Physics undergrad decides to have some fun.

[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

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.

[Boogiemanz1]

I was told the same thing and set out to build a good 5X10 table using maybe the best parts available. I will have 8K in parts including a Max85 hypertherm by the time it is finished. I have yet to build any part of the machine. If I was on minimum wage, I could have bought a small frame for the time I have invested in finding parts and figuring what I needed for this table. I could have listened and bought a small table with Tom's electronics and a smaller plasma and been cutting parts months ago. It will probably the end of Feb before this thing moves. I think the education I'm getting is fairly expensive but being hard headed usually costs more........good luck........jb

[rchacich]

There are many benefits to building your own table, especially if you have more time than money. What irritates me is all of the shipping charges when you purchase from multiple sources, especially small ticket items with high shipping/handling charges. Try to minimize the number of sources, even if the cost is a bit higher and you should still make out better.

I hope you keep a tally on the costs of your build and the time involved. The information would help others in your situation.

After counting inventory on January 1st, I found that we have 10 sets of gantry kits in stock for a special machine that was never launched last year. The thought was to provide a greater value to customers and it targets people in a small shop or garage who lack space. I designed plans for a water table yesterday which would utilize the gantry kits. Here is the print:

http://www.precisionplasmallc.com/My...load/52X40.pdf

The cost is $2K and has a travel of 52" x 40". It allows a user to cut from full 4x8 sheets and can be built with a dry or water table. I estimate that people would have under $4K into it with the gantry kit, electronics, software, and material for the frame. I would have less than 16 hours into the build, but I would send the frame out for powder coating.

My brother would fabricate the frame in less than 8 hours. I would then send the frame off for powder coating. I would mount the rails (drill and tap at assembly) and square the gantry in less than 1 hour. That would leave 7 hours to mount the motors, load the software, and wire the Z home switch. Mounting the card in the plasma unit would take the most amount of time.

I just want to give readers an idea of how much it would cost and how much time it would take to build a Precision Plasma LLC DIY table from one of our gantry kits. I have built many tables and my brother welds every day, so take the times with a grain of salt. You will need to adjust the hours based on your skill level.

Ron Chacich

[Donnelly]

Sorry for not updating - I've been busy this past week. (Out of town for New Year's, and working on various aspects of the personal training business since then.)

The next time I go to the local steel supply center, I'm going to get some price quotes on various sizes of steel and start coming up with a table design.

Now, I can definitely see how these builds can take months, hahaha. But, no big deal. I'm not in a major rush, though "sooner" is better than "later."

Thank you for your input, everybody. I've read over your responses quickly now, but will give you more thorough replies the next time I post.

Have a happy new year, everyone.

[Donnelly]

Ok, winter break went by way too fast. Fortunately, with classes beginning this Monday, I'll have about 14hrs per week during lectures to begin working on the research side of things. (Who pays attention during class nowadays anyway?)

The biggest drain on my time this break was that someone put in a request for me to build some huge, modular pull-up bar/squat rack apparatus. It took over 30hrs to build (always longer than planned), but the kicker was that the guy cheesed out when it came to actually buying the damn thing. I kept the deposit, of course, but now I've got to waste more of my time finding a new buyer. This project included cutting over a dozen brackets by hand (large ones), and now I'm really starting to see the benefit of having a CNC plasma.


Anyway...

Finances: I'm bust right now. New Year's ended up being a huge let down for my personal training business, in spite of spending countless hours revamping the website, creating online content, redoing online advertising, and doing in-person marketing/networking. All that work will pay off eventually, but this is a poor area of Maryland things have only gotten worse since last January.

Of the leads I get, essentially all of them come in for a trial session. About 2/3 of them end up buying one pack of sessions, and another 2/3 of them keep renewing for months more. Those are very high rates in this business, so I know I've got the skill for this... I'm simply not getting the leads.


Machining: There's a machining course at UMCP that I've been waiting to take since late last summer. I was hoping to get into the Winter session, but no dice. At least I'm first on the waitlist for the Spring session. Once I take this course, I'll have access to some very nice mills, lathes, and other tools, which will probably come in handy.


Welding: I borrowed a friend's MIG welder earlier this break. It's a dinky little thing by Matco Tools, but damn, does it make welding easy. I still intend to buy my own Millermatic 211, but that's been put on hold until the finance situation changes.


Other projects: I've got two small ones to tackle before getting on the welding table, which I need for MIG welding practice. After that, the table is the next thing on my list. I'm not taking any more special requests for work after that last guy, unless it's from a friend or referral.


General: I got some price quotes on several sizes of tubing when I visited the steel supplier earlier this week. Now that I know what sizes I can work with, it's time to start learning about deflection and coming up with a design...


I'll start giving you guys the replies you deserve now. Once again, thank you for your input here, and I apologize for not being more active.