CNC
A Change at THMStore
The change is THMS is going to manufacturer many of the products it sells. The Hobbyist’s Machine Shop will be refined and improved as necessary into a higher volume work shop in order to enable production runs of some finely crafted products we have long considered making. These products will then be offered for sale through our e-commerce store or perhaps regional sales representatives.
The Hobbyist Machine Store (THMS) is an Internet e-business. The initial mission statement of the business was to provide replacement steel gears for the popular Asian made mini lathe and mini mills. THMS next expanded its mission statement to include supplying small machine tools, accessories and powered hand tools to any hobbyist constructing precision projects in their personal workshops. THMS does not cater to just the machinist hobby, but to any kind of hobbyist who requires small high quality machine tools for their workshops.
The original plan put THMS into limited competition with other Internet and catalog based small tool providers. I have stated on these pages, it is not the intention of THMS to be yet another supplier of lookalike goods. We never intend to become a large discount supplier of common brand tools and machines, just competing on price.
I have been considering making this THMS mission statement “adjustment” for more than a year. I can’t call it a change of mission as this direction has always been a part of my long range strategy. A change in emphasis may be a better description. The emphasis to produce and market my own products.
THM Store will continue to offer, as long as there are orders, the high quality products that are not readily available through other channels. One example is the excellent Proxxon PD400 metric mini lathe and accessories, imported from Germany. We will… 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…
Smooth Sailing
I ran an 8×10 Lithophane yesterday which required a few minutes over 3 hours of continuous running on the HB2. Not a single glitch. It sounded and ran so good I was able to do a lot of regular work around the shop, like cleaning up.
The sound level is extremely low with the Taig spindle and the new tune up with the finer microstepping. Now the loudest sound is the cutting of the router bit through the material. No problem with normal level conversation right next to the operating machine
Most owners of these machines are using small wood routers. They do a great job (I have one) but the sound level is extremely high. It requires ear plugs or ear cans (headset) to protect hearing. Not so with the Taig spindle.
Now I can spend more time on project design and equipment refinements like material mounting methods. Breaking couplings looks like a problem solved.
So Smooth
I put a little spray of my very special grease behind the thrust bearings on the HB2. Not hard to do as it goes in as a thin spray foam and quickly congeals into grease. A double shot behind every thrust bearing was perfect.
HB2 runs like a new machine! Wow, it is really more effective than I imagined. I just ordered a mini grease gun with this brand of lube to use on the linear bearings. Good stuff!
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