[plain ol Bill]

It has been awhile since I have updated the thread so here goes. I managed to break my first linear stage. While waiting for it to be repaired I got another from a friend and set it up. It is larger and more robust so -----. The pic shows the new torch mount slide.
I got the torch mounted (finally) and could not see any reason it would not work. So I loaded some 10 ga. on the table and made a G code file for a 4" square piece w/ a 2" diameter hole in the center of it. VERY NERVOUSLY I hit the run button in Mach -- the thing took off -- pierced and cut the hole out then moved to the square part, pierced and cut that. Measuring it out it was a little out of tolerance so I started to mess w/ stuff - WILL I EVER LEARN TO LEAVE THINGS ALONE?? I changed motor tuning a little to dial in the length of the X axis and now the damn thing won't recut the file! I tried putting the original settings back in without any luck. It cuts larger and will not finish the last cut to sever the part out now. This is all without the THC on currently - I tried it with it on and it wanted to just drive the tip through the metal. Trials and tribulations!

[semi-lucid]

Looking at that, it seems like the hole should be oval shaped instead of perfectly round, if the X is not feeding at the correct rate. ???

[tinman13]

Glad to see you have had some success! I agree if the hole is round then you have a problem with the drawing.
I don't remember if I explained how I set my steps or not so here goes!
I just typed in the MDI line a rapid command to move 8 feet and measured the travel with a tape measure. Then adjusted the steps to match up to the travel. May not be the correct way but guess what, It works!

Now the learning curve takes another turn........ up!
Its time to remember all the little adjustments you have made and how they worked!

[millman52]

Both My X & Y are set up wit the exact same rack, pinion size, & belt reductions so they are identical. I started with movements of about 12" so I could accurately measure it with a vernier caliper. Then moved each axis the entire length of my tables capacity & measured with a tape. Even as small an amount as .005 per foot will nearly be 1/16" of error in 10'.

Doesn't sound like much but it can cause real problems


A slight problem I ran into once I had my table dialed in. Take your pictured part of a square with a circle burned inside. Keep In mind I am cutting with Oxy/fuel. I drew a teat part very much like yours 4" square with a 2" center hole For a particular torch tip I adjusted the kerf in Sheetcam till it cut a 4" square +/- .005 measuring with dial calipers. The center hole always ended up something like 1.980. In other words I could get the outer dimention near perfect but the ID always ended up small.

I played with it enough on different size inner & outer profiles till I determined The inner remained that .020 or so small no matter what size the part. The fix: I have to make all drawings of Id profiles about 0.020 oversize.

It's not a real problem for me as I run a production oriented shop & pretty much burn the same 50 or so parts over & over.

I could have achieved the same results by setting up a second tool with different kerf compensation for ID profiles. I decided it would be easier to draw it once & not have to remember to use 2 tool profiles.

I don't know if this is common or if it has something to do with OD usually cutting CCW & ID CW. I didn't play around with that either, again because I didn't want to have to change the default cut direction every time I set up a part.

[plain ol Bill]

Steve I did my steps per inch prety much the same way you did. The first time I entered to move the Y 48" it took off and if I had not had stops on the end the gantry would have flown off the table. That is when I started dialing in steps! I have it pretty close but not on the money currently.
I will get out there tomorrow and see if I can figure out what is going on that it will not repeat the original cut.

[plain ol Bill]

Two steps forward and three backwards. Yesterday I ran a new phone line connection to the area of my plasma table so I could talk to tech help. I spent today checking all my electrical connections, grounds and making sure I didn't have anything tied together that I shouldn't. I did find where I had put the wiring terminals from my Hyperthem arc OK signal on the wrong terminals of my THC board:nono:. As a result I had burned something in my CandCNC THC box. I talked w/ them today and boxed it up and sent it in for repair:withstupi. This should be the final thing before starting to cut correctly. I did cut a sample file without the THC today an it did cut and measure correctly. So I am on the right track now I think. I am convinced that electronics knowledge is a black art!

[millman52]

Two steps forward and three backwards. Yesterday I ran a new phone line connection to the area of my plasma table so I could talk to tech help. I spent today checking all my electrical connections, grounds and making sure I didn't have anything tied together that I shouldn't. I did find where I had put the wiring terminals from my Hyperthem arc OK signal on the wrong terminals of my THC board:nono:. As a result I had burned something in my CandCNC THC box. I talked w/ them today and boxed it up and sent it in for repair:withstupi. This should be the final thing before starting to cut correctly. I did cut a sample file without the THC today an it did cut and measure correctly. So I am on the right track now I think. I am convinced that electronics knowledge is a black art!

I had a still unknown problem with a part of my electronics on the initial "getting started stage" of my table. I could run for a short while then the X & A (long axis) would get out of synk with each other. We kept thinking "noise" or something in Windows was trying to run in the background.

Tom repalced some components & all was well afterward. CandCNC was very good to honor their warranty. All told they went above & beyond on the repair. I have run for well over a year now without another glitch.

When I build again I already know what electronics I am going to use.

[millman52]

Haven't heard from you in a while Bill, Any more progress?

[plain ol Bill]

I had to send my THC control box back for repairs after I hooked a couple of wires up wrong:withstupi:I decided to trade it in for the latest design the MPC 3000 being offered by Tom at CANDCNC. Upon receiving it the new box required a different cable (male to female) than the old one did. So another delay ----- finally got one today and will hook it up tomorrow.
Meanwhile I got a phone call from a contractor I used to work for quite a bit before retiring. To make a long story short I went back to work for a couple of months to help them (and me) out and they are working 6-10's. So that won't leave a lot of time to work on the table before mid summer.
I'm going to get that thing up and going no matter what it takes then!

[millman52]

I had to send my THC control box back for repairs after I hooked a couple of wires up wrong:withstupi:I decided to trade it in for the latest design the MPC 3000 being offered by Tom at CANDCNC. Upon receiving it the new box required a different cable (male to female) than the old one did. So another delay ----- finally got one today and will hook it up tomorrow.
Meanwhile I got a phone call from a contractor I used to work for quite a bit before retiring. To make a long story short I went back to work for a couple of months to help them (and me) out and they are working 6-10's. So that won't leave a lot of time to work on the table before mid summer.
I'm going to get that thing up and going no matter what it takes then!

Bill!!! I know it has to feel good that someone wants you back from retirement.......... Did ya think of saying. I'm really liking this retirement thing. I'd like to help but about 4 days a week will be enough for me.....:violin:

[millman52]

Thanks for the reply on the floating head switch.

You still on hold because of working?

I'm coming along slowly on getting mine plasma ready. My gantry rail has got a good bit wear in the linear rail. I have purchased a new larger rail but am upgrading with a second Z while at it. This will allow me to have Ox/Fuel on the front of my gantry & Plasma on the opposite side. No switching out torch heads.

My original rail is 15MM IKO rail. For some reason the bearing carriers had seals/wipers on the ends but were not sealed along the length on the underside. About a year into using the table the rail/bearings is wore enough I have wiggle on my Z axis every time I have a rapid direction change. I'm still getting good parts but I no longer have nice even kerf lines coming out of or around a sharp corner.

I'd love to go into semi-retirement & have time to dedicate myself to projects I want to do. As opposed to filling in for whoever has quit till I can replace/train in new help. I don't have too much trouble in the machine shop end of the operation. It is mostly with welders. You'd think it would be opposite. If I find someone that can do & remember jig ups, Their welding sucks. If they can lay 2 even beads side by side, I have to re train them from job to job. I just don't understand it. It AINT rocket science.......(flame2)

[WSS]

Ron since you already use a plasma you understand just how nasty these things can be. Controlling all that black crap is what the water is all about plus helping to control distortion from heat. The principle is simple really. I use full line air pressure on my table to raise the water and just control it by not opening the valve all the way. I crack the valve and the water level rises into the working part of the table. When the level gets to where I want it I just shut the valve off. The water stays at this level until you open a valve to let the air out and then the water goes back to the bottom of the tank.


I know there are some folks that do sumerge the work under water. The torch suppliers do NOT reccomend this - but some folks do it and get away with it. If I were cutting thin stainless I would likely try it myself.

I have a .pdf file that is too large to load here from Thermal Dynamics about water tables I could send you if you want. Drop me a private message w/ your email addy if you want it.

plain ol bill,

I see You use full line pressure,I assume that is 100psi+ or there abouts, and your table holds aprox 350gls. What do you use for your holding tank? Thanks!

WSS

[skippy]

Hey Millman,
just out of curiosity, what would a (reasonable) welder make in after tax (i.e. take home amount) wages per month over there? As I say, just curious.
Phil

[millman52]

Hey Millman,
just out of curiosity, what would a (reasonable) welder make in after tax (i.e. take home amount) wages per month over there? As I say, just curious.
Phil

An in shop welder, (General without certs but good skills with MIG & hand cutting) Single, 40 hr work week (no overtime) net pay will be around $500.00 per week. That's with the shop providing everything but a personal welding hood & normal workwear.

It can vary greatly between geographic locations.

[WSS]

Millman52,

Is that figuring 50% in taxes?

:drowning:

[millman52]

Millman52,

Is that figuring 50% in taxes?

:drowning:

That would be an emplyees approximate net pay after taxes. I don't even want to figure all the extras. Workmens comp, matching social security, unemployment comp & accrued money for sick days, holidays, vacation etc., that I have to pay in addition..... Too depressing to go there.

[plain ol Bill]

I made my living on the end of a TIG torch or stinger for many many years (union construction Boilermaker). Worked in 32 states and been in all of them + a couple of foreign places. It ain't the easiest way to make a living but it will keep the wolf away from the door. Anymore I run the tool room on a local power plant outage when they have one, passing out tools and selling the custom knifes I make. Seeing all those guys come to the tool room all dirty and sweaty looking for tools sure makes me glad I'm not out there in all the mud, blood and beer anymore. There isn't a bunch of people in the world that can snivel and whine like a bunch of tube welders! (and I was one of em).
Loving this plasma table I built folks!

[WSS]

I made my living on the end of a TIG torch or stinger for many many years (union construction Boilermaker). Worked in 32 states and been in all of them + a couple of foreign places. It ain't the easiest way to make a living but it will keep the wolf away from the door. Anymore I run the tool room on a local power plant outage when they have one, passing out tools and selling the custom knifes I make. Seeing all those guys come to the tool room all dirty and sweaty looking for tools sure makes me glad I'm not out there in all the mud, blood and beer anymore. There isn't a bunch of people in the world that can snivel and whine like a bunch of tube welders! (and I was one of em).
Loving this plasma table I built folks!

plain ol bill, you must post some pics of the knives you make!!! This explains the OCD condition you had when you built your table. :stickpoke

WSS

[WSS]

That would be an emplyees approximate net pay after taxes. I don't even want to figure all the extras. Workmens comp, matching social security, unemployment comp & accrued money for sick days, holidays, vacation etc., that I have to pay in addition..... Too depressing to go there.

millman52,

You forgot to add in the cost of the stuff they break!!

[skippy]

$500/wk take home pay, wow, that's somewhat less than what I was expecting to hear. I'm not referring to your shop or you as I was only asking to get a general idea. My dad went to the US in 1975 and came back telling me that they had signs in the buses in Seattle looking for bus mechanics and were paying $18/hr... Then again maybe I haven't got my facts straight and maybe it was gross pay (pre tax etc.). Certainly the machinists and cnc programmers make a lot more judging by the "how much do you make" pole. Thanks for giving me an idea of things anyway.