Trevor FlowersJan 27, 2023
If you're interested in open DIY CNC mill designs then pop over to Maker Forums for an update about the Chela Mill's gantry redesign.
https://forum.makerforums.info/t/chela-mill-part-2-the-refininging/86812/5
#DIYCNC #machining #ChelaMill
Chela Mill Part 2: The Refininging

I’ve rewhacked the gantry design a bit now that I’ve had a chance to play around with various options. It turns out that the shape of ~every moving gantry out there is a pretty good shape. 🤷 The current placeholder model for the spindle isn’t right as I intend to buy an unpowered head and drive it with a servo. I’ve also started filling out a bill of materials (Chela Mill BOM.fods in the root of the repo) as I think of necessary parts and find sources. Recommendations are, ...

Maker Forums
Trevor FlowersJan 24, 2023
In looking for examples of motion systems like the Chela mill's I ran across Aerotech, a company that makes custom machines. Their "split-axis overhead gantry system" has a similar above-the-fray gantry as the Chela mill's though theirs is configured for low force, high precision work instead of medium-precision steel cutting.
https://www.aerotech.com/product/custom-engineered-motion-systems/split-axis-overhead-gantry-system/
#Machining #ChelaMill #DIYCNC
Split-Axis Overhead Gantry System – Aerotech US

Suspended planar processing system allows for two-sided access to part High-accuracy air-bearing axes below the processing plane Dynamic linear motor gantry above the plane Unique granite base design that allows for all motion axes to be precisely aligned to the working area Air isolation system reduces externally caused vibration noises Applications include part manipulation, alignment, advanced manufacturing and inspection

Aerotech US
Trevor FlowersJan 18, 2023
There's nothing quite like designing a thing to learn why the existing thing is actually the least terrible option. #ChelaMill #CAD
Trevor FlowersJan 8, 2023
I started a thread on Maker Forums about an open hardware design for a home shop CNC mill that is designed to cut steel. It's called the Chela Mill. Many details are still TBD so if you're experienced with (or interested in) machine tool design then I'd love to see you weigh in, here or in the forum.
https://forum.makerforums.info/t/chela-mill-part-2-the-refininging/86812
#machining #DIYCNC #CNC #ChelaMill #FreeCAD #LinuxCNC
Chela Mill Part 2: The Refininging

I’ve rewhacked the gantry design a bit now that I’ve had a chance to play around with various options. It turns out that the shape of ~every moving gantry out there is a pretty good shape. 🤷 The current placeholder model for the spindle isn’t right as I intend to buy an unpowered head and drive it with a servo. I’ve also started filling out a bill of materials (Chela Mill BOM.fods in the root of the repo) as I think of necessary parts and find sources. Recommendations are, ...

Maker Forums
Trevor FlowersJan 6, 2023
One step closer to using a FOSS CNC controller to make atoms move.
#machining #DIYCNC #ChelaMill #LinuxCNC
Show threadTrevor FlowersJan 6, 2023
I'm having a heck of a time finding a spindle and VFD combination with enough torque at steel cutting speeds (600 to 1200RPM), a power drawbar for ATC, and a taper like a BT30 or TTS. I aim to keep the total Chela mill material costs around $5k so a $4k spindle like CNC Depot's FM series, while excellent for many projects, won't work here:
https://www.cncdepot.net/product-page/fm-series-spindles-march-pre-order
#ChelaMill #DIYCNC #machining
Trevor FlowersJan 4, 2023
This Maker Forums post is my first attempt to calculate power requirements for a new machine tool design (the Chela mill) and I would love for folks with more experience to give it a once over as a gut check. #Machining #DIYMill #ChelaMill #OpenHardware
https://forum.makerforums.info/t/cnc-build-part-1-the-plannening/86693/24
CNC Build Part -1: The Plannening

Here are my current numbers for target speeds, feeds, and power: This is my first attempt at calculating power for a new machine design so if any of you have more experience and want to weigh in then I’m open to suggestions. There seem to be a couple of common spindles like this one from RATTM that have a BT30 taper and ATC but they all seem to be designed for higher speeds like 15k to 24k RPM, presumably for softer metals and plastics. For steel I want more like 600 to 1200 RPM. There are ...

Maker Forums
Trevor FlowersDec 31, 2022

In quiet moments during the holiday I started an open design for a CNC mill that:

- Fits within a 1200mm x 1200mm x 600mm footprint (~4' x 4' x 2')
- Has a cutting envelope of 700mm x 300mm x 200mm XYZ (~2.3' x 1' x 0.6')
- Easily cuts mild steel and can take light cuts on stainless
- Uses a fully FOSS workflow including FreeCAD and LinuxCNC
- Avoids vendor lock-in
- Works with single phase 220

More details: https://forum.makerforums.info/t/cnc-build-part-1-the-plannening/86693/19?u=trevorflowers
#machining #CNC #OpenHardware #FreeCAD #LinuxCNC #ChelaMill

CNC Build Part -1: The Plannening

I sketched in a couple of tank+pump placeholders on the lower shelf as well as a tilted swarf and liquid tray below the table. The control box sits toward the front on the lower left. With the total footprint that I have for this and the cutting envelope that I want (dotted lined box above the table) I think that I can leave space on the left side of the table for some sort of ATC rack. I’m considering Teknik’s NEMA 34 Clearpath Servos that have integrated drivers. This model is driven b...

Maker Forums