryy1022]

Most CNC controllers would design a speed factor to monitor the cut speed, and take EDGE's design.........disable auto when speed is less than 90% of full speed.
We tried before, even 80% speed is not enough, sometimes it would cause diving.

Anyway, its esasy to try it out on a specific machine.

better design would include.... disable auto according to the diameter/semi-diameter of arc shape, distance to corner....

But in practice, on small table, a time-delayer to delay auto at the start of cutting is enough. The torch shaking on corner turning or cut ending is acceptable.