Workshop
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.
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.
X3 Mill Digital Readout
Here it is! The full install of the DRO PROS (brand) DRO on the Sieg X3 small mill. Go to The Hobbyist Machine Shop web site to see all 80 photos and all the details on the digital readout installation. It is currently at the top of the menu list under WORKSHOP. Just click on “DRO PROS – DRO for the Sieg X3“.
The cold weather had been holding me out of my shop for awhile but outside temps up around freezing with two heaters going and some persistence, I got the job done in about four full days of work. I was also doing a lot of documentation and photos.
This conversion will make looking at rotary scales a thing of the past for me. The computer built into the DRO provides a lot of functions that will alleviate some of the layout work.
This review is of only the install process of getting the three axis scales installed. Later I plan to show how the DRO is to be best used. I may make a video for that.
Sneak Peak
I have been putting time into installing a Digital Read Out (DRO) for my X3 mill. These are a couple of spy photos of the installation. What you see here is the completed Y axis scale installation and the nearly finished X axis scale. I am using the mill to make the mounting brackets. That is why you see some dross in the pictures and the vice on top.
I am currently machining a bracket for the X axis carriage mount.Then I have an idea how to mount a cover over the X Scale. That is the reason for the ears at each end. A slightly shorter scale could be used here for the X axis but the longer length is not a problem. I am also noodling out how to mount the Z axis scale.
There will be a full report on this installation and how the DRO operates coming up soon. Lots of action photos on the installation and operation.
Cold Weather Choices
I spent the weekend deciding weather (sic) to spend time in my 35 degree workshop or my 72 degree home office. (Pun intended). You can probably correctly guess the office won the fair share of the coin tosses.
I can warm up the garage with electric heaters and make it a somewhat enjoyable work space at approximately 62 degrees air temperature. However, I am working on installing a very precise digital readout (DRO) on my big mill and I would like the temperatures to be a bit more stable. I can get the air to 62 but it takes awhile for the big chunk of cast iron and steel (of which the machine is made) to get up to temperature.
I have the non critical work done but the fine tuning needs a few days at a bit warmer temperature. It is all in the joy of trying to maintain precision in a changing environment like an unconditioned garage shop. Open the garage door in winter conditions and “whoosh”, instantly floods in 27 degree air.
I am jealous of the climate controlled workshops of some home machinists. Actually the temperature is not a problem when it stays constant. It is the warming and cooling that is the problem. Starting a series of milling operations at 40 degrees and finish at 75, the dimension reference (datum) will change. It changes anyway because the part being milled gets hot while cutting, but it is nice to reduce some of the variables. Home shop projects usually don’t demand super tight control.
The DRO PROS project will have a full product report in The Hobbyist Machine Shop is a few weeks. Watch for it. (Tell ’em Dan’l sent ya!)
The office work consisted of upgrading two of my computers. I won’t spend much… Continue reading