DIY CNC Plasma Table

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Well here it goes! New to the forum, but decided I am going to start building my first CNC plasma table. A little background on meSome experience in CNC, with 3D printers, and a fellow machinist that operates a shop a few hours away, as well as lurking on many forums for a few years! I have owned a small 45 amp plasma cutter for two years. I farm with my father, and a few hired hands, we do all our own maintenance and repairs to our equipment and vehicles, so we have a good collection of tools in our shop, from press brakes, lathe, drill press, TIG, MIG, and arc welders to a homemade 8x4x4' sandblasting cabinet I designed a few winters ago. But one tool me and my dad have wanted for a long time, but never wanted to pay big dollars for was a cnc plasma, or even a mill ( came close to buying used mills at auctions but chickened out )So now after talking to a few torchmate salesmen, no offence if there is any on here, I just cant justify $23K on a 5x10" table, when I could build one for under $6K or less possibly.  So here is what I have come to for a parts list to get started! I wanted some opinions on what I have so far, and what I should change!-Gecko 540 driver-3, Nema 23 380oz.in geared down to 3:1 -48V, 7.3A power supply-Hypertherm 85a-cable tracking- lots of 4x4" 1/2" wall tubing for water table, and maybe lighter metal for gantry table (two separate tables for leveling purposes, and so metal doesn't bump adjustments of the cnc) Now here is where I am stuck and not sure which route to go. I need a way to move the gantry around, looking at using rack and pinion, seems it will give enough accuracy, and speed, just not sure if I can go dual or single drive, so the gantry doesnt bind driving from one side, or is that even going to be a problem given I build it square using jigs, and good bearings??Now the second part I am stuck on, is am going to be able to turn my hypertherm 85 on using the gecko controller? I do not currently own a hypertherm, but it is my next plasma of choice! Or do I need to purchase a different board to do that? Third thing I need advice on is, which way should I go for linear motion parts, V-Groove rail is expensive, but a nice clean way to do it, I could build a similar set up using pipe and angle iron, with bearings, build a small test and was very pleased with its performance!, another option I seen was cold rolled flat iron, one member on this forum build a red table that used them, I really liked that design but wanted more picture and information on his drive systyem and bearings, he purchased the entire gantry kit from a company, it looked clean and well built, curious to pricing on that option, might be ten times easier route. Really excited to get the metal ordered and electronics, just need input from people to see if I am makign the right decision, as it would be a costly and simple mistake to order the wrong parts now! I plan on makign a video series on the build and uploading lots of pictures when I start moving ahead on this project! Thanks!
Reply:Do it yourself can save you some money, but plan on spending a lot of time designing, assembling, testing, disassembling, redesigning, etc. If you figure your time is worth less than about $10 / hour, then you will probably build a do it yourself machine at a lower price than a turnkey machine that we all know will work. I have built 3 DIY machines over the years.....yet I currently have 3 turnkey cnc plasma's (2 PlasmaCam, 1 Torchmate)......which worked well right out of the box.....and have been working well for many years (well...the PlasmaCam's anyway!). I would build another DIY machine after I retire and have the time....based on my knowledge regarding the mistakes I made on the first two...as well as what I learned about the turnkey machines, it would be a fun project, but I honestly doubt it would be much cheaper.There are different levels of DIY machines. I strongly suggest that you go to the www.candcnc.com  site and look at their DIY kits with drives, motors, electronics, cables, Torch height controls and software. Bargain priced and proven with thousands of kits in the field. Also look at www.precisionplasmallc.com as they have a variety of machine (mechanical x y and z gantries) kits that will marry up to the CandCNC components. A good choice for first machines....lower priced than many of the turnkey machines yet a proven design that will save a lot of time and aggravation.If you want your Hypertherm Powermax85 to cut as well as it can...(good choice by the way!) here is what you need your machine to be equipped with:-Little or no mechanical backlash or flex. Anything the machine does in terms of vibration or overshoot will be amplified by the plasma. If the machine is not very tight, and designed to stay tight after miles of cutting, then expect less than good cut quality and part accuracy. Trust me...I work with cut quality complaints daily (have for over 36 years) and most often them are not caused by the plasma cutter, but are a result of poor motion, incorrect height, or a sloppy machine design.  You mention a single side drive......attempted many many times. Will work on small gantries (maybe up to 2' wide) for short periods of time at slow speeds.....but is unacceptable in longer term use or for the full speed range (5 ipm to 350 ipm) required by plasma. Dual side drive can be done with two motors (one on each side) or with one (properly sized) motor with a drive shaft and gears on each side (PlasmaCam does this with a high level of success).-Keep the gantry and torch cariage light, yet rigid in design. Acceleration is the key to good cut quality, and by keeping the moving parts light and choosing the properly sized drives you will be able to achieve optimum acceleration where it is needed.....at the higher speed ranges. Working with established suppliers (Like CandCNC) will get you good advice on machine design (weights, drives, electronics) as well as advice on tuning the x and y drives after the machine is done.-Height control. Read my posts on multiple sites over the last 6 or 7 years. Yes, you can cut without height control......no, the cuts will not be nearly as good as with a properly functioning height control. Without height control you will get dramatically shorter consumable life, you will get varying cut edge angularity, you will have out of round holes....and you will have to stand at the machine to babysit every cut. With a properly funtioning height control you can program 100 parts and walk away while it cuts them.....which is what cnc machines are all about!-Fume control. Downdraft, if you can blow the smoke outside, is relatively easy and produces the best cut quality. If you heat your shop in winter, it will suck the heat out of your shop. Water trays are easy and inexpensive, and good at controlling fumes, but splash water on plate and machine. Water on the cut edge will produce more dross (in many cases, not all) and will roughen the cut edge. Regardless of which you build into your system, you need fume control!There are a lot of people here that can help....search this and other sites for pictures and advice and have fun with your design! Keep in mind that these machines can actually make you some money! When I bought my first PlasmaCam (about $12k) I did enough weekend and evening cutting jobs for local welding shops and contractors....that I easily paid for the machine in less than 6 months. If I had built my own machine from scratch....I would still be building the machine while the PlasmaCam was paying for itself....keep that in mind.Jim Colt    Originally Posted by Michael.TWell here it goes! New to the forum, but decided I am going to start building my first CNC plasma table. A little background on meSome experience in CNC, with 3D printers, and a fellow machinist that operates a shop a few hours away, as well as lurking on many forums for a few years! I have owned a small 45 amp plasma cutter for two years. I farm with my father, and a few hired hands, we do all our own maintenance and repairs to our equipment and vehicles, so we have a good collection of tools in our shop, from press brakes, lathe, drill press, TIG, MIG, and arc welders to a homemade 8x4x4' sandblasting cabinet I designed a few winters ago. But one tool me and my dad have wanted for a long time, but never wanted to pay big dollars for was a cnc plasma, or even a mill ( came close to buying used mills at auctions but chickened out )So now after talking to a few torchmate salesmen, no offence if there is any on here, I just cant justify $23K on a 5x10" table, when I could build one for under $6K or less possibly.  So here is what I have come to for a parts list to get started! I wanted some opinions on what I have so far, and what I should change!-Gecko 540 driver-3, Nema 23 380oz.in geared down to 3:1 -48V, 7.3A power supply-Hypertherm 85a-cable tracking- lots of 4x4" 1/2" wall tubing for water table, and maybe lighter metal for gantry table (two separate tables for leveling purposes, and so metal doesn't bump adjustments of the cnc) Now here is where I am stuck and not sure which route to go. I need a way to move the gantry around, looking at using rack and pinion, seems it will give enough accuracy, and speed, just not sure if I can go dual or single drive, so the gantry doesnt bind driving from one side, or is that even going to be a problem given I build it square using jigs, and good bearings??Now the second part I am stuck on, is am going to be able to turn my hypertherm 85 on using the gecko controller? I do not currently own a hypertherm, but it is my next plasma of choice! Or do I need to purchase a different board to do that? Third thing I need advice on is, which way should I go for linear motion parts, V-Groove rail is expensive, but a nice clean way to do it, I could build a similar set up using pipe and angle iron, with bearings, build a small test and was very pleased with its performance!, another option I seen was cold rolled flat iron, one member on this forum build a red table that used them, I really liked that design but wanted more picture and information on his drive systyem and bearings, he purchased the entire gantry kit from a company, it looked clean and well built, curious to pricing on that option, might be ten times easier route. Really excited to get the metal ordered and electronics, just need input from people to see if I am makign the right decision, as it would be a costly and simple mistake to order the wrong parts now! I plan on makign a video series on the build and uploading lots of pictures when I start moving ahead on this project! Thanks!
Reply:Originally Posted by jimcoltDo it yourself can save you some money, but plan on spending a lot of time designing, assembling, testing, disassembling, redesigning, etc. If you figure your time is worth less than about $10 / hour, then you will probably build a do it yourself machine at a lower price than a turnkey machine that we all know will work. I have built 3 DIY machines over the years.....yet I currently have 3 turnkey cnc plasma's (2 PlasmaCam, 1 Torchmate)......which worked well right out of the box.....and have been working well for many years (well...the PlasmaCam's anyway!). I would build another DIY machine after I retire and have the time....based on my knowledge regarding the mistakes I made on the first two...as well as what I learned about the turnkey machines, it would be a fun project, but I honestly doubt it would be much cheaper.There are different levels of DIY machines. I strongly suggest that you go to the www.candcnc.com  site and look at their DIY kits with drives, motors, electronics, cables, Torch height controls and software. Bargain priced and proven with thousands of kits in the field. Also look at www.precisionplasmallc.com as they have a variety of machine (mechanical x y and z gantries) kits that will marry up to the CandCNC components. A good choice for first machines....lower priced than many of the turnkey machines yet a proven design that will save a lot of time and aggravation.If you want your Hypertherm Powermax85 to cut as well as it can...(good choice by the way!) here is what you need your machine to be equipped with:-Little or no mechanical backlash or flex. Anything the machine does in terms of vibration or overshoot will be amplified by the plasma. If the machine is not very tight, and designed to stay tight after miles of cutting, then expect less than good cut quality and part accuracy. Trust me...I work with cut quality complaints daily (have for over 36 years) and most often them are not caused by the plasma cutter, but are a result of poor motion, incorrect height, or a sloppy machine design.  You mention a single side drive......attempted many many times. Will work on small gantries (maybe up to 2' wide) for short periods of time at slow speeds.....but is unacceptable in longer term use or for the full speed range (5 ipm to 350 ipm) required by plasma. Dual side drive can be done with two motors (one on each side) or with one (properly sized) motor with a drive shaft and gears on each side (PlasmaCam does this with a high level of success).-Keep the gantry and torch cariage light, yet rigid in design. Acceleration is the key to good cut quality, and by keeping the moving parts light and choosing the properly sized drives you will be able to achieve optimum acceleration where it is needed.....at the higher speed ranges. Working with established suppliers (Like CandCNC) will get you good advice on machine design (weights, drives, electronics) as well as advice on tuning the x and y drives after the machine is done.-Height control. Read my posts on multiple sites over the last 6 or 7 years. Yes, you can cut without height control......no, the cuts will not be nearly as good as with a properly functioning height control. Without height control you will get dramatically shorter consumable life, you will get varying cut edge angularity, you will have out of round holes....and you will have to stand at the machine to babysit every cut. With a properly funtioning height control you can program 100 parts and walk away while it cuts them.....which is what cnc machines are all about!-Fume control. Downdraft, if you can blow the smoke outside, is relatively easy and produces the best cut quality. If you heat your shop in winter, it will suck the heat out of your shop. Water trays are easy and inexpensive, and good at controlling fumes, but splash water on plate and machine. Water on the cut edge will produce more dross (in many cases, not all) and will roughen the cut edge. Regardless of which you build into your system, you need fume control!There are a lot of people here that can help....search this and other sites for pictures and advice and have fun with your design! Keep in mind that these machines can actually make you some money! When I bought my first PlasmaCam (about $12k) I did enough weekend and evening cutting jobs for local welding shops and contractors....that I easily paid for the machine in less than 6 months. If I had built my own machine from scratch....I would still be building the machine while the PlasmaCam was paying for itself....keep that in mind.Jim Colt
Reply:Thanks for the information Jim!! I appreciate any advice you give all over the internet that I have seen so far! Very helpful!I have looked at several pre made kits already such as plasmacam, and torchmate, but I can't justify that much money into one without any experience or knowledge for sure if my area will produce any work for it. Lots of oil field drilling going on a little north of me, but other than that this will mainly be used on the farm, unless word of mouth gets around and someone around me needs lots of parts cut, but I can see most of that coming from the oilfield, or maybe a few contractors. I know I have checked out Candcnc prices and equipment, looks well built, and good electronics, big motors. I am impressed with it, going to give it big consideration, especially the gantry kit, that would keep it light like you said, and dual drive would be the only way I would do it. I talked to another fellow about his dual drive set up and he said they usually have limit switches where each side of the gantry hits the switch until is parallel again, to automatically readjust its self, which would work great if you had a solid piece squared up at the end of the table, should be that hard to do. I like that method better than the driveshaft and gear, because that means more points for stuff to wear and slop as well, I am not a fan of that, but you said plasmacam does it with great success, so I will look into that as well, however it is hard to find detailed videos or information in general on most suppliers drive systems I find. Does CandCNC and precisionplasma have height control build in? or is that more in the programming side of things? The reason I ask is because torchmate measures arc voltage doesnt it, and adjusts on the fly using that? I agree completely with the height control, that is another must for me, because a lot of thicker metal always has a bow in it, or isnt always completely flat I find. still pretty interested in doing my own build, will cut costs, and allow me to buy parts when I have the money, as opposed to a upfront cost right aways.Jim do you have a Youtube channel?  Be interesting to see some videos you could make! Seen a few of videos of your tables off of Lance's (Chuckee2009) channel
Reply:> bookmarked > $10/hr.  As Robert Heinliem would say "TANSTAAFL", there aint't no such thing as a free lunch.Do it Jim!  Last edited by ManoKai; 02-04-2014 at 10:08 PM."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:What? Like this one we had at the Sema show? This is actually a GoTorch 2 x 2 (from PlasmaCam).....the top part of the machine only, and the "cube" base is built by my son's business. It is a hybrid water and downdraft table designed for trade show or low volume cutting that traps 60 to 80% of the fumes with water (but no splashing) and then pulls the remaining smoke through two fume filters. At most shows there is no way to duct smoke outside, and we don't like the distraction of a huge fume filtration unit in the booth....so this is a good solution for demostrating cnc plasma cutting at trade shows.  The GoTorch is upgraded with advanced software and height control for essentially the same performance that their larger tables provide.This machine will be at the Conexpo show in Vegas in March in the Hypertherm booth.Jim Colt
Reply:Just for reference I'm building a Precision plasma Standard duty kit with CandCNC ethercut components in a 5x10 right now.  After all said and done I'll be under 8,500 including my plasma cutter (PM45).  Everything has been done a million times, both PP and CandCNC have great support and customer service so it's made it easy.  I'm just finishing my table now so I can't say it will work when I'm done but it's been fairly painless so far.I started out going with a water table but after reading Jim's posts on plenty of forums I've decided to go down draft.  Ron at PP told me about the dust collector from harbor freight and I'll be using the blower off of it instead of water.
Reply:@ JimColt - 'zactly like that, but scaled up in size to, say, a 4' x 4' arrangement.  Awesome setup Jim!"Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Well, looks like the precision plasma LLC table gantry is out of the question now, I should of done more reading on their website to start with. They do not ship internationally, NO EXCEPTIONS. Thats due to their product liability insurance, they go on to say. Kinda saddening, but I am going to look into a PlasmaCam again and see what prices they have for a 5x10 kit. I could still use the CandCNC electronics kit, and just "copy" the PPL gantry kit, might not be that hard to do actually. But like Jim suggested, get a machine up and running as soon as possible to pay off itself and have fun with is always a great thing.