My name is Dave, I have been a lurker on here for quite some time. Never felt the need to say anything on here unless I felt it could contribute.
However, all of my engineering experience is automotive so I am turning to you all to ask if you think my design would work for milling 6061-T6 aluminum.
I've done the math (attempted to at least as much as this bottle next to me allows) and it seems like deflection will stay under 0.001" with 200lb induced at the tool, but we all know real vs paper is ALWAYS different.
I own a mill and surface grinder so the surfaces will be trued up pretty good and I can fabricate, fit and weld pretty decently.
I have already ordered everything, just waiting on the last bits of metal to come in from metalsupermarkets before I start cutting stuff up.
I'm already about $4,000 into this so I had to cheap out on the things I can upgrade later.
Frame Construction:
The entire frame will be TIG welded together
Steel panels will have m5 machine screws every 6 inches along tube, overlapping edges of panels will be riveted.
Frame will have 2 inch, .120 wall square steel tubing. (I'm still waiting on the 16lb polyurethane expanding foam to come in. This stuff is AMAZING at stiffening hollow structures, use it in chassis all the time)
Misc X braces and cross supports are an odd C channel, that is semi closed.
Rails will be supported on cold rolled .5" stock on top of "sistered" square tubes side by side and welded.
Mechanical and movement:
4kw (5.3hp) 18,000rpm air cooled spindle (I removed the direct drive fan and I am attaching an Ametec 120v 5hp blower so it can run at lower rpm without overheating)
Vector control VFD
4:1 reduction 260 oz/in NEMA 23 motors (saving for a set of clearpaths)
20mm "O" style linear rails (saving up for some 35mm so I can do steel easily)
20mm, 10 pitch ball screws off amazon, almost certain that I will have to change these out sometime.
Inductive limit switches
Control system is Centroid Acorn and relay board. Software running on a dedicated for this and freshly imaged laptop. If I feel that I like their software and reliability I will upgrade to the Oak
For cooling I will be using an MQL setup using a dupont "whole home filter housing" as a reservoir and an air supply from a dedicated air compressor with a variable valve solenoid setup.
additionally there will be forced air downdraft from the heavy blower attached to the spindle for chip clearing (anything over 5psi bypasses the spindle and goes through a line to the tool)
I've left a lot of small details out on the cad file because of complicated and technical reasons such as "I got tired of clicking the mouse after 14 hours." Been working on this since Friday night.
Thank You for taking the time to look at this, feel free to roast me. Any and all criticism is greatly appreciated.