Getting into CNC - opinions appreciated.

[handlewanker]

Thanks Roger and Ian,
I'm really glad I came here for some input. I know all about our wonderful country's attitude to giant mark ups and limited service from the industry I work in. It sure sucks but we just have to battle on eh?.

Just a little more about where I'm coming from: I suppose I am thinking on more than one plane. I am a small business in a niche market and - for the most part - mainly a one man show. I am goal driven and hate failing at things (I think my wife calls it f##cking stubborn) and once I get a bee in my bonnet about something I generally start researching and see it through, but I am smart enough (or maybe not rich enough) to make investments without knowing I'll be able to actually make it work , hence my boots and all approach right now getting my head around CAD / CAM and familiarising myself with some fundamental CNC lingo so that I can ask more questions.
I think I will grab a little eBay machine to start having a play with and will continue to research as much as possible about entry level small production machines that will actually contribute to my business. It's looking like a machine of this type will be in the vicinity of $40-$50K plus (I have custom "one-offs" and small production in mind with some prototyping - not large production runs).
I think once I get a few concepts under my belt I'll be on my way to making it a viable investment especially as my experience grows. In other words , yes Ian. I know I need one just need to learn as much as I can first.

Enjoying the thread and please think of me if any interesting information on machine manufacturers or controller options or whatever crosses your path. I hope to keep you posted on my progress.

Cheers,
Jeff.

Hi, prototyping with a CNC machine is a whole lot more complicated than running an established and checked program as you have to know what code to write, but going the CAD and CAM path will get you there eventually once you know how......it's a learning curve thing.
Ian.

[RCaffin]

'Titans of CNC' ... obviously NOT an Australian company. Anyone trying that here in Oz would get laughed into the Harbour.
And their website gave Firefox a fit so I had to kill it. Hugely not impressed.

Cheers
Roger

[RCaffin]

Ian got me thinking: why was the machine being 'thrown out'?

Then I started to wonder about the 80k rpm spec. For a lot of bearing companies, you will only get that sort of rpm for miniature bearings with a bore of 2.5 mm or less. Such a spindle shaft will not be strong - albeit adequate for an engraving tip with a 2 mm shank. You would never use a cutter of more than say, 1 mm on such a shaft.
You can get up to a 10 mm bore with very expensive ceramic bearings, but I would not try that for milling steel. Well, engraving steel maybe, again with very small tips.

The next problem is bearing life. I was discussing this with my dentist. He has a technician contracted to replace the bearings in his high speed drill once every 6 months - with a 6 month warranty. But what always happens is that the bearings have to be replacd every 3 months. I gather it is expensive. On a CNC engraving machine ... hum.

Cheers
Roger

[4140HT]

It might help if we knew a bit more about what you want to do - things like object dimensions, materials, etc. It is one thing to want a 2 m x 1 mm router for making custom wood doors, another thing to want to make wax masters for jewelry never more than 50 x 50 x 50 mm (and yes, we have one of those people here), and another thing to want to machine titanium aerospace parts in a 200 x 100 x 100 mm volume. Needless to say, very different machines!

Who knows: someone here might even be able to suggest the 'perfect' machine for you IF we had more knowledge. That said, having a play with a really cheap little toy might be (will be) educational.

Cheers
Roger

Of Course,
I'll need it for a variety of small parts (typically less than 100mm in length and usually much smaller) and mainly work with toolsteels like 4140HT, S7 Silver steel (annealed), 316 and 416R (26Rc) Stainless and of course a host of non ferrous metals. Nothing big but moderately hard.
I would like to be able engrave (and machine) on cylindrical surfaces but am a little unsure of which mills / controllers are able to support continuous 4th axis machining or how cost prohibitive this feature may or may not be.
Cheers.

[4140HT]

Roger you are not out of date continuous is still soon, 4th axis indexing is fine most of the time, wrapping is wrapping it can be BS'ed but it's still wrapping.

4140HT It would not hurt to jump on the fusion forum and ask if some one near you can help, there's also Titian's of cnc academy that has from basic to advanced cad and cam, with vid drawings and the models TITANS of CNC: Academy

Thankyou,
I have already teed up two people - a mechanical engineer friend who is a solidworks wiz (but reckons Fusion 360 will be no problem) and a customer of mine that is open to trading some of my work for his tuition ( he runs a drafting company) so I'm on track there.
I have subscribed to the program and joined the "Autodesk Community" and have started to communicate with others. Learning the basics pretty well and look forward to progressing with it.

[daniellyall]

Rodger theres about 900 people from Au doing it and one of the trade schools is also doing that courses.

[RCaffin]

Hard metals, with dimensions typically <100 mm. OK.
I will assume that with the <100 mm dimension of hard metals, you will be looking for reasonable accuracy as well.

First of all, I would suggest you forget ALL about the cheap Chinese routers. They will not have the stiffness to handle hard metal. Most of them struggle with aluminium. They are just NOT made for this task.

Instead you are definitely getting into the land of (at least) semi-pro machines, requiring quite solid/heavy metal. You have two possible paths:
Older machine being sold second hand (eg Bridgeport - a classic) and possibly a bit worn. Many of these would require substantial reconditioning.
New machine or near-new, but definitely in the 'CNC machine' class rather than the aluminium-framed router class.

I went through the same exploration, and ended up with a rebuilt Adept machine. These were initially made under contract for the Oz tech college market, but the Edu Dept cancelled. What happened was that a fair number of these very sturdy (students, remember?) machines ended up in colleges and even High schools around Oz, sitting totally idle in the corner, because the none of the staff had the faintest idea of how to drive them. So, second hand, but 'unused'. HA! Typically they are a dual spindle machine: vertical mill and horizontal lathe.
So an enterprising company in Qld started buying these machines, ripping out the old DOS-based electronics, and replacing it with modern Mach3-based gear. They tried to use an Oz company to do the electronics at first, but that was 'not successful'. I replaced all the Oz stuff with ESS and Gecko, and i think they have done likewise. I can and do machine steel to 0.01 mm. The photo here shows my somewhat enhanced version: my electronics and added misting system.

The company is at http://www.adeptcimcentre.com.au/. Speak to either of the Bleisners there and tell them I sent you. See what they can offer. It won't be anywhere near as cheap as the Chinese routers, but ...

Cheers
Roger

[4140HT]

Thanks Roger!.
Looks like something worth investigating - will contact.

[handlewanker]

Hi Rog....that's a nice set-up you have......one thing I noticed and that is you've got one of those tool maker type vices.....hmmmmm.

I also have one, 100mm wide jaw..... and the first thing I experienced was the screw coming out of the nut and the nut dropping down into the bottom cavity........had to do some fishing to get the nut re-engaged with the screw.....again and again.....grrrrrr.

The other thing was when the jaw is back only one thread is engaged.....not very cool......now I'm going to re-work it to have a stud and nut on the outside instead of the cap screw and with a longer loose cross pin in the cross holes for jaw positioning.

This will enable me to pull the pin and move the jaw back and re-insert the pin again.......at the same time having a long stud in the bot6tom nut ensures it won't fall down into the cavity, but more importantly, there will be more threads engaged when I apply pressure.

I like the design but some features are the pits.

It's off topic, but as the pic of your machine was there with the vice I though I'd mention my crusade.

BTW....maybe Skyfire.com can supply the needful for 4140, as according to the latest posts the delivery dates are now very reasonable.
Ian.

[RCaffin]

Not cheap, but very solid. I typically zero to 5 microns.

Cheers
Roger

[RCaffin]

Hi Ian

Having a nice vice is always good. . . . Oh - you mean the one on the mill ... yeah, that too A must-have bit of equipment.

Dunno where you got your 100 mm unit, but my 50 mm one has a long threaded hole in the 'nut' underneath. No problems at all with drop-outs. With some care(!) I can move the nut from hole to hole without pulling the vice off the table.
Um - slightly longer cap head bolt maybe? A short bolt would probably give me the same problems.
I replaced the short cross-pin on mine with a much longer one which sticks out both sides. This does not impeded the clamping down to the table. A tapered end makes reinsertion easier after moving.

Cheers
Roger

[handlewanker]

Yes, on the same lines with my thinking too......the bottom nut with the cross pin for "quick change adjustment" only has a short thread depth due to the cross pin........pulling the jaw back means the thread is at the end of it's travel and 1 thread is your holding force......on mine that is.

When the cap screw came out of the bottom nut it flipped upside down and fell into the cavity.......the bottom nut can also twist and doesn't engage fully with the half round quick adjustment slots .....the longer pin should solve that.

The bottom nut has the cross pin going through it as a press fit so the depth of the screw is limited......this means I need to Loctite a threaded stud into the bottom nut and a have a new nut with visible threads on the top ......but the loose cross pin mod is a first must do.
Ian.

[RCaffin]

Um - yes ... Mine may have been similar.
I am not sure the cross-pin was a tight fit, but yes, it only engaged with the half-round grooves. So, I replaced the short pin with a long one. The outer holes are of course exactly the same diameter as the grooves (they were drilled before the middle cavity was cut).

But if you are having problems with the short thread on the nut, why not replace it with a longer unit? Even mild steel would probably do, although some silver steel, hardened when finished would be neat.

Cheers
Roger

[handlewanker]

Hi, the bottom nut is going to undergo a radically different design as it gives me the pip when it tilts or goes out of line to the side holes and/or drops off the screw.

I'm thinking of a longish bolt with a rounded end...flat sides etc... that has a hole through it for the longer side pin.......there is a definite need to have a nut on top as opposed to the daft cap screw to see how many threads are engaged etc.......that's a quick fix as my graphics pad is over heating with a new design to suite a vice like this.....it's going off topic so I'll end this and see what happens.
Ian.

[RCaffin]

Hi Ian

That's fine, but do remember that mine works very well.

Cheers
Roger

[handlewanker]

Hi, no matter how I attempted to work with the design of the vice....possibly the one I have is of low quality.........the darn nut fell off the screw a number of times when I exceeded the back limit per hole.

That in itself is a worry as it means you have less and less screw threads doing the push as the jaw opening increases and there is no indication of the limit per hole position.

So, as I cannot come to terms with inadequacy, I'm going to attempt a cunning re-design of sorts.....eventually...... but in the meantime I'll be using my swivel base vice, sans base, as that's being used with a chuck for vertical work holding.
Ian.

[warrenb]

G'day all,
This is my first post on a CNC forum and I'm keen to hear any opinions that members may have in regards to getting into CNC machining. I'm a qualified toolmaker and been in the game for 20years and can hold my own in a toolroom / machine shop but I have zero experience with CNC's.
I currently run my own business in Western Sydney with conventional centre lathes and a bridgeport style knee mill as well as a few other machines and would like to take advantage of what a CNC machine can offer by way of limited runs of small part production for a niche industry that I service. Also for complex one off custom parts etc. I mainly work with toolsteels.
I'm not interested in cheap and nasty but am not ready to spend 100K + on something I have no knowledge in.
I suppose I would be looking in the $15000 > $40000 range and would probably start with a 3-4 Axis mill or CNC lathe.
I have been speaking to an Australian distributor of Tormach machines and am showing interest in something like the PCNC 1100 packages. I was directed to download a free trial of Fusion 360 CAD / CAM software which I have done.
I have limited 2D AutoCAD experience and 3D CAD is new to me but I'm hoping I'll be able to get my head around enough of it to be able to put a job together myself. I have never used a CAM program and would need to learn everything from the beginning. There is a lot I can get out of online tutorials but I know I'd do much better getting in touch with somebody (paid or otherwise) that would be able to demonstrate these concepts. I would also like to be able to work through G-Code enough to make a change on the run before I even contemplate a purchase of any machine.
My main questions are:
1. What are your thoughts on machines? Suppliers? Retrofitters of older machines?
2. What are your thoughts on the CAD / CAM program.
3. Anything else to point me in the right direction in terms of getting educated etc.

Look forward to your comments.
Jeff.

Buy used machines. Not sure about Australia. i picked up 2 Fadals for $5k each at an auction. Added it to the other 2 I already had. Rock solid machines regardless of who says otherwise.

But I think... best you hire me as a consultant to come down and advise you. My rates are cheap. Just get me to Australia. Lived a while in Hornsby and loved it. can't wait to get back.

[4140HT]

Buy used machines. Not sure about Australia. i picked up 2 Fadals for $5k each at an auction. Added it to the other 2 I already had. Rock solid machines regardless of who says otherwise.

But I think... best you hire me as a consultant to come down and advise you. My rates are cheap. Just get me to Australia. Lived a while in Hornsby and loved it. can't wait to get back.

Will you take beers as payment? Bring a second hand machine with you and we can play with it!...
Thanks for your input. In a year or so I might have enough knowledge to pick out a good used one or find someone to help me out. I haven't totally ruled out that option.
Jeff.

[RCaffin]

Buy used machines. Not sure about Australia. i picked up 2 Fadals for $5k each at an auction.
Chuckle.
You won't manage that here in Oz. Different world. Much harder to find suitable machines.
To be sure, there is a second hand market here, but the prices are often close to new machines.
Yes - having someone who KNOWs would be useful, but they would need to know the Oz market, not the USA one.

Cheers
Roger

[handlewanker]

Yeah, even if you had a good mate State side who could buy up all those cheap machines, the shipping cost would almost double the price.......unless you had a container and he sent the lot as one big package......it would take a huge undertaking to set up a business like that but with expectations of profits all round the final product could be more than the new price.

In 2014 I had to add 2 grand to the final buying price for my mill due to shipping costs etc when I bought it new from China.....second hand would be just the same.

Nothing is going to change until someone in OZ sets up from the bottom rung of the ladder and makes cheap junk made in OZ machines down to a price that anyone can afford and aren't fussy if the paint peels off as long as it works reasonably well and the price is right etc......they will sell in small quantities enough to go further and improve on the original build.

The mill drills that suddenly hit the market circa 1975 made in Taiwan were as crappy as you could get and were called Taiwanese terrors, but they sold in large quantities as they were the only available machines priced with the hobbiest in mind.

In 1980 I went to Birmingham in the UK 3 times when I lived there to try and get one of those mills to take to OZ as I was emigrating, but they sold out as soon as they landed......they were really crap machines at the best description and needed lots of rework.
Ian.