Newbie- DIY CNC Router Questions...

[kinghong1970]

Heya folks...

so i was up last night till 2am thinking of what new "hobby" project i can undertake that will piss off the missus and i think i found one...

i saw all the awesome goodies that can be made with a CNC mill and now, the DIY Table machines sounds very interesting.

my interest at the moments are in computers... as a matter of fact, i've seen members of my computer forum (XS) here as well.

in any case, question about DIY Table top router machines:

1) can it be used to cut designs on up to 1/8" thick aluminum sheets?
2) can it be used to make CPU water cooling blocks?
3) how accurate are these machines? how intricate of how small can the work detail be on the table machines?

now the material for the watercooling block is copper base with derlin tops and either copper or steel mounting brackets.

i get a feeling that those blocks will require a different sort of machinery?...

i have not even been near a cnc mill but have been around making things and modding computer cases... is this too big of a project to undertake?

sorry for so many questions...

thanks!

[Cartierusm]

Wow lots of questions, I'll see if I can help. First I'm not sure about a wood base CNC router cutting aluminum, depending on how rigid you make it. I have an Aluminum CNC router and can cut Aluminum but I take real shallow cuts, but the feed rate is pretty fast.

I don't know how accurate the cooling water blocks need to be but I think they probably need to be pretty flat, if so it can be done if the machine is solid.

If you're talking about make a solid machine it all depends on your skills with tools. You will need lots of tools to make a good machine that's accurate.

Accuracy all depends, again, on your skill, the tools you own or can borrow and the cost of the parts. You can spend $10 on a lead screw or $1000. Just depends on how far you want to go, but anything that pisses off your missus is fine with me .

Very small work can be done if the machine is made accurately with high end parts.

[kinghong1970]

Cartierusm,

thanks for the reply...
being a complete nub at this, i guess my questions were a bit vague...

Originally Posted by Cartierusm Wow lots of questions, I'll see if I can help. First I'm not sure about a wood base CNC router cutting aluminum, depending on how rigid you make it. I have an Aluminum CNC router and can cut Aluminum but I take real shallow cuts, but the feed rate is pretty fast.

by making it "rigid" are you referring to the material used to make the CNC?
i've seen plans that are wood or MDF based... and i've seen this...



seems that the material used in his CNC is mostly aluminum using the 8020 farmes...
would this be a "rigid" build?

Originally Posted by Cartierusm I don't know how accurate the cooling water blocks need to be but I think they probably need to be pretty flat, if so it can be done if the machine is solid.

well, hmm... lemme read up a bit more and respond later on this issue...

Originally Posted by Cartierusm If you're talking about make a solid machine it all depends on your skills with tools. You will need lots of tools to make a good machine that's accurate.

i'd like to think my skills are good... lol... but as for tools, is it wrong to assume that some of these "kits" are DIY that only requires assembly?

for some reason, i'm under the impression that the cheapest way to do it is DIY as much as you can... but i rather spend a bit more if it'll make it "easier"

Originally Posted by Cartierusm Accuracy all depends, again, on your skill, the tools you own or can borrow and the cost of the parts. You can spend $10 on a lead screw or $1000. Just depends on how far you want to go, but anything that pisses off your missus is fine with me . Very small work can be done if the machine is made accurately with high end parts.

ok, well, i think i got my homework cut out for me... i'll be doing some more reading for now.

thanks again for your reply...

i'm sure i'll have many more questions...

wifey's gonna be pissed... fosure...
maybe i should get her something to keep her busy for a bit...

[Cartierusm]

Sorry are you going to buy a kit or build your from scratch?

Most of mine is 8020 for the basic frame but the gantry and such is a combo of aluminum and 8020. I'm sure it you look a posts started by me you'll find pics of my builds.

[Hirudin]

I wrote a huge reply, but I decided to cut it down to something more concise... ([edit]keeping things concise really isn't my strong suit[/edit])

The answer to your first two questions is: Definitely!
Regarding number two: http://www.cnczone.com/forums/showth...1941#post31941
The answer to number three is: It depends.

It all boils down to how rigid your machine is. To put it another way it depends on how resistant your machine is to bending.
Cutting metal is like trying to push a straw through a milkshake. If the straw is thin/weak it'll bend considerably, if the milkshake is very thick it'll bend even the strongest straw. A thin straw is like a non-rigid machine and thick milkshake is like hard material.

For the most part, the larger the cutting area the harder it is to keep the machine rigid (think of a very long straw). To increase rigidity you can make your machine smaller or make it from stronger materials. Reducing the size makes it cheaper not only in material costs but also in the motors/drivers/power supply required to move the machine around. Larger machines understandably require larger motors (read: more expensive motors).

It sounds like you have two different goals in mind with drastically different sizes. Case mods will require at least 12" by 12" of cutting area (my case, the Antec P180, is roughly 20" by 20") whereas heatsinks only need about 4" by 4" of cutting area, or MAYBE around 5" by 11" if you want to make something gigantic for a video card or something.

General definitions...
CNC Router = big table that stays stationary and a router/spindle that moves around to cut out parts.
CNC Mill = drill press-esque machine where the spindle stays stationary and the table moves around below it.

For case mods a CNC router would probably be best.
For water blocks you'll probably want a store bought mill with a store bought CNC kit.

Both types of machine will do both jobs, but...
For a CNC router to cut thick pieces of metal accurately it will need to be very rigid AKA expensive.
For a CNC mill to cut pieces with a large area it will also have to be very large AKA expensive.

Last thing I'll mention: If you want to have both it would be easier to build a CNC router using a store bought CNC mill than building a mill using a router.

[kinghong1970]

@ Cartierusm,

hmm... honestly, i love the challenge of 100% DIY... and i'm really diggin the 8020 designs such as...

ilya's CNC Mill:


and

Josh's 8020/MDF hybrid... tho i dont see where the MDF comes in... lol...


btw, nice machine you've made!!!

@ Hirudin,

thanks for your abridged version...

i am happy to see that waterblocks can be made... tho i have to ask, did he make them in a CNC mill or a CNC router table?

i love your milkshake analogy... ha ha ha...

i've contemplated buying a pre-assembled machine but as i've read somewhere on these forums... maybe a DIY will help me gain better understanding of the machine.

i understand that i'm trying to kill 2 birds with 1 stone... and to add to the list of "wants" i was thinking that a cutting area of roughly 36"x36" at least...

that's a tall order, eh?
will a machine that size loose it's accuracy due to the sheer size of the cutting area? even with the heavier 8020's?

yea... i know... $$$$

now the 2 builds i've linked above is a good comparison between a mill and a router, right?

now i'm a bi confused as to what you mean by building a CNC router using a CNC mill... mind elaborating a bit, please? linkies would be helpful as well...

thanks again for the lesson in CNC...

[ahren]

kinghong,

Welcome to the zone! I'm glad to see you're looking at 8020 machines -- I think this or an actual mill conversion is the way to go for someone who wants to cut aluminum. A guy I know just built a machine using the 2' x 3' plans posted on my website, and cut himself a panel out of 1/8" aluminum on it, so it certainly can be done. You want to make sure you get metal cutting bits, and either a variable speed router or an actual spindle so you can run at lower RPM's (25000 or so on a wood router will make a lot of smoke with anything larger than 1/16" endmills). Then just take light passes, and you'll be able to cut pretty well.

Let me know if I can be of service. I'd certainly love to see another machine using my parts -- you've linked to some good examples of really stiff machines that are good for this application.

Best regards,

Ahren
www.cncrouterparts.com

[Hirudin]

The definitions definitely aren't set in stone or anything... actually they're very ambiguous.
The bottom pic you posted is what I would call a router, the top one is kinda in between a router and a mill. Here's what I would consider a mill...

The main difference is what the spindle does. On a mill it stays stationary and the part moves around below it. With a router the spindle moves around a stationary part.
I only skimmed this thread, but it looks like this might give some more insight: http://www.cnczone.com/forums/showth...t=19514&page=2

Sorry if I confused you a little. Both types of machine perform the same function in a very similar way.

I'm not sure how that water block was made. I honestly hadn't even read the thread before I posted the link (I just wanted to show an example).

I edited my post above slightly...

[kinghong1970]

Thanks for the explanation Hirudin...
slowly... i'm beginning to understand... i think...

ahren, tyvm for your support... he he he
btw, do you have any pdf's or sketchup files of the items in your shop?
i wanna try out some renderings on sketchup...

i dont have a CAD program and am in the progress of learning Sketchup...

as for use of this machine, it's purely hobby and i dont know how significant it is... but for me, precision is valued over speed and quick turnaround... does that make sense?

there's just so many things i wanna try... lol...

[FandZ]

Originally Posted by kinghong1970 as for use of this machine, it's purely hobby and i dont know how significant it is... but for me, precision is valued over speed and quick turnaround... does that make sense? there's just so many things i wanna try... lol...

Since you plan on working aluminum and copper, you're going to want some speed since you will need to take fast light cuts. I think with slow you will end up having problems with aluminum melting onto your tooling.

PC modding and water cooling is what got me into building a cnc machine. It's not the only thing I want one for but it was the catalyst. Anyways, so I think our goals are similar.

Now that I'm at the end of building my first machine, I'd advise you try to get a kit if possible or at least get parts that require a minimum of fabrication. I'm already designing my second machine and wish I would have gotten better quality parts to start off with. I learned a lot that'll go into my second build but I'd rather be focusing on designing and cutting already. Take your time and read a lot. Try and stick to a design someone else has all ready pulled off. Why reinvent the wheel just to be creative. I'd think of a budget around 1500 would make a nice desktop machine. 900 for materials, and 600 for electronics and motors.

Good Luck man.

Chris

[kinghong1970]

Hey FandZ... ha ha ha.. pc modding gets us to a very expensive hobby, eh?

ok, so i am still reading and "researching" on what i'd like to do...

now here's a question... it seems that there are enough parts out there to make a CNC mill as well as a CNC router...

why is there a DIY section for the CNC Router?

have anyone ever made a CNC mill?
is it because a router is more "multipurpose"?

[FandZ]

Originally Posted by kinghong1970 Hey FandZ... ha ha ha.. pc modding gets us to a very expensive hobby, eh? ok, so i am still reading and "researching" on what i'd like to do... now here's a question... it seems that there are enough parts out there to make a CNC mill as well as a CNC router... why is there a DIY section for the CNC Router? have anyone ever made a CNC mill? is it because a router is more "multipurpose"?

I think what Hirudin said is the best description between a cnc router and a mill but I'm no expert. When I think of a cnc mill, I think of massive amounts of metal being removed from a block of stock. There are plenty of diy CNC mill types around. I think it is the easiest one to do since you can buy a mill and convert it.


I've also seen drill presses converted into a cnc machines. Shoot there is even a post around here where a guy made one out of lego blocks lol.. I guess that was more of a plotter really.


Most of those X,Y tables where the head is stationary or only goes up and down, are usually small. It would be perfect for making water blocks. But I'd like to also make PC cases and know I'll need around an 18x24 cutting area. There are some really big ones, but they weigh a few tons. A bit much for our hobby needs. I'd love to have one though...muhahaha

I think for our purposes a cnc router is the way to go. The most we will ever have to route out is an inch or so of metal and that is really on the extreme side of things. Since a router will take fast shallow cuts on metal, repeatability is also important. It would be terrible to take fifty cuts and wind up with a stair case edge instead of a flat edge.

This website and its members are a god send. Keep reading man. Looking forward to reading your build thread