Newbie, build or buy

[routerdriver]

If you are coming at this as a complete novice,do you need to gain proficiency with some form of CAD first?There can be quite a lot of learning needed for a total novice,just to get a sensible CAD file with all the entities joined at the part boundary and holes in the correct locations.Then you need to learn how to use a program to convert it to Gcode and load it on a machine that will carry out the instructions.Learning how to build and calibrate the machine is another significant step and none of the processes are trivial.

I've seen a few Chinese/Taiwanese machines and they are not all identical.Those built to the lowest achievable price point don't have much in common with the more sophisticated machines but any of them will get you producing parts a lot sooner than building a machine yourself.Not to mention that even the most basic will seem like a quantum leap forward for a man used to working with panel saws,jigsaws and hand routers.What it won't do is produce at the rate of a bigger and more expensive machine or for as long before wear and tear sets in.If you look at a few of the promoted machines online you may well notice that a lot have the same anatomy and a different colour coat of paint and label.

[JAZZCNC]

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.

Chinese machines are like a box of chocolates without the lid and no sell-by date.? You never know what you are going to get and often leave a sour taste in your wallet.

I have retrofit several Chinese machines and have many customers who went the Chinese route only to regret it. Now I'm not saying all Chinese-made machines are bad news but you really need to know what you are looking at because you can easily be buying trouble.

If it's the type that uses what's called a DSP pendant rather than a PC or dedicated controller with a screen and keypad to control the machine then I find these are bad news. Often the pedants break down and start doing crazy things usually within 18months of new, when this happens better to rip it out and retrofit it with a better control system.

With these DSP type controllers, I find it often goes hand in hand that the drives which control the motors (usually steppers) are cheap nasty units that need replacing and the wiring leaves a lot to be desired in terms of safety. It's very common that the wiring is shoddy and wire routing is poor, the quality of the wire is also very poor so between this and bad routing it's common to get wires break which can lead to days of downtime tracking down exactly which wire broke and where.? Often it's quicker and easier to just start again than wasting days tracking it down only for another wire to break somewhere else.

My advice is to be weary and take someone who knows what they are looking at.

[Kitwn]

My local Men's Shed here in Tasmania bought a Chinese machine a couple of years back (before I joined I might add) which has exactly the kind of DSP controller Dean describes. After using 'proper' controllers, first LinuxCNC and more recently UCCNC I find the DSP device hopelessly inadequate and frustrating to use. The machine has hardly been used by the shed members and I think this is one of the reasons. I find it confusing and I already ( sort of) know what I'm doing. Mechanically the machine seems reasonable but I'm hoping to convince the shed to upgrade the controller to something better at some point in the future (that'll be some point when I have the time to do the refit and setting up myself).

If you do consider buying such a machine, my advice would be to budget in an immediate replacement of the controller rather than waste time learning how to use something you will not keep long term.

Kit

[Russjp]

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

Thanks.

I've got no pics at the moment. Its a friend of a friend who's offered it to me. He bought it new 2 years ago, says he's had no problems with it but has had to downsize premises due to the lockdowns. I've not seen it yet as its a 4 hour drive away. All I know so far is single phase, has a vacuum bed, runs with nc studio and he added a 4.5kw water cooled spindle.
I've no real experience with a large cnc, just my desktop OX using vcarve Pro.
I might try to find time to get down there to have a look but, apart from seeing it running, I'm not sure what I need to be looking for!

[Russjp]

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.

Thanks for the offer, I might take you up on that depending on what I decide

[handles]

Thanks.

I've got no pics at the moment. Its a friend of a friend who's offered it to me. He bought it new 2 years ago, says he's had no problems with it but has had to downsize premises due to the lockdowns.

That is one of the reasons I built mine to be configurable, and with rack and pinion . I have a 1.6m wide gantry X axis by 1m Y axis. I can extend it along the Y another 2m simply adding more rack and linear rail to another ally extrusion table and bolting them together.
I haven't needed to do that as I just use my assembly table as an extension, which is the same height, and just slide full sheets along onto the CNC bed.