Some of the steel came today for this project so I got busy on it.
The trunnion supports mount to a .250" thick ground steel plate 4" square. This plate does not have to be ground , but it just makes it a little more precision. It required some imaginative clamping to hold everything in position to drill and bolt together.
I drilled and tapped for 8-32 SHCS to hold the supports. I put the alignment rod, which is a piece of .250" diameter ground rod, through the trunnion supports to keep them aligned while drilling and tapping. I got one screw in each one to get it together and check alignment before drilling the other two holes. To align the supports on the ground plate, the right support is located even on the front corner of the plate. The other one will line up in position by the alignment rod.With the trunnion supports bolted to the ground plate ,the alignment rod should be able to be turned with your fingers.
The other two bolts are installed. It took patience and time to line everything up, but was worth the effort. The clearance holes for the 8-32 SHCS were drilled for "close" on size fit. There is only a couple thousandths movement when loose , but everything is lined up as close to perfect as possible.
With the trunnion supports installed and the alignment rod free rotating, the plate was clamped in the mill vise and the front milled for clearance of the grinding wheel. The distance milled out for clearance is 1.0" and goes back to the front of the trunnion support. The width is not critical, so I milled over leaving about 1" total where the other trunnion support mounts. ( There is a half flat on the center of the alignment bar which will be explained later.)
Next will be to drill and mount the outside trunnion supports that mount on the sliding base plate. Notice there are two thin nylon spacer washers between the two trunnion supports on each side. These are for clearance and serve as bearing surfaces for smooth operation.
With one bolt holding the right trunnion support and before drilling the left side, the ground plate is lined up square with the sliding plate. Then the left side will be drilled and tapped for 8-32 SHCS.
The outside trunnion supports are drilled and tapped and mounted with the same care as the inside supports. This completes the main trunnion assembly and is probably the most critical and difficult part of this build.
The outside trunnion support on the left side has a distance of .362" stamped on the top. This is the distance from the face of the support to the center line of the alignment rod. I put this there as a reference. If I choose to mount this Precision Drill Sharpener on my T&C grinder the face of this trunnion support would be lined up with the face of the grinding wheel to locate the unit for sharpening drills. I haven't decided yet if this will be a stand alone machine or be used with the T&C grinder.
These two photos show the completed trunnion and sliding table. The next process on this will be to locate and drill the holes for locating the chuck and bolting the linear bearings to the sliding base plate.
The first machine I built was mostly aluminum ( as I had the material) and although it works flawlessly and does an excellent job, this unit made of all steel and much better precision is going to be a highly precision and sturdy machine. I am making subtle changes to Mr. Moran's design to try to make the machine the utmost in quality and precision. So far the minor changes are:
1.) The trunnion table is .250" longer to move the chuck a little farther back from the grinding wheel to allow more clearance when grinding the larger drills. This plate is 4" X 4.125" instead of 3.625 as in the original design. I found this to be desirable from using the machine I built previously.
2.) the outside trunnion supports are .250" higher. This raises the trunnion assembly slightly to allow the space for a different design angle setting gauge. Also this was needed if I wish to use the unit on my T&C grinder.
3.) The sliding base plate is increased in size to 6" X 8". This was done to accommodate the linear bearing system. By using all steel construction and ground plate, this makes a higher quality and sturdy machine.
These traits will be continued through out the rest of the build along with other minor changes to the other components to make this hopefully my finest build yet.