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  1. #1
    Join Date
    Jan 2011
    Posts
    141

    RF-45 or old used VMC?

    Preface, I converted a Grizzly Lathe/Mill combo to CNC and really enjoy using it, though the mill portion really leaves me wanting.

    I want a proper mill to do prototype and small production runs of parts. No more than a couple dozen of any one part.

    I started looking at the G0704 but I think I will run out of size capability and get frustrated. The RF-45 has a bit more travel and definitely more rigidity. I can convert one, enclosure, coolant etc... or could look at a cheaper older VMC.

    I know with the VMC I might get better quality of the original build, but will be dealing with an old machine that needs maintenance not to mention the conversion itself which could easily add a few thousand more.

    I'm thinking something like this, it has similar travel:

    Okada VM500 CNC Vertical Machining Center Mill Fanuc Rigid Gearbox Spindle VMC | eBay

    Boston Digital BD22 1 VMC | eBay

    Can anyone provide some strong opinions why I might have a better experience with one or the other? Is the quality of the average RF-45 decent enough to compare to a bigger machine? By custom converting it, maybe I get a package more suited to my uses? Or will I run into headaches when I try to mill larger parts or small production runs?

    Thanks,
    Carl

  2. #2
    Join Date
    Jun 2004
    Posts
    6618

    Re: RF-45 or old used VMC?

    Something to consider. The first machine is 30 years old. For cnc equipment, that is ancient. It says it runs great, but I suspect it is probably close to being worn out. Consider how much replacement parts might be if they are still available.
    The second machine is being sold as is. No telling what condition that one is in. Either would be a gamble. At best, you get a decent machine, but with zero warranty. Could be dead in the water at any moment and production ceases. At worst, they could be no more than artificial fishing reefs.
    I think you might be much better off either converting your own or buying new from Tormach or Novakon. There are other sellers as well, but those two seem to have the best offerings and support. Either of them would get you going much faster than a conversion would. That means you start making money or products faster.

    I would not consider an Ebay machine without inspecting first and seeing it make a part or two. After all, this is what you need one to do.
    Lee

  3. #3
    Join Date
    Aug 2008
    Posts
    962

    Re: RF-45 or old used VMC?

    +1 for the Novakon or Tormach ..

    I have a ZX45 conversion that I've put lots & lots of work into & can make one-off or small batches of parts with, but would never consider starting a business with it.

    To re-purpose an inexpensive Chinese machine & turn it into a reliable & accurate, limited production machine is too many headaches in my opinion. You're doomed to failure in business if you spend as much time working on your machine as you do making parts with it. Unless you're already a qualified machinist with accurate machine tools to use in building your conversion .. you will likely be FOREVER tweaking & tinkering with a conversion project to keep it running reliably.

    Even though the above mentioned machines are also import pieces .. at least they're designed & built to be a CNC macnine with factory support to provide parts to keep you producing for your customers.

    I enjoy my machine immensely, but it's a hobby for me & truthfully, the machine itself is as much of a hobby as the stuff I make with it. Not a good recipe for success in business!

    Gary

  4. #4
    Join Date
    Sep 2006
    Posts
    509

    Re: RF-45 or old used VMC?

    One other consideration is the power requirements for a VMC. Even the small ones need 3 phase and lots of amps (or high voltage). Can't usually get that kind of power in a housing subdivision if that is your plan. (the Boston Digital is probably workable at 240 VAC 3 phase 30 Amps, but I'm betting the Okada is much more power hungry) If you have the power available then its not a concern but then LeeWay's comment on used machines applies...

  5. #5
    Join Date
    Jan 2011
    Posts
    141

    Re: RF-45 or old used VMC?

    Thanks for the feedback guys. I think part of my problem is, I quite enjoyed converting my current machine, and would enjoy converting a new one as well, but like you said, its time spent not towards my ultimate goal of making money and paying bills.

    I've bought from this auction house before, but I doubt this mill will go for less than 25k: Lot 178 - Assets Of Aruze Engineering - LARGE FABRICATION & MACHINE SHOP / WELDERS / FORKLIFTS / CNC & More... - Stronghold Equipment - BidSpotter.com

    The idea is to have it at my home shop while I develop my prototypes, and once I get some orders, lease out a proper shop. I've wired my home shop with 100amp/240v.

  6. #6
    Join Date
    Jun 2004
    Posts
    6618

    Re: RF-45 or old used VMC?

    That is a nice machine there. I think the bid would go pretty high too.
    Lee

  7. #7
    Join Date
    Aug 2008
    Posts
    962

    Re: RF-45 or old used VMC?

    A quick search turned up dimensions of 88"L X 92"W X 104"H for the VF-E .. Obviously the head can be dropped down to the table .. but might still be tough getting it through a standard garage door?

  8. #8
    Join Date
    Nov 2009
    Posts
    4415

    Re: RF-45 or old used VMC?

    Bust the header out!
    A lazy man does it twice.

  9. #9
    Join Date
    Apr 2004
    Posts
    54

    Re: RF-45 or old used VMC?

    I have been researching the exact same situation RF45 CNC conversion vs used VMC. Years ago I swore I would never go down the RF45 CNC path again, my old one never worked as advertised and I ended up scrapping it after over $10k invested and much frustration.

    Today though Charter Oak offers a RF45 variant mill with some features that has me re-thinking that decision. 3hp VFD option coupled with a quieter belt drive = 5,300 rpm spindle, that's a plus my old RF45 2,000 rpm spindle was painfully slow. They have increased Y to 12" for a 12x26 inch work area. They replace the bearings and are good for 7,000 rpms. They tell me they have solved the issue of crap ways with loose and tight spots. They also have a newly designed CNC kit for them, direct drive (no belts) servo's with integrated encoders and drives. I very nearly plunked down the cash for one of these last week but they were all out attending a show in PA. That slowed me down and I started working my calculator...now I'm on the fence again.

    Mill $2,350
    CNC Kit $6800
    3hp VFD option $850
    Belt drive $785
    Shipping $540
    CNC computer $600
    Stand $700
    Enclosure $1,000
    Flood coolant $300

    So $14,000 and for another $6000 I could just buy a used Haas and get way more machine with a tool changer and chip auger. The problem as some mentioned is what if the used Haas needs a bunch of repairs right so I checked into this recently and the components cost less than I expected. More research is needed. VMC power requirements eliminate most of the Haas mills for me but the Haas mini mill 2 can run on single phase 40 amp that's doable. The 20x16 work area is a bit smaller than I would like but for a garage shop that's not bad. 6,000 rpm spindle. 600 in/min rapids, 500 in/min feeds. Rigid tapping. Programmable coolant nozzle. LM ways. For only $6k more than a RF45 conversion? The only reason I hesitate is the potential for an expensive repair on the used Haas.

  10. #10
    Join Date
    Jan 2011
    Posts
    141

    Re: RF-45 or old used VMC?

    Thanks for that. I feel like $6800 is a lot for a CNC Conversion of the charter oak machine. I know its servo based, but how much could I do a smooth stepper setup on my own? I have a CNC machine running now that I could use to create the parts for the bigger machine. So if I could do a charter oak machine for less than 10k it's even more enticing.

    I talked to the auction house selling the last Haas link I posted and he confirmed those machines go for 10-25k depending on condition. My shop has 100amp/220 so I could power it.

    Sent from my SAMSUNG-SM-G900A using Tapatalk

  11. #11
    Join Date
    Apr 2004
    Posts
    54

    Re: RF-45 or old used VMC?

    I thought about rolling my own CNC conversion vs the kit for the Charter Oak but as you point out you really need a mill to pull that off which I don't have. Forget steppers imo its too heavy. My old RF45 CNC mill had servo's on X and Y and a big stepper on Z. The big stepper on Z was a giant FAIL. Think cussing, rude gestures, scrapped parts. It would lose .020 to .040 position on every up movement, cumulative so that in short order the thing was off more than .100. Counter weighting it helped some but did not eliminate the problem.

    The Charter Oak advantages for me personally are size, weight, and mobility. I'm limited on space and even with a full enclosure the CO is a fraction of the size of a Haas. I could wedge in a Haas but would have to get rid of some other machines. Weight my Kubota front end loader can lift the CO mill without any problem, the 4,000 to 6,000 pound Haas would require a rigger. I could put the CO on wheels and roll it over in a corner out of my way when not in use, the Haas that's not happening.

    Make no mistake though, the CO is never going to compete with a Haas no matter how much you spend, the Haas will blow it out of the water in every category. Its not a fair comparison of course. So it really depends on your intended use. At the moment my thinking is save my money and go Haas, I can afford to wait and pay cash.

  12. #12
    Join Date
    Sep 2006
    Posts
    509

    Re: RF-45 or old used VMC?

    Too bad your at the far end of Canada from here - there are a couple of small cnc mills / VMC's for sale nearby - and in the right price range:

    CNC milling machine Fadal VMC-10 | business, industrial | Ottawa | Kijiji

    MIKINI CNC 1610L MILLING MACHINE | business, industrial | Oshawa / Durham Region | Kijiji

  13. #13
    Join Date
    Apr 2007
    Posts
    2580

    Re: RF-45 or old used VMC?

    Well having done both...building a nice RF45 conversion complete with servos and high speed belt drive and enclosure and now having purchased a used CNC Vertical machining center and doing a retrofit on it. I feel I can honestly say that while the used CNC VMC was a bit of a gamble there is simply no comparison no matter what you do to a chinese bedmill to even a worn out beat up VMC. They are far more precise, infinitely more rigid, fully enclosed and everything is included to make the machine do what it was meant to do and that is cut metal quickly and efficiently. My journey has not been that easy as I initially had desires to just repair the original control system on the Cincinatti arrow 500 I bought. However after a few VERY expensive repair and replacement parts I quickly realized that not only was that not going to work financially but it did not really make much sense for the machine either. My machine is a 1997 model so it is not exactly ancient unless you are used to buying and enjoying brand new CNC machining centers. The electronics on the machine were old, dated, slow, short on capacity, and costly to repair. I basically gutted the entire electronics cabinet and sold off all of the working control parts and used the money to buy all brand new servos and drives. Electronically speaking my entire machine is brand new short of the main spindle motor. It has taken me a good long time to do this because I am NOT an electronics expert and I had to do a good bit of research. However I will say that in comparison to my RF45 CNC conversion it was MUCH MUCH easier and faster. I am still working on it but it is getting there and I have been making beautiful accurate parts on this machine for a very long time now. I bought the machine for a VERY good price because it was not working and it has been a wonderful machine for me thus far. Having done a retrofit complete with ballscrews and mounts and motors on the RF45 there is simply NO WAY I would ever do another like that. It is a lot more work than people realize and while it is doable and the resultant machine is quite nice actually if you have ANY desires to make real parts accurately and quickly and sell them it is not really the best idea. What has surprised me the most really is just how simple and well built my machine actually is now. Working on it is really not that difficult and everything is made with quality and durability in mind. I could absolutely not say that about my RF45 experience.

    The other side of this is that while I was able to sell off my RF45 conversion for a good price, a nice cleaned up and retrofit CNC Vertical machining center is worth a lot more when you are finished than the conversion would be and is a lot more likely to be able to make you money if you have work for it than the conversion ever will. I don't regret my decision one tiny bit and I am very pleased with my Vertical Machining center. I will also add that if you do not buy one that is really high HP you can actually run it on single phase input power without a rotary phase converter. Mine is run entirely on single phase. Quality decent CAT40 tooling is actually cheaper than you might think and the first time you see a Commercial machine cutting steel or aluminum you realize pretty quickly that it is a machine built to make parts fast and accurate. I don't mean to come in here and poo poo the RF45, it is a wonderful little mill and I quite enjoyed owning it and even retrofitting it was kinda fun. However if you have intentions to make money with your machine seriously consider the Commercial machinery. Take the time to look around and find a nice clean one and you might be surprised what you can get your hands on for cheap often even less than you would pay for a manual chinese bedmill brand new. I basically STOLE mine.

    I will also add that I chose to use control boards from Mesanet.com. Pete at Mesa is an absolute genius about this stuff and has a wealth of information available to you to help you integrate the controls to the computer. I am using LinuxCNC to control my machine and so far it has been a DEAD reliable control and it is basically infinitely configurable. I would not recommend Mach for a Commercial machine it was less than reliable for me on the RF45. There are of course other control retrofit option available with varying degrees of cost and complexity. This path I chose for my build has been a good one. LinuxCNC is relatively simple to setup the basic machine with and since it is open source and continually worked on you can basically do what you need to with it and always have the ability to update and make changes easily and FREE. There are MANY MANY commercial machines running this control all over the world. I am NOT a programmer type and I have been able to get a lot of assistance from the guys on the IRC for LinuxCNC and they are on there basically 24/7 so you always have someone to try to help you. There are a few smart-asses in there but in general they have a vast and wide knowledge base and can and will try to get you the information you need.

    The Cincinatti I have here now makes me parts whenever I need it and it runs great. I now have TRUE RIGID TAPPING and I am getting acquainted with it. The machine is nearly completed and I am now actively looking for a small commercial CNC lathe to do the same thing with. I guess that speaks volumes about the whole experience. If it was that bad I would most likely NOT want to do it again. Someone who is more proficient than I am with electronics and computers could have probably done the retrofit in half the time or at least a lot faster than I have. At the end of the day a control retrofit on any Commercial CNC mill is just mostly electronics anyways since the motors often are already there as are the ballscrews and home and limit switches etc. etc. Lots of guys just keep the old motors and buy new drives and electronics etc. Then it is just a matter of hooking everything up and tuning the drives to the motors etc. etc. The other nice thing is since the machines are commercial in nature the control and voltages are often 24v and 110v setup so they are far more immune to noise and other problems than hobby type control electronics.

    Understand tho that this is NOT for everyone. The machines are HEAVY, LARGE, and much more powerful. If you are not a good machinist already this is NOT the machine to learn on LOL.. Crashing a machine like this is no joke and can be dangerous and expensive. If you know what you are doing it is however a pleasure to use them and the power and smoothness of these machines is a joy to have available to you. I have worked in several local Pro shops recently full time and I can honestly say that when I run my Cincinatti it is really no different than the brand new HAAS VMC's I ran at work and in some ways it is better. It is even possible to adapt fourth and fifth axes or commercial probing units like Renishaw to the linuxCNC control. I paid a HELLUVA lot less for my machine than even the barest bottom line HAAS and I can fix mine if it ever breaks with off the shelf commercial parts that are available from multiple online retailers. I am not tied to any one companies control system and I do not have to pay for expensive service contracts or even telephone service. The offset is that if it does break I have to fix it myself. Again after building this machine you would be quite surprised at how simple and easy that really is. The parts are just a LOT bigger LOL... Your mileage can and probably will vary. I know that I can honestly say that the only way an RF45 will ever be in my shop again is just as a manual second op mill which would actually be quite nice really. Good luck man. Consider all options out there as there are many.... Peace

    Pete

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