need help with used cnc plasma cutter purchase

looking at a used cnc plasma / router table
I am looking at buying this used machine and need some advice, I know nothing about this machine or any cnc plasma table at all

may I get some advice on buying this used with the work it needs to finish setting it up here are the details

4 X 8 foot CNC plasma or router table.

Built by Practical CNC but has a Cand CNC controller using Mach III software.
Currently setup as a plasma cutting table but have the rails to convert to a router table.
All motors are servos.
Has torch height control.
Complete with HP computer and Hypertherm 1000 with machine torch.
PlazPak-3 , 3 Axis Servo System.
also I think something called the mp3000


needs, someone that can finish some minor software program setup and redo the limit switches.

Also have the hand torch. Other software included is Sheetcam for converting drawings to machine language VCarve Pro for
routing. License for Mach III and Sheetcam included. Air compressor is NOT included. I have 12000.00 invested in this table so it is a good buy for someone that can finish some minor software program setup and redo the limit switches.

thanks, I could really use the help

At the risk of offending this is exactly what the other unmentioned site does.

What you have is a homebuilt table made by one of several companies using control software and parts available on the net.

It looks like Practical cnc wants money to talk to them.
Practical CNC Support

So you might want to check with the suppliers of the parts.

The first of these would be
http://www.candcnc.com/

Give them a call, I believe it is Tom that runs it. Last time I talked to him he was very helpful.

The Mach3 is easy to use once you get the hang of it but it does have some things that don't work as expected. (also a site for that)

Your best bet here is to treat it as it is, a kit, the parts are there and mostly assembled and you have to figure out how to make it run.

Good luck, It is a steep but worthwhile climb.

KIMFAB said:

At the risk of offending this is exactly what the other unmentioned site does.

Click to expand...

first let me say thank you for any help/input!

other site? I did post on another site but never got a response, not sure if it is the site you mention or not

What you have is a homebuilt table made by one of several companies using control software and parts available on the net.

It looks like Practical cnc wants money to talk to them.

Click to expand...

he has said the controller board that came with it from practical cnc had gone bad, so he replaced it with the Cand CNC controller plaspak3 controller, , I assume all that is left from the practical cnc part of it was the table.

Practical CNC Support

So you might want to check with the suppliers of the parts.

The first of these would be
http://www.candcnc.com/

Give them a call, I believe it is Tom that runs it. Last time I talked to him he was very helpful.

Click to expand...

I'm not even sure what questions to ask, not from the seller, or the supplier, I'm not sure what other machine to look into either new or used, and I definitely do not know where to start to fix problems,.

The Mach3 is easy to use once you get the hang of it but it does have some things that don't work as expected. (also a site for that)

Your best bet here is to treat it as it is, a kit, the parts are there and mostly assembled and you have to figure out how to make it run.

Good luck, It is a steep but worthwhile climb.

Click to expand...

is it something a complete novice to anything cnc should tackle? I have never used anything like this, I was an auto tech for years, never got close to any cnc type equipment, I can learn to use software. I played with autocad that was over my head though, not something that I think would be self taught. I did use corel draw an older version, I can learn that type of software, but as far as repairing or knowing how to make a kit work that has been changed? I'm not sure , heck I don;t even really know who it all interfaces together, computer, software, controller, to actually making a part on the machine, he is asking 4500.00 for this setup, he had bought it new, then had to replace the controller, that is how the candcnc parts got to the machine

like I said, I'm not even sure what to ask him when I go look at it today

thanks for your time!

$4500 would be an OK price if the table is working and he is willing to help you set it up and show you how it works.

Without that the unit becomes worth a lot less.
Where does this $12000 invested come in? Have you already bought something?

Sounds like it might be a bit much of a bite unless you have lots of time.

I'm retired with an extensive engineering and electronics background and have already scratched most of my hair off.

Give me a call. The number is on my home page.

KIMFAB said:

$4500 would be an OK price if the table is working and he is willing to help you set it up and show you how it works.

Without that the unit becomes worth a lot less.
Where does this $12000 invested come in? Have you already bought something?

Click to expand...

The 12000 invested was what he says he has in it,

Sounds like it might be a bit much of a bite unless you have lots of time.

I'm retired with an extensive engineering and electronics background and have already scratched most of my hair off.

Give me a call. The number is on my home page.

Click to expand...

Thank you
I'm headed down there now,i will try to find your number

Thank you KIMFAB

Good morning John, (well it might not be where you are yet <g>)

Anyhow, I just wanted to say Thank you for your time on the phone, your time is very much appreciated! Tell your son when we get out that way, I look forward to seeing his jeep, probably next year.

I did look at that machine real close and see why and where that table would need some real strengthening help, the way the bolts slide into parts that are structural could be a issue, heck they reminded me of how the cheap tv stand are made with the little metal pieces that slide into precut hole! Even though we can weld some of it up, that is weak material! but I think I could make that table work for some time, with a couple hundred dollars of metal to strengthen it I bet it could last maybe a couple years,

I would need to move my big welder downstairs though (wow that is a job in itself)

anyhow, the owner and I have not hit the right price yet, but I do understand a tad more (tad, a word used loosely) but I did get a email off to the manufacture of the candcnc equipment and he gave some pointers on what needed upgraded

what I need is a start here (unpack parts) hehe ok that part is already done, but I really do need that basic of instructions , as even though wires are all run and connected I have no idea what they do or why they go where they do. I'm going to sit down and look over the one manual he sent me, it is for the mp3000 rev III, like I said it would be nice to have a start here step by step manual

again thanks for your time!

Tom

it's official~

I have the machine here now!

this should be fun to learn how to do, once I have figured out what versions of everything I have, I wil post them all

Thanks!

tom

Sounds like a bit of a Frankenstein, which can be good and bad. One thing to do a bit of research on are your servos. If that table has been running nothing more than plasma, you have to remember that there is no material load on the head... IOW, all you're doing is pushing air. OTOH, if you want to run a router, you need to make sure the motors can handle the load and dial in your feed rates. Blowing up your servos by overpowering them can be an instant and expensive mistake. How many servos does your table have? The one I run has four: X, X slave, Y, and Z.

Curious Yellow said:

Sounds like a bit of a Frankenstein, which can be good and bad. One thing to do a bit of research on are your servos. If that table has been running nothing more than plasma, you have to remember that there is no material load on the head... IOW, all you're doing is pushing air. OTOH, if you want to run a router, you need to make sure the motors can handle the load and dial in your feed rates. Blowing up your servos by overpowering them can be an instant and expensive mistake. How many servos does your table have? The one I run has four: X, X slave, Y, and Z.

Click to expand...

not sure yet, I just got back in town and have not been able to set it up yet, have a few more things to do and then can start on it
probably be the weekend or monday when I start on it

KIMFAB said:

$4500 would be an OK price if the table is working and he is willing to help you set it up and show you how it works.

Without that the unit becomes worth a lot less.
Where does this $12000 invested come in? Have you already bought something?

Sounds like it might be a bit much of a bite unless you have lots of time.

I'm retired with an extensive engineering and electronics background and have already scratched most of my hair off.

Give me a call. The number is on my home page.

Click to expand...

Well sir, you are surely correct, this is a lot to take a bite out of, heck just sheetcam is going to be a real learning curve in it self

I hope the tutorials are much better than my glances over them seem to be

today will be putting all the cables back on, and look for step one as far as where to start, it is going to be a steep learning curve, I'll give myself a month to have it setup and functional, to tel the truth just glancing into the software's of machIII and sheetcam, I hope I can get it up and running in a month!

Looking at autocad 14 which I had been given, that is one intense program in itself, got a good suggestion for a drawing program that would be easy to use to start off with?

ttm said:

Well sir, you are surely correct, this is a lot to take a bite out of, heck just sheetcam is going to be a real learning curve in it self

I hope the tutorials are much better than my glances over them seem to be

today will be putting all the cables back on, and look for step one as far as where to start, it is going to be a steep learning curve, I'll give myself a month to have it setup and functional, to tel the truth just glancing into the software's of machIII and sheetcam, I hope I can get it up and running in a month!

Looking at autocad 14 which I had been given, that is one intense program in itself, got a good suggestion for a drawing program that would be easy to use to start off with?

Click to expand...

I suspect you'll need more time than a month. I hope that's a self-imposed deadline. Luckily your dealing with 2D and simple DXF files. That should make the learning curve a bit easier. I use AutoCAD LT 2012 to do all my drawings, then use my table's native DXF converter to write the G code. That part probably sounds like Greek but it's pretty straight forward. I think the thing you'll be dealing with is getting that thing moving around and then figuring out how to fine tune it for predictability and quality. I would say it's taken me two years to feel really confident with what I do.

Sheetcam is SUPER easy to learn if you need help I may be able to walk you through it. We have a BullTear table at our shop and we use sheetcam all the time.

Curious Yellow said:

I suspect you'll need more time than a month. I hope that's a self-imposed deadline. Luckily your dealing with 2D and simple DXF files. That should make the learning curve a bit easier. I use AutoCAD LT 2012 to do all my drawings, then use my table's native DXF converter to write the G code. That part probably sounds like Greek but it's pretty straight forward. I think the thing you'll be dealing with is getting that thing moving around and then figuring out how to fine tune it for predictability and quality. I would say it's taken me two years to feel really confident with what I do.

Click to expand...

yes self imposed deadline, but to be clear, I have give myself that time to have the machine setup with correct movement and be able to run it, not be comfrtable with all aspects, if I can have run doing the x,y,and z movements correctly by then, I iwll be pretty happy, then to learn the rest of it enough to be comfortable to say I can operate it!

i might get it done by the time i die is the way I feel right now! and I'm only 50 <grin>

Speedie said:

Sheetcam is SUPER easy to learn if you need help I may be able to walk you through it. We have a BullTear table at our shop and we use sheetcam all the time.

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thank you, I know I will take you up on that offer soon! we are about to put power to the table setup now



Tom

ttm said:

yes self imposed deadline, but to be clear, I have give myself that time to have the machine setup with correct movement and be able to run it, not be comfrtable with all aspects, if I can have run doing the x,y,and z movements correctly by then, I iwll be pretty happy, then to learn the rest of it enough to be comfortable to say I can operate it!

i might get it done by the time i die is the way I feel right now! and I'm only 50 <grin>

Click to expand...

Getting it to run the x,y, and z movements is all any of us are trying to do! Ha! Sometimes it can be useful to get a notion of what you're trying to accomplish with a plasma table. You've got a few variables to deal with, and if you can simplify that in your mind, you'll have a better shot at trouble-shooting your table.

The things that will generally dictate your machine settings will be material and material thickness. Your hypertherm manual will have machine settings in it, but I think their feedrates are way too fast. Others in the forum may have different opinions, but what I'm usually trying to do is run the machine as slow as I can to keep the quality as high as I can.

In general, the machine settings you'll need to figure out will be feedrates, set points, motion delay, amperage at the generator, and torch height. All of those make up a kind of soup that you'll adjust to get the thing to do what you want. Without knowing exactly what software you're using, it goes on from there.

As you get up and running, feel free to put up more questions. Photos would be good too.

DeltaCAD is a very easy CAD program for me.

Curious Yellow said:

In general, the machine settings you'll need to figure out will be feedrates, set points, motion delay, amperage at the generator, and torch height. All of those make up a kind of soup that you'll adjust to get the thing to do what you want. Without knowing exactly what software you're using, it goes on from there.

As you get up and running, feel free to put up more questions. Photos would be good too.

Click to expand...

thanks, right now the z axis (torch height control) is kicking the estop every time I try to move it by keyboard, the x, y, move fine by keyboard

i have the Candcnc plaspak mp3000 ubob III controller
mach III and sheetcam, (have not even looked into sheetcam yet, still trying to get he machine basics finishedm keep in mind, this was a system setup partially by the previous owner, so i really have not done much at all yet.

motojoel1 said:

DeltaCAD is a very easy CAD program for me.

Click to expand...

thanks I will look for it and check it out

Curious Yellow said:

The things that will generally dictate your machine settings will be material and material thickness. Your hypertherm manual will have machine settings in it, but I think their feedrates are way too fast. Others in the forum may have different opinions, but what I'm usually trying to do is run the machine as slow as I can to keep the quality as high as I can.

In general, the machine settings you'll need to figure out will be feedrates, set points, motion delay, amperage at the generator, and torch height. All of those make up a kind of soup that you'll adjust to get the thing to do what you want. Without knowing exactly what software you're using, it goes on from there.

As you get up and running, feel free to put up more questions. Photos would be good too.

Click to expand...

it is up and running now, I have ony cut 14g and 1/8" steel on it so far, I have had some more help and have a basic understanding on sheetcam and the very basics of mach3, on the rectangle plates I cut there was a very small amount of dross, which on some 14g i had almost none. one thing I do need to do is get a better way to fine tune the steps for the servo motors, I need a way to precisely measure out 100" I used a 12ft steel tape but it was only in 1/16's, i think I am going to try using a dial indicator for that run and just make sure it goes exactly to the same spot each time, I used a .001 caliper for the 6" z axis, my x axis will run 52" as well

I'm not sure what you mean by motion delay?
anyhow, I have a long way to go but now is to fine tune the machine better, learn the softwares better and start putting a data sheet together for the different thickness metals so I have kerf widths, speeds and torch settings in a file that works good for my setup.

oh yea, learn to use a cad program, which is gong to be tougher than I thought... particularly when I put the router on it

ttm said:

it is up and running now, I have ony cut 14g and 1/8" steel on it so far, I have had some more help and have a basic understanding on sheetcam and the very basics of mach3, on the rectangle plates I cut there was a very small amount of dross, which on some 14g i had almost none. one thing I do need to do is get a better way to fine tune the steps for the servo motors, I need a way to precisely measure out 100" I used a 12ft steel tape but it was only in 1/16's, i think I am going to try using a dial indicator for that run and just make sure it goes exactly to the same spot each time, I used a .001 caliper for the 6" z axis, my x axis will run 52" as well

Click to expand...

I know what you're trying to do, but before you pull your hair out trying to do it, there are a few things you should keep in mind. Relying on the servos to get you as close to your target tolerance as possible is going to lead you into endless headaches. In my experience, there are too many variables to bother even flirting with thousandths. You've got to remember that you're dealing with consumables, so as your nozzle and your tip start to give up, you're tolerances are going to change. This is not a huge concern, but the things that really will affect your measurements are going to be your material thickness and therefore your feedrate, since those things affect your kerf and therefore your finished part size. All I'm saying is that your facing a lot of real fluctuating variables, and I'm worried for you if you're aiming for ten-thousanth-ish tolerances or something. Maybe you should explain a little about what you're trying to do, or imagine you want to be able to do, and we'll be able to give you better guidance...?

One more thing to consider is whether you're trying to save the inside piece you're cutting or the outside. If you're using a Hypertherm, the swirl ring spins the air in such a way that to save the inside piece, you need to travel around your part clockwise. If you want to save the outside part, you need to travel counter-clockwise. Your lead-ins/lead-outs need to work with this as well. If you have THC, usually it needs .75 seconds to get its height set as well once it kicks off. Keep that in mind as you cut parts and measure your finished product against your drawing.

ttm said:

I'm not sure what you mean by motion delay?

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Motion delay is a way to give the tip a chance to pierce the material before it starts cutting the pattern. If you're dealing with 14ga, at 40 amps, you wont need it. If you start going into .250 or something, you're looking at a .25-.35 second pierce delay at 60 amps.

ttm said:

anyhow, I have a long way to go but now is to fine tune the machine better, learn the softwares better and start putting a data sheet together for the different thickness metals so I have kerf widths, speeds and torch settings in a file that works good for my setup.

oh yea, learn to use a cad program, which is gong to be tougher than I thought... particularly when I put the router on it

Click to expand...

The data sheet is useful, but it might be a bit premature at the moment. I'd just do some experimenting and tell us what you're seeing.