[ngkey1x]

Hi everyone,

newbie here, looking to build my first CNC.

I am looking to build a machine that will only have to cut: thin foam (depron, insulation foam, anywhere from 1mm to 2 inches) and thin woods (ply and balsa, less than 1/4" thick). I would also like to be able to cut very thin fiber glass sheet (less than 1/16") and carbon fiber sheet (maximum 2mm thick).

I have been looking at rail available from OpenBuilds Part Store and have been thinking of using NEMA 23 stepper motor electronics kit from NEMA 23 CNC Router Stepper Motor kit (option #3 on that page). Is it necessary to use 4 steppers (2 on the X-axis)? Or for such light materials is only one motor on the X required?

I want to make a 2x4 foot Cnc. I was thinking of using 20x40mm rail for all axis and using a pulley system using timing belts. It will be a lightweight system.


Will a small router (porter cable or dremel) suffice as my cutting tool? This machine will not have to cut metals or woods that exceed 1/4" thick.

Will this setup be able run a lightweight CNC that will fulfill my needs? I am a complete newbie to CNC so it would not surprise me if I am completely wrong about this...

Do you guys have any recommendation for kits or plans that I should take a look at?

Thanks for the help!

[ger21]

The main question, is, what is your budget?

CNC Router Parts has some good kits at fair prices.

CRP2448 2' x 4' CNC Router Kit | CNCRouterParts
PRO4824 4' x 2' CNC Router Kit | CNCRouterParts

These are not lightweight machines. But, building a lightweight machine doesn't work too well when you get over 2ft in length. The bigger the machine gets, the stronger and more rigid it needs to be to give good performance.

A heavier machine will let you cut your parts much faster, with better quality cuts, and will allow you to cut materials you couldn't consider with a lightweight machine.

AS far as that motor kit. Almost everyone here would recommend a Gecko G540 kit over that one. It's a little more expensive, but you get a much better product, in a much smaller package.
But you shouldn't really be buying a motor/drive kit until you know exactly what your building. Some motors are better for certain applications then others, and buying something that doesn't work well for your application usually means buying then twice.

I wouldn't recommend a belt on a 4ft axis. But if you must, use at least a 25mm wide belt, with at least a 3:1 or 4:1 reduction to the drive pulley.

[ngkey1x]

I have been looking at the JoeCNC model 2006 Do you think it would be too much for a beginners build? I think it would suit my needs perfectly and then some. I would like to keep this build under $3000 if possible.

[wizard]

Hi everyone,

newbie here, looking to build my first CNC.

I am looking to build a machine that will only have to cut: thin foam (depron, insulation foam, anywhere from 1mm to 2 inches) and thin woods (ply and balsa, less than 1/4" thick). I would also like to be able to cut very thin fiber glass sheet (less than 1/16") and carbon fiber sheet (maximum 2mm thick).

Depending on your goals it might be advantageous to build two machines. One to handle the light materials and another optimized for the fiber reinforced sheets. Why? Well this, if your needs with the foams and wood isn't tight tolerance wise you probably can get buy with a cheap build using belt drive, low ver cost axis bearings and the like. At the same time that machine can run pretty fast. Mind you when I think of machining foam I don't imagine this being a precision endeavor.

Fiber sheets in the other hand are notorious for their abrasiveness. Further the sheets may require a vacuum table to help hold them in place. Further I imagine these sheets need to be machined to tighter tolerances.

I have been looking at rail available from OpenBuilds Part Store and have been thinking of using NEMA 23 stepper motor electronics kit from NEMA 23 CNC Router Stepper Motor kit (option #3 on that page). Is it necessary to use 4 steppers (2 on the X-axis)? Or for such light materials is only one motor on the X required?

You need to work out a bit better what your machine will be like. There re multiple arrangements of the mechanical components that re possible. Have you even decide upon fixed gantry or moving gantry?

I want to make a 2x4 foot Cnc. I was thinking of using 20x40mm rail for all axis and using a pulley system using timing belts. It will be a lightweight system.

Timing belts in place of lead screws will work fine for you lighter needs. I'm not sure how that will work on the fiber reinforced materials though. I just don't have experience with that material to say for sure. However due to the abrasiveness of that material cheap is preferred over wearing out expensive lead screws.

Will a small router (porter cable or dremel) suffice as my cutting tool? This machine will not have to cut metals or woods that exceed 1/4" thick.

It all depends upon the cutting tool size and how fast you want to run. Further I'm not sure a typical shop router will do well with the fiber dust. Again the concern is the abrasive dust getting into the motor. That said many of those materials can be done with a small router. My question though is why bother, a full size router doesn't cost that much more and allows for the power when you might need it. You say 1/4" wood today but tomorrow could find you doing 1/2" or 3/4" sheet goods, thicker fiber panels or who knows what.

Will this setup be able run a lightweight CNC that will fulfill my needs? I am a complete newbie to CNC so it would not surprise me if I am completely wrong about this...

I don't think you are wrong completely, maybe just jumping the gun a bit. One good thing, you have a good idea about what you want to do, the materials and so forth. That information should lead to good comments here.

Do you guys have any recommendation for kits or plans that I should take a look at?

Thanks for the help!

My best recommendation is to search the net for example of home built routers and that people actually use in the way you have in mind. Especially in regards to machining fiber sheets. Also you need to evaluate accuracy that you will need across all of the materials. If you need to maintain high accuracy then you may have to take a more robust approach.

[wizard]

I have been looking at the JoeCNC model 2006 Do you think it would be too much for a beginners build?

Depends upon the beginner. Seriously building the machine has nothing to do with CNC unless you get somebody to mill out the parts for you. In this case it is more about your wood working and mechanical skills.

I think it would suit my needs perfectly and then some.

Well this depends!!! 😜😜😜😜. Really you need to evaluate if it meets your tolerance requirements, this is key to selecting the right machine. There is much to like about the machine and a few things that bother me personally. In any event best to talk to somebody that has built one.

I would like to keep this build under $3000 if possible.

It might be possible, it all depends upon what you can scrounge up cheap and how well equipped you are shop wise. For example there is nothing wrong with working with MDF or other wood products but proper assembly requires the use of a lot of woodworking tools that you may not have. Especially clamps. Even if you buy a pre cut kit you still have a lot of assembly work to do and that requires shop tools. Without more info it is hard to say what your final cost will be. In otherwords without knowing where you are coming from and what your resources re it is hard to say what your real cost will be.

[ger21]

You should be able to build Joe's hybrid for around $3000, and it'll be a much better machine. Easier to build, too. While he calls it a 4x4, you can build it virtually any size you want.
Just carefully price everything out before you start buying.
A Joe's 2006 should be buildable for about $1500-$2000, but requires decent woodworking skills if you're not buying a pre-cut kit.

[ngkey1x]

Hi guys,

Thank you all so much for the input!

I have been thinking about what I am looking for, and have decided that for my current needs a small CNC will manage just fine.

Here is what I am looking for:
-Budget: $1000-1500
-Cutting area: 1x3 feet
-Material: Foams and thin plywood. Thin composites and possible plastics (none are thicker than a few mm)
-Tolerance: For foam 0.01 inches. 0.005" for woods and composites would be ideal (0.01" is fine however.)
-Moving gantry
-3 stepper motors
-Track material: V slot rails (V-Slot - OpenBuilds Part Store)
-Electronics: I was looking at this setup G540 3-Axis NEMA23 270 oz in PSU 48V/7.3A | Automation Technology Inc

I have looked into both acme screws and rack and pinion systems. I have yet to decide between the two. What parts would I need to assemble a movement system using acme screws? I know that you needs couplers and backlash prevention pieces, and a slide that goes on the rod, but I dont know what else.

I do not have the woodworking tools necessary to scratch build using MDF, so I would like to build the whole machine (base and everything) using extruded rails and make the sliding gantry using the v rail wheels and plates.

Sorry if my first posts were vague, I didn't realize how many aspects there were to this. I hope I was able to clarify some things with this information.

-Ngkey

[wizard]

Hi guys,

Thank you all so much for the input!

I have been thinking about what I am looking for, and have decided that for my current needs a small CNC will manage just fine.

Here is what I am looking for:
-Budget: $1000-1500
-Cutting area: 1x3 feet

One foot is a bit narrow unless you have very specific uses in mind.

-Material: Foams and thin plywood. Thin composites and possible plastics (none are thicker than a few mm)
-Tolerance: For foam 0.01 inches. 0.005" for woods and composites would be ideal (0.01" is fine however.)
-Moving gantry
-3 stepper motors
-Track material: V slot rails (V-Slot - OpenBuilds Part Store)
-Electronics: I was looking at this setup G540 3-Axis NEMA23 270 oz in PSU 48V/7.3A | Automation Technology Inc

I have looked into both acme screws and rack and pinion systems. I have yet to decide between the two. What parts would I need to assemble a movement system using acme screws? I know that you needs couplers and backlash prevention pieces, and a slide that goes on the rod, but I dont know what else.

It is pretty obvious you aren't familiar with machine tools and the building of them. That isn't a big problem but it does take time to learn the basics. So I'm going to suggest trying to find a local hacker space, model engineering club or just a guy with a router, the idea being to get a physical handson with the various parts of a machine.

By the way there is nothing to say that a machine can't have a different drive mechanism on each axis. For example you could have an acme drive on the Y, rack and pinion on the X and a belt drive on the Z.

I do not have the woodworking tools necessary to scratch build using MDF, so I would like to build the whole machine (base and everything) using extruded rails and make the sliding gantry using the v rail wheels and plates.

If you don't have woodworking tools then how about metal working? Unless you buy a precut kit you will need to cut those aluminum extrusions. Frankly to get good results you need cuts better that the average wood worker would do.

As to those V-rails they are an interesting modification to the basic extruded rail concept. However I'm not convinced tht their roller axis solution is the most robust in the world. It may very well get you started though.

Sorry if my first posts were vague, I didn't realize how many aspects there were to this. I hope I was able to clarify some things with this information.

-Ngkey

Actually your posts have been far better than the average post seen here. At least we understood the what the materials where.
My suggestion is to low down a bit too get a handle on what will be required to put an extrusion based structure together

[ngkey1x]

Hi Wizard,

I think 1 foot should be fine for me (thought I dont see why I couldn't make it 1.5 or even 2 feet, which I may). I am mainly looking to cut 10x30 inch foam sheets mostly. I considered building something larger like a 4x4, but space and mobility is an issue for me.

I don't know of anyone local who owns a CNC. Do you know of any build guides that go through the basics?

From what I have read and pictures I have analyzed it seems that there are 5 types of parts to using an ACME screw for linear motion:
1) stepper motor attached to...
2)ACME screw using a anti-backlash coupler
3) A bearing block to support the acme screw (on both ends)
4) collars to prevent linear movement of the acme screw
5) the sliders that move on the screw itself.

Am I correct? Or am I missing parts?

I have also looked into my rail system some more. Do you think standard extrusions (8020?) with a L bend attached to the extrusion as the track would work (like in Joes 4x4). In this type of system do you need wheels to run on the L bend? Or can you just use bearings? (sorry if I am not making sense, I don't know how else to explain it)

I have no real woodworking or metalworking tools, just your standard stuff like drill, dremel, small router, files, and hand saws.. I was thinking that I would cut the extrusions with a chop saw or a angle grinder, or even a hacksaw.

Ngkey

[ger21]

From what I have read and pictures I have analyzed it seems that there are 5 types of parts to using an ACME screw for linear motion:
1) stepper motor attached to...
2)ACME screw using a anti-backlash coupler
3) A bearing block to support the acme screw (on both ends)
4) collars to prevent linear movement of the acme screw
5) the sliders that move on the screw itself.

#5 is an anti-backlash nut.

There are different ways to mount an acme screw. A simple method used by CNC ROuter Parts needs no machining. This appears to be what you are describing.
http://www.cncrouterparts.com/images/exploded6.jpg

The bearings blocks hold the screw radially, and thrust bearings and collars prevent the screw from moving axially, and take the load during movement.

The method I use uses fewer parts, but takes a bit more work.
http://www.cnczone.com/forums/diy_cn...out_lathe.html

[wizard]

Hi Wizard,

I think 1 foot should be fine for me (thought I dont see why I couldn't make it 1.5 or even 2 feet, which I may). I am mainly looking to cut 10x30 inch foam sheets mostly. I considered building something larger like a 4x4, but space and mobility is an issue for me.

If space is an issue then your best bet is to compromise and make the unit no wider than a counter top or bench top you might have. That should easily give you something between 1.5 and 2 feet. If need be it can be moved to make space for something else.

HOWEVER you don't want to be moving the machine around a lot due to the need to set up and align the machine each time.

In effect you are making a task specific machine with those unusual dimension. Nothing wrong with that but a wider machine just means more versatility down the road.

I don't know of anyone local who owns a CNC. Do you know of any build guides that go through the basics?

Good ones no! There are a few on the net but I can't say that they are that great.

From what I have read and pictures I have analyzed it seems that there are 5 types of parts to using an ACME screw for linear motion:
1) stepper motor attached to...
2)ACME screw using a anti-backlash coupler

Those are key components.

3) A bearing block to support the acme screw (on both ends)

Actually you need different blocks at each end. The motor end should have blocks that can take thrust. A bearing at the free end may or may not be required. It is certainly needed on the long end but the other axis may not require a free end block.

4) collars to prevent linear movement of the acme screw

Leadscrew nut maybe??

5) the sliders that move on the screw itself.

I'm not sure I follow the above. An axis needs linear bearings of some sort so I suspect that is what you are talking about. In your case your tolerance or accuracy requirments are loose so you and loads low so you can get by with a fairly cheap machine or design.

Am I correct? Or am I missing parts?uuj

I have also looked into my rail system some more. Do you think standard extrusions (8020?) with a L bend attached to the extrusion as the track would work (like in Joes 4x4). In this type of system do you need wheels to run on the L bend? Or can you just use bearings? (sorry if I am not making sense, I don't know how else to explain it)

I'm not sure what you are saying but there are many ways mount linear rails.

I have no real woodworking or metalworking tools, just your standard stuff like drill, dremel, small router, files, and hand saws.. I was thinking that I would cut the extrusions with a chop saw or a angle grinder, or even a hacksaw.

A good quality crop saw, properly setup can be used to cut extrusions. Rq

Ngkey

[ngkey1x]

Hi wizard,

I drew a picture in paint to show you what I mean. I also found a picture of an actual setup.

One of the photos shows what I meant by having the system move by having bearing run along some type of flat rail...

The other shows what I meant by having collars to prevent axial motion of the screw.

Thank you for your help!

NG