I made some steady progress on the new surface grinder attachment over the weekend. It's coming along nicely. So far I've been able to work through the design of each part, but I won't know for sure if it works until I get the whole thing built. Here are some photos of this weeks progress.
The next step of this build is to mount the axis assembly to the tool arm. To do this, I need a part that will attach the two together so that the axis is located in just the right place and at just the right angle. I opted to use a piece of 1-1/2" square bar stock for this assembly. It needs to be rigid to eliminate flexing. The four holes that I am tapping in this photo mate with the axis assembly. I had to tap a lot of holes in this build.
Here I have the axis assembly bolted to the angle bar and temporarily clamped in place so that I can get the proper angle and location figured out. Once I had it determined, I drew lines around the mating surfaces.
Now the angle bar is attached and I'm making sure that the linear guide will glide up and down properly without hitting into the cabinets below. I could have avoided this whole angle bar, but the linear guide would have been completely vertical. I think it will be easier to manage at this angle.
The next item of business is the table that will attach the linear guide to the magnetic chuck. The easy way would have been to bolt two pieces of 1/2" stock together at a 90 degree angle, but I decided to fire up the mill and make some chips, milling it out of a solid piece of aluminum.
I should have gone for bolting the two pieces together!!! This is a problem with this particular mill. I'm sure that they manufactured this gear out of plastic so that it would fail before metal pieces started to shatter inside the gearbox. Luckily this was the second time I've thrown this gear, so I had another one that I had purchased earlier on hand. 15 minutes later and I was back in business.
Here is the table sitting on top of the linear guide. I've located it on the guide at the right spot and drilled the three holes that will serve to attach the two parts together.
Here I have the table and magnetic chuck temporarily held together with a couple drops of super glue so that I can locate four mounting holes in the right spots. The table is slightly offset. This is by design so that I can build some swivel into the table in order to make tapering tangs possible.
Here's a pic of the table, magnetic chuck, and the liner guide mounted together. You can see that the table at the bolt on the right side has a slot cut out of it. This is so that the table can swivel forward, pivoting around the bolt of the left. The middle bolt will need to be removed in order to do tapering, but it will help to keep things true when set parallel. I may need to add some stops too, but I don't think they will be necessary.
This last pic is of the whole grinder all assembled. I'm so close to the end of this project that I can taste it. I can't wait to fire this thing up and take it for a spin. I still need to add a handle to the linear slide to make it comfortable to operate and add a bumper stop to keep the linear slide from sliding right off the axis assembly and dropping to the floor. I think I'll do a couple of cosmetic mods also (just round off some corners) and maybe make a bigger knob to adjust the Y-axis. With fingers crossed, I'll be grinding parts by next weekend. I might even try to figure out how to add a depth indicator. . .
Thanks for following along with me on this build.
- Brandant Robinson