Looking for CNC Cutter plans

[mt_100]

I love scratch building, but hate cutting parts out. Anyone know of some plans for a small CNC machine that can cut them out from CAD drawings? I know lasers are far too expensive but I thought maybe a CNC cutter would work.

Has anyone built one? How was it? Would it be cheaper to buy one?

[jtprouty]

Try hobbycnc.com. They have links to sites that have plans avaialble and also offer a set of plans. I built a CNC hot wire using their driver boards and plans from another site. It's been running flawlessly for over 4 years now.

Happy flying,

Jimmy
KD0DOI

[Brandano]

there's a whole section dedicated to home brew CNC routers on the CNC zone forums, http://www.cnczone.com (it might be difficult to find the section you need, since the forums are quite extensive and variegated. Here's a direct link to an "open source router" message board: http://www.cnczone.com/forums/forumdisplay.php?f=297 ). There's some plans available, but from what I can see nobody really sticks to the plans verbatim, most of the successful machines are customized in some way

[Fluffy Monster]

I have built one :D
Use EMC2 to control it.

I would say I have spent more time on it and its associated tools (2D and 3D CAD programs, EMC2, electronics to run it etc) than on building planes :o .

Attached is a few images of stuff I have done. I also use it to drill PCB's.

I must admit, I am now taking what I have learned over the last 12 months and designing & building one slightly larger that will be able to mill small metal. Also will be making an addition 2 axis so I can cut foam wing cores.

[mt_100]

Fluffy Monster, looking at your machine it looks like the bottom table surface moves as one of the axis, is that correct?

That looks like it would simplify the movement of the 'gantry' to only the vertical and one other axis, is that correct?

How do you think it works out overall?

[Fluffy Monster]

Yes, the bottom table moves. See http://www.rockcliffmachine.com/cnchome.htm for the one I built. So gantry is fixed and Z axis is moved along the gantry. I enlarged it to a 600mm x 600mm table. The problem with a long gantry and the bearing method they use, is that the whole head can flex. The other issue I have is I used the Triton version of a Dremel and the slop in the bottom bearing is woeful. But rather than using a Dremel, I would like to go to a small router instead (better range of cutting bits). But the head flexing worries me with the extra weight.
Overall I am pleased with the results. And it was a great introduction. It was quick to build and cuts fairly accurately. I have test routed some ribs but have never actually built a wing. For majority of the foam and balsa stuff it is fine but I also wanted to be able to cut holes in aluminum panels and the current design/config does not allow for that. Fortunately I scored some real linear bearings and acme threads so I can build a larger version that will be stiffer and capable of having a beefier cutting head.

Fluffy

[jeffs555]

The moving table with fixed gantry does simplify construction. One of the main problems with building a CNC machine is making the structure rigid, and this is usually easier with a fixed gantry.

The disadvantage is that it takes twice the space of a moving gantry machine and you need longer linear bearings for the X axis.

[Kwok_Yu]

Fluffy Monster,
When you cut the thin sheet of depron and balsa, how do you keep from cutting your table? Can you say alittle about, if that is a pain to deal with? What do you use to secure the sheet?

mt_100,
I am building the Phlatprinter, which works with a roller like on a desktop printer. It's mainly designed to cut foam sheet. Here is the thread on it:
http://www.rcgroups.com/forums/showthread.php?t=888387
Construction thread is better if you just want to see the machine:
http://www.rcgroups.com/forums/showthread.php?t=923747
My progress so far, which is just the z-axis:
http://www.rcgroups.com/forums/showpost.php?p=10768899&postcount=186

-Kwok

[Fluffy Monster]

I have a bit of coreflute clamped to the table that is sacrificial. And double tape the balsa/depron to the coreflute. You could use foam, balsa or any other soft scrap material. The double sided tape works well. I used to use to to hold my PCB's for drilling till I made up a good clamp.
For 3D shapes, I get a big block of foam and clamp it to the table. After cutting the shape, I get a long sharp blade and slice it off. For the attached picture, I made two and glued them together to make a drop tank.
Hope that helps (took me a little while to work it out).

[mt_100]

I saw the Phlatprinter but noticed the designer said balsa wasn't something it was meant for.

I am looking around yet, hopefully I can find something in the price range I am looking for. I am willing to build the frame myself, buy the motors and controller.

Mainly, I want to cut wing ribs and formers, so 3/16" balsa and 1/8" light ply at the thickest.

Hopefully, ~$300.

[Kwok_Yu]

Fluffy Monster,
That info was helpful to explain it. Kind of figured it would be tricky.

mt_100,
Someone is cutting out controls horns out of 1/16" ply, I think. He just posted a video:
http://www.rcgroups.com/forums/showpost.php?p=10807080&postcount=1672
Yes, it's not designed for it, but who knows?

I think you are under estimating the cost by 50% for a dirt cheap unit. $300 will just cover the electronics. You might look at this website. I was thinking of making a cnc router next. Notice how much the current kit cost and the cost of the electronics. But look at the video tutorials of how to make an inexpensive one yourself, with a minimal of tools. That one is basically his prototype. Apparently, he built it in his apartment:
http://buildyourcnc.com/default.aspx

-Kwok

[Fluffy Monster]

Cost wise in Australian dollars
$200 in bearings
$35 in MDF
$10 micro switches for limit switches

I was very fortunate that the following were donated.
lead screw (8mm all thread)
lead nuts ( taped delerin)
stepper motors with inbuilt controllers.
power supply

The smallest suitable motor would cost me $55.00 each, power supply (24v 6+ amps) $100, stepper controller $40 each.

All up, it could easily have been a $700+ project.

[JimDrew]

Definitely try www.hobbycnc.com. Dave's kits are the best, the help is great, and Dave is a modeler so he knows what people need.

We have a 36 x 24 x 12 setup that works amazing for making virtually anything.