Sorry I really don’t, I never tried cutting aluminum with the plasma cutter. But I really wish to see some nice result from you!
Thanks for the kind words too 
Did you pick a plasma cutter already?
@forcerouge
Hello!
I bought the lotos 3200, it’s the HF type, the cheapest model with consistently good reviews here in the u.s.
That YouTube user i mentioned previously has an amazing troubleshooter video for HF where he systematically tests the configurations for protecting the equipment. He ends up with 2 relays stacked to control torch ignition, and seperated the wire from the torch control away from the torch main air line and his electronics worked after many tests. Here is the link if you are interested. Parts 1 and 2. https://youtu.be/Hb9KUkUAXg8
https://youtu.be/xL_f-pTlP3g
Somehow he doesn’t need a copper wire mesh shield setup but im going to work from your design, i prefer the careful protection. 
I’m excited to be part of this community. Thanks for the comprehensive thread and pictures you posted
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Well im about halfway done setting this up. The z axis has a manually set height, and will have a sled that can hold the torch, provide h20 and rises up if it is pushed onto warped metal or any height discrepancy. Sure is a great project! Need to build the table next…
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hello again there
I’m getting to the end of this build to the point of being useful. one question I need to ask is- what is the best way to determine things like jog speed, tiny delay after torch activation, and generally determining max speeds and other settings. I am using V1’s marlin on a discount reprap mega ramps setup. right now the code is mostly stock. I’m guessing the previously mentioned settings are best manipulated in a gcode program like cura, I just don’t know the best program to prepare code for an s.d. card. should I be messing with marlin very much. what route is optimal for triggering a relay optoisolator circuit with the ramps. what pins would you reccomend? I’ve found a few suggestions but I would like to hear from anybody here who has a bit of knowledge… optimizing, code, and the pin issues. hope I find you well… happy new year and thanks for reading!!
Hello again Dui !
Sorry to bug you,
I am reaching out to you about your setup, specifically in the regard that you used a ramps + MEGA setup for your plasma setup previously (before your new build).
I took your project and one other individual that had a similar succesful plasma setup as the main baselines for my build, as you both had similar specs (cheap HF plasma as main factor).
I believe I underestimated the aspect of rarity of factors, there are people using marlin successfully for laser, milling, and plotting, 3d printing, etc. however not so many doing plasma.
Im having trouble locating additional information… In my instance I am trying to use an SDcard with the marlin / ramps in order to remove a wired connection from a computer, to limit HF bleed into a computer linked line, possible computer damage issues.
So I wanted to ask you, how did you control your ramps? I have been trying understand how to get GCODE generated using various methods that will work with ramps fan pin and m106, slowly learning about trying to edit and understand marlin (If my brain will let me),
or how to generate an optimized cut list as far as small pieces first or the cut path starting and ending inside a cutout for cleanliness, and there is no great solution I’ve found so far in these regards.
I figured it can’t hurt to ask a pro, much less somebody who knows this seldom taken path. no worries if you don’t have time to reply right away or anything, I hope you are doing okay and thanks for taking the time to read this… sorry to bother you! Thanks again in advance!
Sure, no problem, but I’m really really far from being a pro, I only did a few cuts with the plasma machine actually.
I was controlling the ramps using the SD card, so just the same way as you plan to do it.
To generate the Gcode, I was using Estlcam, which is the program most people use here for generating paths for cnc milling.
You can define the order for each cut path in estlcam, so I guess you can tell it to cut the small parts first and then the bigger ones, in the order that you prefer. you can also tell estlcam to start the cut outside of the part you are tyring to cut in order to get a better finish (the point where the torch starts the arc is wider thant the rest of the cut, so it’s better to start somewhere outside the part)
It worked okay for me, but I haven’t used it a lot. I don’t think I made any particular changes to marlin aside from assigning the pin for torch start, for which I gave it the same as for a laser setup. All the rest of the work was made in Estlcam.
Estlcam is okay for doing plasma cut, but I think that a dedicated plasma cutting software will do a better job, there are some subtilities in plasma cutting, like you want to go slightly faster on the corners, stuff like that, and only a dedicated program will account for these things. But I’d advise you to start first with estlcam (or any equivalent program capable of generating gcode paths compatible with Marlin), get some experience and maybe later jump to a dedicated solution if you feel the need for it.
Hello and thank you for the fast reply!
That is invaluable information you have provided in regards to estlcam. I had seen posts about it for different things of course but never considered that it was a good choice. the connecting thought just wasnt there. thank you!!! I am super excited to be nearing completion of this project. so many things to make with a precision cut.
Dui you may not see yourself as a professional however you found self made success over and over, that implies persistence and the desire to take things to completion. often overlooked qualities. additionally, you are quick to share useful information with others, seen many posts in seemingly random threads and there you are. well thanks for being a force for good in this community.
it must be nice there in china, i have seen some video on youtube of massive hardware malls, huge warehouse complexes with vendors selling any and all components and anything needed. you could walk out with all parts for an automated factory or any dream project. dunno if thats near your area but thats what i imagine when you describe the goings on. In any case thanks again for the help, its really invaluable to me. What an inspiration of success. Small things. Thanks again and take care Dui !!!
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Hello Hello all!
I used to make ceramics as a “serious” artist, so I know all to well about the inclination to hold out for perfection, always hoping for the perfect result.
well in this build ive decided to stop waiting for perfection. The major issue is the lack of a real THC. I currently use a “sled” arrangement, a floating Z that rises somewhat to accommodate things.
This is a terrible idea. the torch catching on things, dragging the work around and generally being an unmanageable nuisance. metal warpage really needs that THC. Thats what my perfection is perceived as, otherwise this build turned out pretty good for me being such a noob with low time to make things. as i can find time i will implement the Arduino standalone voltage sensing THC. I think.
As for some details, I couldnt find a source of new copper so the “brains” housing is pretty shabby. it does let in some EMF and sometimes the marlin MEGA ramps setup displays some awful garbage and sometimes stops remembering what its doing. i need to re do this item pretty badly. everything else works OK.
The LOTOS 3200 (not pictured) is triggered via D10, two stacked opto relay and using the two wires stock from the handheld trigger. in the photo its the wires on far right. they plug right onto the LOTOS.
I decided to build the whole enclosure to contain the sparks and smoke and noise. it works ok. many details were unnecessary. why did i think a downpour of water was a good idea. tray much better, for space, too. In the next plasma cnc iteration i will be able to use much knowledge from this build.
the metal cutouts show when the work was dragged around or the cuts failed as i was getting everything tuned up so to speak.
the dog is next to a ground wire and sunken pipe.
I will be revisiting an update when ive more worth mentioning. this frankenbuild really stands apart from all the fancy and nicer builds seen around here. enjoy!!!
Thank you so much to all the amazing people here!!! you know what you did.
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Reminds me of:
I can’t speak to it’s effectiveness, and it looks like in later videos he moved to electronic THC, which might tell you something - just something that came to mind.
Hi Tuco!!!
I had originally hoped that the mechanical THC in question would be my saving grace.
In Minh’s setup (video) his Z axis is very lightweight, some small pieces of wood with a large diameter vertical cutting torch.
the fact of the large diameter and lightweight design enabled the success in his example. the sled moves up and down very neatly…
Sadly my massive Z axis weighs a lot. I was originally going to add a counterance like a spring so that it can lift easier.
after watching many drooly THC videos with the torch going up and down neatly with the warpage I cant really get away from that level of precision.
cutting on secondhand metal will probably be common for me, and i already am having a hard time in this regard.
I am currently looking into using a “AC clamp on voltage sensor” similar to the multimeter ones. its a ferrite toroid with a winding, an OP AMP to increase the gain and thats the simple premise to avoid tying directly into the cutting voltage… arduino mini here we go!
Thanks for commenting there TUCO, hope all is well with you there and take care!!
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