hobby
New Publication Format
I am nurturing an idea for a “future state” THMS web publication. The literal big picture is video. I believe Internet bandwidth and present day hardware are fully capable of exploiting this content delivery method. Example: My last post contains video.
Since the beginning of the World Wide Web, but more so as it became commercial, the medium has been handicapped by the belief (and a self standard) we could not abandon the old obsolete tools and practices of the past. Some websites today are still being constructed to accommodate text only browsers. I am not trying to be a techno snob but, TEXT ONLY BROWSERS!! Give me a break.
The Amish value the “simple” life, so the horse and buggy make perfect sense. But just like the horse, text only browsing is not in my view a mission of the modern highway called the Internet. Yes, it can be accommodated over on the berm*, but it is truly out of place. (*Chiefly Indiana, Ohio, Pennsylvania, and West Virginia. the bank of a canal or the shoulder of a road.)
I am designing my future messages using the visual method of quality video presentation as well as continue my present standard of high quality photography. The video and new photo story pages will be in a new format section linked to the present THMS website. The present “frames” site and this blog will continue unchanged.
Blogs are the hot delivery medium, and I already have three. I decided not use the blog format for my new design. I won’t be looking for easy feedback, as blogs attract a huge assortment of low life and spammers because of that feature. I presently reject 99.9% of entered comments because of off topic abuse. In my… Continue reading
HB2 Action
I ran some Lithophanes this evening. I realized I had my iPhone in my pocket so I grabed a short segment of the HB2 in operation.
What you need to note is the quiet operation with the Taig spindle running at 10.600 RPM and the bit cutting at 50 IPM (Inches Per Minute). Most of the noise is the cutter in the Corian solid surface material making the 0.10 to 0.20 depth cut. If you listen carefully you can also hear the higher pitch “chirping” of the z axis stepper motor. I am “eighth stepping” the motors so it takes 1600 steps to make one shaft rotation. You are hearing those steps.
Most folks are running very loud (screaming actually) routers or high speed rotary tools to do this work. It’s hard to even think over the noise level. I have to wear ear protection with those spindles, but not with the Taig spindle. It’s nice…
Still a Drag?
I had a great weekend. I had to mow the grass but that is expected and still makes for a great weekend. For this Blog it was great because I got to put a lot of run time on the HB2. About six hours in total.
I even ran the Mayan calendar in a 7.75″ diameter on some Corian. I’ll post some pictures soon. The detail was excellent.
I think I may still have a little drag on the axis screws. It didn’t bother the CNC work this weekend. I have some spray bearing grease I will inject behind the Thrust bearings and see if the intermittent slight rubbing noise goes away.
If the grease doesn’t help, I already have a plan to put a “step” at each end of the screws and just remove the thrust bearings. That way the only thing the screw end can contact is the center race of the bearings.
That’s what I should have done in the first place. I did find out how easy it is (when you have a lathe) to modify the ends of the axis screws.
How I noticed what may be the rub is I changed my micro-stepping from quarter to eighth. I now run 8,000 steps per inch rather than 4000. That’s 0.000125 inches per step, way too fine than really useful . This was done not to increase accuracy but make the steppers run a lot more quite (but also a lot hotter).
Quarter stepping was still more accuracy (0.00025″) than I needed and it is supposed to provide more torque. The motors run cool. The noise however is more than 3 db higher and the twin Y’s were driving me crazy with their loud sound. Now I hear a sweet soft… Continue reading
HB2 Bearing Replacement (X – Axis)
Here is how I trimmed the Axis screws for the added thickness of the thrust washers (bearings). They are really being used as washers to keep the screws from impinging on the bearing seals.
I thought I might have to protect the screws when in the lathe chuck but I discovered clamping firm but lightly did no damage. Also the screw nut never gets that far down to each end of the screw. I generally use aluminum cut from a soda can for protection when needed.
I was surprised to see the “juices” leaking from the far end bearing The grease didn’t show while assembled.
The thrust washers turn with the screw shaft. The close up picture shows the washers do not ride against the bearing seals. They actually contact the flange on the inner ball bearing race. So in my opinion they are working perfectly as intended. Note the high quality of the thrust washer finished edge.
All axis screws are barely end loaded. Just barely on the loaded side of touching with zero end play.
After doing all the investigation and testing and more reading, I remembered a drive screw specification I studied long ago that affects how fast a drive screw can or should go in RPM. It all has to do with the end bearings support, screw diameter, unsuported length and preventing vibration. The best set ups are double bearings at both ends for rigidity. The lessons I learned here on the HB2 are the bearings ARE the most important factor for a good running machine. However, I doubt I need double bearings on each end. HB2’s screws theoretically could run over 3K RPM as they are. I’m not going there!
I have settled in… Continue reading
Good Feeling
I received the thrust washers for the HB2 yesterday. Great quality and FLAT washer type bearings. I am so used to seeing and using stamped washers with a crown and rounded edges and imperfect holes, it is a simple pleasure to see a perfect square edge. Why do I feel good about such a simple part? I guess it is just the precision of a well made part and the machinist in me.