After a short and frustrating day yesterday, where I struggled to mill the first of the motorcycle brackets to its 35mm depth because of all the table turning,  I decided to leave the brackets and have a go at the gears project for a child’s electric jeep.

Arc Eurotrade managed to delivery the hobb very quickly so the first task was to create one test piece and two blanks followed by a hobb holder. The two blanks were simply turning jobs and didn’t take too long although I did have one new experience. I found on section of brass that could be turned to size and when trying to take cuts it was hard to cut. I tried both HSS tool steel and carbide tipped turning tool. I couldn’t get a good finish no matter what I tried. I thought that since it was a while since using the lathe it must be me. Eventually however, I changed to another piece of brass and lo and behold it turned beautifully whatever tool I used.

So the brass bar I used first must be something ‘special’. With the replacement brass bar in the chuck the two required blanks were soon finished to size. Once again the advantage of having DRO’s came clearly into focus because Thomas wanted the parts in metric and since I work in imperial you would expect that change to bring difficulties but it only needed just one button to convert the machine into metric.

After the proper blanks I decided to make another piece to the required diameter so I could practice cutting with the hobb since I have never used one before. Looking closely at the metric hobb you can see that the teeth are arranged in a screw pattern. Since the spur gears I want to machine require teeth at right angles I will need to have the gear blank offset to the cutter so some material to practice with is a must.

The next task was to make a hobb holder. After finding a suitable piece of steel it was over to the lathe. This time however I used the refurbished Myford ML7 with its 4 Jaw chuck because I wanted to ensure the hobb ran true. Once one sectioned was turned to size I threaded the end and made a nut to suit the 5/16” x 36tpi thread.

By the time I had completed the tasks above I had had enough so ended the session until the next time.