"Would be" CNC hobbyist seeks help !

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Stanza
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"Would be" CNC hobbyist seeks help !

Post by Stanza »

I'm just about to try and set myself up with a CNC machine - initially for hobby purposes, but developing ideas if I get the hang of it. I've read a lot of the vectric info, but with a very modest set-up budget ( £1000 max ) am unsure the spec of machine I'd need, the most appropriate software, and exactly what computer spec required - I believe a laptop isn't adequate ? I'd like to work up to 400mm x 300mm max size. Plenty of questions there - any answers ? Thanks. Stanza.

garylmast
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Re: "Would be" CNC hobbyist seeks help !

Post by garylmast »

Not much of a budget, but I've notice some low priced Chinese CNC machines starting from $800 (£575). Do a search on https://www.alibaba.com and type in mini cnc machines.

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Rcnewcomb
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Re: "Would be" CNC hobbyist seeks help !

Post by Rcnewcomb »

I believe a laptop isn't adequate
Any laptop that can run Windows 10 will be adequate.
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop

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Leo
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Re: "Would be" CNC hobbyist seeks help !

Post by Leo »

Rcnewcomb wrote:
I believe a laptop isn't adequate
Any laptop that can run Windows 10 will be adequate.
Or a desktop or Win 7 or win 8

It just does not need much for computer power
Imagine the Possibilities of a Creative mind, combined with the functionality of CNC

LittleGreyMan
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Re: "Would be" CNC hobbyist seeks help !

Post by LittleGreyMan »

You will probably need 2 computers.

You'd better have a specific computer to run the machine control software, especially if it is Mach3 which is generally used with these chinese machines.

In this case uou need a computer with a parallel port. AFAIK avoid laptops. An old and cheap second hand XP PC without any internet access, screen saver or other software is OK. Mach3 users will give you better advice.

Run the CAD-Cam software (the Vectric stuff) on another computer. As other said, you don't need a high end PC.
Best regards

Didier

W7 - Aspire 8.517

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wmgeorge
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Re: "Would be" CNC hobbyist seeks help !

Post by wmgeorge »

FYI I run Mach 3 on a old IBM Lenovo laptop that I have decommissioned just about everything from and it runs Windows XP, but the controller is an Ethernet connection. It also runs VCP 9.xx just fine for those last minute corrections. My main design computer is in the house. I will never have Windows 10 on any of my work computers.

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IslaWW
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Re: "Would be" CNC hobbyist seeks help !

Post by IslaWW »

Do you mean "work computer" as in design or as in CNC control?

Now don't get me wrong, I am not a big fan of Win10, but virtually all of the top end CNC controllers currently require Win10 and being current on upgrades. I fought it, but I finally succumbed and am impressed. I setup maybe a half dozen a month and have no reported user issues. (with Win10 that is :? )
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GEdward
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Re: "Would be" CNC hobbyist seeks help !

Post by GEdward »

I used a Dell Inspiron laptop with Windows 10, Core i5 processor and 8 Gb DDR4 ram to run Mach 3 for a time and had trouble with the usb data stream being interrupted to the point that the UC100 buffer could not compensate. The result was loss of positioning and a number of ruined projects. The laptop was dedicated to the router, it was not connected to the internet or WIFI and there were no other programs running in the background. I used a shielded cable with ferrite chokes at both ends and STILL had the issue. I ended up buying a refurbished Dell Optiplex desktop with Windows 7 OS, keyboard, mouse and monitor for $130 on Amazon and all my problems went away. I am using one of the USB 2 ports along with the UC100 usb/parallel interface buffer but the computer also has a parallel port available if I wanted to go that route. The point is is that with Mach 3 it does not take much of a computer; in fact I'd say less is more in this case. In my opinion the old Windows NT OS was one of the best, second to Fanuc, for dedicated use with CNC control back in the day.

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IslaWW
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Re: "Would be" CNC hobbyist seeks help !

Post by IslaWW »

With the release of Windows 7 in 2009 it became very obvious that CNC controllers as we knew them then would have to change. Windows security features and the quest for less energy hungry PC's and laptops were making CNC communication, especially USB very difficult. With each Windows update or version, it kept getting worse.

There seemed little hope whatsoever for parallel ports, they became nearly extinct. Those controllers offered hardware option for controlling CNCs using a USB port as a virtual serial port. (Comm or communication port) The problem is that a comm port is a way into the computer and all comm ports were looked at by computer security programs (and therefore Windows) as a security risk. Each update made keeping a CNC connected via a virtual comm port more difficult.

To make it even more difficult to keep our CNCs connected, the chipsets that control the internal actions of the PC were given instruction to turn off, or suspend USB devices when they were not "active". Active is defined as "having user input, via keyboard or mouse". Your CNC control software could be sending thousands of lines per second to the machine, but the computer assumed it was not active.

It became obvious that a new method of CNC control would be required. Some bolstered their existing PCI based controllers, most that used USB started offering ethernet options. As hardware and the updated control software became better over the next few years, ethernet and direct serial became much faster. Where USB was capable of ~30kbits/second comm rate, direct serial was creeping over 100kbits/second and ethernet was over 200kbits/second. The numbers are even more impressive than they seem. With USB 30kbits is the total for all axes. With direct serial the numbers are 100 kbits per axis (more now) and ethernet is 200 kbits per axis (up to 400kb/sec now.

As you can see a 3 axis machine on USB may only see a 75-85% comm efficiancy, yielding an average of 24kbits/second or no more than 8000 data bits per second per axis. Commanding a machine at a speed that exceeded those numbers resulted in a "data choke", which causes "lost comm". USB is also very susceptable to static discharge, where ethernet is not. The list goes on and on, and with every passing day and "improved" computers the chance of reliable connections to CNC controllers gets harder.

"Back in the day" we able to use just about any old cheapo computer and make it work for CNC control. Not so much anymore. Have you noticed the frequency of "got a new computer and now my CNC wont connect" postings along with "my old computer ran my old CNC just fine, but it wont connect to my new CNC on the same controller"? Its simple, new controllers are made for new computers, and they are not required to be compatible with the old ones.

Today most CNCs that wish for high resolution, i.e., over 6000 steps per inch (.00017 per step) are using the PC just as a GUI and have an ethernet connection to an onboard motion controller or complete ARM processor. You can tell the good ones because they recommend or require a current OS (Windows 10).

My advice to those that are still running on USB control: start looking for a new method of connection or a new controller completely. The days of viable CNC control via USB are numbered.
Gary Campbell
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GCnC411 (at) gmail.com

LittleGreyMan
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Re: "Would be" CNC hobbyist seeks help !

Post by LittleGreyMan »

Thanks for this detailed explanation Gary.
Best regards

Didier

W7 - Aspire 8.517

GEdward
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Re: "Would be" CNC hobbyist seeks help !

Post by GEdward »

Ditto for thanks for the explanation. Kind of what I got from other forums when I was searching for an explanation for my problem. You just did a better job.

Here is the rub. The actual requirements of an OS to control CNC motion has not changed much since the 90's. Now advances in OS are pushing consumers to buy motion controllers compatible with them. According to your advice you can tell a high end controller based on its requirement to use Windows 10. Given this paradigm there will be no end to the engineered obsolescence of any given controller over time. It is a great model for motion controller manufacturers but not so much for the average hobbyist on a budget.

I believe that there is a market for a very basic computer/OS combination that emulates the successful CNC systems that ran the machines of the 90's, and even today for that matter. Just a basic no nonsense inexpensive computer that does one thing and one thing only; act as a GUI to run a CNC machine. There is no need for connection to the internet, no need for security updates and no distractions from any other programs for processor priority. My $130 refurbished Dell is kind of what I arrived at for a solution for my particular application; and it works.....for now.

At some point, when I can afford it, I will upgrade to an ethernet controller. Until then I have a parallel cable and a parallel port on the computer as backup should the USB start giving me fits again. Mine is not a high production operation and more accurately could be described as a hobby operation that pays. As such I can live with the limitation of speed that USB imposes. My stepper drivers are set to 1/4 step resolution and I seldom push my rapids past 50 ipm so the data stream is handled well enough.

As an aside, my 3D printer controller is capable of running a CNC router just as well. The great thing about it is that it is not tethered at all; it uses a micro SD card and a dedicated 4 line LCD GUI to perform basic functions like jog, zero setting and the like.

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Rcnewcomb
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Re: "Would be" CNC hobbyist seeks help !

Post by Rcnewcomb »

GEdward,
Nice to see another person from South Dakota here. My grandparents had a farm outside of Andover.
- Randall Newcomb
10 fingers in, 10 fingers out, another good day in the shop

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