Wisdom of the forgemind


#1

I’ve been asked to take charge of a metal machining oriented CNC machine including developing some training classes and use guides with sample projects but I’ve not seen one of these. It’s their 400T model.

Anyone here have any experience with one? Tips?

TIA


#2

It doesn’t look terribly special, IMO. For instance, unsupported round rails are less than ideal as far as rigidity goes, and rigidity is probably the most important consideration when it comes to milling. Although I’ve heard good things about Kress spindles, I’m guessing that spindle isn’t going to do you many favors with milling metal. I’m guessing the spindle is high-speed, which is good for small bits, so that’s a plus. But small bits take small bites, and using a small bit to mill away a lot of material will take a very long time, especially if rigidity is an issue with the machine. And in the end the surface finishes will probably be terrible. If you want to use larger bits, you’re going to need/want to use slower speeds, which some spindles cannot do. A way to avoid milling away lots of material is to do “slot” cutting. Slot cutting works OK on paper, but it is problematic in a variety of ways. Their commercial doesn’t show any coolant being used - slotting without coolant is a recipe for disaster (and adding coolant to a machine that isn’t designed for it can be disastrous too). Steel will also require slower speeds.

How much is it? How important is the price of the machine in your decision? Is one of the intentions of the training class to use a low-cost machine, possibly with the goal that some of the students will buy a similar one?

Using this machine will probably mean your class will mostly be about working around the limitations of this machine and about hand-finishing metal parts. I can’t remember how much you’ve talked about milling, @jamesdhatch, but it’s not something that most people can pick up in a short amount of time, especially not with the proficiency required to teach it to others. In my opinion, laser-cutting is absolute child’s play in comparison.

I haven’t looked at what small mills are available in a long time, but (despite my ignorance) I’d say the Tormach 440 is probably the smallest/cheapest you’d want to go if you’re looking to do “real” CNC metal machining, and I believe they run around… I don’t know… $8k or so when you add up everything you’re actually going to need.


#3

Thanks for the info. This is coming fully tricked out including a cooling system and enclosure (plus all their other accessories). Getting it on a temp basis from the US rep of the factory - he’s heading to Europe for the next several months and figured it could get some use while he’s away.

I’ve done light metal milling on the Shopbot - aluminum & brass using an air jet cooling system but nothing killer. Did create the training materials and curriculum for the Makerspace’s CNC so doing a basic operation class seemed doable. But I won’t know until I get at the thing and can run it through its paces.

Funny about the Tormach - we’re looking at one of those for the Makerspace. Just need to do some shuffling of things around and build some more benches/etc so there’s room :slight_smile: That’s my next project. Gives me something to keep occupied with over the winter.


#4

Ah, great! Even going from no coolant to some coolant makes a big difference, even if it’s just a handheld spray bottle, so hopefully the setup they’re including makes a big impact. And enclosing it will be nice too, I’m sure.

From a distance the Tormach 440 looks pretty sweet. Sure, it doesn’t have the longest travels, but it seems to be able to take some serious cuts.


#5

Pretty much what we thought. The size is a trade-off. We don’t always have a ton of room and we’re not sure how much it will get used. We’ve got a big flat-bed vinyl cutter that only gets used rarely so all the rest of the time it’s just a big table (we’ve got a piece of plywood over it). So the smaller Tormach seemed to be the right choice. They have some sweet larger ones though :slight_smile: But the prices start going north pretty quickly.


#6

That is not a metal cutting CNC unless we are talking thin aluminum or brass. Take a look at the Novakon machines, lesser known competitor to Tormach. I’ve got one of the all servo machines that is pretty impressive.


#7

thanks. We’ll look into Novakons when we look to pull the trigger on the Tormach.