Finally found the series of THC videos

[lilow]

Finally found the series of videos released by AdrianH a few years ago.

These were taken down as he was continually hacked and spammed.

If you wish to build something like this, watch the series and take notes as he may pull them down anytime he likes.

I have taken the concept and modified the board to suit my applications.

This being for Plasma and Tig welding.

My standalone THC on the plasma has been working hassle free for 22 months.

I have now taken the comparator board and have it working integral with the Masso THC mode.

You will find him on YouTube - adrian ph.

https://www.youtube.com/channel/UCHb5LeztLIZiUE2KDajor0Q

Cheers

 

[lilow]

Lets simplify this.

These are the videos that I started with, it was said it wouldn't work.

But if you have the time and a bit of initiative you will save yourself from buying something that may work.

For a bit of effort, along with some low cost parts, you will learn and have a stable THC to work with your Masso controller.

The below videos are all that is needed to get going.

Wiring the THC part 1​

Wiring the THC part 2​

Wiring the THC part 3​

These videos have been put together because he must a brilliant electronics technician.

One thing obvious was, himself not being in the industry and not completely having the knowledge of understanding of everything that can be put together.

This doesn't take you away from purchasing an instant solution for a THC on your new, self built Plasma table.

But this works, if you have taken that much time to put together that dream.

It's a cheap look at it.

Cheers.

It works for me.

 

[peter35]

Lilow, thanks for putting up the videos, am sure some will be studying these very hard.

 

[lilow]

Peter35.

Go for it.

Just remember adrian ph could have an intellectual property title on this.

I have been able to go further with it than he did.

And also I thought about marketing it.

But he did the homework, I just modified it for a better deal.

But if it is useful to yourself with your application, go for it, it works for mine.

Cheers.

 

[lilow]

Now with everyone out there.

There has been 74 looks but no actual comments.

Lets put it to you, do you want learn or plug and play.

This guys videos will actually make an element of learning substantial.

I have pulled the situation out of this that makes it it work.

There is something here that no one has got used to yet.

Yes, build your own THC.

Some photos below, now ready after a lot of time.

Now ready to connect it with G2, all circuit drawings have been rethought to take it out of Stand Alone mode to allow it to work with G2.

It works in simulation in G3.

Next weekend will be a cruncher.

Cheers.

 

[segoman-designs]

Some actual commenters has been busy getting their machine ready for this stage of the game while dealing with the winter elements that can kill productivity. Others are processing the information so don't give up on us yet dingo wrangler.

This is a great build and needs to be packaged as an online PDF for sale to allow you to recoup your R&D, the originator has basically said it is for all to share however contact him and perhaps share your profits with him - just an idea to think about while drinking that Foster's that you love // end sarcastic font..

Actual Questions:

I see:

3 leds are they Arc Ok / Z Up / Z Down ?

2 SPDT switches explain those if you will..

How big of an enclosure is this in?

I will have more as I get closer to the actual build.

G'Day Mate!

 

[lilow]

SegoMan Designs.

Thanks for asking.

The 3 leds are OK, Up, Down as the signals go to Masso.

SPTD relays are for Plasma start, comparator board turn on.

( I use normal relays in the G2, so will stay with what works with that )

The relay for the comparator is to allow for arc stabilisation prior to the Masso reading and the start of cut process.

This has worked with the standalone perfectly, so why change.

All done with the application of post processor commands.

Box size is 165 x 121 x 55mm.

Toggle switches, the top one swaps between Masso , neutral and mechanical start of the Plasma.

The toggle switch near the volt metre can swap from set voltage, flick it up and the metre will display the read voltage that is preset.

The 10K / 10 turn pot ( this will become a 5K / 10 turn or maybe a 2.5K / 10 turn for finer tolerance ) is wired into the back of the comparator board, this can adjust the height of the torch while all is working.

This will also adjust the volt of cutting height at any time needed.

( when I say volt, this is 0.003 volts, by adjusting this pot only lifts the torch height up or down )

( the set dead zone is all set by the resistor )

The volt metre is a 5 digit unit, capable of reading 00.000 volts.

Needed because of the fine dead zone tolerances preset.

Cheers, a remarkable board.

 

[lilow]

I finally found time to change the Z axis with a standalone THC for an integrated THC working within Masso.

Good news or bad news.

First the good news, finally able to have all signals from the THC comparator board operating within the Masso 5 axis controller.

Even cutting with a remote PS supplying 108vdc to the divider board, in turn puts out 7.975 volts to the THC.

The changes are made by a pot that can set either set voltage or read voltage.

The bad news is don't get distracted, a friend came in and the mind frame didn't get back to where it was.

Didn't recheck and put the high voltage from the Plasma into the negative of everything.

It blew the comparator capacitor, but is saved, the divider board is OK, but shagged the Masso G3.

I have sent email to Masso to send an invoice for another G3, to be paid tonight.

You can get this when you are doing it differently.

Below is the email to Masso this morning.

((( Thank you for your reply.

Since I sent that message.

I have disconnected the G2 and replaced it with the new G3 you sent in January.

( the one I sent for repair )

I loaded all files and reconfigured it to work in the Plasma that was running the G2 with standalone THC.

Swapped to TTL relays for the G3.



I ve gone right back to the Plasma voltage (108 ), checked divider board voltage out ( 7.975v ), checked all cables to the THC.

Double checked everything that has to work with G and M codes.



This morning I brought in a 200 volt variable DC power supply, set the PS on 108v.

Changed a resistor value for the dead zone / dwell time of 0.003 volts to a resistor value that changed the dead zone to 0.03 volts.

I loaded the file below and disconnected the X axis plug, allowing the Y and Z to move.

By adjusting the pot while the file is running, the z axis is moving up / down according to the THC output through the Masso.



G00 X20 Y20

G38.2 Z-75

G92 Z0.0

M667 F50

M03

G04 P500

M08

G01 X600 F1800

M666

M05

M09

G0 Z60

G00 X0 Y0



I am going to hook the Plasma power back into the divider board and see if everything remains constant. )))))

This is where it went wrong with the distraction.

Cheers.

 

[lilow]

The good news today, I had a spare G3.

I ordered another this morning as well.

The more I go forward with this THC hook up the more I believe it not set up for various THC's.

One, I can put scenarios through the Masso in standalone ranging at over 100 milli seconds.

2.

Now Masso.

Set a M667 F50

Mo3

Mo8

With 108 volts going into the divider, 7.97 volts out.

It all works fine by adjusting the pot.

The Z axis works both up and down.

3.

But start a file and run it with the same voltages, by adjusting the pot for set voltage read, the Masso will only go in one direction by adjusting the up / down signal.

Even though the milli seconds has been dropped to around 54 milli seconds.

I have still got a few trials to do, so maybe I can get some answers.

Cheers.

 

[lilow]

Well finally after a week at it, destroying a new G3 controller.

I had the comparator board working in THC mode without the machine running.

This code written in the MDI, I am able to adjust the Torch by a turn of the read voltage pot.

M667 F200

M3

M8

This worked well.

Now if I use the above commands in a cutting file and run the machine.

Such as below, the down signal is not recognised and will continue after the change from up to down in the same CW direction albeit at a slightly slower speed.

I m starting to think I need to put a capacitor across the up/ down inputs to ground.

M666

G00 X0.00 Y0.00

G38.2 Z-75 F1000

G92 Z0.0

M08 ( comparator relay Masso +ve voltage in )

M3 ( plasma start )

G04 P200 ( arc stabilisation )

M667 F200 ( THC on with federate )

G01 X500 F1000

M666

M05

M09

G00 Z55

X0 Y0

Well, I installed 2 / 10uF capacitors to the UP / DOWN signal inputs, it all works fine in CW and CCW directions.



Now let's put the real Plasma voltage into it.

Cheers.

 

[lilow]

Today, I finally got an up / down signal to work.

That is show a turn of the Z axis, CW then CCW.

It was a nearly good cut.

But the signal got lost.

Then Masso refused to work.

This controller is so slow.

I gave myself 7 days to get this THC comparator incorporated into the Masso.

So far a total waste of time.

I give myself tomorrow with a few other ideas, if it doesn't work with simple up / down signals.

I will go back to the standalone using the simple boards in the photos.

I contacted the makers of the board on the right, how fast does this switch between high and low signals.

Instantaneous was the reply from Ocean Controls, Masso cannot do this.

I cannot talk to anyone there at Masso.

So tomorrow is the last day on this.

I did the same thing with the G2 in 2018.

Lets hope tomorrow gives some new results.

I don't need the THC to work internally in Tig welding, just seeing if it would work with their Plasma mode.

Non event.

Cheers.

 

[cncnutz]

@lilow

I've been following your progress with interest and also watched the videos about the comparator board. Very interesting project but what looks simple at the start sometimes isn't when it comes to actually doing it.

If I understand correctly the dead zone between high and low at the plasma torch you have set at 0.4V which divided by 13.5 is 0.03V at your comparator board. When cutting I should imagine the high and low will be constantly turning on and off given the small dead zone. Maybe I'm wrong and the dead zone spans a several millimeters so the up and down are not turning on and off as quickly as I think. I don't have any real world plasma experience so I'm probably wrong but I am curious about the real world height difference between your high and low setting.

Proma uses 8 volt dead zone on their unit so if my calculations are correct yours is 20 times more sensitive.

I don't know what the response time of Masso inputs followed by actual movement of the axis is so can't help you there.

How do you have the up down and arc ok relays connected to Masso. Are you switching Positive voltage through your relay contacts or do you have the resistors in place and switching ground? Switching Ground like on the Proma wiring diagram will give the best noise immunity. Could noise be causing an issue when you tested with the Plasma?

Is the comparator board run from it's own 12 volt power supply or is it run off the Masso supply? Using the same supply could introduce noise into the system once the Plasma torch is struck, especially since the plasma arc is connected to the comparator board through the divider.



Just a couple of my thoughts and don't give up, I'm sure you will get there.

Cheers Peter

 

[segoman-designs]

My .02 cents on the THC subject,

Proma has more bad reviews than good on all of the forums that I have researched. The price units has some of the best reviews out there in part by isolating the arc voltage signal at the plasma box.

However no one on this forum has admitted to making it work properly with the Masso. The latest attempt being here:

MASSO Community Forums

www.masso.com.au

Without THC any table larger than 2'x2' is useless as no table is perfectly flat and the term "Flat Metal" is an oxymoron.

Lilow has done the most research on the integration of Masso and THC that I am aware of, with all of the expenses out of his own pocket. He needs access to hi level tech / code writers for Masso. You guys need to set up a Skype conference with him and figure this out once and for all or stop marketing your unit as a CNC Plasma System.

THC and other features such as touch screen has turned into a kick the can down the road scenario with no noticeable improvements or new product releases from Masso. People who incorporate your products into their commercial endeavors can not sit on things for a year or so waiting on the can to be crushed.

I still have confidence in Masso we just need results.

 

[lilow]

Thanks for the support.

The stand alone THC using the step pulsar board works with dead zone of 0.003 volts between the Up / Down signals.

The switching of the relays is controlled by the comparator board.

The supply through the relays was 5 volts from the step pulsar board.

This has worked fine for 22 months.

Peter, the same style of comparator is hooked to the Masso.

Yes, it appears that the dead zone is around 0.05 volts of the divided voltage.

The relays are using the Masso 12 volt supply, the Arc OK / Up / Down signals deliver that power to inputs 11,12,13.

This is switching positive power to the inputs.

Peter, you mention about using resistors and switching to ground.

How is this done ?

Masso has its own 12 volt power supply.

The comparator board has a separate 12 volt power supply. ( fully isolated - no earth )

I've attached a PDF file of the layout.

Peter, have a look and if you suggest to use switching to ground instruct me with a sketch.

Anything is worth a try.

Noise, I've never had any noise issues with the original G2 working with the stand alone THC.

The divider board is taped into the raw arc voltage prior to the HF unit.

Cheers.

 

[segoman-designs]

Dingo Wrangler,

This is the wiring on a Proma for the G2 the G3 should be the same:

Link no worky - see attached photo)

Proma Compact THC 150

www.masso.com.au

Which shows a different config on the 5.6K resistors than on the inputs from the limit switches (post 2 here):

I'm sure Peter will clarify this

 

[lilow]

Segoman / Peter.

Thanks , but I have tried that.

I found the Touch plate wiring.

Is this what Peter was referring to ?

I've redrawn the configuration.

As there is 12 volts through the relays, individually switched on, I've put the 5.6k resistor in line to join between UP / Down and negative.

PDF below.

Cheers.

 

[cncnutz]

Hi @lilow

Good to know you have already proven the comparator settings. I wasn't sure if the values you choose were based on testing or not.

With regards switching ground rather than +ve I remember doing a write up on it but can't find it now. It may have nothing to do with your issue but is simple to try. The wiring is the same as shown on the Proma Page. https://www.masso.com.au/masso-documentation/?section=proma-compact-thc-150 Just remember to invert the inputs back to the LOW state when not active.

The advantage of this is that if there i induced noise in the lines the idle line will not be affected because the LED is already turned on. When the relay in your board turns on it will ground the input and turn the LED off. It will take a lot of noise to override either of these states.

When you switch the positive voltage as you currently do you are ok when the input is turned on but what it is off the input is floating free and will pickup any stray high frequency noise in the area. This could easily turn the input on when it shouldn't be. You would need an alternative way to light your LED's but that shouldn't be a big issue

I'm not saying noise is the problem but I believe that switching ground is a more robust method of signalling to Masso as there is no floating inputs.

You mention you lost signal in your testing. Not sure what exactly that means or what indications you saw but hopefully this will help.

I'm inspired by your project and have ordered parts to make an inductive THC. Not for Plasma as it wouldn't last 5 minutes but to make a dummy plasma for testing. It should be easy or a total failure, either will be fun. I'll be using the same comparator board as you and a proportional inductive sensor that outputs 0-10 volts over a distance of 1-18mm.

Cheers Peter

 

[cncnutz]

I was writing my reply as you were writing yours.

Neither drawing is correct. The 2nd one is the closet but the relay common (green) should be connected to Masso -ve not positive. In the drawing have the +ve to the commons of the relays.

It would mean that the leds will not work unless you reverse them and connect the +ve to their anodes but you don't need the led's for testing and you have the board relays if you need them.

Hope this makes sense but if not I can draw you a diagram. It will won't be until later tonight when I get some spare time.

Cheers Peter

 

[breezy]

@lilow

I found the Touch plate wiring.

Is this what Peter was referring to ?

I've redrawn the configuration.

As there is 12 volts through the relays, individually switched on, I've put the 5.6k resistor in line to join between UP / Down and negative.

NO, what Peter is referring to, is to supply a permanent positive to the MASSO inputs through 5.6k resistors and connect the input to switched negative. This results in the input held high and then pulled low when the signal switches. This way the input is solidly held in states that noise cannot disrupt.

Looking at your drawings you need to reverse the connections on the indicator LEDs to make them work with the changed input wiring.

Great work by the way, I'm following with interest.

Regards,

Arie.

 

[lilow]

Breezy.

Not quite following your suggestions.

Could you supply a drawing ?

I appreciate your input.

I can swap the LEDs to the normally closed side of the relay.

So connect LED to NC side of UP and call it the Down LED.

Cheers.