[Question] Help needed deciding which hobby level CNC machine to purchase.

[Colonel_Cheng]

Greetings Guys : )

I am new to this forum and CNC Milling, so please forgive me for my rather beginner question.

Having developed an interest in Maker culture and a taste for producing random items, I decided to look into buying an entry level CNC milling machine for hobby purposes.

My objectives for the machine are as follows:
Capable of milling plastics such as PVC and PEEK efficiently
Capable of milling moderately hard wood such as teak efficiently
Capable of milling soft metals such as Aluminium to at least some extent, even if not well.
Capable of being controlled by common software whose textbooks are widely available.
Since I am planning to use this for hobby purpose, high throughput or large working area is not a high priority.

Question 1
One of the more promising suppliers has offered me two options which I am strongly considering [1]. The price difference between the two are significant, USD 2300 and USD 4950, with the main differences as far as I can see being as follows:
1) The cheaper machine uses linear ball bearing on chrome smooth rod, whereas the more expensive machine uses linear guide rail
2) The structure of the cheaper machine uses Aluminium, whereas the more expensive machine uses steel construction.
Do these two factors affect CNC operation that significantly? Is the cheaper machine likely to be able to fulfill all of my objectives noted above? Which of the two devices would a more experienced CNC operator such as yourselves recommend?

Question 2
This machine comes with the option for an additional two axis over what seems like the most conventional 3 Axis setup for a CNC mill. I have decided to take this option since the increase in cost is very modest. Is it realistic for me to expect these two axis to actually work in practice? Am I correct in understanding that milling in 5 axis greatly increase the difficulty of CNC milling operations compared to 3 axis?

Question 3
Am I correct in understanding a 2.2kW spindle is generally better than a 1.5kW spindle with no significant downsides?

Question 4
If anyone feels that these machines would not suit my objectives, I would be grateful for their advice. Please understand though that my objective is purely hobby level of fabrication, so I am not exactly looking for an industrial grade Haas machine. If possible I would like to maintain a hard price cap of at most USD 8000

[1]
https://www.dropbox.com/transfer/AAA...muSDUtd-IE8SM0

[Zorbit]

An older commercial machine might be a good bet. I was recently given an old ( 1999 ) AXYZ 8' x 5' router, it's a nice solid machine, great basis for retro fitting with modern electronics.

[awerby]

Greetings Guys : )

I am new to this forum and CNC Milling, so please forgive me for my rather beginner question.

Having developed an interest in Maker culture and a taste for producing random items, I decided to look into buying an entry level CNC milling machine for hobby purposes.

My objectives for the machine are as follows:
Capable of milling plastics such as PVC and PEEK efficiently
Capable of milling moderately hard wood such as teak efficiently
Capable of milling soft metals such as Aluminium to at least some extent, even if not well.
Capable of being controlled by common software whose textbooks are widely available.

[There aren't really many textbooks about CNC control software. Each company that makes it provides their own documentation, but that can range from well-written PDF manuals to sketchy bits of badly translated info on websites.]

Since I am planning to use this for hobby purpose, high throughput or large working area is not a high priority.

Question 1
One of the more promising suppliers has offered me two options which I am strongly considering [1]. The price difference between the two are significant, USD 2300 and USD 4950,

[That sounds cheap for new American machines; are these ones supposed to ship from Jinan China? Be warned; there are lots of problems you'll encounter if you attempt to import a machine from there. Shipping and tariffs add a lot of cost and unpredictability, to say nothing of fake software, unreliable electronics and workmanship issues - and that's if the thing shows up at all. Check the "Chinese Machines" section of this site for various people's long sad stories. But some people seem happy with what they got. ]

with the main differences as far as I can see being as follows:
1) The cheaper machine uses linear ball bearing on chrome smooth rod, whereas the more expensive machine uses linear guide rail

[The linear rails will work a lot better if you're cutting aluminum.]

2) The structure of the cheaper machine uses Aluminium, whereas the more expensive machine uses steel construction.

[Steel is considerably stiffer, all things being equal.]

Do these two factors affect CNC operation that significantly? Is the cheaper machine likely to be able to fulfill all of my objectives noted above? Which of the two devices would a more experienced CNC operator such as yourselves recommend?

[Without being able to see the machines you mention, it's hard to say. Can you provide links to each of them? There are lots of factors to consider besides the ones you brought up.]

Question 2
This machine comes with the option for an additional two axis over what seems like the most conventional 3 Axis setup for a CNC mill. I have decided to take this option since the increase in cost is very modest. Is it realistic for me to expect these two axis to actually work in practice? Am I correct in understanding that milling in 5 axis greatly increase the difficulty of CNC milling operations compared to 3 axis?

[Yes, and the CAM software's a lot more expensive too.]

Question 3
Am I correct in understanding a 2.2kW spindle is generally better than a 1.5kW spindle with no significant downsides?

[If you've got the power for it, then yes.]

Question 4
If anyone feels that these machines would not suit my objectives, I would be grateful for their advice. Please understand though that my objective is purely hobby level of fabrication, so I am not exactly looking for an industrial grade Haas machine. If possible I would like to maintain a hard price cap of at most USD 8000



[1]
https://www.dropbox.com/transfer/AAA...muSDUtd-IE8SM0

[That should be enough for a smallish 3-axis router stiff enough to handle aluminum reasonably well, but software and tooling would be extra.]

[GME]

Folks here on the Zone have reported problems with the Chinese machines. Many, if not most, have to redo the electronics and have to deal with mechanical issues. Personally, I wouldn't go for either one.

Yes, 2.2 KW spindles are generally preferred over 1.5KW. With a 2.2 KW spindle, you get an ER20 collet size, which allows you to use mills with a larger shank, e.g., 1/2 inch. A 1.5KW spindle is sized for an ER11 collet, which, I believe, maxes out at 1/4 inch. I recall seeing an ER11 collet for 5/16 in, but your are likely to have a very difficult time finding an end mill with a 5/16 in shank. You also have to decide whether you want a water or air cooled spindle. Many like the air cooled, but they will burn up at lower speeds. I opted for water cooled, but you have to add a pump and water lines. Finally, virtually none of the Chinese spindles come with a ground wire connected inside the spindle. That means the 4 pin connector only has 3 pins actually connected to something. You will need to open it up and add an earth ground.

For a small bench top CNC router, $8,000 should be more than enough, including software and tooling. You could probably go larger with your budget, especially if you are willing to put a kit together. Take a look at this this website. They have machines that do what you want, and the customer service is second to none. Avid CNC | CNC Router Parts

I suggest you think ahead a bit. Many think a small machine is all they need; however, once they start cutting things, they quickly find that a benchtop is too small. I too am a hobbyist. I don't sell anything. I get by with a 4' x 4', but wish I had a 4' x 8' or 5' x 10'. I don't have the room for anything larger.

Gary

[routalot]

An older commercial machine might be a good bet. I was recently given an old ( 1999 ) AXYZ 8' x 5' router, it's a nice solid machine, great basis for retro fitting with modern electronics.

Unless it doesn't work,you will be cutting parts sooner if you run the standard software and the parts it came with.AXYZ are good machines even if the control software of that vintage is rather exasperating.The AMC package is a good upgrade if the machine is capable of running it.

[Zorbit]

Unless it doesn't work,you will be cutting parts sooner if you run the standard software and the parts it came with.AXYZ are good machines even if the control software of that vintage is rather exasperating.The AMC package is a good upgrade if the machine is capable of running it.

The standard software was the reason the machine was mothballed, the PC crashed, and general opinion was it wasn't worth repairing for as it was so awful, so I got it on condition that I removed it in pieces ( it had been in there so long that the building had changed enough to prevent it moving in one piece). Frame is very heavy, as is the Siemens vacuum pump.

I've ordered "

UC300ETH-5LPT + UCBB breakout board + 2xIDC26-IDC26 cables + free UCCNC " for it. I already have stepper drivers.

This should make a useful machine, for less than £500 all in. The only downside is that the Perske spindle has a weird collet, max 1/2" tool, and no tool changer. I might have to change that.

The complete original control electronics are available if anyone needs them, Camtech Z7 .

[routalot]

The standard software was the reason the machine was mothballed, the PC crashed, and general opinion was it wasn't worth repairing for as it was so awful, so I got it on condition that I removed it in pieces ( it had been in there so long that the building had changed enough to prevent it moving in one piece). Frame is very heavy, as is the Siemens vacuum pump.

I've ordered "

UC300ETH-5LPT + UCBB breakout board + 2xIDC26-IDC26 cables + free UCCNC " for it. I already have stepper drivers.

This should make a useful machine, for less than £500 all in. The only downside is that the Perske spindle has a weird collet, max 1/2" tool, and no tool changer. I might have to change that.

The complete original control electronics are available if anyone needs them, Camtech Z7 .

I think you may have a challenge adding a toolchanger unless the spindle is able to release and pick up using air pressure.The old Toolpath software was very,lets say "individual" ,but once you became used to it's (very) oddities it was solid and only really used to transfer files,which then stayed in the controller memory.If the machine came with a tool length sensor it will be a big advantage.It seems that you might be able to avoid the need to buy an RS485 interface which will be a very useful boost to the wallet and the old controller would only work with a vintage baud rate of 9600 if memory serves.

[Zorbit]

The spindle would have to be changed if I want a toolchanger. Perhaps I will, not sure, I already have a 5 axis Morbidelli with 12 tools, so I could just use the Camtech for simple stuff. I have a regular task cutting 1.5mm alu sheet, currently done on the Morbidelli, but means I have an hour+ cleaning it up before I do wood again, so perhaps the Camtech will be used for that.