PDA

View Full Version : Newbie So there are some DIY CNC routers...



jeroen870
11-18-2010, 04:31 PM
I want to make a cnc router, but after some searching I really don't know witch design I have to take.

I found a lot of designs. Can anyone give some tips?

Grz,

Jeroen

Benonymous
11-18-2010, 05:00 PM
To suggest anything, the forum needs to know the following:

The work you intend to do with the machine.

The size of the machine needed.

Your budget

With this information, we might be able to steer you towards the most suitable design for your purposes.

jeroen870
11-18-2010, 06:10 PM
Well, but these are 3 variables for me. I'll not spent more then 1000, but the size doesn't really matter. This because I think the size will do something with the resolution of the machine (and the cost). (big machines ll flex and bend I think). But the size has to be between 48"x28" and 12"x18".

Because there are so much design's, there are different combinations of accuracy, size and cost. What is the best combination of these 3 variables?
I really don't know were I have to begin. So if somebody has experience with one of the routers in the pdf file... ?

microcarve
11-18-2010, 06:17 PM
My $0.02...

BTW....That's a very nice comparison chart you made....:)

If you want to be *using* a machine in a reasonably short
period of time, then a kit of pre-cut parts or a bolt together
machine will get you there *much* quicker.

Once the machine and electronics are all in place and working
as they should be, then the software is where the real learning
curve begins. The mechanics and electronics should be relatively
problem free and need very little attention for a long time.

With the necessary software to make the machine do anything useful,
the sky's the limit. That can consume massive amounts of time and
money. From free to $$$$$$$.

If you enjoy the challenge of actually *making* your own machine, then
the plans you need do depend on what you want to make, your space you
have, your time, your $$$ you can devote to it.....and among
other things, your own skills at building things. Along with the
tools and materials you have access to.

Only the guy doing the building can possibly know his/her own
limitations. There's a ton of homework that is absolutely necessary
for success. No plans maker can be faulted if something isn't
understood by the builder. It's not possible to account for every
scenario that may/will come.

*Making* the machine can be a highly enjoyable project. It can also
be the sleigh ride of someones life. Nobody knows but that person
if he's up to the challenge.

A few points....

Flat and square matters. Most materials you buy are not flat and square.
That can mean more tools than someone initially imagines. There may
be many times that a needed part has to be specially ordered. Often
times, tools that you only use one time have to be bought. It can get
way more expensive than someone accounts for. Fast...;)

But, if you're up to the challenge...and it likely will be a challenge,
then there's a whole lot of help available 24/7 here to help you along.

Just getting the software and learning it is one of the biggest hurdles
to actually making things with any machine. There's where the most time
and expense can easily go.

If you want to be using the machine instead of tweaking and upgrading, then
a kit could be a good idea. It all depends on what you want to make.....and
*when* you want to make it....;)



:)
John

jeroen870
11-18-2010, 06:45 PM
Time is the one thing I do have. :p.

But one of the problems that I'll have to face (as you pointed out), is to make all things square and fit together. It seems that most plans require a cnc machine to make the machine (ironic isn't it? :rolleyes:)... There are solutions to this problem (leveling screws), but that is what makes a good design.
And that is what I'm looking for.

CAM and CAD is no problem for me (I have a degree in these things :cool:).

microcarve
11-18-2010, 07:06 PM
Designing in CAD is a great thing, but it does sometimes throw
a bit of a monkey wrench into the works.

A design made in CAD assumes perfect lines, squares, rounds.
Not very many cost effective real-world materials are anywhere
near what they need to be. Aluminum extrusions...(commonly used
6061)....can be cupped so badly as to be nearly unusable without
machining.

Best thing I ever did was buy a mini lathe and mini mill before I built
my first machine. I then had the means and tools....along with a bit
of knowing how to use them...to make the parts I needed for most
any machine I wanted to make from then on....(reasonably sized of course!...;)

I personally think starting with a small MDF design is a good starting
point. It's one of the flattest materials I've come across and the practically
inevitable mistakes aren't so painfully costly

Lots of tweaking of a design is cheap and someone learns where the problem
points are with a larger next design.

I'd build a cheap one first. There could be plenty enough surprises in that one.

;)
John

hemsworthlad
11-18-2010, 10:13 PM
HI,

You need to start by concidering really really hard what you intend to use the machine for or more importantly what materials you intend to cut.
Knowing the main use and materials you want cut gives lots of usefull information that will point you in the right direction regarding the rest of the machine.

This information is the key to designing the right machine using the right components and IMO the single biggest area new people to Diycnc go wrong.

Knowing this Info gives the following important information.

Best style(IE: moving/fixed gantry etc) suited to intend purpose.
This will then give an indication to ridgidity needed. Which will give an indication to materials to use then giving weights or mass to move, which inturn leads you to the best linear drive system(IE: ballscrews,belts,R&P etc) and motors requirments to move this weight plus achieve the neccesory speeds n feeds needed to cut this material correctly to the accurecy required or desired.
This info then guides you in the right direction with regards to correct power supply sizing and best Drive choice to achieve these speeds and also guides other area's of the overall control box design.

Their are many choices you will have to make in the building of a succesful machine but there are some that are Vital you get right else it's doomed to fail from the start.

These choices are Correct.

Linear drive system.
Motor type and sizing.
Best Drive's suitable to run motors to there full.
Power supply size matched to motors (Very important for best stepper performance)

All this Info mainly comes from and revolves round the machine's main intend purpose.

The real trick is getting all this to fit within the budget.

Good luck.

sonicwonder2000
11-19-2010, 11:12 PM
Look at David Steele's designs - solsylva.com. I bought his plans a while ago and it was THE best investment of the project. Very detailed plans, awesome machines, and a set of designs at each price-point. I don't work for him, I'm just a happy customer! In the end, you'll probably end up learning a load from the plans, and customize them for your own purposes.

Custom designing a cnc from scratch is definitely not something one does to save money. In the long run, the development cost can be significant...

Best of Luck!

msimpson99
11-20-2010, 05:28 AM
Something to keep in mind if you are going to build your own. Most of the plans that are availalbe are just a set of drawings. No instructions. Do your research and find out what its you are purchasing before you spend the money. I recomend you build one that has step by step instructions. A build log is not instructions.

For example for $100 for the Joes CNC plans you get A set of drawings. You also get a access to build logs similar to what you find on this web site. Had I known that I would not have spent the $100.

If you like to tinker then a mostly wood/MDF router will be fun to build. I have built 4 and each time I make improvoements on the last. The last one is one durable little tank.

The most expensive part of all the DIY builds is the electrics. IF you purchase quality electrics (motors, controller, power supply, ect.) you can use it on just about all the kits and plans.

Next thing to keep in mind is that actual size of the machine will be larger than your working area. For example my last has a 15" x 34" cutting area yet the actual dimensions is 36" x 54". Unfortunatly for me since I aready have a packed work shop I can only fit a router or two of this size.

My last build cost me $1600 complete. Not counting software and PC.

Dont discount the PC. A low end PC will limit the top end speed of your machine and the kind of software you can run.

The sky is the limmit for the software. I am a PC person so thats the direction I went. Thats also where you have the most choices.

I purchased Corel Draw off ebay for $90
Mach3 for $175
Cut2D $149.
Gearotic $75



This allows me to cut all kinds of things. My next purchase willprobably be Vcarve Pro.

The most important thing you can do is take your time and do lots of research. You really need to determine if your primary goal is to cut metal or wood. This will set your basic direction. Im thinking wood since most of the machines you listed are for cutting wood or similar products. They can cut softer metals but they are not a good fit if thats your goal.

hemsworthlad
11-20-2010, 05:30 AM
Custom designing a cnc from scratch is definitely not something one does to save money. In the long run, the development cost can be significant...


Not strictly true.? Yes it's not cheap but you do save money.

The savings designing/building your own custom machine even concidering development or cockup cost's are still significant compared to buying an off the shelf commercial machine and when compared to a commercial custom built machine it's massive.
Even small commercial machine's which are built basicly using the same techniques available to Diy builders and often same components cost thousands of $.

A commercial machine which doesn't work any quicker or accuratly or built any stronger than what i've built would have cost me a minimum of 15,000 ($24,000).
So far i've spent less than 3,000($4,800) which includes several major development changes inc a complete rebuild of the control box with new Gecko's and custom built PSU and motor upgrade. (@ that price I still have the old drive's & motors has backup or for another build.)
I'm just about to change the bed (1400x1200mm) to a custom built T slot Aluminium bed which will just about tip me over the 3,000 mark.
The components are resonable quality incorparating profiled linear rails, zero backlash ballscrews, Water cooled 2.2kw spindle all built round a strong steel box section frame. . . . Yes cosmeticly it doesn't look has good as a commercial machine but it wasn't built for it looks but to do a job which it does very very well.

Edit: @ 3,000 that inc's Mach 3, Bobcad v23 software and a smooth stepper(With a 2nd hand spare for backup) so I can run from a laptop.

msimpson99
11-20-2010, 07:11 AM
I have to agree if you compare the same size machine and the compontes its alwas cheaper to build your own. But you must compare apples to apples. IE Dual X axis is much better than single X axis.

hemsworthlad
11-20-2010, 07:25 AM
I have to agree if you compare the same size machine and the compontes its alwas cheaper to build your own. But you must compare apples to apples. IE Dual X axis is much better than single X axis.

Yes I agree thats why my machine use's duel ballscrews on the X axis.

Edit: Here it is in it's early days(approx 2yrs ago) running with the old make shift control box and PC no pics of it today but pritty much the same just tweaked and a new control box with laptop on a stand fastened on one corner and a lot more dirty.

GeorgeRace
11-20-2010, 09:10 AM
A couple of years ago I went through the same line of questions as you are thinking about now. I wanted something relatively simple that would be able to machine aluminum up to at least 1/4 inch thick. It had to be accurate, flat, and relatively sturdy. Here is what I ended up with

I purchased the following:
From K2CNC - basic router frame - KT2514
From Hobby CNC - 3 Axis Servo and Electronics Kit
From Menards - Bosch Router Motor
From China - ER25 Collet Holder and ER25 Collet Set
Several sizes of Carbide 2 flute cutters - 3/32 and 1/8 most commonly used
Mach3 CNC Software
CamBam CAD/CAM Software
Had a nice used Dell Computer for the software to run on.
My total bottom line, less then $3000 for the complete system.

You can see some of the stuff I am making at:
Airplane Builders Supplies (http://www.mrrace.com/Products/)

If you need further information on any of the stuff listed above, please let me know. I can give you web addresses for everything if you need them.

Having my own small CNC setup is one of the best moves I ever made. Being retired, there is always another project waiting to be built.

Hope this helps,
George