Need help, buy or build to cut steel, stainless steel, titanium etc

[george uk]

WTF wrong with how I put it.? . . . It tells it the way it is.! . . .

Nothing Jazz, your just not very encouraging, but i, like most, prefare people to be direct like you, thats not in anyway a criticism.

in his first post he says

I am a bicycle frame builder by trade and I am looking to up my game

.
Thats a skill set what is directly would lend itself to building a decent CNC machine, he is a buisness trying to solve a problem with a machine, that means he will commited to doing it

Originally Posted by JAZZCNCIrvings correct when it comes to milling Titamium and even SS your into a massively differant machine to any router based machine you'll see on here.

To Mill SS or and Ti to any sort of acceptable standard you will need massive flood coolant and machine twice the ridgidty of Jonathans best effort.

i suggested jonathans machine early on when he said he wanted a general cnc machine, and thats a great machine for anyone to start with. Its after that, when he showed what parts and what material, i would not have suggested that because clearly, a milling machine is more appropriate.

[Jonathan]

Cutting stainless steel and titanium with a 500x500mm machining area is definitely challenging, especially if you need to do a lot of it on a limited budget. However, if we're only talking about a few parts a week (so speed is not an issue), then I wouldn't rule it out altogether. The machine mentioned earlier is about the size you need and was designed to be 'sufficiently strong' to cut mild steel (not stainless). Although I've not tested it much, at least from a stiffness point of view it does appear to meet that specification. I measured the stiffness of that machine (parallel to the X and Y axes) and it's comparable to my milling machine - i.e stiffer in one axis and a bit weaker in the other. Stainless steel and titanium both require a (relatively) low speed spindle, so for me to try cutting these at any reasonable rate would require a different spindle. However, since the stiffness is similar to my milling machine and I know that my milling machine tolerates cutting stainless steel, I can be reasonably confident in predicting that the 'sufficiently strong' machine would be able to cut stainless steel with the right spindle. Just to emphasize - I don't mean it would cut at a high rate but quick enough to be useful for the occasional part. Looking for a big enough milling machine would still be you best bet, but you'll need a lot of space for it.

Perhaps the main difficulty with cutting titanium and stainless steel, compared to aluminum, is that in addition to being much harder materials they also work harden. This limits the extent to which you can get away with just taking smaller cuts, so the machine must meet a certain level of stiffness before you can do anything useful (except perhaps engraving).

[JAZZCNC]

Jazz, the OP said this, so go with this comment and forget the other, it's just easier.

Eddy it's hard when I get Folks who only 6weeks ago didn't know the differance between nema23 & nema 24 motors and pointing someone to Bloody Pin routers to Mill Titanium telling me I'm being negative just because I give somebody who freely commented they have no experience with CNC a very realistic idea of what there about to get into.!

Helping hisn't always about helping to build.? Sometimes it's in peoples best interests not to build and look at alternative solutions and in this case I feel it's in OP best interest not to build.

I'm just starting to get slightly pissed off that my words are being taken out of context and twisted into something completely differant.!!

[Clive S]

post 1 Something like a desktop version will be so ideal for my workshop but the sad thing is I can't seem to find anything online that will fit this criteria. and post 3 gear hangers out of materials like titanium, chromoly and stainless steel. So yeah small parts but I would like the machine to mill a surface area of 0.5m x 0.5m allowing me to make jig parts if necessary.

george uk If you had read the posts you might have seen the criteria for the machine So a big lump of iron won't fit the bill ..Clive

[george uk]

Clive, i agree ( accept what your saying ) , i was just chatting to get an understanding of what he needed any why

As sooin as i see he needed to cut hard material, by here http://www.mycncuk.com/forums/worksh...html#post54478 i recomened he gets other more experienced machinests opinions on cutting that. I do know were my limits are and i would not advise anyone byond what i am confident myself in.

But, i persevered . because he said, 1. it was for a business 2. Money was not a worry. He also mentioned that he might want to machine some jig parts. I looked at all what he had posted, and thought them machines would be a very good starting base for what he needed to do.

One of them pin router tables i pointed to £ 300, for a mill base, thats got a workable area close to what he needs. they are rock solid. It would be easy to mount XY on that and motorise the Z and be strong enough mill. apart from the spindle, £ 700 extra should do the job at a push.

Eddy it's hard when I get Folks who only 6weeks ago didn't know the differance between nema23 & nema 24 motors a

Ok Jazz, i will bite. I openly asked what the main differences were apart from just higher rating, and got the answer. I was also from the start it was suggested that i was looking at a too powerful motor ( nema 32 ), but the further i have got down my plan, the more they seem the correct choice. I will know over the next week or so, as the frame is assembled so i can test the Y design.

Point 2 ( i said i will bite ).

I'm being negative just because I give somebody who freely commented they have no experience with CNC a very realistic idea of what there about to get into.!

He clearly has the skill set BUILD OR UPGRADE the mechanical side of a CNC machine. He builds frames for a living, when someone like this says they have no cnc experience/understanding, it usually just means they dont understand the motor movements to the computer relationship. the Computer Numeric Control part.

any you will notice, that i recommended that he look at meshcam, as that gives a none cnc person, an easy to understand look at ( visualisation ) possible machining limits. Very easy to learn and pick up and free for a month.

I still stand by what i suggested. but dont wish to be confrontational, just clear

[kingcreaky]

Welcome to the forum fatguyslim.

"I think" you need to catch the CNC bug!!. once you have caught it, it changes your perspective on how you go about doing any job. Your initial requirements are a perhaps a little High for somebody starting out, but that doesn't mean that you should just give up. There is a entire other world just round the corner, that as you say, will vastly aid your goals. Perhaps see if you can buy yourself a cheap machine that meets your storage & workshop space requirements for now. Something that perhaps is only any good for cutting wood and plastic. That way you can learn the software experiment and see just how powerful it is.

Then, once you have a little confidence, you will see just how easy material you think "wont ever bend" bends and flex's before your very eyes, and its with this hands on experience you will be able to see clearer the points that have been made above. Then, Like some of the more experienced members have suggested, I would buy myself a solid milling machine.. something off ebay etc, as a milling machine, then convert it to cnc, that sounds like a huge job to a newbie.. which is why im suggesting you buy yourself something small so you catch the bug learn the concepts, then you can use your "hands on" skills previously described to convert a machine to your ultimate requirements.

They come up often enough, you buy it cheap learn all about it, no doubt you will be able to sell it on once you have finished playing!

Im perhaps too far away (leicester) but you would be welcome to come and play with my wood router which although nothing like your requirements, would give you the enthusiasm you need to get on with it.

Please dont give up, or put it off. I wish you all the best.

[JAZZCNC]

Ok lets just backup here.!! . . . First George sorry for Snapping I was out of order for that, but of late it seems my words are being twisted out of context.
To be accused of being Discouraging is somewhat insulting to me because often I'm the first to Chim up and encourage people, freely giving advise and often getting involved in some way or another off forum. (Which for the Record I'm going to offer my Hand to Fatguyslim via PM.)

I never said give up on CNC I merely gave a very realistic dose of reality to someone with no experience. I also gave some very good Alternatives and recommendations on correct machine design if the guy did continue down the DIY CNC route. . . I then wished him Luck.!!

So Between this and other Post's where what I'm posting gets twisted or misread I've decided I'll be taking a back seat from now on and refrain from posting. I'll be around just not offering advice. (well not publicly anyway)

Happy CNC-ing to all. .

(Oh before those that feel the need say it.! This is not me throwing the Teddy out the Pram it's me saying enough is enough and I don't need the hassle.!!)

[fatguyslim]

I would like to add that I wasn't discouraged by what Jazz said. It was in fact very good straight forward reply. Not just that but everyone who has contributed to this post has been very helpful. This is by far a very active forum, I never knew how big this community is? Ok so lets start off with a budget... I would like to add that I am happy to spend anywhere in the region of £5k-£10K. And if it happens to cost more to achieve small yet then yes I can stretch a bit more. The reason I got on this forum was to learn if someone has build something of this sort before or if anyone is currently working on one? But I take it this is a whole different ball game.

To give you guys a bit more background on what I do... I make bike frames out of bamboo. Currently my frames are going through BS/EN testing so soon they will be up for sale. Now the whole cycling frame industry only caters for steel frame builders and aluminium frame builders in general. All major carbon frame companies machine their own frame ends as far as I know. S for someone like me I am looking to make custom parts for each frame. I use carbon for my joints and to align carbon properly to compensate for all various stresses I need something custom every time. Now if you imagine asking a metal cutting company to cut just a couple of these parts every time I need a frame it will end up costing me quite a bit over and over (sometimes they don't even do it and simply say no lol).

I get told from my friend's that I am at early stage of this thing so I shouldn't be looking into CNC machines but I believe that is bullocks as I know how powerful and useful these machines can be. I don't just wan to limit myself to frame building but rather use this machine to create new things and maybe a bit of prototyping here and there. So yeah now you know the story. And if anyone is up for the challenge to build something this "nuts" then I will be happy to pay them for their services. Cheers

[routercnc]

Hi Fatguyslim,

I'm not sure if the few last posts have piqued your interest again or not, so this question may not be relevant.

But if you were to design and make your own bike bits for these higher stress areas and sell them to the public where do you stand in terms of liability in case of failure? Would you need to carry out your own stress and durability analysis on those safety critical items, and is that something you were planning anyway?

EDIT: Crossed with your post. Ignore - BS/EN testing mentioned in your post . . . apologies.

[fatguyslim]

Hi Fatguyslim,

I'm not sure if the few last posts have piqued your interest again or not, so this question may not be relevant.

But if you were to design and make your own bike bits for these higher stress areas and sell them to the public where do you stand in terms of liability in case of failure? Would you need to carry out your own stress and durability analysis on those safety critical items, and is that something you were planning anyway?

Not sure if you read my last post but my bikes are currently going through BS/EN testing for MTB, Road and City frame so if they pass this testing then i can get public liability insurance for my bikes.