Newbie, build or buy

[Russjp]

Hi
I'm Russ from Manchester.

After messing around with a desktop cnc (ox) I'd like to add an 8x4 to my joinery shop, mainly for cutting sheet material for cabinets, templates etc.
I've been thinking of building an Avid style cnc but have been offered a second hand machine (awaiting details) for not much more than it would cost to build my own. I'm confident in the build but not so with the electronics. Anyone got any advice on build or buy, assuming the buy is in good working order?

Thanks

[handles]

After researching and designing my machine from the best spindle down to the last bolt length for my specific needs, finding decent suppliers at a good price and shipping them, was in retrospect the "simple" part. Building my machine hardware accurately without a CNC, purely with hand tools, drillpress, tablesaw and handheld router to mill aluminium was another "simple" part. Then came troubleshooting the electronics and safety systems to all talk to each other and work properly, the hardest and most frustrating part, and then learning the cad/cam/cnc software, calibrating the machine and how to use it, not too simple either, I came to a single conclusion:
Next time pm Jazz on this forum and get him to build me a decent machine and I will spend my time just learning how to use it!

Jokes aside, I have learned so much valuable information that I wouldn't do it any other way. I knew nothing of electricity and electronics before I started, but it was a hard and frustrating road for me personally. So many easy mistakes to make. Case in point is I still have my spindle tripping the limit switches randomly. I have everything star grounded including cables, EMI filter on VFD, all electronics in separate cabinet but it still happens. I am beginning to wonder if it is the quality of limit switch and just going Pepperl-Fuchs. So many little things can and do go wrong. I see now why so many home builds take years or end in failure.

If you dont have oodles of time, patience and want to get up and running quickly I would buy a decent build with good electronics. As Jazz has said, good electronics make the machine, I will second that.

W

[Kitwn]

After researching and designing my machine from the best spindle down to the last bolt length for my specific needs, finding decent suppliers at a good price and shipping them, was in retrospect the "simple" part. Building my machine hardware accurately without a CNC, purely with hand tools, drillpress, tablesaw and handheld router to mill aluminium was another "simple" part. Then came troubleshooting the electronics and safety systems to all talk to each other and work properly, the hardest and most frustrating part, and then learning the cad/cam/cnc software, calibrating the machine and how to use it, not too simple either, I came to a single conclusion:
Next time pm Jazz on this forum and get him to build me a decent machine and I will spend my time just learning how to use it!

Jokes aside, I have learned so much valuable information that I wouldn't do it any other way. I knew nothing of electricity and electronics before I started, but it was a hard and frustrating road for me personally. So many easy mistakes to make. Case in point is I still have my spindle tripping the limit switches randomly. I have everything star grounded including cables, EMI filter on VFD, all electronics in separate cabinet but it still happens. I am beginning to wonder if it is the quality of limit switch and just going Pepperl-Fuchs. So many little things can and do go wrong. I see now why so many home builds take years or end in failure.

If you dont have oodles of time, patience and want to get up and running quickly I would buy a decent build with good electronics. As Jazz has said, good electronics make the machine, I will second that.

W

So what electronics do you have? Maybe other forum members can help you.
You might want to start a thread of your own rather than end up hijacking this one.

Kit

[Dodgy Geezer]

You have a commercial shop. Get a professionally designed and built machine. Not only will it be easier to run, but easier to maintain as well.

If you are doing CNC as a hobby and like fiddling with things and optimising tensions on belts, etc, then the reverse applies. Because overcoming the build problems are part of the fun. It's like art - if you want to see the image, buy a painting rather than a jigsaw....

[handles]

So what electronics do you have? Maybe other forum members can help you.
You might want to start a thread of your own rather than end up hijacking this one.

Kit

What are you smoking, brah? The man asked for an opinion on whether to build or buy, which I duly gave. How is that hijacking a thread?

A custom machine by someone who does it for a living, or a good commercial is optimized. The problems that you haven't even thought of as a newbie are all ironed out.
A homebuild contains all the errors and mistakes from someone doing it for the first time. Therefore that will require tinkering at best, or rebuilding from scratch at worst.

As DG said, if you want to tinker because it is fun, build it yourself. If you want to run it as part of your commercial operation buy a custom made or a commercially built one.

[Russjp]

Hi all

Thanks for the replies

The reason I asked was I've been thinking of building one for a while but fear it could be one of those projects that never get finished! Plus I've been offered a Chinese made 8x4, almost new, for less than the cost of building.
I do general joinery, doors/windows etc but I'm looking to focus more on cabinets and thought a cnc might be beneficial.
Anyone got any experience with chinese machines? I don't need a workhorse as there'll be days/weeks where its not used but at the same time will want it to run properly when needed.

Thank again
Russ

[Kitwn]

What are you smoking, brah? The man asked for an opinion on whether to build or buy, which I duly gave. How is that hijacking a thread?

A custom machine by someone who does it for a living, or a good commercial is optimized. The problems that you haven't even thought of as a newbie are all ironed out.
A homebuild contains all the errors and mistakes from someone doing it for the first time. Therefore that will require tinkering at best, or rebuilding from scratch at worst.

As DG said, if you want to tinker because it is fun, build it yourself. If you want to run it as part of your commercial operation buy a custom made or a commercially built one.

You mentioned that you still have your spindle tripping your limit switches randomly, I was referring to that. Apologies for not being clear.

Kit

[handles]

You mentioned that you still have your spindle tripping your limit switches randomly, I was referring to that. Apologies for not being clear.

Kit

No worries, Kit, I was just giving the OP an example that you can do the research and all the "right things", and still hit problems if your electronics are too cheap. They are the only cheap electronics on my machine and I will be upgrading them soon, so all good.

The reason I asked was I've been thinking of building one for a while but fear it could be one of those projects that never get finished! Plus I've been offered a Chinese made 8x4, almost new, for less than the cost of building.
I do general joinery, doors/windows etc but I'm looking to focus more on cabinets and thought a cnc might be beneficial.
Anyone got any experience with chinese machines? I don't need a workhorse as there'll be days/weeks where its not used but at the same time will want it to run properly when needed.

Sorry, cant help you with experience on Chinese machines. If you do decide to build your own, however, I built an Avid replica and can give you a lot of useful info on this to fast-track you.

[Kitwn]

No worries, Kit, I was just giving the OP an example that you can do the research and all the "right things", and still hit problems if your electronics are too cheap. They are the only cheap electronics on my machine and I will be upgrading them soon, so all good.

Been there, done that, got tears all over the T-shirt. There's quite a saga in the archive here of problems I've had with the spindle causing spurious tripping of limit switches when using a cheap Chinese BoB and LinuxCNC via a parallel port. I'm still not entirely sure where in the chain from BoB input to PC motherboard the problem really was. The shiny new AXBB-E controller and UCCNC software installation running via Ethernet have been faultless so far.

Kit

[Clive S]

Hi all

Thanks for the replies

The reason I asked was I've been thinking of building one for a while but fear it could be one of those projects that never get finished! Plus I've been offered a Chinese made 8x4, almost new, for less than the cost of building.
I do general joinery, doors/windows etc but I'm looking to focus more on cabinets and thought a cnc might be beneficial.
Anyone got any experience with chinese machines? I don't need a workhorse as there'll be days/weeks where its not used but at the same time will want it to run properly when needed.

Thank again
Russ

Russ You might be lucky. But I would post some pics or maybe a link to it. its a minefield out there.