PD400 in Action
I know some readers just like to look at action shots. So I have thrown a few pictures in here for your enjoyment. This is the Proxxon PD400 lathe and I am making the standoffs shorter that I use on the HB2 router. I installed the new couplers on the HB2 this weekend and I discovered I can bring the screw shaft and the motor shaft closer together using the new couplings.
I needed to remove 3.18mm from each end of the standoffs then extend the threads a bit deeper into the aluminum standoff. That was about 1/4″ overall for you non metric holdouts. 🙂
It was short work and the HB2 is purring along just nicely. So you see the PD400 does get a little workout from time to time. Oh, and it didn’t hurt that the lathe was about 2 feet away from the HB2…
Metric Thinking
I have been selling some metric tools (Proxxon) and actually using them too. I have discovered it is actually quite easy to work in either metric or SAE (inch) standards. There is no evil in either. I (almost) hate to admit I enjoy metric.
Of course the U.S. general prejudice to metric stemmed from our indoctrination, from what I now view in retrospect, to be a very lame educational system of the time. Post WWII there was a push for the USA to go metric. The requirement was to teach young children to exactly convert through (then) seemingly complex formula from one system to another. Remember, there were no calculators in those day. I could derive the equivalent answer but it made no sense why we would want to do this. The same thinking was crammed into our brains about temperature conversion.
In those days a student was not permitted to question the process but only to do as instructed.
As in learning a new language, it is very cumbersome to convert every word from one language to another. You only become efficient when you start thinking in the other language without the conversion. That is how metric should be understood.
I learned Morse code as a radio amateur. All radio operators will tell you that you do not become proficient until you stop counting dots and dashes and start “hearing” the sounds of letters. The really good can hear words. The very best hear Morse as a conversation.
When using metric hand tools I do not think of what millimeter is equal to in inch measurement. A good mechanic looks at a bolt and can say it is ½ inch or 12 mm, not stopping to think they are almost the same. When cars started using a lot… Continue reading
Fixing the Broken Axe
I received the new couplings today for the HB2 from PDJ, Inc.. The new one is the bright and shiny one in the picture. The black one is the original style that has been giving me problems with breakage. (6208K6 @ McMaster-Carr)
The new one is rated for 495.6 oz-in. The old one is rated for 42 in-pounds (peak). That is 672 oz-in! So the old one should be the strongest, right? The new one LOOKS stronger and is a different style. They are both considered Helical Beam Couplings. If you want to see what a broken one looks like check HERE.
So what gives? Well, the old couplings certainly do. Maybe the key word is the “peak” rating rather than a continuous rating. I can’t tell. The Mark One eyeball says the new one is stronger. That’s old Navy jargon for eyeball engineering.
I think I will soften the acceleration on the steppers a bit more to lessen the start stop shock loads.PDJ has been using these shiny couplings without failure so I hope my problems are over, at least with the couplings.
Weekend Puttering
While waiting for the new stepper couplings for the HB2 to arrive, I decided to do a little house cleaning around the shop. After pushing things around for a few hours, and sucking up what debris I could with the shopvac, I figured I should lube the ways on my machine tools. I can appreciate a one shot lube system as I have to do mine the long slow way. I finished and every machine is operating pretty slick now…
I spent a lot of time detailing out the Taig CNC mill. It is still in wonderful shape after all the machining it has done. That is really a great little milling machine in its size and class. I had to fire it up with the MACH3 in control and it wasn’t long before I was dreaming about the next project I should be running in CNC on that machine. In fact I “air cut” a couple of projects just to give the parts (mechanical and electronic) a little work out. It runs so sweet!
I have added a new Proxxon rotary hand tool to my workbench. I have more than I can handle (literally) but there is always room for just one more. This new tool is the Proxxon Micromot 50/E low voltage rotary hand tool. This is the first one of the 12-18 volt tools I have tried and I am amazed!
I already have and operate the Proxxon IB/E professional 120 Volt rotary tool. It is wonderful and definitely exceeds my two Dremel rotary tools in quality.
The 50/E is about ½ the size and power of the IB/E but is every bit as good. It is lighter, smaller and easier to hold for long periods of detail rotary work. I think I will prefer using… Continue reading
Broke My Axe
The HB2 broke a coupling on the Y axis again. The couplings have been fine for 6 months. Must be more loads on it than I thought, but it is the axis with the dual steppers. It should have ½ the loads. The X and Z axis have never been a problem.
I thought it was most likely an alignment problem causing the couplings to flex too much. I was very particular in checking the alignment in the last replacement.
This time I am ordering extra heavy couplings from PDJ. They are the same style and exact size as I have been using but are built much stronger. They are a bit less expensive too, probably because Phil buys them in greater volume.
The failure spoiled a project I was cutting. Always happens near the end don’t you just know… I am glad it was a concept part and not some valuable slab of rare wood.