[sburck]

Well this is my first post here, I've been creeping around a little bit and there don't seem to be many (or any...) sticky threads for newbies. Ive looked around on the internet too and have come across some info, but I want a whole lot more.

As the title states, I need resources to learn about this stuff. Can anybody recommend some books, websites, good blogs etc? I have a whole lot of newbie questions that I need answered.

Some more background info, feel free to comment:

I am a senior mechanical engineering student, and I am planning on building a CNC Mill with some money that I will be getting for graduation gifts, the job I (hopefully) will be getting, savings ETC. A couple things of note. I would like this to be a DIY project because I believe it will be fun, and I want to learn a lot. I do not expect to save money by doing this by myself, however that would always be a welcome bonus. As this is the case, I am not looking to simply buy a manual CNC machine retrofit it with CNC hardware.

I have been checking out various things online and found this guys channel on youtube:

Simpsons36's Channel - YouTube

I really admire his work. I understand that I should probably start with a simple 3 axis machine and go from there, but I really like all of the neat stuff he came up with such as his fourth axis (which he can use as a lathe...), trunnion table, etc.

Some things I am looking for:

-Ability to do steel.
-At least 18" x 6" x 4" travel.
-I would like the ability to grind sharp edges. (possibly upgrade to this capability eventually)
-Machine must run on household 120v AC without blowing a 15a breaker.
-Machine must be able to be broken down for moving, without any individual parts that weigh more than ~250lbs.

-Thanks!

[bob2231]

"Machine must run on household 120v AC without blowing a 15a breaker."
I'm certainly no expert,but I think that requirement may well sink your boat.

[vidio1]

Sounds like a pretty ambitious first project. There are several build threads here if you look around some more. The trend seems to be cast and poured from home made molds and then machined/ground, or tubing filled with epoxy-granite (more popular). Typically the 4th axis and trunnion are an add on that is bolted to the table or fixture plate so you can start with a 3 axis and build from there. 18x6x4 isn't huge so you should be good with 110v although not the best choice. 15a with get you 1650 watts or just over 2hp which is probably more than most will ever need for a home brew mill.......Good luck.

[sburck]

"Machine must run on household 120v AC without blowing a 15a breaker."
I'm certainly no expert,but I think that requirement may well sink your boat.

Was going to say what he said below, 2 hp is plenty. If need be, I can run everything else off of a different outlet/breaker so that the motor has its own breaker.

Sounds like a pretty ambitious first project. There are several build threads here if you look around some more. The trend seems to be cast and poured from home made molds and then machined/ground, or tubing filled with epoxy-granite (more popular). Typically the 4th axis and trunnion are an add on that is bolted to the table or fixture plate so you can start with a 3 axis and build from there. 18x6x4 isn't huge so you should be good with 110v although not the best choice. 15a with get you 1650 watts or just over 2hp which is probably more than most will ever need for a home brew mill.......Good luck.

I've seen a couple of people cast epoxy-granite molds, but wouldn't these have to be sent off to shops to be flattened and squared?

[vidio1]

Anything you build is going to need to be machined and/or ground if you have any hope of it being square and level. There are a few books mentioned in build threads on the subject. If you don't have access to machinery yourself it's going to add considerably to the finished cost of your machine. Generally speaking you can only build something as precision as the machines you built it with. In other words don't expect a machine built with a hacksaw and drill press to hold and repeat with the same tolerances as a ground machine..........

[sburck]

Anything you build is going to need to be machined and/or ground if you have any hope of it being square and level. There are a few books mentioned in build threads on the subject. If you don't have access to machinery yourself it's going to add considerably to the finished cost of your machine. Generally speaking you can only build something as precision as the machines you built it with. In other words don't expect a machine built with a hacksaw and drill press to hold and repeat with the same tolerances as a ground machine..........

This I understand. I do plan on having some parts made for me. I just see it being difficult and expensive to grind down a cast epoxy granite base, as it will not have a single square edge in the first place.

[vidio1]

I'm not sure you have a firm grasp on what you are considering undertaking. I recommend checking out this sticky about epoxy/granite: http://www.cnczone.com/forums/epoxy_...es_thread.html

There are a few books mentioned that are recommended reading as well.

[sburck]

I'm not sure you have a firm grasp on what you are considering undertaking. I recommend checking out this sticky about epoxy/granite: http://www.cnczone.com/forums/epoxy_...es_thread.html

There are a few books mentioned that are recommended reading as well.

In all honesty the E/G thing seemed a little bit too complicated at first, and after doing more reading it seems to be even more complicated than I originally thought. Designing the molds, building the molds, applying mold release and possible gel coat, picking the proper aggregate, picking the proper resin, compacting the aggregate, de-gassing the mix once poured, releasing the mold, and grinding everything flat. There seem to be so many different instances where one could screw up and ruin the whole process. Filling steel tubular structures with concrete or E/G seems to be very worthwhile and more forgiving, but casting a quality base seems to be far outside the scope of what I am willing/capable of doing.

I would definitely consider filling steel members with E/G, but as for building the machine structure itself out of the material, that is not something I want to deal with. I am more interested in the hardware and the control system itself. Many DIY people seem to get pretty solid results building machines from laser-cut plate steel, E/G filled steel tubes, 80/20, etc... I might be able to find a good pre-made base plate, or even solid chunk of an appropriate material with the correct tolerances and dimensions from some other application, which could be adapted for use in a mill. I am not looking for the perfect machine, but just one to suit my needs.

[BobWarfield]

I did an E/G fill of my Industrial Hobbies mill and it was a very worthwhile project. If I wanted to build a machine from scratch, I wouldn't hesitate to consider a welded frame with E/G fill.

Some information on how I went about doing the E/G fill here:

CNCCookbook: Epoxy Granite Fill

Here are some design sketches on a fairly large E/G gantry mill:

CNC Cookbook: An Epoxy-Granite Mill Design Sketch

As for the precision aspects, you can have a local machine shop machine the mountings for the linear rails on their VMC. Once you have the linear rails up and going and square, you can let the machine face mill its own table.

Cheers,

BW

[sburck]

Been doing a lot of reading on the e/g stuff. It looks complicated, but it also looks like it is doable without a whole lot of expensive equipment if you put the time in for research. One big disappointment is that I could only find a few documented diy e/g mill projects even though there is so much talk about the subject dating back to 2007. All I could find was the German mill, the mill from the practical machinist forum (which has a lot of research and part drawings, but I am unsure if this project was ever actually finished), and a couple of projects where people simply built bases for their machines or filled an existing cast iron structure.

[aarggh]

[QUOTE=sburck;1027002]Been doing a lot of reading on the e/g stuff. It looks complicated, but it also looks like it is doable without a whole lot of expensive equipment if you put the time in for research.QUOTE]

Dead right! Don't be daunted by the sheer scale of what you trying to achieve, it is very doable, BUT, as you are no doubt starting to find out, it is a massive amount of research, and reading between the lines with others advice, experiences, and qualified opinions.

The best advice I would give is keep it as simple as possible to avoid ending up with a stalled or dropped project. Aim for using as good as possible, materials for the build to avoid heartache with a bad finish design or end result. Obviously this will mean your budget may not be as low as you anticipate. Part of the learning process of building a CNC whatever, is finding out afterwards the many things you did wrong with the materials used, the design of the machine, the greater than expected forces involved, etc, etc. This is why the practice of recommending to people starting out on a XX' x XX' build that they start out with a much smaller X' x X' first is so valuable.

I started out planning an 8' x 4' originally, but the more I learnt of what was involved, the more daunting it became, I ended up buying a few small machines, and over the last few years have learnt so much from having them I'm now in a position to tackle the big one next year with much more knowledge.

Trawl youtube and this site, apart from simpsons36 you mentioned, some of the great youtube users I regularly watch for machining, milling, feedrates, tooling, build info, etc, are:

3sectionmonk
atienzalouie
blmartech
cnccookbook
cncdiy
cncnutz
cnctapintok
cncwoodworker
hossmachine (awesome stuff here!)
jonblissett
marcelmx3
mdavidlem
mindhive
mrpete222 (mostly lathe, but LOADS of good cutting/tooling info)
myfordboy (great casting info)
neo7cnc.com (great all round cnc stuff)
saunixcomp (you'll like this one!)
tormachllc (of course!)
zerodegreec
zhazka123 (just cause it's a beautiful machine!)

If the cnc machine links don't seem applicable, it helps to think of a mill as a very rigid, fixed gantry, 3 axis cnc machine

Of course, the people here are a fantastic resource, and hoss and ger21 to name just the most prominent ones I know of, are probably the very best and knowledgeable resource you could get here, go through their threads and you'll learn heaps. Hoss especially should really have his own "Pimp my Mill" TV show!

Go slow, look at as many pictures and videos of others work and machines as possible, to see what they did right, or wrong, and mentally picture how you could do it better or differently, using the same or other materials. A good case in point, if you had to flat surface a molded base, if you have a router you could easily rig up on a firm and flat surface, (a decent kitchen table top would be adequate in most cases) a sliding frame or sled to use the router overhead, such as shown here:

Router Sled Planer

Obviously using some good machined aluminium as the guides gives a more accurate result, but you get the idea, there's loads of ways to simply achieve a result in lieu of the more approriate tools.

cheers,
Ian

[sburck]

[quote=aarggh;1027035]

Been doing a lot of reading on the e/g stuff. It looks complicated, but it also looks like it is doable without a whole lot of expensive equipment if you put the time in for research.QUOTE]

Dead right! Don't be daunted by the sheer scale of what you trying to achieve, it is very doable, BUT, as you are no doubt starting to find out, it is a massive amount of research, and reading between the lines with others advice, experiences, and qualified opinions.

The best advice I would give is keep it as simple as possible to avoid ending up with a stalled or dropped project. Aim for using as good as possible, materials for the build to avoid heartache with a bad finish design or end result. Obviously this will mean your budget may not be as low as you anticipate. Part of the learning process of building a CNC whatever, is finding out afterwards the many things you did wrong with the materials used, the design of the machine, the greater than expected forces involved, etc, etc. This is why the practice of recommending to people starting out on a XX' x XX' build that they start out with a much smaller X' x X' first is so valuable.

I started out planning an 8' x 4' originally, but the more I learnt of what was involved, the more daunting it became, I ended up buying a few small machines, and over the last few years have learnt so much from having them I'm now in a position to tackle the big one next year with much more knowledge.

Trawl youtube and this site, apart from simpsons36 you mentioned, some of the great youtube users I regularly watch for machining, milling, feedrates, tooling, build info, etc, are:

3sectionmonk
atienzalouie
blmartech
cnccookbook
cncdiy
cncnutz
cnctapintok
cncwoodworker
hossmachine (awesome stuff here!)
jonblissett
marcelmx3
mdavidlem
mindhive
mrpete222 (mostly lathe, but LOADS of good cutting/tooling info)
myfordboy (great casting info)
neo7cnc.com (great all round cnc stuff)
saunixcomp (you'll like this one!)
tormachllc (of course!)
zerodegreec
zhazka123 (just cause it's a beautiful machine!)

If the cnc machine links don't seem applicable, it helps to think of a mill as a very rigid, fixed gantry, 3 axis cnc machine

Of course, the people here are a fantastic resource, and hoss and ger21 to name just the most prominent ones I know of, are probably the very best and knowledgeable resource you could get here, go through their threads and you'll learn heaps. Hoss especially should really have his own "Pimp my Mill" TV show!

Go slow, look at as many pictures and videos of others work and machines as possible, to see what they did right, or wrong, and mentally picture how you could do it better or differently, using the same or other materials. A good case in point, if you had to flat surface a molded base, if you have a router you could easily rig up on a firm and flat surface, (a decent kitchen table top would be adequate in most cases) a sliding frame or sled to use the router overhead, such as shown here:

Router Sled Planer

Obviously using some good machined aluminium as the guides gives a more accurate result, but you get the idea, there's loads of ways to simply achieve a result in lieu of the more approriate tools.

cheers,
Ian

Thanks, thanks a lot of useful info. Lately I have been reading about various spindles. I am unsure as to what speed spindle I need for the work I am going to be doing.