Miscellaneous
Halloween Thought
I have discovered I might have all that I need to die happily in my machine shop. Well, almost. It’s that “almost” that will keep me alive in the long run. Just one more tool then I will die happy. It may be the “just one more tool” that keeps me alive forever. What do vampires know about immortality? HA! All that awful yucky blood and stuff…
It’s bad enough when I nick my finger. I have a cute little scar on the back of my left hand middle finger where earlier this year I let a 10,000 rpm end mill remove some flesh. CSI (Crime Scene Investigators) would have enjoyed figuring out what happened at the scene of the accident from reading the resulting blood splatter. <’ulp…>
Ninety nine point nine percent of the time I practice safe workshop. That’s ok as long as the last tenth remains minor. The vampires can stay in their dark places, thank you.
Small Stuff
I am still in lust for the smaller projects. I had a discussion with a caller about machine tool size. I admitted I liked some of the larger machine tools, but I have no projects that can justify them. Mostly I cannot justify the very high cost of the tools or the materials. I’m just in my comfort zone where I am.
I have been doing some recent machining so small I have to wear one of those dual lens magnifying hoods to see the work. When I push it up or take it off, I always feel amazed at how tiny the work is that I was doing. I think it is a lot of fun doing miniature machining.
There is a trade-off between modeling something very small for display and… Continue reading
Teaser
What is this set-up for?
I am busy making the parts to make a special part. It requires the use of the 4 inch rotary table. here I have squeezed it on the table with the screw vise. However, once I center the rotary table, I won’t be making any table moves until I complete the part.
This is just a teaser for now. I am not saying what I am making. Sometime soon (after I make all the mistakes) I will show off the project.
12 Inch Slip Roll
Finally, I found a high quality small slip roll.
This is the highest quality 12 inch slip roll you will ever see, use or own. I just unpacked this new sheet metal forming machine and will soon have a full report in The Hobbyist Machine Shop.
This product is so exquisite compared to the Chinese junk I once owned for a few days, I can hardly stop starring at it. This picture barely does it any justice. The complete report will show a lot more close up pictures.
This is the model PR12W made by Accu Cutter. A definite high end machine tool. Well priced for the professional high quality US made tool that you see here.
I haven’t cleaned it up at all at this point. It still has a light coat of white grease which will be seen in all the “first look” photo’s taken. I will show how it was packed for shipping which was also first class double boxing.
UPDATE: Full writeup, more pictures in The Hobbyist Machine Shop – Under the “Workshop” tab.
Do You Need The Balls?
There is a common conception in the amateur machinist world that ball or roller bearings are always the preferred selection to bushing or solid surface bearings. That is not always the case. Machine engineers, of all people, should know it always depends on the application. There are many applications where ball bearings are contra indicated, meaning they should not be used. Some of those reason can be as simple as cost over performance, excessive noise or the possibility of bearing contamination in harsh environments.
The primary benefit of using a ball bearing over other types is the greatly reduced drag due to its small rolling surface contact point. Their use is preferred when low friction is a high priority and other factors like low noise is not. They will reduce power requirements, help reduce friction heat and provide long periods of operation. If they are properly sealed, they will reduce maintenance. The best, high quality ball bearings can reduce run out and take thrust loads. These are worthy goals but sometimes are higher goals than necessary.
To quickly get to my point, I’ll examine the bearing needs for the lead screws on all the axis of a small manual mini lathe. First, do radial ball bearings “increase machining (position) accuracy” on any of the calibrated axis including the Z axis main feed screw over a bushing type bearing? The answer is an absolutely no.
This is because the linear slide position accuracy is a function of axial (not radial) screw loads affecting the amount of compression/expansion of the lead screw, drive nut thread engagement, drive nut mounting rigidity, thrust surface material and screw shaft bearing end play. This as combined is commonly called backlash. Minor drive screw side play (run out) is not a factor.
Radial bearing loads… Continue reading
Cutting Slots
I present a few more action shots on the X3 mill. The DRO is wonderful for cranking in the proper cutting dimensions even after a careful layout. The layout marks confirm the location but the caliper like accuracy of the DRO makes sure the cut is exact.
These parts will be used to braze up the coupler pocket for the A3 tender. I am not showing all the work involved, just some of the unusual. The saw here is the same thickness as the brass plate. I am cutting two layers at the same time. That way opposite sides will be exactly the same. The pieces will be assembled like an egg crate.
The cuts are made on one side of the vice but unseen inserted on the other side of the vice is more brass material the same thickness. This is to keep the vice clamping equal so that it doesn’t “rack” when tightened.
I will be posting more pictures of how the coupler pocket is assembled and finished.