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My first CNC (plasma) machine
« on: March 01, 2015, 11:44:47 PM »
Hello, just thought Id show the community what brought me to this forum. Im currently working on my first CNC machine. Im building a CNC plasma table that I hope will also be able to mill aluminum and maybe even take some light cuts in steel. Instead of making twenty posts to show my build log, I will just post a link to my Facebook album that contains all of the pics.

https://www.facebook.com/media/set/?set=a.524830614326022.1073741829.100003972633149&type=3
« Last Edit: March 01, 2015, 11:50:30 PM by xtjoliverx »
Re: My first CNC (plasma) machine
« Reply #1 on: March 02, 2015, 03:00:18 PM »
If you try to view the link on your phone, after clicking the link hit your settings button and request the desktop site. Sorry I just now noticed it did that.
Re: My first CNC (plasma) machine
« Reply #2 on: March 05, 2015, 07:25:25 AM »
This is only my first machine, and although the first one isnt done yet I am open to any suggestions, improvements, crticism, etc. As soon as this one is up and running Im starting my next one. This being my first machine I knew going in that I would find improvements and different ways of doing things. Its already much different then the solidworks model I designed.  Also, I will not be building any of my next machines from a pile of scrap. The owner of the place I work wanted to scrap it all. I was just showing him the value and use in it, and that it could be put to good use. So i offered to cut and clean it all up in my time for some of it. Thanks again for any suggestion and criticism ahead of time.

Offline Chaoticone

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Re: My first CNC (plasma) machine
« Reply #3 on: March 05, 2015, 10:14:05 AM »
Good on you! I hate to waste stuff too. Not sure what your using as a motion device but electrical noise can be a huge problem with plasma cutters. I don't like to have 5v outside of the cabinet of any machine. Far less likely to have issues with 24v. Have a look at this topic and be sure to read all the manuals you can.

http://www.machsupport.com/forum/index.php/topic,25616.0.html

You have likely done most of this already but this is from our FAQs page. I think the whole page is well worth reading.

Where do I start? Are there steps?

Yes! For anybody just beginning with CNC, the following steps are absolutely essential. Even pros with many years of experience may be able to pick up a few pointers. All machine controls are different, and even a person who has run, worked on, built, or installed CNCs for many years using any particular control will experience a learning curve when using a different control. Mach3/Mach4 is quite capable of controlling a machine, but there will be differences between it and any other controller. Also, the hardware used in a CNC can have a dramatic effect on how the software and complete system operate. The bottom line: each system will behave slightly differently. The control (no matter whose) is not capable of understanding the operator; therefore the operator/designer must be capable of understanding the control and creating their system.

1) Read the manuals. Even the most seasoned pro will often reference the manuals when they have a question. Reading the “Mach3Mill Install and Config Guide” in its entirety, and making notes of any questions it may prompt, is a great first step. It is important to fully understand how the software operates to create and use the system that is created. The knowledge the manual provides can reduce the chance of expensive or time consuming rework.
2) Watch the tutorial videos. These are fairly short and loaded with information. They can be found on the Tutorial Videos page of the website.
3)   Establish requirements and write them down. List the requirements the machine must achieve, such as the tolerance it must hold, repeatability, rapid speeds, feed rates, acceleration, coolant, power source, etc.
4)   Gather information. Collecting any and all relevant documentation available from the outset of the project. This includes any manuals or data sheets for the machine and/or the components. Components or machines with poor documentation may require careful consideration.
5)   Make an I/O map. Using a spreadsheet to list all of the I/O (inputs and outputs) and document which pin of which device they will be wired, can save effort with both configuring Mach3/Mach4 and troubleshooting any issues. This will likely be used for the life of the machine.
6)   Draw diagrams. Diagrams for the electrical, pneumatic, hydraulic, coolant, etc. systems can be important when troubleshooting a machine. If the machine is a retrofit and did not come with any diagrams, it may be well worth the time to create them.
7)   Generate a parts list. Document what parts are needed, where to acquire them, their cost, part numbers, etc.
8 )   Review, edit, and update. At this stage, there should be a solid understanding of what type of machine is desired, what parts are necessary to produce it, and a pretty good idea of how everything ties together. Chances are that along the way, required adjustments have been made, so now is the best time to update the documents accordingly to reflect these changes.
9)   Gather components. It should now be possible to make educated decisions about the components required to build the machine and feel confident they will give the desired results. If this is not the case, it is time to backtrack as far as necessary in the process to reach that comfort level before actually ordering any parts.
10) Bench test. Once the components are gathered, it is time to assemble and test them. It is advisable to initially perform this process on a bench (desk, table, work shop bench). Testing before permanently installing the hardware and routing the wires in the machine will often save a lot of time, trouble, and frustration. It is not unusual for things to fail to work exactly as expected with a new setup.
11) Assemble and test. After the hardware has been bench tested, it is time to install it on the machine. It is the responsibility of the builder to make sure that assembly is done correctly in order for the machine to meet the specifications that were set. Care should be taken to ensure that everything is done properly the first time. If questions arise, they should be researched and addressed before continuing otherwise the machine may not perform as expected.
12) Purchase Mach3/Mach4 & Enjoy! If everything has been done correctly up to this point, the only thing left to do is purchase a license for the software. If everything has not been done correctly, the decision must be made as to whether or not the results are acceptable or if things need to be adjusted.

Brett
« Last Edit: March 05, 2015, 10:16:36 AM by Chaoticone »
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: My first CNC (plasma) machine
« Reply #4 on: March 05, 2015, 12:26:16 PM »
Yes your right, I have done all of this. But, I wish I would have found all this info in one place before I started this project. This is good info that should be stickied. I am worried about the noise though. Any recommendations?

Offline Chaoticone

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Re: My first CNC (plasma) machine
« Reply #5 on: March 05, 2015, 01:07:58 PM »
Our FAQs page and the members docs boards are some of the best (but often overlooked) resources.

http://www.machsupport.com/help-learning/f-a-q/

http://www.machsupport.com/forum/index.php/board,78.0.html

Just read and follow the information at the link in my last reply. That should get you off on the right track and give you a fair chance at avoiding noise issues all together. You should probably browse the forum to see issues others have had and how they solved them.

Brett
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: My first CNC (plasma) machine
« Reply #6 on: March 06, 2015, 10:54:48 AM »
Thanks for the info. I tried looking into the opto 22 converters but dont really know what Im lookjng for, think you ciuld give me a nudge in the right direction? Also, have you or anyone wlse ever used a wire mesh shielding sleeve with any success?  According to wikipedia, this stuff should act just like a Faraday cage. From what I read in your links, grounding these sleeves should help even more. I have shielded wire i am going to use, but if that stuff is worth it ill use that as well, and maybe one of these optically isolated converters. Think that will be enough to eliminate noise?
« Last Edit: March 06, 2015, 10:59:00 AM by xtjoliverx »

Offline Chaoticone

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Re: My first CNC (plasma) machine
« Reply #7 on: March 06, 2015, 12:03:45 PM »
I have used these  http://www.opto22.com/site/pr_selector.aspx?cid=4&qs=1003  The G4 single channel has a big selection. They have all sorts of racks for them. The ones that have a separate terminal for each relay pin are the most versatile but require the most wiring. You will have to decide which modules and racks would suit you best.......... if you decide to go that route. Probably the easiest and cleanest way to get 24V IO would be to use an external motion device with the optos built in. CSLabs and Vital systems offer those. Either way (external motion device with 24V IO or optos of some kind) is going to cost more. Robust solutions almost always do though. The higher price of the external motion devices offering 24V IO is usually a wash when you consider the expense of rolling your own. I have gotten good results with both. Any time I didn't use one or the other I wished I had and made the necessary changes so I could.

Good shielded cable has the wire mesh sleeve under the outer sheath or at least somewhere that is covered (sometimes several layers deep)............... which is what you want. Heat shrinking the ends is a good idea too. You dont want to give the noise a way to easily follow your wires. You want to make the possibility of that as low as possible. Shielded cables give the best of the 2 features you want. Make it hard for noise to get to your control cables to begin with but give any that does get through the insulation (sheath) an easy path to ground. External braided shield would make more of an antenna (which is not what you want). It would give the noise an easy path to ground though but still best to avoid it I think. Igus makes great cables designed for all levels of noise immunity and they sell everything they offer by the foot if you want it that way. Again, it isn't cheap but it does work........................ if used/installed correctly. The used/installed correctly is the magic dust in the whole noise immunity recipe. You can take the best parts known to man and make a mess or the most inferior parts and make woks of art. Planing, planing and more planing should be the first line of defense. Good patrs is cheap insurance IMO.

Brett
« Last Edit: March 06, 2015, 12:06:43 PM by Chaoticone »
;D If you could see the things I have in my head, you would be laughing too. ;D

My guard dog is not what you need to worry about!
Re: My first CNC (plasma) machine
« Reply #8 on: March 07, 2015, 11:48:16 AM »
Once again, thanks for the info. I have already decided to build my own enclosure. I already had the sheet metal ordered at work, and I think it will probably be delivered early this week. However, after reading the articles you suggested, looked at the products youve recommended, and considered your advice, I am going to rethink the design. Since I am the manufacturer, middleman, and customer I can build an enclosure that suits me while using better materials. Since I am the customer I am not worried about keeping costs down and will be using 14 gauge sheet metal. If youve seen the pictures you can probably tell I am not worried about keeping weight down, except when it comes to the gantry. What about putting that wire mesh sleeving over the plasma torch lead? You mentioned that stuff would work like an antennea? Think it would help to keep some noise from escaping the lead?
Re: My first CNC (plasma) machine
« Reply #9 on: March 07, 2015, 09:21:30 PM »
I am also look for criticism on the design. I would like other viewpoints on things people would change, etc. This is my first machine, but there will be more. I knew coming into this project that it would be a learning experience, and I plan to use the experience, and knowlege in future machines. If anyone of you were building this machine what would have have done differently, and why?

I probably should have mentioned some info you cant get from the pics before now oops:

Mach 3
Sheetcam
1232oz/in nema 34 motors (x axis is slaved there will be 2 motors moving that gantry)
proma THC
Hypertherm powermax 65 plasma