New Machine Build- Phife's First Build. Gantry CNC.

[Phife]

Hello all, my first post here. Started a build on a CNC machine that was originally created by the guys over at LumenLab. Ive been wanting to build a CNC for a few years now and they help me get started. Im left with trying to finish the machine with myself with no machine design experience. But I learn very quick and have made some good progress. I hope to finish the machine in the next few months.

If anyone hasnt seen the RoGR gantry robot over at Lumenlab.com, its a suspended gantry style robot.They have their prototype built and I am building off that. I bought their bearings and servos/encoders.

I am making all the aluminum peices either myself or via a local shop. I have already built the frame from 2.5" square steel. Its about 70l x 4w x 48 h. Cutting area of around 51"x25"x8".

I will be using this machine to route, carve wood, and mill aluminum to make more parts. I will have some sort of spindle for a tool. I eventually want to build add ons like an ATC, 4th or 5th Axis'

I have been learning all I can in the last year in preperation for building this machine. Im a woodworker by trade but started out with computers and can learn almost anything quickly. Since ive only had some time at nights after work i've been designing the machine in sketchup, i am learning solidworks now.

Machine is pretty much complete in 3D except for the screws. I am also not sure the final design of the Z axis.

Heres some pictures for you guys. lemme know what you think! Im very excited to jump into this world of CNC's!

[Hirudin]

Yo man!

[Phife]

made some progress.. Frame is built, going to machine some of the motor mounts and bearing mounts myself on my X2 Mini mill. I'll post some pics soon.

Almost everything is chosen and will but purchase soon.

Heres a break down of what im using:\

4 Servos: 5/8" shaft, 800oz/in, 1200rpm, 72vdc12a Max
4 Encoders: Quadencoder 1440ppr
4 Drivers: Gecko G320
1 Power supply: 65v 20a Keling Unregulated (*Is this ok?*)
1 C11G Breakout
30mm Linear Bearings on X
25mm on Y
20mm on Z
2 1/2" steel square tube frame.

Anyone know if the power supply would be ok? I want to add extra axis later on.

My other power supply option is a 48v 12A Regulated

[Phife]

Well, its been ages since I posted. I finished my machine last august and have been busy building my new shop and starting my business.

My machine was based on the LumenLab.com RoGR, it was the first CNC machine LL sold kits to. They have since put aside the RoGR project to work on a smaller unit. Being one of the early adopters I figures I'd buy the Kit from them hoping to have support from them.

I can say I really regret that choice, IMO LL has never had great support for their products. I bought the Bearing Kit and Servo Kit from them, and I also based my frame design on theirs, since I had no CNC experience I was trying to copy what they had by looking at pictures, which was fun.

I ended up having to design my own machine in CAD since I had no dimensioned drawings to go off.

Taking on this project was a great learning experience. I now feel very comfortable with CNC machines, Electronics, CAD, CAM, and all the other things I had to learn to finish this machine.

I will start at the beginning posting pictures and information from where I left off almost a year ago with this thread.

[asuratman]

Hello Phife,
Good day, do you use ametek motor? What voltage on power supply for this motor? If I am not wrong that this motor have 38 volt nominal. On this cnc zone, somebody use 48 volt (unregulated) for motor. I have 4 of ea, and I want to use it on my mill.

[Phife]

The Frame:

The design of the frame was based on the LL RoGR, It is made of 2.5" x 2.5" 0.125" wall Square Steel. The outside frame dimensions are approx. 72.5"Lx42"Wx48"H

The working area for my machine is X48.75 x Y24.75 x Z8"

The machine is bolted together with 1/2" x 6" bolts.

The design is pretty much exactly the same as the LL machine. I didnt know anything about building CNC's so I went with the kit I bought.

Its bolted together in a way that it tends to want to square itself up. I primed and painted it a nice Mint Punch.

[Phife]

Motors and Linear Ways:

I bought the LL motor and bearing kits.

The unsupported rods are of the following diameter:

X=30mm x 1650mm (~67")
Y=25mm x 950mm (~37.5")
Z=20mm x 500mm (~19.5")

I find the flex on the X rods to be way to high. I wish I had gone supported rods or rails on the X and gone with the 30mm rod on the Y. At 200ipm the whole gantry bounces up and down when its near the center.

The motors are restickered ametek motors. They are rated for 38V DC 10A max. The Lumenlab sticker has them rated at 72V 12A with speed control.

I am running them at 72V. They use a US Digital encoder.

[Phife]

Electronics and Other Parts:

I am using 4) Gecko G320's to drive my Servos. The geckos are connected to the PC via the CNC4PC C11G BOB.

I am using a Keling 72V 20A (Includes 5v Regulated) unregulated Power Supply. This was probably overkill, I have an amp meter and havent seen it rise above 3.5A max with all 4 servos running at load. I havent seen any issues with running the servos beyond their actual specs. Had I known they were only rated for 38V nom. I probably would have gone a little less.

I use shielded CAT5 Cable for my encoder wiring and sheilded 16awg cable for my servo power. Wiring is cleaned up with Network cable breakouts at both ends and SLR connectors for motor power.

I am using leadscrews purchased from LL. They are 1/2" Acme 6TPI. They were cheap, and regret it a little. I was going to go with ball screws but couldnt afford it at the time. The X screws are too long and cause the screw to whip pretty bad. It keeps my top speeds below 150IPM.

To try and combat the screw whip I have 35mmOD x 10mmID 6202 bearings. There are 2 on the X motor drive end and 1 on the other X end so each X screw has 3 bearings.

The leadscrew nuts are made of UHMW and were made by LL.

[Phife]

Electronics Enclosure:

My electronics and computer were originally going to be mounted in rack enclosures, but they are quite costly and decided to use the rack but with a rack shelf and standard computer cases. I bought 2 matching cases that fit nicely in my rack.

One holds the PC to run Mach3 and the other has the PS, BOB, Geckos, etc.

I have a couple of relays to control my startup and power estop, I also have a solid state relay that is use to dump DC voltage to a large resistor in estop or power down conditions.

I have a 6 port RJ45 Breakout on the front along with 4 XLR Chassis connectors and a digital DC AMP and DC Voltage meter.

The rack has a tiltable top which I mounted my LCD and Flexable silicone keyboard.

I am also using an Xbox controller in Mach3 to control my machine.

[FandZ]

Good job on your build. The only negative thing about it is the unsupported rods but that isn't too hard to fix. Do you plan on changing the rods? Just and idea, for about a hundred in cncrouterparts.com's linear carriages and some cold rolled steel and 2 more square tubes, you could end that flex. It would be a simple and effective upgrade.

[Phife]

Aluminum and Machine design:

The machine is made entirely of square steel and 0.75" 6061 Aluminum. I designed the layout of the machine in Sketchup and used it to produce the dimensioned drawings I gave to my brother who is a millwright and machined the aluminum for me.

My design is quite different from the LL version, I made the changes where I thought the design needed improvement.

The machine is a hanging gantry type, If I were to design it again I would go with a more traditional design. Having the frame and gantry to high up makes the machine bed hard to access. I would also definatly go with Supported rails.

I bought a router mount from K2CNC and used that to hold my 2 1/4hp Poter Cable Router. I plan to buy a spindle eventually.

[Phife]

Well, thats its pretty much it for now.. If I missed anything or if anyone has any questions, comments please feel free to ask.

Heres some more pictures of the machine, and some signs ive made.

I am using Mach3 as my machine controller, and I have VcarvePro, Cut3d, and ArtCAM that I am using to do my CAD/CAM work.