Buying a used CNC

[Bill George]

I think Roctech is Chinese made, and Imported by RoctechUSA. If your going to run production, get the CAMaster and you can upgrade to a tool changer or add it to your order.

[Brad Shipton]

It sounds like you want ATC too. The panther is out with that budget. Are you fixated on a speed?

Did Routech offer a single phase option? The parts listed on the routech seem reasonable, and the mass of the machine is promising. Mass can solve many problems. I know nothing of the controller they listed on their site, but there is nothing wrong with Yaskawa servos. To really figure them out I think you will need to hire someone like Gary to assist you. Gary has imported machines to fix up and fixed import machines for others. If you watch the first two videos form his Acorn retrofit series you will see him show some problems he has found when he takes things apart. If I were buying a new machine now I would consider an import, but at this point I have figured out a lot of things the hard way. If I were to go back in time I would likely tell myself to stick with a machine with a good network to help. I did get a lot of very productive help from my machine supplier to get going.

We had a similar discussion just like yours not long ago about the blue elephant machines.

[bobby milam]

No plans on running a production. It is going to be mainly used as a hobby machine and hopefully will generate a small amount of money when I retire but not planning on working too hard in retirement.

Yes, Roctech is single phase. No on the ATC, it is out of my budget even in the Chinese models. The FTC from my understanding will stop when it needs a tool change and then will go to a touch plate on the side of the machine and measure then resume cutting. I am assuming that CAMaster doesn't include a touch plate in the base price. Basically, I am looking at the added mass, steel gantry over aluminum, servos and all that I need is a vacuum pump if I choose to go with vacuum in the future vs. the Camaster.

My last machine was a Shark and I was really unhappy with it. It worked ok but you had to work within heavy restrictions because of the material they use for the entire machine. I would make something that took 30 minutes to produce ont he machine and then spend an hour or more trying to clean it up sanding and scraping and could never really get it perfect. It was really more of a toy than a machine IMO. I know that the Stinger will do what I need but for me 20K is a lot of money to invest in a machine and I want to get the most bang for my buck.

As far as the speed, yes I guess I have a little fixation on it. That is why I keep looking at the heavier frame and the servos. I'm not against buying used and have been watching the Camaster forum daily looking for someone who is selling a machine but they sell fast and I realistically won't be ready to purchase for about a month.

[Brad Shipton]

I would resist the urge to focus on cut speed too much. I have a 4'x8' ShopSabre that uses steppers. My max cut speed is 400ipm, and I do not seem to go much over 300ipm except for when I clean up the spoilboard. The longest cabinet sheet of many parts is maybe 20 - 30min. If I could cut at 1000ipm maybe I would save 8-12min, but then I will need a monster vacuum for hold down instead of the little single phase one I have. While my machine is cutting I can be assembling the box I just cut or do something else. I do not leave it unattended, so I have to do things nearby.

The Shark is in a different caliber than the ShopSabre/Cammaster/ShopBot/Laguna. We have happy members of all those machines. We are all wired a bit differently, and work on different projects. This will be a challenging decision. I suggest you read Gary's write up on Camheads for the first time buyer.

Have you watched Mick Martin's videos? He has many great ones. Here is the FTC on the Cammaster: https://www.youtube.com/watch?v=_zWdYCdZYEE

The biggest thing you gain with the US investment is the support team. The support teams at these manufacturers are not huge, but are invaluable if you have a question that needs answering. Beyond that, I think you can find imported models of equivalent quality in the entry level category. The Chinese business model is to sell units and move on. If you search on Alibaba and see the numbers some plants can crank out, you will see why that is. If you are prepared to figure it all out yourself and be patient while you search for information wherever you can, the import concept might be fine. Maybe Rotech has a good team, I really do not know. It is hard to find info on the import models online. Any thread that starts discussing the pros and cons of imports tend to go sideways. You can find lots of Laguna users, and those are imported as well. Robert B. is a member here and likes the two smartshops he has. I don't know him very well, but he seems a straight shooter and is cranking out a lot of product from what he has described.

The importance of the $20k investment limit will depend a lot on how well you can sell yourself. If you are good at it like Jim or Keith, I don't think you will need to work very hard to pickup whatever you need to help pay down whatever you think you need to to justify this purchase. I still have a day job that pays more of my bills, so I have to be careful not to overextend myself.

By the way, here is an old auction for a Smartshop from a few months ago: http://machinerymax.com/Event/LotDet...NTER-YEAR-2012 Robert found one on Ebay as well. Even if it is 3ph, someone can convert that over to single phase relatively easily so long as you find one with a 5 - 10hp spindle. My 10hp spindle runs off single phase using a VFD.

[Gary Campbell]

Bobby...
Brad makes some good points. I would be the last to say that there are not some real cost savings realized when buying Chinee machines. That said, I can look at the components and tell what grade they are. There seems to be 3. A super cheapo DIY grade, a midgrade clone of a higher end product and in rare cases actual branded high end components.

Electronics are another story. In most cases the provided components, although they are claimed to work well at international voltages and 50 htz, most do not "play well" when run on US 240vac, 60htz. Make sure your budget allows you to replace "everything with a wire connected to it" (my rule).

Then we get to control. Hacked versions of Mach3 and non English metric pendants. Don't get me wrong, they will work. But, the comparison is similar to a current version of M$ Word on a good computer and a early 80's typewriter. Yes, to all the kiddies that want to save dollars, they do work. But is it worth it? I make a good living traveling the country replacing obsolete or sub standard CNC controllers. Choice is yours

[Jim Becker]

Bobby, when I was "shopping", I originally was considering one of the smaller, more mass market machines. Then I started commiserating with folks like Gary and Keith and some others here. I surely ended up with something quite different and invested just a couple grand less than your stated budget for my 4x4 machine with all the goodies. I think that Brad and Gary hit the nail on the head with their comments. While a "stouter" structure might seem appealing at first, it's the finesse parts of the machine that truly make or break things and since most of us are not electronics or even mechanical experts, support counts for a whole lot. I've already benefitted from that multiple times. Quality, control and support matter, especially when this kind of money is involved, IMHO.

Spindle, counterbalance and FTC are a really good combination and I'm enjoying them on my own machine. I also opted for the heavier motors on my Stinger II. I somewhat wish I would have ordered the gantry lift to provide a little more comfort when doing things like material handling and changing cutters (it doesn't change the z-limits, however) but I'm convinced I ordered the best combination for what I perceived my needs to be and I can always delve deeper into the vacuum world at any time if that becomes useful...vacuum fixtures are fine for what I do currently. While the Panther is heavier and offers the servos...those things probably benefit a production shop more than for many others, although for extreme precision work (likely in metal), I guess there can also be a benefit, at least relative to the motors. For wood, foam and other non-metal materials...I'm not convinced there will be much of a perceivable difference. So relative to Camaster, if you decide to go that route, the Stinger III with the added features could be a really nice machine with great support for what you seem to want to do.

[Brad Shipton]

In the event you need to replace parts inside that box standing beside the Rotech machine, I found an example from a retrofit guy I have spoke with many times that shows what is inside. If you bank on replacing all the parts with wires you might break even if you could do all the wiring yourself, but you could easily go far over too if you start researching things without a solid knowledge of what will or will not solve a problem. If you are serious about the Rotech, I would find one and look at in person. Take pictures and hire someone knowledgeable. The other option is to roll the dice.

Example-Control Box.JPG

[Bill George]

Its kind of like the Chinese lasers, they are all using same power supplies, motors and controllers anyone can purchase off the shelf. I do not think there are stepper motors or servos Made in USA anymore. The driver boards, there are decent ones and crappy ones and there are a couple USA Mfg. As an industrial electrician who worked in the trade for over 35 years and for some major companies, I can tell you the Chinese AC motors are not that great, we used all US sourced controls and motors. When a motor says 208/230 3 phase the 50/60 Hz only means it will run slightly slower on 50 cycles than the 60. Since the most of the parts in that panel are DC, its important you have a good DC power supply.

My question of the poster, do you have room for a machine of that size and weight? Yes Gary knows the good, the bad and the ugly.

[Jim Becker]

I do not think there are stepper motors or servos Made in USA anymore.

Here's what's on my Stinger II...900+oz NEMA 34 High-Torque Steppers from AMT. While I suspect these are actually contract manufactured, which is normal for the electronics industry at this point, the specialty supplier to the CNC manufacturer is at least a USA business and offers these under their own name. Aside from the Italian made HSD spindle (also tends to be the industry standard for machines of this size) and these steppers which likely are contract manufactured as noted, I'm happy to know the extreme level of USA made content in my machine. I believe that ShopSabre is similar in that respect.

IMG_1485.jpg

[bobby milam]

My question of the poster, do you have room for a machine of that size and weight? Yes Gary knows the good, the bad and the ugly.

Yes it is going into a 3 1/2 car garage so plenty of room.

[bobby milam]

Well, the Roctech sold and now with the increased tariffs, the new price bumps it up out of what I am willing to spend so that is off the table now. Right now, it is between a Stinger 3 and also looking into a techno but don't know much about that one yet.