DIY Machine with 30k Budget

(pre read disclaimer - if any of you know of any great machine building forums, please direct me there. you guys always have the best suggestions so i wanted to post here first)

So was talking with the boss. I really want to buy a stand alone graphite milling machine. were doing all the graphite milling now in our 2 3 axis mills, and they arent set up for it at all. I saw a machine in a magazine article a few months ago that would of been perfect. They were only about 2'x 2' footprint with about a 8x8x8 work envelope (just based on visual) anyways, I cant find those machines anywhere. I cant even find the article again. SO i started looking at some machines from hurco, and other comapanies that are dedicated to doing graphite, and they tag in about 60-140k.

I told the boss i thought we could build our own, and I told him that i felt confident that we could build a pretty nice one for 30-40k. so right now I have the following ball park prices

granite epoxy base - $4500, i already checked this price, i just need to supply the mold
60k rpm nsk spindle with positive air, tool changer and drives - $6500
5th axis setup (4th axis with rotary) - $7000 - 10,000 (dependent on drives)

so roughly, that would leave me about 10-15k to build the "rest" of the machine. with this i would purchase linear ways, (graphite is light duty) ball screws, XYZ servos, Drives, sheet metal for enclosure and panel, and all the buttons switches and possible a screen I need for the control, and a vacuum system. I didn't throw Mach4 into this quote.

when I start to think about it, I dont know if 10-15k can cover all that. I dont want to jump in and then find out its gonna cost 60. I should of just bought one at that point.

So Im open to all suggestions, experiences, and ideas to cut the cost down. I really would like to build one. (I'd like to use toshiba drives as well but that's a business thing I cant get into.) Id hope in the future that I could build 2 or 3 more. were getting busier and busier and 5 axis graphite work is becoming almost mandatory for us. so what your intial thoughts on this? Im open to all criticism.

Hah! As soon as you've mentioned granite-epoxy bases, I'm betting you'll be pointed at that "other forum" where they've got the never-ending discussion on such things.

More seriously, DIY machine building will always be more effort than you think, as there's a lot more than just getting a base and throwing linear ways on it. Proper preparation for the ways is critical, you must have level/parallel beds for them, with hardpoint fastening inserts as required. Doing this means lots of hours and measuring/fitting, so remember your time is a cost burden that must be factored into the estimate. What could you be doing that's productive while this work is going on? Another loss...

Making sure your vacuum system works is fun - did you get the right filters so you're not sending 10 micron dust around the shop? Are the linear ways and rotary table protected, or are there all sorts of areas for the dust to get in, so it can "lap" away at those nice, accurate steel parts? Is your tool changer going to work reliably? Don't want to be tossing endmills and holders at 30K. Safety interlocks? No way for Curious George to open the system while it's running? Insurance Co approved? It goes on...

Having said that - I want to build my own machinery too, the idea is quite seductive until you look at it closely.

Sounds to me like your budget is a little thin. Whenever I've set out to build a piece of equipment when all is said and done (cost plus labor) it's ended up costing the same as buying off the showroom floor. It's when you have more time than money that building from scratch pays off.

In my opinion.

Jordy

If you have skill to build, then better get a beat-up used machine and do an overhaul.
There are about million details, which are usually present in "series production" machine but which you must find out (the hard way) in DIY machine.

Buy a good used Brother for around 15k. It will have a grease pack spindle and grease ways not way lube. Spend 10k getting it mechanically tight. Buy a decent shop vac. Go on vacation with whatever is left.

I also would buy another machine. Hell you could buy 2 for that price and be making parts by the time the GE sets.

I see a fair number of Makino high speed graphite machines for sale fairly often on the internet, like machine tools.com. I'd be looking at those, as they seem to go for between $15-25k. Not the newest, but dedicated machines.

In fact... https://www.machinetools.com/en/for...hdGFQcm9wXzEwPWNvdW50cnkmc1NlYXJjaF8xMD0yMzA=

Uh Oh...So, maybe now your in a pickle. Told the boss you could build one cheaper and more reliable than a new machine that cost 100k. If I was the one who said that to the boss then decided "Errr... maybe I was wrong (i.e. foot in mouth)" how am I going to gracefully get out of this?

I like going to him and saying, "Boss, as I was researching this DIY thing, I found a used machine that was already made to do the graphite and within our budgeted price! Isn't that great! We don't need to build a machine (not that I couldn't do it). We just buy one of these, go thru a little refurbish, BTW, it's a Fanuc control, and we are in business. How about that!"

Unless you are buying a high end graphite specific machine, you probably are better suited not buying a standard machine with a half backed " Graphite Package". I have sold them before and they are a pain in the ass. Grease packed spindles and greased ways if you can find them and take your best shot at maintaining the machine. Vacuum daily, pull covers monthly and grease, grease and more grease. Then clean up the excess grease.

The time that it would take to develop a machine from scratch could be used to setup a used Brother and clean/rebuild it many times over.

you have only listed parts cost.... is someone paying you to put it togeter?

Unless you are running emc/linux and ebay motors/ drives/ rails/ screws you need to have about 40k for a good control/ motors/ drives and another 5-10k for rails/ trucks/ screws. Don't forget ballscrew motor couplings, not cheap. By the time you buy all the electronics a $50k-60K new vmc is often cheaper than you can buy the components unassembled, and without warranty.

Lol no i am not in a pickle. The owner isnt a dummy. He knows a in house built machine for 30k isnt going to perform like a 100k one. Besides it was just general chit chat about cnc machines

So going over it and looking at some prices today, the only way to do it for around 40 would be to get alot of used stuff. (Drives, servos, panel, etc)

So i guess at the end of the day, the jump from hobby diy to semi pro/pro machine diy is still to great. You can buy a lot of good parts, but it will cost. Anyways, with that in mind, Ill just keep shopping for a new one. I dont buy used mills unless they have a pretty well recorded history and they are hard to find.

Motorsports-X said:

Lol no i am not in a pickle. The owner isnt a dummy. He knows a in house built machine for 30k isnt going to perform like a 100k one. Besides it was just general chit chat about cnc machines

So going over it and looking at some prices today, the only way to do it for around 40 would be to get alot of used stuff. (Drives, servos, panel, etc)

So i guess at the end of the day, the jump from hobby diy to semi pro/pro machine diy is still to great. You can buy a lot of good parts, but it will cost. Anyways, with that in mind, Ill just keep shopping for a new one. I dont buy used mills unless they have a pretty well recorded history and they are hard to find.

Click to expand...

A while back I fully designed in CAD my small shop footprint dream VMC, designed everything and was super excited. Cataloged all the parts I wanted, one shot lubes, coolant, internal air pumps, everything, with 4th axis and trundle bed cause I wanted to machine my own Mono engines for dirtbikes. When I costed it and the parts it was only about 5 or 10k cheaper then simply buying a Harding or Hurco (except in Australia cause everything pays a sunshine out our arse tax.) IE: Ad 50%, double it, and add piss money. Which is the only reason I'd ever embark on this. But, I doubt the machine I built, would ever be as good as theirs, off the shelf, hassle free.

So, its my retirement plan now. Building it. Cause I have neither time nor money (Studying a Masters degree, which also makes me poor) I am buying a second hand VMC for that reason. Run it for a few yrs, Repaint and refurbish, sell it. Buy another.

That Brother Graphite Machine

2outof3 said:

Unless you are buying a high end graphite specific machine, you probably are better suited not buying a standard machine with a half backed " Graphite Package". I have sold them before and they are a pain in the ass. Grease packed spindles and greased ways if you can find them and take your best shot at maintaining the machine. Vacuum daily, pull covers monthly and grease, grease and more grease. Then clean up the excess grease.

Click to expand...

Hi I have a Brother T-22. It is a great machine that is supper fast.

Rapids 2200+ in/min, .7sec. tool change, 12K spindle and a 26 tool tool
changer.

I will sell it as I'm ready to give up machining (getting to old).

I would run EDM fluid as a coolant, Make a coolant curtain with the
pop bead coolant tubes, run the dirty coolant through a centrifuge
(look up Calrifudge) to get rid of the graphite dust, and your in
business for a LOT less than $40K.

If you are interested give a shout: [email protected]

Interesting offer, but need a 40-60k spindle. How much do u want for it, just out of curiosity

Motorsports-X said:

Interesting offer, but need a 40-60k spindle. How much do u want for it, just out of curiosity

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You can buy an air motor for under $5k.

Hi Motorsports-X:
Apologies in advance for being a Dickhead, but you could always buy a Haas!!!
(For those who have no idea what I'm blathering about; follow this link):
http://www.practicalmachinist.com/vb/cnc-machining/absolutely-through-haas-306953/

Seriously though, the big problem as I see it, is that by your own admission, your homebuilt is likely to be inferior to what you could buy.
I will guess that you mean inferior accuracy, inferior speed, inferior versatility, inferior lifespan etc etc.

Thing is, if you can't rely on your electrodes to be accurate, you've got a major pain that will bite you on the ass with every job.
It's like starting with a block that's not parallel and square; every subsequent operation is more difficult.
You can't measure anything easily, you can't rely on anything, you are fucking around forever on things that should be simple and would be simple if only you could trust your foundation.

Of course not all electrodes for sinker EDM work are like that, but many are.
Of all the things to compromise on, trodes are one of the most consequential, because they're relied on for down stream setups and operations.
They're also expensive as hell to make and expensive as hell to use.

I'd get the best damn trode machine I could put my mitts on, unless I'm totally misunderstanding what you intend to do with them.
If you're considering specific machines, here's what I've heard from some of the local guys I know:
One of the local toolrooms around here runs a Fanuc Robodrill tricked out for graphite, and they're lovin' it.
Another runs an Okada, and they apparently had a lot of pain before they got it to work properly.
A third had an old beater Makino and nobody talked good or bad about it.

Cheers

Marcus
www.implant-mechanix.com
Vancouver Wire EDM -- Wire EDM Machining
Clarus Microtech

I would say GO FOR IT...!!! If you have the time AND you think there is some value to having the experience of doing this and learning something new. I would say the value is in a learning experience that you can go on to do better with or branch out a bit or make a really specialized set of niche systems from your researches.

For more basic XY and then Z precision Parker Daedal and the like have been marketing and selling machine "elements" based on precision guideways, tables , rotary tables ball screws , drive mechanisms and all that for decades. So MEGA rigidity may not be such an issue with your application and these standard elements are designed to have straightness and flatness within 3 micron or less (depending on grade) and within arc seconds... Given that you are doing graphite it might be worth a go, but I think the main benefit is "Exploratory"... And if you are slightly lucky you may end up with a machine that exceeds your expectations.

What are you sourcing for 5 axis/ rotary?

I really love it when you see a practically ancient weird giant machine that has new control systems and glass scales and encoders and Heidenhain (and the like control).


Sounds like a potentially cool project that may pay off in ways that you could never imagine right now, ( assuming that time and funds spent on doing that would be an acceptable risk even if for some unlikely reason that it was a total fail).

In any case, (funds and practicality not withstanding) actually sounds like a really cool thing to do... :-) Under $30K... That is going to be the biggest challenge perhaps.

Eric

[As someone that works in R&D it takes 95% of the effort to finish the last 5%... Watch out for that one :-)].

cameraman said:

I would say GO FOR IT...!!! If you have the time AND you think there is some value to having the experience of doing this and learning something new. I would say the value is in a learning experience that you can go on to do better with or branch out a bit or make a really specialized set of niche systems from your researches.

For more basic XY and then Z precision Parker Daedal and the like have been marketing and selling machine "elements" based on precision guideways, tables , rotary tables ball screws , drive mechanisms and all that for decades. So MEGA rigidity may not be such an issue with your application and these standard elements are designed to have straightness and flatness within 3 micron or less (depending on grade) and within arc seconds... Given that you are doing graphite it might be worth a go, but I think the main benefit is "Exploratory"... And if you are slightly lucky you may end up with a machine that exceeds your expectations.

What are you sourcing for 5 axis/ rotary?

I really love it when you see a practically ancient weird giant machine that has new control systems and glass scales and encoders and Heidenhain (and the like control).


Sounds like a potentially cool project that may pay off in ways that you could never imagine right now, ( assuming that time and funds spent on doing that would be an acceptable risk even if for some unlikely reason that it was a total fail).

In any case, (funds and practicality not withstanding) actually sounds like a really cool thing to do... :-) Under $30K... That is going to be the biggest challenge perhaps.

Eric

[As someone that works in R&D it takes 95% of the effort to finish the last 5%... Watch out for that one :-)].

Click to expand...

As someone who also worked in R & D for the defense industry, You never make a machine you can buy, even if it cost a little more upfront, because in the long run, you will save a bunch. The general rule of thumb in the industry has been... a very successful build on a custom machine will be the cost of the machine plus one to one and one half times that cost being spent in testing, rework, and complete integration. From a management standpoint they tend to add 30 to 50% to the original estimates rework allocation. This is on a machine done by professionals in the trade and it is not uncommon for the number to go higher.

In comparison, when buying an existing machine (new or otherwise)... it is the machine cost plus 25% to 50% for complete integration. The extra money is spent mostly on transport, site preparation, tooling, integration...plus,if it is used, refurbishment and repairs.