How did you build yourself a cnc plastable? need advice

[jadhunter]

I am working on setting up a plasma table for our shop we have most of the hardware, we have a used table that we where able to get our hands on, tracks on it, we have some motors for it too. The only thing we need to figure out is what software, and electronics we want and how to install and set them up.

I dont know much of anything about electronics or wiring, so any advice on where to get some guides, and any suggestions on providers that you have used and would recommend for a reasonable price would be very apricated.

also any advice in general too.

thanks in advance for the help.

[acourtjester]

Look hard at LinuxCNC the software is free and has a great site for info and problem solving for beginners (that was me). And the electronic controllers are fair priced. Mesa has both controller cards with optional Ohmic sensor, and THC that nice prices. You can use either stepper or servo motors your choice. This can be couples with different PCs as a nice package. There are post processors in SheetCam and maybe Fusion 360 that work very well with LinuxCNC. And their QTPlasmaC GUI have some nice functions built in for smooth operations.

[tcaudle]

Before you scurry off in that direction having never done this before it should be stated that Tom (AcourtJester) has built at least 6 tables (maybe more) and has been doing this for years.He is also retired and not under a great deal of pressure to get one done on a schedule. I guess it all depends on how much time and patience you have to lend to this project because you are going to need both. Kinda like building your own car from spare parts, it's not a process of going out and buying some motors and some other parts and sticking them al together and hitting a button to make it cut. Will the controller handle your motors? How good are you with software and computers? There are a lot of Physics involved in building a table that actually performs and makes good cuts. I know the goal is to save money but if this is a commercial table, designed to make money, and be operated by more than one person, doing something like this with no human (aka Phone) support can be a challenge. So if you don't own the company and decide to leave, your company is screwed!. Of course, if your goal is to learn new stuff and learn from mistakes you will make then , by all means, go for it. Its going to be harder than you think and cost more than you plan. Several guys have built tables and documented the journey here. I don't know how many of them were first time builders and had no experience in Electronics or wiring .

You have to deal with everything form the motors tot he linear drive ratios up to deciding what kind of THC you are doing to pick and wil lit work for the kind of cutting you intend to do> Was the table you picked up a plasma table? You have to realize that the way they built tables 20 years ago was a LOT different than a modern table. Anyway good luck .

[TJS]

I built my own table using Tcaulde's CandCNC Command CNC product. It has been running for many years. I was super green and probably still am compared to others here. You can see my build in my signature. You learn everytime you hit that run button.
T.J.

[jadhunter]

Before you scurry off in that direction having never done this before it should be stated that Tom (AcourtJester) has built at least 6 tables (maybe more) and has been doing this for years.He is also retired and not under a great deal of pressure to get one done on a schedule. I guess it all depends on how much time and patience you have to lend to this project because you are going to need both. Kinda like building your own car from spare parts, it's not a process of going out and buying some motors and some other parts and sticking them al together and hitting a button to make it cut. Will the controller handle your motors? How good are you with software and computers? There are a lot of Physics involved in building a table that actually performs and makes good cuts. I know the goal is to save money but if this is a commercial table, designed to make money, and be operated by more than one person, doing something like this with no human (aka Phone) support can be a challenge. So if you don't own the company and decide to leave, your company is screwed!. Of course, if your goal is to learn new stuff and learn from mistakes you will make then , by all means, go for it. Its going to be harder than you think and cost more than you plan. Several guys have built tables and documented the journey here. I don't know how many of them were first time builders and had no experience in Electronics or wiring .

You have to deal with everything form the motors tot he linear drive ratios up to deciding what kind of THC you are doing to pick and wil lit work for the kind of cutting you intend to do> Was the table you picked up a plasma table? You have to realize that the way they built tables 20 years ago was a LOT different than a modern table. Anyway good luck .

I know this is going to have quite a learning curve to it, and that's part of the point, but i also dont want it to take to long or be to expensive.
we have a lot of the equipment, it mostly the electrical parts and the software we need to make a decision on what we want to us, and get it installed.
so what would you suggest I do?

[Sampson Jones]

Buy a kit from candcnc . 100 thing have to mesh right for a table to cut properly .

[tcaudle]

If you have never done this before then your chances of having bought the right "electrical parts" is pretty slim. Stick building anything is not an easy task even when you have experience . Buying controls and cards from different vendors and trying to make them work together is a level of frustration you may not wish to experience. You wont get support form one vendor to connect their products to another vendors parts.
If you buy imports your support is limited to short emails not to mention a language barrier. The hidden expense in any system is the support . If you sell it too cheap you can't afford to offer much support before it eats your profit.

In your case I would suggest you consider more of a turn key type approach that matches everything together on the electronics side and offers features you probably don't know (yet) you need. What you are doing here is a retrofit of an existing table and in some circumstances that is harder than just building your own table mechanicals . Certain things are already decided for you and you have to work from there. It may look simple but buying some motors and sticking them on a table can have interesting results. If you don't understand the concepts of motor RPM, motor torque versus RPM, and optimum speeds versus the needed torque, you end up with a dud. The weight (mass) of the gantry is important to know in the choice of moors and the drivers you use . That is just one aspect. If the current table used old servos there is very little of it you can use. Just the rails and the rack and the raw gantry.

The good news is after you build one table and fix all of the problems the next one gets easier and the one after that will be even better.



.

[jadhunter]

If you have never done this before then your chances of having bought the right "electrical parts" is pretty slim. Stick building anything is not an easy task even when you have experience . Buying controls and cards from different vendors and trying to make them work together is a level of frustration you may not wish to experience. You wont get support form one vendor to connect their products to another vendors parts.
If you buy imports your support is limited to short emails not to mention a language barrier. The hidden expense in any system is the support . If you sell it too cheap you can't afford to offer much support before it eats your profit.

In your case I would suggest you consider more of a turn key type approach that matches everything together on the electronics side and offers features you probably don't know (yet) you need. What you are doing here is a retrofit of an existing table and in some circumstances that is harder than just building your own table mechanicals . Certain things are already decided for you and you have to work from there. It may look simple but buying some motors and sticking them on a table can have interesting results. If you don't understand the concepts of motor RPM, motor torque versus RPM, and optimum speeds versus the needed torque, you end up with a dud. The weight (mass) of the gantry is important to know in the choice of moors and the drivers you use . That is just one aspect. If the current table used old servos there is very little of it you can use. Just the rails and the rack and the raw gantry.

The good news is after you build one table and fix all of the problems the next one gets easier and the one after that will be even better.
.

it is my intention to get better at this kind of stuff.

do you have any advice fore where to get a kit from a company that has a good customer support system?

i am currently looking at a CandCNC kit, i have read some good things from them in my research. I am also looking at a Openbuild kit i have seen them menschen a bit, but they seem to be geared towered smaller hobby builds.

any thoughts?

[SegoMan DeSigns]

it is my intention to get better at this kind of stuff.

i am currently looking at a CandCNC kit, i have read some good things from them in my research.

any thoughts?

Jad,

tcaudle "Tom" is CandCNC, his customer support has already kicked in and your not even a customer yet.Time-wise his kit is probably the fastest way to go, if you want to research and do it all on your own there is plenty of do it yourself kinda guys on here willing to help you out.

acourtjester The other "Tom" has 10 builds (w/ multiple controllers) to his name, both he and I can show you a chain drive system for movement if that is the direction you choose.

Post up some pics of what your working with and the P-Spider Borg will help you make your decisions.

Steve

[jadhunter]

A small mis understanding, the table we already have is not used, it was just made before my time here, it has been siting for a while.

IMG_1641.jpeg

IMG_1642.jpeg

[acourtjester]

Well its a start, the grate looks to be galvanized and you don't want to use that due to the gas release when it gets burned. I hope you have the gears that match the racks on the table. You may want to look at changes in the drive assemblies for the axis motors to get a gear reduction in place of direct drive. IMHO have fun

[tcaudle]

Ouch.

[cutnweld]

Ouch.

Well said

[adbuch]

I think you've got the makings of a workable table there. This should be a fun project for you and also a great learning experience.
David

[Sampson Jones]

Looking at this pic, I start a whole new build . Lots of rough looking sloppy rollers on mild steel / non gear reduction motors . I built my table years ago . Cnc zone was a big help . Personally , I like HARDENED VEE RAILS and gear rack and pinion from Moore gear . 80/20 Aluminum extrusions for the gantry . I forgot who makes a bolt on vee rail extrustion to the 80/20 gantry but thats what I used . I ve done many revisions to the table over the years , building my own motor drives etc . I finally drove in my head if someone has figured out a componet thats rock soild your better off just buying it . Pay once - cry once - start cutting and making money . Cnc router parts makes some great gear reduction motor mounts . Candcnc makes a z axis that works great with their motor control system . Going this route you’ll still save some money over buying a manufactured table .
But if you have almost zero mechanical ability / welding skills , etc. just buy a complete table . I see some good deals on used but you need to be educated on what your buying

[jadhunter]

so I also need switches and sensors for the table, I am sure that will be easy to find, but I just wanted to ask if anyone has any suggestions for some good affordable places to get them?

[acourtjester]

Here is a post showing the proximity sensors I used, worked great, I switched from mechanical switches. Only draw back is you will need on input per sensor, with switches you can put them in series to one input. You can buy them from eBay or amazon (Comimark 3Pcs TL-W5MC1 5mm 3 Wire Inductive Proximity Sensor Detection Switch NPN DC 6-36V this is for 3 at $12.) these are much more compact then the tubular ones.

https://plasmaspider.com/viewtopic.php? ... or#p240943

[SegoMan DeSigns]

These are the "PNP / NC" inductive type I use. this allows a fail safe mode and non contact switching. Generally speaking the bigger the hole for the switch the longer the detection length (tear the info on it):

https://www.ebay.com/itm/301801247259

PNP.jpg

PNP W Bump Stop.jpg

PNP NC Wiring.jpg

I would start your build by cleaning up the table and take an inventory of what you have and how true the machine is, like Tom said the galvanized grates must go.. I would recommend a water pan in the system for smoke collection.

[adbuch]

My cnc router tables use proximity switches similar to your photo. My plasma tables use nc/no type limit switches which require physical contact to depress the button.
David

[adbuch]

For your galvanized grates, you can simply soak them in acid to remove the plating and expose the bare metal. So no particular need to replace them.
David