It’s getting that time again. Our Machine Shop Committee meeting is in about a week and a half.
We will debrief the past month for problems, improvements & ideas.
Go over our consumables of what we need.
Areas of improvement we need to do.
Any issues or concerns
Bring in your items you have made in the past month for show & tell
Come join us, you do not need to be a machinist to be in our committee. If you want to become involved with the committee, show up.
Just FYI … 2nd Thursday, Will be there.
Reminder that the Machine Shop Meeting is this Saturday. Join us for our monthly meeting & discussion, Then afterwards lets enjoy some grub.
Unfortunately I will be out of town for a wedding, but I want to share some of what I have been working on in the past month. This will be a long post, but there’s been a whole lot of work!
As many of you know I am designing and building a small CNC milling machine for home use. I had been machining parts on the Bridgeport up until recently, but had long had aspirations of HAAS use and since I was making many parts in a quantity of two, I figured it was as good a time as ever to start making things on the HAAS. Most of these could just be saw cut and hand drilled, but why do things efficiently when I could learn to use an industrial VMC?
I have been hard at work programming parts in Fusion for the assembly that mates the spindle drawbar booster and spindle motor to the spindle head, while allowing for belt tensioning. Above is the mess of toolpaths that will lead to finished parts.
So far I’ve only made two different parts of that. I started simple with a small part that simply holds a screw for belt tensioning. It was a simple hard jaws and parallel job. I used my own tooling aside from a face mill.
Setup:
Op1 (face, mill, drill)
Op2 (mill overhang, face to thickness), finished parts:
Overall this went very well. No crashes or vise dings. So, I was buoyed to go on to something a bit bigger.
The next parts were simple risers for a the drawbar booster. Same workflow but with an op3 for drilling the holes perpendicular to the top and bottom.
The finish is excellent, and the dimensions created by the end mills were essentially perfect for all the parts (within a thousandth of an inch with absolutely no adjustment).
Overall it’s been a great experience getting to learn this machine. It performs very well. I have been primarily running somewhat HSM toolpaths, 180 inches a minute, 50 thousandths stepover, with 7000 RPM on a half inch 3 flute ZrN endmill (about .005ipt accounting for chip thinning) from Lakeshore Carbide.
Thanks to @malcolmputer for getting me checked off!
For the committee meeting, I would like to comment on the condition of the HAAS and its tooling. The HAAS itself seems to be in very good condition. The parts I made came out almost exactly the same between one another, and the only issue I had was a faulty toolchange (commanded from MDI, but the machine didn’t orient the spindle first). A power up restart put the machine back in a good state, and there seemed to be no damage.
For the tooling, I have noticed that the tool holders have sustained quite a bit of corrosion. Many of the ER holders had the collets and collet nuts left sitting in them and hadn’t been cleaned and dried after being taken out of the machine at some point in the past. The bad coolant dried in the toolholders and the bare metal surfaces (i.e. the collet seat and the collets) became very corroded. After a cleaning they still appear to work, but we need to avoid this in the future by properly disassembling and cleaning the toolholders for storage.
On that note, the coolant is definitely going bad again and is not doing its job as a rust preventative. Every time I have come to the machine, the vise has new corrosion spots, even when the standing coolant is dried from the bare metal surfaces. I have been cleaning them off and stoning them away as best I can when I see them, and have started putting rust preventative on the vise when I leave. However, I believe the coolant is to blame. It already has turned a greenish color and has a strong nutty odor. I am guessing that because we did not remove the sacrificial plate, old bad coolant sludge has propagated the infection.
I will be available for several days during next week (Monday-Wednesday, potentially Friday, Saturday, Sunday) to assist with this issue and other things of importance in the machine shop. Would anyone be interested in joining me between 9 AM and 6 PM one of those days to remove the sacrifical plate, and potentially drain the coolant and reclean the machine? I think we should act sooner rather than later on this as it will only get worse. Regardless, unless there are objections, I will at least try to pull off the plate and have a look.
Yep, it is starting to turn again. I removed the cover for the aerator & have found some growth. We have been evaporating a lot of water a of recent. I put 10 gallons in about a week & a half ago, but I would rather loose water than have it get stagnant. After we clean it again, we need to still keep a close eye on it.
We do need to check the PH & look into getting an RO system to top the water off. Perhaps we can get cost together before this weekend to vote on it.
Reminder that the meeting is tomorrow.
Here are the meeting minutes. Once I figure out how to post them to the “Meetings” Wiki, I will. But for now they are on our Committee page under Committee Meetings.
