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I have been working on tuning the final filter stage. The graph below shows the difference between 40 uF, 68 uF and 100 uF used in the low frequency filter (for 60 hz).

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While the 100 uF...

Yeah. Part of the object of this was to come up with a DIY solution for brave souls. I figured once I was done I'd order boards from SeeedStudio (China) because I can get lots of 10 for about $5 a...

The concern with the 100 uF is that kerf detection won't work that well. With the noise on the 40 uF being about 1/2 volt, I can probably only control the torch height to 3/4 volt (probably good...

With my son's help, I figured out what was doing on with the 60 hz noise. I hadn't realized that the frequency I entered in the R-C filter calculator was where the filtering started not the...

Just got the last problem figured out to bring the board up. It was a software error in the PC control app. The app currently looks like:

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The plan is to integrate the interface program...

Progress has been painfully slow.

One big time waster was messing up wiring of the DB-9 connectors I added. The connectors make board assembly and connection to the Plasma/CNC a breeze. The...

I didn't see anyone respond to your comment about not needing a laptop.

If you use Mach software to drive the table, it needs to have a parallel printer port. Laptops don't have parallel printer...

I haven't done much in the last couple weeks. It's been a combination of being tired of getting cold working in the garage and travel for work.

Today I just got the Rev C shields back from fab.
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Was the kerf it was crossing part of that G-code file? If so, a "smart" processor could know the torch is crossing a kerf and accelerate it (while possible to do, I'd be surprised if there was...

You are right - the flash is an issue. I currently use 18k+ (UNO only has 16k) for code and 1.6k of RAM. The Uno only has 2K RAM, so that is cutting it close too. Also, if you use an LCD shield,...

Excellent work! All I can say is "keep working it" :)

Today my wife had said she wants a new railing on the front porch. The existing one is wood and she wants to stick woth wood. I said that I...

After building two sets of Rev B hardware and doing extensive testing, I am going to declare it a fail. With the same single pole filter that got rev A to +/- 1 count (1/7 volt), rev B hardware is...

Feel free to jump in - that's what its all about.

I reached the point with the first pass of hardware where I have filtered the 60 Hz out. The signal is very clean an only has +/- 1 A/D count...

Tom,

I'd like to understand how you use it. If the control of the THC was on the "default" Mach screen - would that make a difference?

I've found the Mach screens are overwhelming. So I was...

I've finished building the Rev B board. The initial testing has been on the serial port. With the old hardware, it would only go 38,400 baud. With the new design it will do 115,200 (I haven't...

I'm still waiting for the Rev B PCB's to come in (expecting them on Monday). However, I wanted to get everything posted as promised.

The Rev B hardware design (eagle files), Arduino THC code and...

I looked at a lot of different kits and components. The biggest thing to consider is how comfortable you would be with:
- building your own table
- putting you own drive electronics together

I...

Taking all the advice, I checked all the motor settings. It turns out that the Y axis had a different acceleration that the X/A. I didn't think that would make a difference, but I set the Y to...

Thanks all.

I tried the cut as the last thing for the night. I hadn't realized but the saved Mach config had the THC off. I realized when it was giving constant torch up commands. I guess the...

I've spent a while working on the THC and its finally at the point of letting me cut something real.

I did my first cut of any complexity. I was hoping for:

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What I got was this:

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I've implemented an initial kerf detection that looks for rapidly changing voltage. While it can probably be impoved, it does work.

This graph shows the kerf crossing. The voltage is in blue and...

I can't tell you how many things I've screwed up because "if a little bit is good, a lot has to be great!" :)

As Rambozo said - the G-code has no idea of what's already happened. I use Sheetcam. It would be possible for it to figure that out and insert it in the G-code, but it would probably make the...

The idea of trying to detect it by voltage change sounds good. I would think you'd still need to limit how long you ignored the voltage difference before you try to start controlling again.

With...

I had hoped to start playing with my new 200DX over Christmas, but it just didn't happen.

I set time aside today, watched some basic videos and gave it a try. Wow - I'm blown away at how much...