I am going to build a CNC machine, What do I buy?

[mtt.tr]

Just seeking a bit more guidance here.
I was going to buy a couple of rolls of .5 or .75 cable for my panel build, do you think I am going a bit light on the cross section?

https://chaloncomponents.co.uk/product-category/cable-management/tri-rated-cable/

but then I was going to buy some terminal blocks, what a minefield:

https://chaloncomponents.co.uk/product-category/terminals/entrelec-terminals/

Can anyone just give me a bit of guidance on this, I figure 30 would probably do it, I can always order more.

What amps are you expecting?

 

[northwest]

What amps are you expecting?

2.5 - 3 that's about it really

 

[mtt.tr]

.75 is about 6 amps and its easier to terminate than .5

I would likely go 1mm as again is easier to terminate

 

[Hood]

These are the ones I usually get.

https://chaloncomponents.co.uk/product-category/terminals/jxb-range-feed-through-terminals/

Regarding the wiring, depends what it is for, if signal then .5 would be fine, if power then probably not.

 

[Hood]

BTW a crimping tool and bootlace ferrules are a good idea but most kits don't have small enough ones for 0.5 wire so often better to but a bag of suitable ones.

 

[Hood]

Something like this.
https://www.ebay.co.uk/itm/1300PCS-...4207997916569ec00b8d|ampid:PL_CLK|clp:2334524

 

[MCKDAVID]

I went with .75 for the signals, as it was twisted pair (in the panel, but twisted the pairs and twisted pair / screened for out of panel field connections). Used 1.0mm for all the panel "power" side AC and DC drives, mainly because I had it, but it gives you more margin if you need to upgrade later... no difference in termination size anyway, all the kit I had was fine..

 

[MCKDAVID]

.75 is about 6 amps and its easier to terminate than .5

I would likely go 1mm as again is easier to terminate

really? how do you figure that? no difference in real terms... especially using ferrules, which are pretty much an necessacity on this size of wiring.

 

[mtt.tr]

really? how do you figure that? no difference in real terms... especially using ferrules, which are pretty much an necessacity on this size of wiring.

Because the individual strands are thicker and tend to splay less and a a roll of 1mm will do everything.

 

[MCKDAVID]

Obviously, but that won't make terminating them any more complicated, if you've done the preparation properly.

 

[mtt.tr]

Obviously, but that won't make terminating them any more complicated, if you've done the preparation properly.

Totally agree,

 

[northwest]

These are the ones I usually get.

https://chaloncomponents.co.uk/product-category/terminals/jxb-range-feed-through-terminals/

Regarding the wiring, depends what it is for, if signal then .5 would be fine, if power then probably not.

Well, I bought 30 terminals and see how I get on, two rolls of .75 and two rolls of 1.0. I have ferrules and a decent crimper. I am just waiting for some more bits to appear and I can try laying the panel out. My pal found me a cabinet and I cut about four inches out of it, welded it back together today and off to the powder coaters tomorrow.

 

[mtt.tr]

Have to told us what you are building?

 

[northwest]

Well, I already have the machine and it is working well at the minute:

however, it is limited and now that I have a very good understanding of what it is and what I am doing I want it to perform to it's maximum. So I have rebuilt the machine mechanically, new bigger ballscrews, new oilways, a central oiling system and so on.

The current control system is very underpowered, under voltage, and a bit underwhelming to be honest. It is running on an old and, by modern standards, large, bulky HP desktop running Windows XP. I can now have Windows 7 running on a tiny HP micro PC that is near silent. As opposed to the three or four large fans blasting away in a box bigger almost than the whole new control panel. It's a Win-Win. (BoomBoom!)

 

[northwest]

Out of interest, how much would it cost to convert a mill to cnc (excluding the ballscrews etc?).

I don't think anyone addressed this did they.
The answer, as often is the case with these things is: depends. You can get yourself on Aliexpress and buy a kit to convert a small (mini) milling machine for as little as $160 like this one HERE Then you need some ballscrews, time and a little skill. You could assemble the electronics in a tupperware container and use an old computer.

The snag with this seat-of-the-pants-fix-it-as-I-go-along approach is it can be very unreliable. Not a problem if you are doing this as a hobby and the build is part of the interest. I need to build a machine and make it work, reliably.

Consequently it is Industry standard controllers, Industry standard interface boards and a steel cabinet all laid out with Din rail, I probably spent as much on the IP Controller/Interface as someone doing this as a hobby would spend on the whole installation. But I am going to do this once only to this machine and then I am going to put it to work. Not constantly tweak and tune and reset. I will probably put the whole of the existing controller/power supply up for sale when I am done. Quite possibly the cheapest part of the whole installation is the actual Mill itself, the electronics are double that.

But then I could have gone with the £160 kit above and a simple enclosure........ But the fun really starts if you try to sell it.

 

[minimutly]

I don't think anyone addressed this did they.
The answer, as often is the case with these things is: depends. You can get yourself on Aliexpress and buy a kit to convert a small (mini) milling machine for as little as $160 like this one HERE Then you need some ballscrews, time and a little skill. You could assemble the electronics in a tupperware container and use an old computer.

The snag with this seat-of-the-pants-fix-it-as-I-go-along approach is it can be very unreliable. Not a problem if you are doing this as a hobby and the build is part of the interest. I need to build a machine and make it work, reliably.

Consequently it is Industry standard controllers, Industry standard interface boards and a steel cabinet all laid out with Din rail, I probably spent as much on the IP Controller/Interface as someone doing this as a hobby would spend on the whole installation. But I am going to do this once only to this machine and then I am going to put it to work. Not constantly tweak and tune and reset. I will probably put the whole of the existing controller/power supply up for sale when I am done. Quite possibly the cheapest part of the whole installation is the actual Mill itself, the electronics are double that.

But then I could have gone with the £160 kit above and a simple enclosure........ But the fun really starts if you try to sell it.

Hmmm, thanks for that. What size mill is yours? I'm thinking of converting a bridgeport size machine - I guess the ballscrews will be big, as will the motors? Do I need a dc motor for the head? I guess no reason why?

 

[Hood]

Ballscrews on my Beaver NC5 are 32mm, I would say 25mm at a minimum if like a series 1 Bridgeport, if a heavier machine then 30-32 might be better. Then again you have to think of whether there is room for them, especially the nut.

Regarding the motor, a VFD would be fine although going up a size or two on the HP may not be a bad thing if you won't be using the gearing.

 

[mtt.tr]

Im specing what i want to achieve its a mine feild of choice.


Hats of to those that have built them, just the choice and then finally nailing your colours to the mast and going for it is hard enough

 

[northwest]

The panel so far:



I have been looking at the various options and right now I don't have to commit to anything so I will stare at it for a few days. Bits still on the way and cabinet is at the powder coaters. @MCKDAVID has been giving me a few pointers as his cabinet is the same size as the one I have so looking for any pitfalls. I have pre-drilled the cabinet with what I hope are the right holes, in the right place.

 

[mtt.tr]

The panel so far:

View attachment 269501

I have been looking at the various options and right now I don't have to commit to anything so I will stare at it for a few days. Bits still on the way and cabinet is at the powder coaters. @MCKDAVID has been giving me a few pointers as his cabinet is the same size as the one I have so looking for any pitfalls. I have pre-drilled the cabinet with what I hope are the right holes, in the right place.

I hate starting wiring stuff like this, but once you commit it goes well