[Haltec]

Hi guys,


Can you gave me an advice regarding buying CNC machine.

Goal is to be possible to machine watch case from 316L stainless steel.

Should be desktop or large desktop size.

Is there anything that you can point me into because if I am going to investigate myself it would be tremendeousely time consuming due to my overthinking tendency.


I did checked those 3040 5060 chinese cnc but there's so many info about linear guides (ball shaft etc) precision advantages / downsides ...

So.. any advices and pointers are welcome.


Kind regards

Haltec

[peteeng]

Hi Hal - My advice is to find a contractor and have them made. Watches require precision and by the time you buy a suitable mill (which probably will break your desk) and tooling and fixturing you would have made 100s of watchs by contract... then you can decide if you want to do it yourself. Happy to quote for instance if you have a cad model and spec drg. Peter

[joeavaerage]

Hi,
machining stainless is even tougher than steel. None of the cheap 3040 or 5060 type gantry routers are even going to come close. You need a seriously rigid machine
or stainless will just laugh at your attempts. Think thousands even tens of thousands.

Peteeng is right, get them made for you, making them yourself is going to cost a fortune.

Craig

[peteeng]

something like this ...
https://youtu.be/AjTcWxl_BLA

https://youtu.be/127FyxcA-e8

[metalmayhem]

The reasons that you likely want to use 316l should be an indication of the factors that will work against you while machining , it isn't a forgiving material . Routers are meant for wood and you are looking at the wrong type of cnc , and any desktop mill available isn't going to produce great results on a consistent level . It's not to say it can't be done , but they won't produce fast enough if you want to make any kind of money

The ideal type of machine for something like that would be a mill designed for mold making . High rpm spindle , fast feeds and rapids are one thing you need , a solid machine is a major thing you need . A small used hermle for example would be great for something like that . I hate the heidenhain controls but thats a personal preference and hermle are fantastic machines .
There are other similar quality mills out there but the hermle may be good mills to look at so you can have a more realistic view of what you should be looking at buying . Peteeng provided a good example as well and is worth a good chunk of change

edit : I was referring to an older used 3 axis hermle , the new 5 axis mills are a bit more mind blowing on price and functionality

[joeavaerage]

Hi,
the recommended surface speed of stainless steel with uncoated carbide tools is around 50m/min. You might increase that to 75m/min with a coating.....but that's about it.

A 1.5mm diameter tool (1/16th inch) 50 / (0.0015 x pi)= 10612 rpm. A 3mm tool (1/8th inch) =5306rpm.

I imagine you'll use tools around this size and smaller. That in turn suggests a four pole asynchronous spindle rated at 12000 rpm with a 400hz input.

Craig

[Haltec]

Hi guys.

Firstely - thank you for all your inputs and replys. I am trying to avoid to appear overconfident since I do have some general experience with machining/repairing/finishing machined parts in Jewelry / Watchmaking or a reaonably small objects.

Amount of knowledge needed to meake perfect buyimg decision is unreachable to me in a reasonable amount of time.. so really thank you for all your help.

Comcerning Europe availabillity I found this one:

https://www.haascnc.com/de/machines/...ktop-mill.html

Priced about 10.000$

Opinions ?

[peteeng]

Hi Hal - I hope your not related to the HAL9000 I have been puzzled about this claimed "mill" ever since it came out. Haas should know better than to say its a mill. They say its designed for plastics and tooling wax. So there's your answer. I expect it will struggle with 316... The columns are way too thin for a mill. Its designed as a Haas controller trainer and lead in for sales to their machines. I'm designing a near benchtop router (maybe upgrade it to a mill once I get it detailed out) and its columns/walls are 100mm thick UHPC. Thats the sort of territory you'll need to be in. Peter

[joeavaerage]

Hi,
Hass is a good name and is probably a fair buy.

I would insist that the sales staff demonstrate stainless steel machining in the exact same machine you want to buy.
The pictures do not tell how rigidly it has been constructed. From a reputable and experienced manufacturer I would suspect its good, in which case they would be happy
to demonstrate the machine with the materials you need to cut.

Craig

PS I see peteeng has done some more research and what he has turned up does not look to good. To do stainless the machine MUST be rigid, and this machine
looks to be pretty marginal. Let them demonstrate it......anything else is pure guesswork.

[metalmayhem]

haas supplies a lot of schools with cnc's . I think that ''mill'' was their low cost solution to give students basic motion to work with . It's much cheaper to repair damage caused to it by inexperience vs a bigger mill . The thing is basically a toy and I doubt it can make anything decent beyond plastic

A reason I brought up hermle is that they are a German company and a lot of their machines are spread around Europe , they aren't as popular here in North America . A used 20-30 year old hermle mill will be much more machine and more capable than any desktop available . Their machines are much better than a lot of the industrial machines out there , and the used prices are fairly low .

An alternative in a 10k price range would be a tormach 440 . They aren't as rigid as industrial mills but they are capable little machines . I have four 440's that I only use for machining aluminum and I'd be confident to run anything on them if I needed to . I have a lot of industrial experience which gives me that confidence and know how to get things done , even with top of the line equipment there is a learning curve when working with different materials . I do a lot of 2.5d surfacing and the surface finishes are spot on and clean with my parts from the 440's .
A lack of rigidity comes with a sacrifice of time it'll take to machine tougher materials .
They also heave a nice 4th axis option for that series of mill , I don't have one but from what I've seen they look pretty solid

[joeavaerage]

Hi,
I have attached a pic of my own design and build machine.

I was hoping to achieve about 50N/um rigidity and be a match (rigidity wise) for a Hass Mini-Mill, but it has turned out to be a little over 20N/um rigidity.
This makes it broadly comparable to Tormach and some of the better drill-mills, not that the drill-mills are CNC, but rigidity wise my machine is similar.
I rather suspect you'd be happy to use my machine for stainless watch cases, with smaller tools anyway. I use it for steel and stainless, and with care can
get very gratifying results.

I have not seen any of the Hermle's, at least of the vintage that metalmayhem recommends, but the current five axis Hermle's sure would 'put a horn on a jelly-fish'.
I could only wish my machine could compare but it never will.

I had the axis beds cast in iron, quite expensive in itself, and then they were precision machined , and that was eye-wateringly expensive, it has ground C5 ballscrews by THK,
linear rails/cars by THK, and 750W servos all around. The build cost me about $30,000NZD or about $20,000USD. Not cheap!

It must be said building your own is always more expensive than buying new (Tormach for instance) or secondhand like a Hermle. I would guess that if I had bought rather than built
I could have ended up with a machine as good or better than mine for around $10,000USD.

I will say that I do not regret building my own machine, even and despite it costing more. I've , perforce, learned a great deal and had a great deal of satisfaction, but I've paid
quite heavily for that privilege. That in turn results from the fact I'm a CNC hobbyist and get satisfaction from the design and build. Were I strictly business focused then my machine
is too expensive and either a new Tormach or a second hand Hermle would make economic sense.

Craig

[joeavaerage]

Hi,
one other thing about making your own is you get to decide how and what to build. I built a fourth axis a while ago, and have recently converted the fourth axis into a trunnion.

The fifth axis is very nearly ready to run. It's been a long and expensive experience...but getting very close now!

Craig

[Mr-MaW]

cnc-

[Mr-MaW]

I took a closer look at the equipment of the Haas,His overall weight is only 164KG.

So its rigidity is very doubtful, can it demonstrate the processing of stainless steel?