[DY123]

My version of a Momus. I started off buying the Momus plans and using it as a guide. I changed it a lot, but overall it keeps the same basic design elements (top dust cover, integrated electronics and elevated rails built into the plywood structure). 26" x 15.5" x 5.5" cutting envelope.

Attachment 223798

Attachment 223800

Attachment 223802

[snailshoe]

Cool looking machine. Is there a vacuum in the bottom?

[DY123]

Yes there is a Rigid 14 gallon vacuum in the cabinet.

[Levictus]

Sweet build...are you going to show some pics of the internals?

[ClintonH]

That looks like it turned out really nice, I agree you should post up some pics of the internals and give some details. That is of course if your willing.

[DY123]

My initial title "my kind of momus" stemmed from the fact that my machine is kind of a 1/2 momus and 1/2 cnc router parts hybrid. When I saw the momus plans for the first time, I loved how well thought out they were and how integrated everything looked. I also loved the cover. I wanted mine to be larger and more heavy duty like one of the cnc router parts machines.

My machine is all based on using the carriages and z-axis mount from cnc router parts. I had to make custom gantry brackets to make this all work (otherwise is would have all been pretty much plug and play) But unlike both the momus and the cnc router parts machines I used acme screws not rack and gears.

Here are the full specs:

80/20 extrusions. 3" x 1.5" for the Y and Z. 3" x 3" for the X
4" x 1/4" ground rails
4 cnc router parts 320oz motors. Master/Slave Y axis
1/2" acme screws all around.
Dumpster cnc/cnc router parts anti backlash nuts
Ugra CNC 2.2kw water cooled spindle
Hitachi VFD
Gecko G540
Smooth Stepper Ethernet
Shuttle mini intel kiosk computer
small pc touch screen
Mach 3
I'm sure there is something I have forgotten. Ask me if you want more info.

Thanks to Ahren at Cnc router parts, Jeff at Soigeneris and Ugra CNC

Here are a few pictures of my build log:

I first built the base and leveled it so I would have something flat to build on.
Attachment 223890

Torsion box core
Attachment 223888

Body going together
Attachment 223892

Custom gantry brackets to use cnc router parts carriages
Attachment 223894

Carriages, brackets and rails
Attachment 223896

More carriages, brackets and rails
Attachment 223898

Inside the finished machine
Attachment 223900

[Levictus]

Wow, that gantry tube is massive! Internal pics look great. Looks really expensive in a good way...

[DY123]

Yeah it was, but I built it over time. I started it about a year and a half ago. Most of the cost came at the end.

[snailshoe]

What's that little digital display in the last pic?

[Levictus]

Where did you source your aluminum frame/gantry pieces if you don't mind?

[DY123]

That is a temp monitor. It is called an STC-1000. It is wired in line with the e-stop. You can set it to trigger an event if it gets too hot or too cold. I have the sensor on my spindle and if it gets too hot it will shut everything off. It is in Celsius.

I don't even think I need it, but in the beginning I wasn't sure. I think I have it set for 40. I haven't seen it go above 34.

Attachment 223936

[DY123]

I bought the extrusions straight from 80/20's ebay store.

[ger21]

Looks a lot more serious with the hood open.

[Mac.CNC]

Sir, in a nutshell: WOOOOW! 8-)

That's one sweet piece of engineering and craftmanship there. Congrats on your build, very impressive!!! :-)
I do have a lot of questions, lol.

About your spindle, why didn't you go with the air cooled version (Ugra)? I love mine, no problems whatsover. Just wondering what the deciding factor was...

I really like your cable management setup - that took me weeks to figure out, going with the cheap chains first (which was a failure) and then going with an Igus product instead.
What type of chains did you end up using?

The fact that you're driving the x axis from both sides just confirms one more time what I've found out the hard way if you want to push this type of machine to a certain limit (need for slave x motor).
Why did you make that decision from the start? (I'm glad you did, it'll pay off for sure)

Your dust collection system looks interesting. Here again, that took me weeks to figure out too.
I'm wondering why the hose goes up on the side, instead of in the front. Aren't you restricting your cutting envelope on the y by a lot that way?
Did you make the acrylic plate yourself? Looks a little bit like Kent's design ;-)
Is that a 3" hose? I went with a 4" that comes up from the front and still can't get enough CFM with a 1hp collector to get it all up - I mean it works great, but there's room for improvement - getting all the cuttings out of there.

What will you be making with it? Please post some videos with chips flying, please - pretty please... :-)
Looking at your garage, are you planning to make bike parts with it?

Again, awesome work and engineering!
--
Mac

[DY123]

Thanks Mac.

You are very observant. I actually build bikes.

The dust shoe is from Kent. I sent him a shrunk down design (to work with 2.5" shop-vac type size hoses) and had him make it. His regular design is great but way too big to be used inside my space. It would have limited my X and Y travel because it would have hit the side walls and front door. Here is a picture of my smaller design.

Attachment 224140

I use a Home Depot 6hp vacuum and it has plenty of suction. When I surfaced the MDF spoilboard, there was zero sawdust after. In fact it sucks so hard that it pulled in one of the siliconed in windows. I've since added some vents for air inflow and added clips to mechanically hold the windows in place.

Why did I go with water cooled? Noise. That's also why I went with a cover. In the end it was probably not necessary because the vacuum is the only thing you can hear when it is running.

The cable tracks are from Ugracnc.

In my mind the only way that a machine this wide could work was to have 2 motors on that axis. The red carriages are 48" apart at their widest.

I cut the aluminum compartment doors with it. Cuts with no problems. I did take a video or two. I'll try to get it posted.

[DY123]

Here are some stills of the doors being cut. When I cut them I didn't use the vacuum. I probably will in the future but I just wanted to see how much mess it would make. I had the dust shoe on there (other than when taking photos) just to keep the chips contained.

Attachment 224142

In picture 2 you can see what I call the "Sharpie Test" I create a tool path that is the same as my cut out tool path but it just goes down .001". I load up my Sharpie and trace the tool path.

I used the holes that would later be used to mount the doors as my hold down screws while cutting the doors. The clearance between the screws and bit are very close so I wanted to make sure I wasn't going to have any collisions. The Sharpie test allowed me to check the clearance of the screws without risking a real bit. It sucks to break $30 or $40 bits running into a screw.

Attachment 224144

Here they are installed on the machine.

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[Levictus]

Great details...love seeing things like this...really gets the wheels turning :idea:

[Mac.CNC]

This is so cool!
As far as I know, you are one of very few (documented) builders that cuts aluminum with a Momus based design. I haven't gotten into the aluminum world yet myself, just been cutting pine, poplar and maple so far. I'm still afraid of hard oak at this point, but that's next - in terms of feeds and speeds :-)
What worked best on my machine so far were two flute >=1/4" bits at around 60ipm feed rate, half diameter depth @ around 9500 to 12500 RPM. I tend to crank up the RPM for smaller bits, but stay way under 60ipm - not sure why, it just feels and sounds better. If I go above 60ipm, no problems but the surface quality becomes quite crappy then.
I studied the text book calculations for figuring this out, but whatever that came out to was way too aggressive for some reason for this machine, even in soft wood - so I'm winging it at this point, lol.

May I ask what type of cutting bit(s) you used to make these plates with? Some must have been super tiny to make these awesome fan grates that way (tight radiuses). What were your feeds and speeds, pass depth as well?
Did you use any lubricant or did you just dry cut them?

Very nice. I still don't have a decent operator panel on mine and was planning to do that with an aluminum plate similar to what you did. Knowing a little more about your process to make these would really help out :-)

PS: Thanks for your reply earlier. Good point about the noise choice for a water cooled spindle, mine becomes pretty loud when it needs to go higher than 13k RPM.
--
Mac

[DY123]

After the basic machine was done I used it to cut the cover parts.

I'm kind of winging it too and seeing what my machine can do.

I cut the holes for the windows in the plywood with a 2 flute 1/4" Diablo upcutting spiral bit from Home Depot.
Conventional milling
Pass depth 0.125"
Spindle RPM 12,000
Feed 100 IPM

I cut the Lexan windows with a 1/8" Onsrud Oflute upcutting bit. part# 63-515
Conventional milling
Pass depth 0.125"
Spindle RPM 8,000
Feed 40 IPM

I cut the Aluminum with an 1/8" Onsrud Oflute upcutting bit. part# 63-610
Climb milling.
Dry
Pass depth 0.005"
Spindle RPM 12,000
Feed 36 IPM

I think I could go more aggressive with the Aluminum but I wasn't in a hurry and it was the first time. It can easily do 0.010" depth per pass in straight lines but with some of the tight circles of the grill I took less of a cut.

[diyengineer]

This is gorgeous. Good work!