[Donnelly]

I came across this website after bumping into DIYEngineer on YouTube, and I've got to say this is a great resource. I've already read nearly a hundred pages of build threads so far and some of the stuff here is truly amazing. I'm amped to get working on my own.

So, I'm going to start off this thread with a few posts I've written up. They're mostly detailed background information and rambling, but it was helpful for me to type them to organize my thoughts and I like to keep detailed records of things.

As I get further into my ramblings and arrive at the point where I have questions, I've put the questions in bold, so they stick out.

If you have the time and patience to actually read my ramblings and give feedback, I'd greatly appreciate it!

[Donnelly]

Ok, so I am an undergraduate student at U. of MD, shooting for a triple degree in physics, math, and computer science. In hindsight, I should have done mechanical, electrical, and computer engineering, but whatever - that's not important. What is important is that I've got a mind that likes working with numbers, and in turn, likes designing things and working with tools.

Coincidentally, I've also been working as a personal trainer for over two years. I've got this going as my own LLC, with my website here.

A few months ago, I got the chance to begin oxyacetylene welding. That's right up my alley, so I jumped on the chance. And what did I start building? Fitness equipment, of course!

So, now I'm getting pretty good at this and would like to take this work from "hobbyist" to "light industrial." I'll be buying a MIG welder in the next week or two (looking at the Millermatic 211) and I'd like to get a plasma table running in the next few months.

Within the next 10-15 years, I could see this expanding into a chain of 5-8 gyms and a full-blown equipment company, but I'm getting ahead of myself here. Back to the topic at hand.

[Donnelly]

I'd mostly be working with 1/4" mild steel plate, batch producing brackets and other odds and ends for equipment. There'd also be a good amount of 1/8" plate, occasionally 1/2", maybe 1" on the rarest occasions. Accuracy to within 1/32" would probably be sufficient, but the more accurate the better. More important would be reducing the amount of manual work involved in measuring, cutting, and grinding. The ability to cut smooth shapes and bolt holes would also be big.

I'm into strength and conditioning type training, so here's one example of that sort of equipment that could benefit from a CNC plasma table. It's a set of speed sleds I built for for the football and track coaches at a local high school. Basically, you load it with some weight, strap it to the athlete, then have at it. Simple, but effective.



Currently, I've got to measure and draw all the cut lines by hand, then set up guide-rails to let me get straight cuts with my oxyacetylene torch. Then I've got to grind the cuts smooth, and don't even get me started on that... With a sufficiently large plasma cutting table, I could cut ten of these sleds out of a 4x8' sheet in very short order, with very little grinding afterwards, and that's the brunt of the work.

In fact, because the sleds are relatively simple and large, they'd actually benefit less than many other parts. There's better applications with equipment strongman and powerlifting, but nothing that I have photos of offhand.

[Donnelly]

Right now, I'm leaning towards making it purely a plasma table for the sake of simplicity. It seems like adding secondary functions to the table (eg. routing) greatly increases the requirements for rigidity, drive power, etc. Keeping it simple with plasma is nice, because there are no cutting foces from bits or torque on the gantry from mounting heavy spindles.

Still, I will keep these additional functions in mind as this build progresses, and hopefully I'll find some way to incorporate them:

1. Boring - The ability to put small (1/8 to 1/2") holes in sheet steel and square tube with accurate relative spacing would be awesome. However, if I can't get this, I could always do pierces at the proper positions to act as pilots and then ream them later on with a drill press. It simply wouldn't be ideal.

2. Vinyl/Stencil Cutting - For cutting vinyl stickers and spraypaint stencils for marking the equipment I produce. This doesn't seem like it'd be too hard, I simply have no idea how this sort of cutter is supposed to work.

3. Wood Routing/Aluminum Milling - If I could get both plasma cutting and light-duty milling in one package, I'd be in heaven. Wood routing would be for producing furniture (for myself). Aluminum milling would let me take on small jobs from my physics professors. I know most of them pretty well and they often mention needing some odd part for their lab work (not necessarily with ultra-tight tolerances), which they can't get from the campus machine shop because the shop is always overbooked and overpriced. However, this would probably be the hardest feature to add, and it's getting furthest away from my original goal of producing fitness equipment, so I'll probably drop this.

[Donnelly]

Practical Concerns:

1. Location - My machine shop is currently the garage of my rental home in College Park MD. The landlord is perfectly fine with my welding and whatnot, as long as I don't burn the house down. However, this isn't my house, and I'll have to move out eventually. I'll be graduating in 2.5 years, and where I end up really depends on where I get hired. It could be for some company local in Washington DC, or it could be all the way out in Washington state.

If my table is either large, heavy, or welded in a single piece, I might have to sell it after graduating. Is that a problem? Actually, with the people I'm friends with, I'm sure I could find a buyer, so that's no problem.

It would however, mean that this table would effectively be a test unit. That's not a bad thing either though, because that means when I come up with all my "If I were to do over again..." ideas, I can actually incorporate them when I do it over again.

If I built a smaller, transportable table, then I could take it with me when I move, but there'd still be a lot of hassle in disassembling it and reassembling it again, and if I buy my own house, I'm going to want to put the biggest, baddest tools I can afford into the garage, so I wouldn't even want to have any table that's so small it could be transported anyway.


2. Transportation of Raw Materials - I drive a Dodge hatchback at the moment. I can fit sheet steel up to 2x8', but no 4x8's, so is there really a point to having a 4x8' capacity table? Well, yes, because I can always rent a Home Depot truck for an hour or two or get a friend to help when I need to stock up on sheet steel. Futhermore, I'd like to trade my current vehicle for a truck in the nearby future. Before I graduate? Not sure about that, but maybe.


3. Purchasing of Raw Materials - My supplier does sheet steel in 4x8' pieces, so I'd need, at most, a 5x10' table. There's no need for a 6x12' or anything like that, and since I don't have a crane, there's no need for an x-axis extension to keep the gantry out of harm's way when bringing sheet steel down. I'll probably end up installing some sort of half-ramp with a roller on one end to help me load full 1/4" sheets manually. Thank goodness I lift weights, right?



Table Size:
I could probably get by with a 2x4' capacity table at this stage in the game, but in consideration of the above, I think I'll splurge and shoot for a bigger one. Regardless of the table size, you've got to buy all the electronics and the torch, which are the biggest costs. What's a few more feet of linear rail when you just shelled out $2500 for a torch?


Construction:

Assembly Type - If I were going for something small that I could take with me when I moved, I'd go for a bolt-together thing made out of 80-20 aluminum framing. However, for a bigger table, I'd go with a welded frame, which seems to be the popular choice. While I'm concerned about the heat causing warpage, that seems to be correctable (from Jellingson's and Millman's build threads). If I get good with MIG too, I should be able to minimize the warpage... At least, it'd be better than if I tried doing it with my oxyacetylene torch.

Perhaps the legs will be bolted on in some fashion, so they could be removed later to load the whole table on a flatbed, if/when it gets sold.

Water Table - Definitely going to want this to be a water table for cleanliness. Something starting with about a 3" depth on one side, then sloping down to a 4" depth on the other so I can drain it for the occasional cleaning. How and why do some people move the water to a secondary storage when the table isn't in use?

Other - Might consider appending a 4x2.5' area for welding on one end and storage underneath the table. Definitely give it some sort of leveling feet, and possibly wheels like what AndiKid is working on.

[Donnelly]

As a college student, I'd like to keep things easy on the wallet, but I can anticipate and accommodate for $2500-4000 in the table and electronics and about $2500 for the torch.

Fortunately, January is a good time for personal trainers such as myself, so I really hope to push work hard for the next few weeks to save up some money. Then I'll buy the table materials, shortly followed by the electronics, followed by the torch itself, so I don't need to have all the money all at once, but I can continue working as each new part comes in after the last.

Certain parts of the table, such as wheels or an area for welding, can be postponed or nixed for financial reasons.

[Donnelly]

Hypertherm gets a lot of recommendations, so I called and spoke with Jim Colt last week about which torch to get. Seems like the Powermax 45 would suit my purposes. I'll get it with the machine torch first and buy the hand torch lead later on (unless I can afford them together).

While getting only a hand torch could save some money, I don't want to spend a lot of time fiddling with the thing in a special mount whenever I change consumables.

[Donnelly]

4 Axis Stepper System, with DTHC - On Jim's recommendation I looked into the systems sold by Tom Caudle (might not be spelling that right; he posts here too, but I can't remember the username offhand). The 4 axis drives with stepper motors look sweet and I like the idea of having digital torch height control. I'd either go with the 620 oz-in. motors or the 300, depending on how heavy the gantry is planned to be (100lb and 50lb maximums, respectively, I believe).

I'm not going to even think about building my own drive system with parts from multiple companies. I don't have that kind of electronics expertise (should have done EE and CE!). A kit's the way to go.

I've seen a few people describe stepper motors as some sort of horrible, cheapskate option, but having seen what Millerman's oxyacetylene table can do, I'd be perfectly happy with those kind of results. I figure if I can just get the right gear ratios


Belt Drive for X and Y - I was considering a rack and pinion design originally, but I really didn't like the idea of having to deal with preloading the rack to reduce backlash. Getting all the parts arranged for the spring to pull the pinion and rack into meshing properly seemed so contrived and full of hassle. Not to mention that you've got to drill and tap the rack itself into the rack every couple inches. Doesn't sound too fun.

I've got to say that Fiero Addiction's belt drive system looked sexy. This will be driving a much longer system, but I may go for 3/4 or 1" wide belt with the lightest possible gantry to minimize stretching. So, the X direction (long axis) would be driven on both sides, as usual. The Y direction would have a single drive along the gantry.

Gear Reductions - No idea here. Need to plan a gantry (to find a weight) and do some math to find out what motors I'd like to use and how fast I'd like my rapids before picking a reduction size. I already know to keep the stepping rate as low as possible (depending on the desired resolution) to maximize torque.

Linear Motion - Borrowing from several of the desings I've seen, the vee rails look like a good option. I looked at the precision ground linear rails from McMaster, and damn they were expensive! (Over 30 cents per millimeter.) Those things would also be overkill with a belt drive and steppers. The vee's looked much better for this sort of purpose.

Revisiting the Multifunction Table Options - Now, with the combination of vee rails, a belt drive, and stepper motors, I'm looking at a machine that'll probably be within my desired 1/32" accuracy for plasma cutting. If I have vee rails on the top (to guide the gantry and Z axis mount) and the bottom (to stop either from being pushed off the top rail), then I should even be able to do boring. However, this doesn't seem to be beefy enough to handle that wood routing and aluminum milling I mentioned earlier, but like I also said, that's okay. It's simply not ideal.

Z Axis - Seems to be normally acme screw driven, since racks or ballscrews let the axis drop and crash when the motor is disengaged.

Do people normally buy a machined Z axis and bolt it onto the gantry, or do they make their own from scratch?

[Donnelly]

Through the university computer labs and a machinist I know on campus, I've already got access to AutoCAD (which I've used a decent amount) and SolidWorks (haven't used), which seem to be the two best CAD programs out there. So, questions:

- How do I take what I've done with AutoCAD already and turn it into toolpaths?
- What is CAM Works and what does it have to do with SolidWorks? (Remember, I could learn to use Solidworks, but I haven't yet.)
- What exactly is Mach 3 and what does it do? (It seems to be a required part of the motor driver kits from CandCNC.) Does Mach 3 come included with the CandCNC packages?

[Donnelly]

Ok, that's all for now. Thanks for putting up with my rambling, and even greater thanks for any comments you can give. I'm looking forward to watching the project unfold over the next few months. But for now, I've spent enough time thinking about this, and I've got to get ready for work.

[leeleatherwood]

Donnelly, the best tip I can offer is to use Solidworks combined with this website:

Free CAD Models, Free 3D Models from 80/20 Inc.

Input the model number of the 8020 piece you are looking for, download the file and insert the piece into a Solidworks assembly. Learn to use the Mate function of Solidworks and you can design yourself an 8020 machine in a few hours.

That website also has other models which will be helpfull such as NEMA motors, bearings, etc.

EDIT: You can also use that website to create custom length extrusions for you instead of modifying the part in Solidworks. Just use the custom length function, saves TONS of time!

[ger21]

- How do I take what I've done with AutoCAD already and turn it into toolpaths?

Typically with a CAM program. Although I wrote an AutoCAD macro that utilizes polylines and circles as the toolpaths, and exports the g-code for them.
For plasma, a lot of people like SheetCAM.

- What is CAM Works and what does it have to do with SolidWorks? (Remember, I could learn to use Solidworks, but I haven't yet.)

A CAM program integrated into Solidworks.

- What exactly is Mach 3 and what does it do?

Mach3 is a machine control program. You load g-code into it, and it controls your machine. It's $175

[Teknition]

[QUOTE=Donnelly;869627]As a college student, I'd like to keep things easy on the wallet, but I can anticipate and accommodate for $2500-4000 in the table and electronics and about $2500 for the torch.QUOTE]

Considering your budget, you may want to consider a prebuilt table like this.

PRECISION PLASMA LLC 2X3 DIY CNC PLASMA TABLE - eBay (item 150502144387 end time Jan-01-11 18:08:25 PST)

With a complete control package like this.

http://www.candcnc.com/BladeRunner_Dragon-Cut.html

The Dragoncut 300-4 is plenty to drive that table.

Then all thats left is buying and learning the software. Tom has software packages available for a reasonable cost

http://www.candcnc.com/PlasmaSoftwareBundles.html

And if you wanted to do more artistic designs, just add coreldraw version 12 or up from fleabay for as little as 25.00

Brad

[Torchhead]

Right now, I'm leaning towards making it purely a plasma table for the sake of simplicity. It seems like adding secondary functions to the table (eg. routing) greatly increases the requirements for rigidity, drive power, etc. Keeping it simple with plasma is nice, because there are no cutting foces from bits or torque on the gantry from mounting heavy spindles.

Still, I will keep these additional functions in mind as this build progresses, and hopefully I'll find some way to incorporate them:

1. Boring - The ability to put small (1/8 to 1/2") holes in sheet steel and square tube with accurate relative spacing would be awesome. However, if I can't get this, I could always do pierces at the proper positions to act as pilots and then ream them later on with a drill press. It simply wouldn't be ideal.

Recommend you consider a scriber/marker as several others have done to accurately mark centers for holes, part numbers, and even bend marks. A Boring head will force you have a lot more rigid and heavy gantry. You can't use a conventional router on steel drilling. There is a scriber build thread in the PrecisonPlasma sub-forum posted by UNIXADMIN.

2. Vinyl/Stencil Cutting - For cutting vinyl stickers and spraypaint stencils for marking the equipment I produce. This doesn't seem like it'd be too hard, I simply have no idea how this sort of cutter is supposed to work.

Vinyl cutting needs: A way to hold the thin material flat (vacuum surface) and you need "tangential" cutting and things like blade offset. A drag knife (swivel) could be used but it needs to "float" or you just cut through the 2 to 3 mil vinyl and then through the backing (not good!). As cheap as vinyl cutters have gotten (like the ones from USCutter) it does not make sense to try and use a CNC table to cut vinyl. The models that have the registration mark sensors built in are nice. It would allow you to get vinyl multi-color printed and make professional decals then contour cut them on your machine.

3. Wood Routing/Aluminum Milling - If I could get both plasma cutting and light-duty milling in one package, I'd be in heaven. Wood routing would be for producing furniture (for myself). Aluminum milling would let me take on small jobs from my physics professors. I know most of them pretty well and they often mention needing some odd part for their lab work (not necessarily with ultra-tight tolerances), which they can't get from the campus machine shop because the shop is always overbooked and overpriced. However, this would probably be the hardest feature to add, and it's getting furthest away from my original goal of producing fitness equipment, so I'll probably drop this.

Milling aluminum is different than doing wood routing, is different than doing plasma and is different than doing vinyl cutting. You are correct in your observation that they are all basically the same thing (XYZ motion) and can all be originated from the same or similar software BUT it's the final process that makes all the difference. It's like wanting to build a High Speed Sport Dump Truck that floats. You can do it (the ARMY has all kinds of neat multipurpose vehicles!) but each one will be a compromise so you end up with a machine that is either very expensive or does none of the jobs very well.

Just like in physical training there are different machines that are better than the one-machine-does-it-all like the Bowflex approach.

It's easy to let your excitement in CNC get you in deep water faster than you want.

TOM caudle
www.CandCNC.com

[Donnelly]

Lee, thank you for the link to the 80-20 CAD generator. I wish I knew about that when I was building some shelving for my physics lab internship... Heh.


Ger21, thanks. I was really wondering if Mach3 would generate G-code from toolpaths or if it'd simply run the code on the motors. Since it's the latter, I'll look into CAMWorks for actually taking the DXF files, making toolpaths, and popping out the code. Hopefully I can find it or a substitute in one of the computer labs.


Teknition, I had seen the Precision Plasma table before, but it really doesn't look like a deal to me. Since you still have to get your own electronics, that means you pay $3000 + S&H just for the table frame and linear rails and drives. While it has the bonus of being easy to assemble in a squared, aligned way, I'll be damned if I couldn't build a 2x3' table of my own for far less than that, or a 5x10' table for probably about the same. I don't want to spend $20k on this thing, but I'm willing to put a good couple of grand into it.


Tom, I would love a high speed float sport monster dump truck! If it could fly like a helicopter, that'd be a plus too. Hahah. Yeah, that's what I thought. I'll keep it to plasma then.

My idea for the boring was to build a mount for a powerful hand drill that straps to the Z-axis, which I've seen done, but yeah, I'm not sure how much more beef that necessitates in the gantry. I wasn't planning on using a router spindle for it. Regardless, that's far less important than the plasma cutting.

I'll look into the scriber. If it provides enough of a dimple to prevent a bit from walking as it bites into the metal, that would be good enough for me. Thanks for naming the subforum too - there are so many sections here that I'm not sure I could ever read all the information that's available (but I'll sure try!).

[Teknition]

Teknition, I had seen the Precision Plasma table before, but it really doesn't look like a deal to me. Since you still have to get your own electronics, that means you pay $3000 + S&H just for the table frame and linear rails and drives. While it has the bonus of being easy to assemble in a squared, aligned way, I'll be damned if I couldn't build a 2x3' table of my own for far less than that, or a 5x10' table for probably about the same. I don't want to spend $20k on this thing, but I'm willing to put a good couple of grand into it.

Value all depends on your objectives and skill set. If your objectives to learn how to build a table and figure out how table electronics work then building from scratch may be your best option. However, if being able to cut out steel parts you design and build weigh lifting equipment and other things is your goal, a premade table and electronics kit may be the way to go.

If you look at the overall picture, you could be up and running, producing parts in a few weeks by going with the PrecisionPlasma table and one of Cncnc.com's kits. You would have a table that you know is square and aligned as well as an electronics kit that you know will work and both products come backed with support if you have problems. Thats where the value in the kits comes from.

On the other hand, yes it MAY be done cheaper by building from scratch or it may not. If you design your own table and build your own electronics kit from parts and pieces off fleabay, there can be alot of trial and error that comes at a cost of time and money. Just learning to weld while minimizing distortion can be a major learning curve that can take months, if not years to learn. If you slap together a table that ends up being out of square, your parts will be out of square and you have to start over. If you gather up all your electronics parts off fleabay and they dont work properly, you have no support to get them running, if in fact they will even work together.

If you take the time to go thru the build threads here, you will see some great tables. You will also see some not so great tables as well as some of the costly mistakes and stumbling that comes along with designing and building your own. Alot of these tables also took many months, and some took years to build. One expensive lesson I recall seeing on here was a guy that wanted to save some money and build his own floating Z axis. After spending more than it would have cost him just to buy one already made, not to mention his time spent, he still had a Z axis that wouldnt work.

Personally, I'm going the kit route for a few reasons. While I do have the skills to build the mechanical part of the table, I lack the electronics knowledge to build the electronics end of it. I really have no desire or time to learn how to build and troubleshoot plasma tables from scratch. I would rather be cutting out parts and making money from them.

Whichever route you decide to go, good luck, and dont forget start a post in the build thread :cheers:

Brad

[MonoNeuron]

Just a simple test of what you would be up against with a boring head and milling on a gantry machine.
Get a 4" square tube about 6 feet long and fix both ends then clamp a piece of wood about 3 feet long on the end and across the tube at 90 deg in the middle and apply light hand pressure to it and see how much it flexes. You will be surprised at how much.
Apply the pressure of a drilling machine (and the weight of it as well) and you will soon come to the conclusion that unless you put 2 Hp motors on the thing and have a cast steel webbed girder for the gantry then you will get a huge amount of flexing and vibration. Things a machine has a lot of trouble with and engineers spend a lot of time designing them out. Just look at the mass of a good milling machine and you will see what I mean.
Good luck on the build and your business venture.
Rich.

[Torchhead]

Teknition, I had seen the Precision Plasma table before, but it really doesn't look like a deal to me. Since you still have to get your own electronics, that means you pay $3000 + S&H just for the table frame and linear rails and drives. While it has the bonus of being easy to assemble in a squared, aligned way, I'll be damned if I couldn't build a 2x3' table of my own for far less than that, or a 5x10' table for probably about the same. I don't want to spend $20k on this thing, but I'm willing to put a good couple of grand into it.

Because you put no value on your time a valid cost comparison is erroneous. No doubt I could build a lot of the stuff I buy cheaper if my labor was free. There is a tendency to grossly underestimate the time and level of craftsmanship needed to build a CNC table. Even the time chasing parts and then finding you made mistakes would have value if it is not glossed over as being free. The other points of value are the R&D and engineering time put into the Precision products. It's taken Ron not months but years of work to refine and offer a quality precision gantry system.

Perhaps for you, the piece by piece design and build process makes sense because you don't have a lot of "overhead" (mortgage payments, insurance, family costs, etc) and you put no value on your time. For more mature guys it's a balance between understanding that the faster the table is functional, the quicker it starts to pay versus saving money by doing the labor themselves.

I don't know where your numbers came from but my math says that 3000 + 1428 + 299(software) don't add up to 20K. Heck for 9995.00 you can buy a completely assembled, tested, 4 x4 plasma table with water tray and a Plasma machine too.

Being in the business of providing electronics for CNC builders I have been amazed at the number of builders that still have a kit in the box more than a year after they started out. Priorities get rerouted (job, family, health) and things happen. How well I understand. So if you have lost $10,000 in profits to save $5000 in cost is it a deal? Even a hobby deal at some point needs to actually move and cut something (unless you are building a boat in your basement you will never sail).

"There is no substitute for experience"

TOM caudle
www.CandCNC.com

[rchacich]

Donnelly,

I commend you on your entrepreneurial spirit. Also, congratulations on the success of your business. I have started a few businesses over the years, and I still have one, Precision Plasma LLC. The best piece of advice that I can give you is to get product liability insurance. Since you are producing products which could harm people if they fail, you are at risk of being sued. It would be a shame to work so hard to build a business and to then have it taken away.

I also understand your comment that you can build a plasma table for less that what is sold by precision plasma...you can. If you want to build your own table as a learning experience, I would recommend designing and building one just for the feeling of accomplishment. If your goal is to make money, I would balance the time that it will take to design and build one versus the amount of money you could make producing your own products on the table in that same amount of time. If you really sit down and add up your cost and time, you may be surprised at what the most cost effective solution is.

I also want to clarify the pricing and features of the 2x3 table. We will be running a special on cnczone for the table kit which includes a wiring arm but no slats for $2500. This does include the 16 ga stainless water pan with integrated slat holders. If you wanted to purchase just the water pan from a vendor in your area in a quantity of 1, it would cost you $350-$500 depending on the vendor. Slats are 1/8" x 3" HRS, so shipping the slats cost as much as the slats themselves, so we don't sell them in the kit. This table is powdercoated and the frame is flat and square. The trick to welding, as you will learn, is to estimate how much the frame will move once the weld cools and to compensate for it. Also, you must be careful about how you design your frame to eliminate welding, which could bow your critical tubes.

This table was also designed with a c-shaped frame. This allows a full 4x8 sheet to be inserted and then supported with stands along the table. The upper portion can also be removed with 4 bolts and used as a portable table to be set on heavy material rather than trying to get heavy material up onto the table.

In order to save money, I suggest just using a handheld plasma torch. The cut quality is the same and it also allows you to do freehand if necessary. A handheld plasma torch can be installed or removed from our tables in less that 1 minute. We use a 1" clamp collar to hold the Hypertherm torch and a 3/4" collar to hold the torch cable. The rest of the cable then is supported on the top of the wiring arm with 2 broom clips.

You can't go wrong with the candcnc.com electronics package, but you will also want to purchase the Mach3/Sheetcam software package from them for $299. Draftsight.com is a free cad program that you can still use once you graduate, and the Hypertherm 45 is my plasma cutter of choice.

I hope this blog is helpful to you and good luck on your venture.

Best Regards,
Ron Chacich
Precision Plasma LLC

P.S. There actually isn't much margin made on the 2x3 tables and we build them 10 at a time.

[leeleatherwood]

Donnelly,

I commend you on your entrepreneurial spirit. Also, congratulations on the success of your business. I have started a few businesses over the years, and I still have one, Precision Plasma LLC. The best piece of advice that I can give you is to get product liability insurance. Since you are producing products which could harm people if they fail, you are at risk of being sued. It would be a shame to work so hard to build a business and to then have it taken away.

I also understand your comment that you can build a plasma table for less that what is sold by precision plasma...you can. If you want to build your own table as a learning experience, I would recommend designing and building one just for the feeling of accomplishment. If your goal is to make money, I would balance the time that it will take to design and build one versus the amount of money you could make producing your own products on the table in that same amount of time. If you really sit down and add up your cost and time, you may be surprised at what the most cost effective solution is.

I also want to clarify the pricing and features of the 2x3 table. We will be running a special on cnczone for the table kit which includes a wiring arm but no slats for $2500. This does include the 16 ga stainless water pan with integrated slat holders. If you wanted to purchase just the water pan from a vendor in your area in a quantity of 1, it would cost you $350-$500 depending on the vendor. Slats are 1/8" x 3" HRS, so shipping the slats cost as much as the slats themselves, so we don't sell them in the kit. This table is powdercoated and the frame is flat and square. The trick to welding, as you will learn, is to estimate how much the frame will move once the weld cools and to compensate for it. Also, you must be careful about how you design your frame to eliminate welding, which could bow your critical tubes.

This table was also designed with a c-shaped frame. This allows a full 4x8 sheet to be inserted and then supported with stands along the table. The upper portion can also be removed with 4 bolts and used as a portable table to be set on heavy material rather than trying to get heavy material up onto the table.

In order to save money, I suggest just using a handheld plasma torch. The cut quality is the same and it also allows you to do freehand if necessary. A handheld plasma torch can be installed or removed from our tables in less that 1 minute. We use a 1" clamp collar to hold the Hypertherm torch and a 3/4" collar to hold the torch cable. The rest of the cable then is supported on the top of the wiring arm with 2 broom clips.

You can't go wrong with the candcnc.com electronics package, but you will also want to purchase the Mach3/Sheetcam software package from them for $299. Draftsight.com is a free cad program that you can still use once you graduate, and the Hypertherm 45 is my plasma cutter of choice.

I hope this blog is helpful to you and good luck on your venture.

Best Regards,
Ron Chacich
Precision Plasma LLC

P.S. There actually isn't much margin made on the 2x3 tables and we build them 10 at a time.

$2500 is an amazing deal compared to other solutions I have seen.

Unfortunately I am the type of person that will not buy something I can make myself. Sometimes this ends up costing me more money but the vast majority of the time it saves me money.

On the other hand, after tottalling the cost of my build (so far) and time (so far) I am quite sure your kit may be a better value.