# CNC files



## John S (Apr 13, 2008)

Brief Intro then cut to the chase.

Over the past couple of years I have been involved with CNC mill conversions, mainly based on the Sieg X3. Recently I have been working closely with Sieg themselves to offer a turnkey CNC milling machine as a plug and play exercise and recently it's starting to come to fruition, at least in the UK and the the US should follow shortly.

This is not an advertising stroke and that's as far as the intro is going.

Now the chase.

Because we drag these things to shows we like to show them working making parts relative to model engineering.
One such example is a loco wheel and a con rod from a generic IC engine.

These get a lot of interest at shows, that much that a software company, Vectric, who make a nice CAM package have adopted both these items as samples for their 2-1/2D software.
See Cut 2D at http://www.vectric.com

Sorry if this sounds like an advert but it's only trying to put flesh on the bones.

I can see the time when designs be it IC, steam etc will be exchanged / sold as G code file for CNC machines to make. Possibly buy a kit containing all the castings, bar material , plans and code on CD.

What I'd like to know is do others share this view and is there a free design out there that will lend itself to being done by a beginner to CNC ?
If so then I'm willing to code all this up and make the first one as an exercise for what can be done by CNC.

This will then be made available for anyone to copy free of any charges.

Idea's, flames, bricks thru front windows ??

John s.


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## AllThumbs (Apr 13, 2008)

I have heard of this type of thing before. On another site regarding model airplanes, not model engines. One problem I forsee is that not all machines run all gcodes the same. Since most of the parts will be one offs, parts will be ruined along the way, not to mention the possibility of machine damage and/or personal injury. Add to this that you are talking about offering this to beginners, which would compound the problem.

Eric


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## Cedge (Apr 13, 2008)

John
Neither bricks nor flames. CNC is getting cheaper, although it remains somewhat prohibitive for the poor hobbyist like me...(grin). The idea has merit for those who are into the CNC end of the craft, but my personal take is that it would soon become akin to watching paint dry.  Once the code is loaded, an odd tool change and the occasional metal swap wouldn't excite me all that much. No denigration is meant by my comments... I just enjoy the primitive part of turning dials, marking out and measuring that manual machines offer.

Your idea is a pretty logical next step to what Liney engines is doing these days. They supply drawings for little money or they can ship a kit with precut metal, drawings and instructions, for several engines. They seem to be doing rather well with them. I can see it working for at least some of the CNC crowd as well. 

I am investigating the possibility of getting into some CNC, down the road. A friend is holding a couple of bench top CNC mills that are quite tempting. 

Steve


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## Mcgyver (Apr 14, 2008)

Hi John,

the next step in the evolution is just ship the completed engine ;D

If I dissected where the fun is in model engineering, Id say it's in the solving the puzzle...the puzzle of sequence of operations and reference surfaces and set ups to make a part. There's a sense of accomplishment in this. imo this is why it is as fun for the more experienced practitioner as it is the beginner. Remove or diminish this and i wonder if a lot of the intrigue is removed as well. Not saying that's whats happening with your idea, but at some point, codification takes the fun away, taken to the extreme it would like putting together a plastic model

at the same time I can see how cnc changes the way parts are made. Your example of making a driving wheel pre-cnc was a complex machining task, enough so that mostly castings were bought. Still, if I'm buying a cnc mill and loading a program, its not like I've accomplished much or solve a puzzle, I might as well just buy the wheel. 

The other challenge is it would have to be one heck of a set of digital instructions to accurately replicate the driver with the correct taper and profile to each spoke etc. My sense is that whether its machine tools or cameras, unless you are working with quite high end stuff, digital is often the poor sister to analogue in representing the real world. Maybe this is where the opportunity lies, given the price of castings. I have no interest in a cnc engine project carved out plate that is going to look hokey compared to a simple analogue engine, like say a Stuart 7a. However, couldn't the cnc programs be advanced to the point that they'd carve out of a chuck of darabar parts for similar engine that held even finer detail and correct form than the 7a castings....Surpass what we have and, well, it becomes highly desirable.

I pine for a cnc. I'm 80-90% through making a simple cnc including the electronics. I do think however that the more one's work is one ofs, the less value it has and the more its role is as a specialized tool augmenting manual machines. That is partially because of the added burden of cad cam to produce a cnc part, but also because we are unlikely to end up with cnc that can compete with our older iron it terms of hp and rigidity - . 

I've gotten got a kick out of making the cnc and trying to learn the electronics and think it will be just great for things like circuit board routing, odd shaped parts like oval flanges and reversing gear brackets etc . What I've made (the mechanical part) is a bit of a joke, really just some slap together mechanics to see if i can do the electronics - I may ultimately purchase the type you are talking about. I see either cnc (my diy or bought) as being a fantastic augmentation to the shop.


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## SmoggyTurnip (Apr 14, 2008)

Rather than having files for making engines, why not have files for making tools. Not everyone who has a cnc machine will want to make engines but everyone needs to make tools, jigs, etc.


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## BobWarfield (Apr 14, 2008)

Turnip, you bet, Tools and all kinds of things will be popular. This is the model of the future. CNC often requires fixtures that are a bit different too, such as soft vise jaws so you can flip parts to machine both sides. The g-codes can include any purpose-built tooling along those lines. Also, many types of things just aren't that much fun once you've done it, or may not be possible at all without CNC. I've made an indexable dovetail cutter. It was fun, and I'm glad I did it manually. If I wanted to make a slightly different one, I'm not sure I'd be that much more stimulated versus just firing up the g-codes the next time around. Or, consider a clamp I designed for CNC:







These would be a real pain without CNC. Especially if you wanted a set of 4 for the mill, and 4 extras for the drill press or whatever.

CNC is here and much bigger than people realize. CNCZone is by far the biggest of the hobby boards whether you like going there or not, and it produces very cool results. Zuesrekning is using CNC on our Team Build and getting great results, so it's even here on this board.

There is a tendency to dismiss CNC as taking all the fun out. You might as well ship the finished engine, sez McGyver. 

Well, some of the puzzle is gone, but so is some of the drudgery. If you're going to CNC castings, you will need to have some pretty precise setup skills. The more complex the engine, the more careful setup work will be called for. It isn't just slap a block of stock in and hit the button. Additionally, the majority of folks do not have a full range of CNC. Most have just a mill, for example, and must still manually do all turning. Most will not have a 4th axis if the job calls for that. Or, use the CNC to make the masters out of wood for a mold the way Wes does and then do some casting.

I'd say go for it, John. Makes total sense.

Best,

BW


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## Cedge (Apr 14, 2008)

Bob
Easy now...LOL. No one is putting CNC out to pasture here. Most of us are not in the position to invest that kind of money yet. Let the prices drop a bit and a lot of us would go there. I enjoy the challenge of manual machining and yes... I often envy the capability of CNC operations. I suspect many of us do. Truth being told, its nice to have CNC members that we can steal ideas from...(evil grin)

I love to pop in on the CNC boards sometimes to see what they've been doing, but I have nothing to contribute but eyeballs and a bit of keyboard drool. I've spent hours on your site enjoying your efforts and your style of sharing the information. Hell... I'd ask questions, if I knew what questions to ask. I'd have to know what it is I don't know that I don't yet know to even ask them.

We sometimes forget that Baskin Robbins is a successful ice cream retailer BECAUSE they offer 31 flavors..... at least one to appeal to every taste that walks in the door. There are just some flavors we ain't tasted yet.

Steve


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## Mcgyver (Apr 14, 2008)

> You might as well ship the finished engine, sez McGyver.



No i didn't say that. Please don't quote me incorrectly or take remarks out of context. I said the next step in the evolution is that and smiley clearly indicated the remark was to be taken tongue and cheek and was a bit sarcastic. I went on the say how and why cnc interests me. I have built a cnc, ground up, and am 90% there and in trials - you don't do that unless you have a serious interest and think its both fun and holds a lot of promise. I suggest maybe before you cast aspersions like i think cnc takes all the fun out of it you more carefully read what i wrote. Besides, why waste time tyring paraphrase what you think i think?



> There is a tendency to dismiss CNC as taking all the fun out



where did you observe this tendency? That hasn't been my experience, I see a huge interest in cnc from the hobby sector. Including me.

I also push back on some of your comments about what is required on set ups for complex engines and/or castings - you know this how? I've done lots of both, while I lack the depth of experience with cnc that I have with manual machines I don't think it much matters cnc or manual - the challenge with say castings is creating datum surfaces that can both be measured form and clamped to without distorting the part....anyway i think the set up challenges are more relative to the part not whether its cnc or manual.


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## Bogstandard (Apr 14, 2008)

I have been having a bit of a discussion about available CNC millers with Cedge.

I know absolutely naff all about CNC, other than some keyboard work is done, a lump of whatever is clamped to a table, a button is pressed and 10 to 15 mins later, or even less, a part that would take me all day to make manually, would be ready to be used. You might class me as a bit of a moron not knowing about such things, but I am sure what I have just said applies to the majority of people that use this site.

The reason I am starting to get interested in it, is not because I want to, it is because of the speed it can hack out the bits that I need, repeatedly.

This is because I don't have enough hours in the day to produce all that is required of me. There is nothing really that cannot be made manually in what we do, it is the time issue and repeatability is the main plus point of CNC.

I will still carry on making engines the 'hard' way, it is that side that gives me the enjoyment I crave. But when it comes to my other commitments, I am forced to look the CNC way, and I am actively seeking a miller that will suit my needs. Just waiting for a well proven, reasonably sized and priced one to come onto the market. Then it will be a massive learning curve for me to climb to get the bits made. 
Then maybe I will be able to talk with the ones in the 'know', without being baffled by all the jargon.

John


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## BobWarfield (Apr 14, 2008)

McGyver, you deal in curious shades of meaning. I'll stand by exactly what I said.

I look at these forums as a conversation. If these posts had played out as a conversation around beers, John would say what he said, you'd say what you said, I'd say what I said, and suddenly you're up out of your chair, voice raised. It makes no sense to me for you to do that given this conversation. If you want to clarify your position, by all means do so. Where's the point in attacking or getting upset?

And why would you waste time trying to paraphrase what you think I've said if you don't want me to paraphrase you (see how silly this all sounds?), or attack whether I have a clue how to set up castings for CNC?

As for the castings, I've simply pointed out that g-codes or no, you're still going to have to have some setup skills to get it to work. How do I know this? First, because I've seen it done. Second, because there's castings all around us on this site. I was looking at Hilmar's posts, for example, and imagining how I would deal with his Stuart on CNC machines. As for the topic in general, this setup issue is relevant. There's more to CNC machine work than g-code, and it isn't equivalent to getting a finished model nor even to assembling a plastic model. If you do or don't want to do CNC, more power to ya, it's all fun.

Calm down fella, quit looking for a fight. There isn't one here to be had and it isn't in the spirit the board wants to work on if there was. 

Life and conversations are a lot happier if you assume (rightly in this case) that the whole world actually likes you!

Cheers,

BW

PS I'll buy the next round of beer!  ;D


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## shred (Apr 14, 2008)

I have a little CNC mill. It works pretty well, but it's far from "load up some stock, push start and walk away" like the big machines are. Without an automatic toolchanger, you're limited to what you can do before a toolchange, and without a 4th axis, you're limited to one setup.

On single parts I don't think it really saves any time over a good DRO-- I spend a while thinking about how to hold the raw stock and how to cut it, then drawing up each of the cut steps on the computer, then converting that to G-code, then going out to the shop, squaring up a block, proofing the first program cutting air, then running the first program, changing the bit or the setup, proofing the second step program, running the second program, etc, etc ...

Then I usually end up watching the little robot make parts anyway, because it's cool (or I'm worried about something going wrong), so it's not like it even frees up much of my time

For multiple parts or complex curves, it's absolutely great-- the fan blades on my mini-fan were a perfect example-- I got a copy of the 1890's patent, traced around the blade shape, pulled that into the CAM software and made G-code. Then it was only a matter of sticking a plate of brass to a sacrificial board and hitting 'go'.

Thing is though, I couldn't take that G-code up to my friend's place and have him run it without lot of tweaking-- where I think machine zero is isn't where his is, the tools he's got are different, his axes are setup different, etc.. and that's only a simple 2D part. There needs to be a lot more work in portability before G-code sales make much sense. CAD drawings, maybe, but then there's still a number of steps to go through.


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## firebird (Apr 14, 2008)

Hi

We all know that we need to encourage more youngsters into our hobby. It seems to me ( I have the experience of 3 kids) that they seem to lack the patience to make something by hand or by hand operated machines. What they are good at is playing on computers. If they can sit there and design something on the screen of a computer that is a skill in itself and something I doubt I could do. If they could as you say bolt a lump of metal to a mill and push a button and let the computer programme make it for them then so be it. I think thats the way it will go. As time goes on CNC machines will become cheaper and one day maybe find itself in my workshop. If complicated parts can be machined from a solid instead of the usual sometimes expensive casting then more complicated models that I probably wouldn't attempt or be able to afford would become a realistic proposition especially if some kind soul wrote the programme for me and posted it on forums like this free and for all to use. I say go for it John.

Cheers


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## John S (Apr 14, 2008)

May I make a few more points without appearing to be standing on a soapbox ?
In fact I don't actually sell anything to the general public.
Most of my work is done at development level for companies.

Firstly CNC is now affordable, OK I know for some it's not but in relation it is there and getting there faster everyday.
My big 3 tonne CNC cost about £34,000 when new, and no i didn't pay that. Of this £34,000 possibly £10,000 was earmarked by the controller. This controller could be replaced tomorrow by a $159 licensed download. The drivers which cost £800 each to buy and £125 just to test when they go pear shaped have been replaced by modern £70 units that are streets in front of the old units.

CNC is also getting more acceptable as the flat earth society guys are dying off and the creeping Jesus guys are being shouted down. Bob has mentioned CNC zone, not a nice place to visit but it's a victim of it's own success. If there was no interest it would have faded into obscurity. 
Go to You Tube and do a search on CNC, last time I did this there were 12,000 videos. OK so some are commercial and posted by the likes of Haas etc but the bulk are home shop guys either converting a lathe or mill or even building a router type machine from MDF, draw slides and all thread.
Don't laugh they work and more to the point they work enough to make the MKII. In fact for some CNC has become their hobby but we don't want to go that route.

Bogstandard brought a good point up when he mentions time and CNC as a means.
I must admit I'm not into building models, I spend a lot of time building special tooling and jigs etc and like models some of it is interesting and some is just boring. 8 widgets, all the same needed for the same job. OK let the CNC do those whilst I get stuck in to that nice interesting setup.

In the UK in the 60's and 70's our intrepid Muddle Engineer would have his tea and disappear into his shed / workshop every night and probably some of the weekend. Try doing that nowadays. Her indoors would soon have something to say. CNC can help here. You spend two nights INDOORS doing your programs on the computer then you get to run those on shed nights, perfect and in a 1/4 of the time it would take normally.

So your two shed nights are now four because if you are indoors you can't be accused of being outdoors can you ? :

My concern is what do people do when they have unpacked or built their new machine, had a play and made it run up and down the table a few times.

It would be nice to have access to a CD with files on it pre-done so they can bolt a bit of scrap on the bed and go to it as part of the learning curve.

Allthumbs mentioned that many machines don't run G code the same but I was thinking of Mach3 as the controller which by price alone with probably be the controller of choice.
The G Code this machine uses is very generic, in fact my big old CNC can read this with only one line change for tool offset being needed.

What would be needed is a way to edit the published code for feeds and speeds depending on what machine runs it.
This is easy to do in a simple editor like Notepad and the G Code is only a text file, after a time sad people like myself can actually read this and know where the tool is going to go, yes sad isn't it 8)

Some while ago I drew a Harley Davidson badge up and coded it for a friend. I have lost count of the number of times I have been emailed for that file and it was never advertised or offered for sale.

Bogstandard, Try to make it to the Harrogate show on the 9th, 10th and 11th of May, I can promise you some interesting things.

Firebird. Agreed, kids today are wizz's on the computer. My son drives Solid Edge for a living designing heat exchangers. He's jsut done an enclosure for a mill that opens up and warns if somthing clouts something else.
I can't do that but having said that I know a retired guy in a home who 'building ' a full sized Fowler plowing engine on the computer because he has no workshop.
Great guy and the last time I saw him he told me he hasn't broke one tool yet ;D


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## Cedge (Apr 14, 2008)

John
Your retired friend and I would have fun together. I modeled the Minnie in 3D using ray tracing software, a couple of years ago. Over 3000 parts and almost 400 animation paths to were used to make it run. Then I discovered that my computer was too light to render the animation sequence, once it was all done...LOL. I still have the files and am looking to buying a stronger computer soon. These days big memory comes cheap. 

Here is a stationary rendering of the project.
Steve


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## AllThumbs (Apr 14, 2008)

I have a converted mill. I love it. It doesn't take any fun out, nor does it remove the challenge. It's very challenging to get the part right the first time, everytime. It still takes skill in that the operations need to be made in the right sequence, the part must be clamped in often imaginative ways. Plus you can make some very cool parts.

Eric


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## John S (Apr 14, 2008)

Not geometrically correct in that the cutter was only a vee cutter but still interesting from the simple setup required.

[ame]http://uk.youtube.com/watch?v=FkzqwIjjBhs[/ame]

Another variation on the same theme.

[ame]http://uk.youtube.com/watch?v=fps0OR1eF_s[/ame]

Ignore the shaking about, the machine was on a transport stand ready to go to a show.


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## zeusrekning (Apr 14, 2008)

I'll put what input I have. I think this is another one of those questions without an answer. So I'm speaking from my viewpoint with projects including engines, off road karts and powered equipment. There are a lot of things I can do on our CNC mills that I just can't do on a Bridgeport. And some things that could be done but would just take forever, at least for me.  But as far as turning, there really is not much of an advantage(again, for me) and this is assuming just a basic single spindle single turret lathe. Cutting thread is easier, making multiple parts is obviously much easier, and cutting tapers and radii is easier. Back to the mill, If you want to take advantage of a CNC mill you really need a good CAM package. What we use at work is just a simple 2-1/2 axis package. This would not work well for what a lot of us would like to do. I do think software has and is continuing to come down though. If you want to take full advantage of a CNC mill you would want to do 3D milling I think. 
I think setups are basically the same for manual versus CNC. The more complex setups on a CNC mill are usually required when doing what would take a couple operations on a manual.

Now to what really interest me. I went to the SouthTec machine tool show a few years back. They had "Touch to Teach" machines. I'm not confident the brand or actual name they were called. But you could run the lathe just like a manual lathe, but say you turned up to a shoulder and needed an external radius (G3) you would type in the radius you wanted and while you moved the carriage, the cross slide would move automatically to cut the radius. , same for tappers. You could also push a button after every move you made and it would store it so you could run the part again, or multiples of , with out writing a program. There are similar conversational machines for milling.


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## alan2525 (Apr 14, 2008)

This is my first proper post (excluding the welcome one)

I'd be interested in the idea of a package containing all the cnc files for a project. At the moment I'm using a Roland EGX 300 to cut out model parts, engrave and cut thin brass sheet for the cab of a small loco.

The loco is 16mm:ft and I'm looking to convert a Taig Mill to cnc and work on machining larger parts for the loco too. 

One area that mystifies me a little with cnc is the actual machining sequence for a particular part, in manual machining the greatest difficulty is often holding the item in position for the various machining steps. A part by part set of machining instructions to go with the files would be an excellent learning tool.

Would sort of level of cnc knowledge would one need for your idea and also what kind of cnc setup? Small Taig Mill, Micro Mill or large 5 axis setup that can machine Ferrari V12 Engine blocks - like the cnc machine I dream about owning?


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## Mcgyver (Apr 14, 2008)

> McGyver, you deal in curious shades of meaning. I'll stand by exactly what I said.



stand by whatever you want, but you said 





> There is a tendency to dismiss CNC as taking all the fun out. You might as well ship the finished engine, sez McGyver.


 that is a misquote and takes my post out of context, anyone reading it who hadn't read post would assume i was somehow anti-cnc. I don't appreciate either the misquote of the repacking to suggest i dismiss it or think it takes all the fun out. It's neither true or what i wrote or curious.



> As for the castings, I've simply pointed out that g-codes or no, you're still going to have to have some setup skills to get it to work.


that's a reasonable statement, valid point and i buy it. Your original statement was far more absolute. The point is valid but but the lecturing tone from someone who has done neither was over the top so i called you on it, same as someone would over beers. 

For someone in a conversation to declare BS it doesn't have to mean they're angry. I am neither upset, jumping out of my chair or looking for a fight. otoh, to use your beer's analogy, if you were confronted by someone you think is getting hot under the collar telling them to 'calm down fella' is a rather incendiary remark likely to escalate rather than diffuse. Not me though, I'm just not upset


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## Cedge (Apr 14, 2008)

Alright you two... cut it out. Go find separate trees to pee on. 

Steve


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## alan2525 (Apr 14, 2008)

One area where cnc really excels is repeatability, often in model engineering jobs you have to make multiples of the same part. I find that really soul destroying as I'll happily make one part but it's one reason I don't model 17th century galleons...on account of all of those guns!

I think the affordability of cnc machines can only encourage people into the hobby, plus the cnc machine won't do everything for you! There's still a whole range of skills and additional processes that need to be carried out often manually.

More Beers?


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## DICKEYBIRD (Apr 14, 2008)

John S makes some very good points. I can relate to the statement about CNC becoming a hobby in itself.

My life-long hobby/affliction/obsession (until starting this machining thing) was designing & building r/c model aircraft. I began using CAD to enable me to generate a clean & clear plan to share my stuff with others of like mind. Then I saw a magazine article about home-built CNC and built a myself a CNC router. Once the learning curve (which was very steep 10-12 yrs ago) was over, I looked for excuses to make EVERYTHING on the router. Many parts could've been made a lot quicker the "old way" but I chose to use CNC if at all possible. There's something extremely rewarding about being the master of a robotic device that does your bidding and can make things with extreme accuracy and repeatability. I found myself completely absorbed in the process of CAD/CNC creation of my parts and enjoyed every minute of it.

I don't use it as much now since I've pretty well dropped out of the aircraft hobby while learning to machine metal. I have used it to spot & mark hole patterns for machining projects since it's positioning is very accurate. It's made from MDO plywood and uses drawer sides so is useless for cutting anything other than balsa and thin plywood or plastics.

I read the X3 conversion threads on CNCZone with mouth open and drool running out. Unfortunately, my very limited budget is soaked up adding tooling now & then to my shop. I'd do it in a heartbeat if the funds were available. Sigh, someday.

You guys that can afford it should go for it; you won't be sorry! ;D


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## alan2525 (Apr 15, 2008)

When cutting parts out with a cnc machine I really enjoy the feeling of getting something for nothing and enjoying a cup of tea and an episode of Eastenders (OK maybe enyoy was too strong a word) whilst my machine plays it's little stepper motor concophony as it cuts away - then checking in on the machine to see the cutter back in the home position and a little assortment of completely professionally finished parts awaiting assembly.

The alternative is to see the shank of the cutter and a assortment of partially cut out parts and the cutter conviniently next to a hold down after setting the clearance to 2 mm rather than 12 mm!

I also like the fact that once the part is drawn it removes some of the worry about messing a bit up if the part had a huge number of man hours work into it. It's nice to know it's easy to change the design and adapt it to suit and easily cut it out again.

I also like the fact that I can switch my work light off and close the door whilst the machine makes parts for me.


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## shred (Apr 15, 2008)

zeusrekning  said:
			
		

> Back to the mill, If you want to take advantage of a CNC mill you really need a good CAM package. What we use at work is just a simple 2-1/2 axis package. This would not work well for what a lot of us would like to do. I do think software has and is continuing to come down though. If you want to take full advantage of a CNC mill you would want to do 3D milling I think.


2.5D will do fine for 90+% of what a CNC does.. 3-D (and 4th Axis) are nice, but not really necessary for a whole ton of stuff. I thought I would use 3D a whole lot more than I do, which is rarely.


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## Julian (Apr 19, 2008)

Hi All,

My next two projects for "Tooling" are to make my xi into 3 or 4 axis cnc and to build a dedicated cnc machine from scratch. The first because my hand aches turning the handles and how many times have you turned it the wrong way and had to start again!!!!!! The second machine is because it is a challenge and why not? I'm still building something I either want or need or both. Whether anyone likes it or not cnc is here to stay, grow and become the norm. An example...... how many complained when the electric lathes threatened to take over from the peddle or belt driven. I bet they said "Thats cheating and it will not last!!!"

Look at it this way....does it matter how you make the parts you want? Not to me it doesn't...bring on the cnc.

Julian.


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## Alphawolf45 (Apr 19, 2008)

Julian  said:
			
		

> Look at it this way....does it matter how you make the parts you want? Not to me it doesn't...bring on the cnc.
> 
> Julian.


.
 .It does certainly matter how you make the parts, this isnt really about the parts is it?..If it were just about the parts I'd have some one of these experts build my parts and save me the bother...No this is about having your own machinery and enjoying the using of that machinery...And naturally the choice of machinery is beauty in the eye of the beholder..Its your choice... I'll take one of each if I get my druthers , I like'em all- dont you?...... ;D


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## Julian (Apr 21, 2008)

Alphawolf45  said:
			
		

> .
> ...No this is about having your own machinery and enjoying the using of that machinery...And naturally the choice of machinery is beauty in the eye of the beholder..



But if you have build that machinery to make the part wheres the problem. I don't beleive it matters where the part comes from. If you've made it yourself by ANY method with ANY machine....fine. If for some reason you can't or don't want to make that part......buy it. Thats fine too because thats your choice. If you bought all the parts ready machined as in a Stuart model or one of the 2" or bigger kits.......so what? you've still built something. As far as I am concerned it does not matter how much one makes or buys ready-made its the "doing it" that gives this hobby its variety and appeal. 

I am NOT having a go at anybody here but accept that CNC is moving in fast and then whatever follows it!!!I say "Bring it on. If it helps me I'll buy it or make it". I am gonna build a cnc machine to use in my shop. Is this different from making any other tooling for the shop? NO!!! Trust me we need guys like John to help the developement of this type of product. Don't knock it...use it.




Julian.


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## alan2525 (Apr 21, 2008)

Well said that man!

CNC is just a very useful tool, it's an extension of having a digital readout on a mill, the machine just rotates the hand wheels like a very elaborate power feed!

The world of machining has always been about striving for accuracy and machine tools have been invented to make the job easier, more accurate and also faster to produce. I don't think it undermines a model, however it's been created.


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## John S (Apr 21, 2008)

HOW you make parts does matter depending on your view on the model, your leisure time, personal build up, experience and the knowledge and ability to learn.

If anyone expects that they can go out and build or buy a machine load a code and it spits a perfect part out is in for a shock.

Just as when you were first let loose on a lathe you didn't do an internal multi start thread did you ?
Chances are the first few threads you did were crap - mine were 

Just as making a run of parts on a turret or capstan lathe will differ in setup and operation from making 10 one off on a centre lathe so will learning to operate a CNC.

For a start a lot of the important work on a CNC is done away from the machine [ hint extra play time whilst inside with her indoors ] For some this becomes an extension of their hobby. Speeds and feeds are very important, there is no 'feel' on a CNC so you have to understand this more so than working manually.
We should be able to understand feeds and speeds as it is but like many you can get away with 'feel' and sticking your tongue out the side of your mouth makes up for a lot of short comings .

Then we get onto holding methods, again probably totally alien to how you would do it manually.

Take a crank web, manually you would drill and ream the two shaft holes then using a pin in a rotary table you would mill the radius then reclamp and mill the outer web shape in anything from 3 to 7 settings.

On a CNC the quickest way would be to mount a piece of round bar vertically in an old chuck on the bed. Rough the holes, rough round the outside then finish the outside and the holes in one pass at full depth, climb milling all the way for a smooth cut, then part the slice off in the lathe or even two slices if needed.

The skill is still there but it's a different skill.

I recently made this:-







It's a selector cam out of a racing bike gearbox, can you imagine the amount of jigging and special tools, followers etc needed to make this ? Fine for industry when they were making 1,000's but this was a one off and not even a copy.
Worse it didn't work as required and the second one had a different profile on the last cam to stop it clouting the 4/5 gear.

There was absolutely no difference in the setup between the MKI and the MKII

60 Years ago most home shops had a lathe and possibly a drilling machine - period. When I first got interested in home shop engineering no one I knew had a mill, everything was done on the lathe.
Slowly mills came in to supplement the lathe. CNC's will be no different. They won't take over but will be there to supplement existing tooling.
CNC Mills are very adaptable.

Not got a 1" x 20 tap for that special job and it too lopsided to go in the lathe ? Simple take an old broken 3/8" BSF tap grind all but 1 flute away and you now have a thread mill.
Drop it in the hole, start up, move the the side of the hole and do one circle lifting the tool 1 pitch as it goes round. 
Perfect thread in one pass and that tool will do ANY 20 tpi thread it can fit into or even thread the outside of a shaft in one pass.

Want a nice flowing shape for a carburettor body and a form tool will be too wide and chatter if you can grind a nice enough shape ?
Simple bolt you lathe toolpost to the mill bed, stick the carb body in a holder in the spindle and switch on. You now have a CNC vertical turning lathe.
Change the tool for a boring bar sticking vertical and you can form the inside shape to get a uniform wall thickness.

Same part - different skills.

.


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## Bogstandard (Apr 21, 2008)

I am really enjoying this post, it is giving me a lot to think about, and John has dispelled a lot of fears about it, and explained very well the way things are done.

As I have stated before, I am a manual machinist, but have eventually got to go down this route. Thru necessity, not want.

I am just about to start on refitting my workshop, and I would have loved to be able to get a small CNC miller that could just be switched easily from manual to CNC, so allowing me to carry on manual milling whilst learning the art of CNC. 
But the 836 machines I am looking at just don't seem to be able to do that. Unless you know different. 
So that does limit me at this time to buying an 836 and later getting a dedicated smaller CNC mill, maybe the same size as the Sieg X3. 
I am very tight for space, that was the reason for the manual/CNC combination thought. Maybe it is the leadscrew bearing systems that would prevent it being able to be done.

Any thoughts?

John


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## alan2525 (Apr 21, 2008)

I downloaded Mach3 and Lazycam today just to have a play and get an idea of what is involved setting up the machine, workflow (IT speak) I actually got it to simulate cutting a couple of rectangles which was something! There's a free trial so might be worth a look if you are thinking of going the cnc route, plus the option of using the machine in 'manual mode'...i.e. just giving it basic commands to operate it.

I've bought a little Taig but haven't picked it up yet!

The software looks like it'll take a little getting used to to avoid the endmill from crashing straight into the table! I'm sure it'll be a bit of a leap of faith taking the first cuts on a cnc! Also I think why they use matrix plates a lot on cnc converted machine, just to save or hide lots of "oops's" on the table!


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## John S (Apr 21, 2008)

Again two schools of thought.

Now I don't want to put words into peoples minds or thoughts but get them to think for themselves.
There will be some people for whom CNC will never fit if hell froze over, not because they won't adapt but because CNC won't fit their needs.

At some of the shows and even a couple of clubs I have given talks on CNC, The nuts and volts so to speak. Just out lining the facts as it's too deep a subject to get into in an hour or so.

In this talk and I won't go into it too deep here I identify 8 reasons to adopt CNC. There are more than 8 but that covers the main points. Starting off with lack of trained people given there have been no apprenticeship schemes for the last 20 years to speak off, computer literate people coming into the hobby from office and clerical jobs, ease of setups like that cam, the workshop supporting another hobby like restoring vintage vehicles up to CNC now becoming a hobby in itself.

They I say it's like the pools take any 3 from 8 but hardly any two people will take the same 3 reasons.

Anyway to try to get back on track to John's query about manual machining it is possible to keep some of the manual machining features on the X and Y axis by fitting double ended stepper motors and handwheels but it's usually harder to do the Z axis because the motor has to be mounted either on top or under the column.

Dependant on design and size of machine it's possible to use the CNC'd head or knee as a 'power feed' and the quill as a manual feed.

The other way and eventually many go this route is to use the computer as a glorified all axis power feed.
In many conversions we have been asked to fit handwheels for the manual work. We have explained about using the computer in either MDI mode or conversational, where you fill the blanks in but we still do as they ask.

Later when we ask how they are managing the vast majority say they have removed the handwheels.

Here's a conversational screen:-






It contains simple everyday machining operations that can be done by filling the boxes in and it automatically writes the code.

Things like bolt circles, cut circle, cut arc, pocket circle and rectangle, in fact most modules that make up common shapes and they can be added together.

The next screen take you to the box filling bit:-






This is the material surfacing screen where it works out prepping a block up for machining.






Circular groove for trepanning or 'O' rings.

These are done at the control and only take a few moments to fill the boxes in, when you Post Code it then goes back to the main controller and the code has pre preloaded ready to run given the right tool and location.

.


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## zeusrekning (Apr 21, 2008)

I would say go with the handwheels. At work our CNC's have the handwheels, MPG's,. I often use this to do "manual machining" on the CNC. It is often that do don't want to make a program for something simple. EX. flycutting, machining a step in jaws, drilling a hole.
Tim


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## shred (Apr 21, 2008)

FWIW, a good deal on a manual Taig mill just crossed my path and it's going to go right next to the CNC Taig for those manual jobs I used to do on that. 

It's possible to drive the CNC in manual mode, but this is nicer


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## rake60 (Apr 21, 2008)

I am also enjoying this thread.
I admire the accomplishments of home machinists who are capable of converting
small machines to CNC.

John S wrote:


			
				John S  said:
			
		

> There will be some people for whom CNC will never fit if hell froze over,



I'm afraid that would be me.
Please allow me to offer an explanation as to why.
Today at work I set up a job in the CNC machine I operate. 
It's a ring with a critical ID, OD and dovetail groove that also has a critical
tolerance. Each side of the part has a total cycle time of 29 minutes.
There are 124 forged rings on the stock pallet to be machined into those rings.
It's a job perfectly suited to a CNC operation.
After 11 hours a day of simply maintining an operation by adjusting tool offsets 
as the tooling wears and hydraulic temperatures fluctuate, it's the last thing I'd
want to do at home. 

Please don't take that as a negative comment.
It's just my personal view, tainted by far too many hours spent 
trying to trick a Mazatrol program into doing what it needs to do.

Rick


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## shred (Apr 21, 2008)

My trick is to completely ignore tool offsets and cutter comp and all that for the time being. Makes things much simpler on a little machine.


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## Brass_Machine (Apr 22, 2008)

I am going to be going to CNC probably very soon. I am playing around with what I want to use for software... I haven't really decided yet. My lathe will probably get the CNC treatment first, followed by X3 or IH mill. I will keep the X2 manual. I have a deal to get some 80/20 extrusions to build a router as well (just need to get off my @$$ and tell him what I want).

I am OFC, doing this for a completely different reason than the hobby of engine building. I am trying to get a business started... I can handle making the parts manually for a little while, but it will get to the point where I need the CNC. May end up buying a second larger lather to CNC


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## Alphawolf45 (Apr 22, 2008)

I have 2 cnc mills..One is old Acroloc , weighs 5000 pounds , retains its old controller - not fun inputting programs one line at a time but has automatic toolchanger and can still do the job....
.
 But I also have an old Hurco cnc mill, weighs 4000 pounds, I replaced the servo drives and computer and VFD , power supply and limit switchs..Runs Mach3 on a PC...Real good machine..
.
 And I have a 5700lb Miyano cnc lathe that I bought with dead controller for 500 bucks...I'll have about 3K in it by time its making chips.
.
 I'm willing to discuss pros and cons of buying / rebuilding old cncs...I rather go that route than to CNC a manual machine but there are significant disadvantages as well.
.
 And I second the sentiments expressed by rake60...I hate it when I have to run a cnc for hours on end.majorly boring....I prefer to be doing oneoffs with manual mill......A cnc has some 'cool factor' but it dont give me the warm fuzzies like a ton and a half of old American iron...


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## John S (Apr 22, 2008)

Alphawolf45  said:
			
		

> .
> I'm willing to discuss pros and cons of buying / rebuilding old cncs...I rather go that route than to CNC a manual machine but there are significant disadvantages as well.
> .



Very good advise on machines of a certain size.
I often get asked what will it take to convert my Bridgeport to CNC ? The flat answer is forget it.

On one hand you have a manual machine with a worth of say $1,500 to $4,000 taking a broad out look.
You then need to but 3 motors at $150 to $200 each. A set of three ballscrews at probably $600 to $800. Harder still you have to drive a quill that wasn't designed for it and put up with leverage and unsupported forces.
Add to this drivers, transformers, case, switches etc, etc and that adds about $500 to the plot.

So add that up and on a base machine of $1,500 it comes to about $3,400 and on the better machine, $5,900

Only problem is you have now got a hybrid worth about $500 to $800 max.

The best bet is to keep the Bridgy as a manual machine if you have the space and buy a dead CNC. If you don't have the space think about selling the Bridgy to finance a dead CNC and you should be able to do the conversion with money left over.

The old Bridgeport BOSS 1's to 5's are ideal for this. Every college and school had then and many still exist stuck in corners somewhere. The iron is still good, in fact most of these did very little work as the electronic of the day were naff and they blew up at regular intervals.

These had a quill designed for motor drive, a rigid ram, ballscrews fitted to all axis, pressure oiling, fitted motors and cases full of useful gubbins.

When we get onto the smaller machines this same example doesn't apply as there is a very limited source of CNC ready small machines. In the UK there are the Boxford and Denford training CNC, again with obsolete software but even broken they fetch far more than they are really worth on Ebay so as a costing exercise there isn't much difference in taking a Chinese mill, treating it like a donor and converting it.

Often you can be in front as you will be using the latest new steppers which are far superior to the old round ones. Another plus is you can often squeeze greater travels out of a conversion than a design that was written in stone.

.


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## Cedge (Apr 22, 2008)

John S
Your thread has had me doing a bit of looking around at home built CNC. I'm pleased to see controller and stepper kits have come down in price to a level that is becoming attractive. The CNC Router idea has merit for many of the types of things I'd be wanting to do. 

I also have a perfectly usable mini-mill that was recently replaced with a larger mill, which might be a candidate for the conversion route. Any particular suggestions for a dependable but economical source for the hardware/ software... etc? Would one be looking for 2.5, axis 3 axis, 4 axis, extra outputs.... for doing things like cylinders or shaping engine bases? 

Guidance....?

Steve


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## BobWarfield (Apr 22, 2008)

For a mill, I'd be tempted to build out the electronics for 4 axis so you don't have to worry about it later. This way you'll have made sure your power supply is beefy enough and so on.

Lots of great electronics to choose from out there. This page is not absolutely the latest in up to date, but it ain't bad and may serve as an introduction:

http://www.cnccookbook.com/CCBreakoutBoards.htm

That unused mill sure is a perfect place to start!

Cheers,

BW


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## John S (Apr 30, 2008)

Didn't want to start a new thread so tacked this on the end of this one.

For any UK based people interested in CNC then ArcEuroTrade has announced their new range of Complete CNC's.

http://www.arceurotrade.co.uk/Catalogue/New-Products

Hopefully if I can get the cabinets finished in time then both will be at the Harrogate show.

.


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