machine
Grizzly Disk Sander/Grinder Switch
Quite awhile back I purchased a Grizzly G7297 12″ disk sander/grinder. It is one of the most used power tools in the shop. Sometime I just have to grind something off flat or square and this is a fast and accurate way to do it.
The switch is apparently the weakest part in the machine. It stuck in the always on position. As you can see the points are badly burned. The concept was good as it is a double pole single throw (DPST) switch. Both power and ground are broken when switching off. But not good when they weld both sets of points to their mate.
My assumption is this is the same switch used for 220 volt A/C models.
The switch is mostly plastic and the toggle has a plastic part that can be pulled out to supposedly lock-out the switch from functioning. I never used that function and I hazard an assumption that almost no one else does either.
I saw no good reason to use an OEM (Original Equipment Manufacturer) switch as a replacement. I could have ordered a DPST toggle but I had a 20 amp single pole on hand. My shop is wired correctly for 120VAC and the power cord has a safety ground so no real need for a double pole switch. I wired my switch to break the hot side.
I had to fabricate a plate to cove the huge square hole that was in the junction box cover for the original switch. Not much of a task for a machine shop.
The Cutting Edge
I viewed a series of videos called Knifemaking Tuesday’s sponsored by Tormach. The hyperlink in the previous line will take you to the video location in the Tormach website.
The video series is a non professional production but it is an engaging story about a couple of Canadian knife makers, John Grimsmo and his brother Eric Grimsmo. It picks up their story when they first start using the Tormach machine.
John and Eric are a couple of entrepreneurs starting a production knife making business in I assume John’s garage. (I haven’t seen the videos from before Tormach sponsoring.)
The investment they made for all their recent upgrades indicates they must have deep pockets somewhere or the previous knives they sold before using the Tormach tools must have been VERY expensive and profitable. There is a lot of talk about what they are spending on development of the new production system and design run but zilch about profits, then perhaps that is not our business… so to speak. 🙂
Tormach sponsors this YouTube “Channel TV” program because it showcases the Tormach PCNC 1100 machine and a lot of their accessories, except the ATC (Automatic Tool Changer).
This is definitely more an amateur reality TV garage workshop sit-comedy of errors than a typical Tormach training series. There is way too much goofing around and trial and error mistakes for calling it training, but I did learn a bunch about amateurs trying to become serious professional knife makers. I also gathered a bunch of new information about using CNC for knife making. The knife products do look good by the week 26 video.
The video work, even with as low a production effort as seen here, takes a lot of time and effort from the actual work of knife making.… Continue reading
Gear Cleaning
I import steel gears for the mini-mill and the mini-lathe. I have sold over 200 sets of gears to people all over the world. Most buyers are machinist, used to working with wire brushes and getting dirty hands cleaning gears covered with grease or a little surface rust. Most carbon steel will rust. However, I show nice shiny gears in the photo’s. My Bad. The real gears have to be cleaned because there is some “gook” used to preserve them from rust while shipping across the salty brine. (Ocean to you land lubbers.)
Most gears are well “gooked” but a few, especially the change gears are only “oiled” a bit light. There is a coating but looks like almost none and as shown here, have definitely gathered some surface rust. The first picture is a worst case gear I could find (65 tooth change gear ). It is the largest in the group and the only one showing rust. It really does look nasty but looks are deceiving.
I think some salty air got into the last shipment. Only one side had this rust and all the other gears clustered in one group on a long bolt with this one had no rust. It is cosmetic and does not make the gear defective.
A spray with WD40, about a 5 minute soak and two to three minutes with the brush shown and the gear is photo perfect. Perhaps too much work for some people with arthritic hands. It is hard for me. A rotary wire brush would do it faster and easier.
I could clean and inspect all the gears, shine them up like shown in the store photos, re-coat with that heavy LPS3 grease for maintaining protection in storage and sell them for about 50% more… Continue reading
Thinking Small for 2012
I am investigating very intently the world of very small CNC machining. I am looking at small items such as mold machining for model parts and jewelry sized items using very small milling bits and high speed spindles. Actually I should call it CAD/CAM/CNC. It is far more than running the CNC mill.
I also looked at micro machining but that is a very high tech world that is still outside the needs and abilities (and machinery) of the personal machinist. It is truly amazing what can be done in the very tiny micro machining. I am not going there.
What I can do using my Taig CNC Micro Mill and a +10,000 rpm spindle is overwhelming. My recent Christmas ornament project is what has driven me into this investigation. The fantastic finish in wax that I was able to obtain actually surprised me. The Taig is a truly capable machine in this precise machining task.
I have now found web information of other, higher speed spindles added to the basic XYZ Taig movement. The Taig non-linear bearings and ways actually are up to the task for precision machining. I have many hundreds of hours of operation on my machine and it is still holding the performance line.
For now I consider myself “good” as far as machinery needs. I also have the appropriate software for CAD/CAM. That may change but not for quite some time. I will be adding a forth axis very soon, but other than that, I am comfortable.
I have the HB2 for larger projects and I will use the Taig for my miniature machining. I hesitate to use the word “micro-machining” but I am thinking it within my own definition.
I will also continue in my mold making and casting of components. I will definitely… Continue reading
GWizard – First Looks
A visitor to this blog named Bob Warfield left a comment about a post he made in his blog HERE. Bob is also the creator or progenitor of machine shop “Speeds and Feeds” software called GWizard. It probably isn’t fair to call it just a Feeds & Speeds as it does so much more.
Bob told me he was known for The CNC Cookbook Blog as well as anything. So naturally I had to dive in and take a look. Sure enough there was Bob standing there grinning and holding plate with pumpkin pie. You’ll probably have to scroll way down to find him now (and the pie). This CNC Cookbook is a great place to read and study about the “science” of rotary machining.
I like a guy that doesn’t hide his face from his peers and customers.
I perused carefully everything I could find on that web site. Where was this when I needed it!? Of course always the skeptic, I had to figure out what was the “deal” going on here. The biggest question for any CNC machinist (well at least for me) is how hard can I push feeds and speeds and what are the reasons. It would seem obvious that this sort of program would have been offered long ago. But… it is a very complex subject. Tool manufactures are of course going to shade any such tool program toward their own products.
Bob admits it could be done with a spread sheet and in fact that is how he started. When I first started CNC machining I eventually found the safe speeds for the kind of work I usually do, but it had taken a lot of effort. I could have built a spread sheet myself but the effort would have kept… Continue reading